石塚 真由美 (イシヅカ マユミ)

獣医学研究院 獣医学部門 環境獣医科学分野教授
大学院教育推進機構教授
高等教育推進機構教授
One Healthリサーチセンター教授
Last Updated :2025/11/06

■研究者基本情報

学位

  • 獣医学博士, 北海道大学

Researchmap個人ページ

研究キーワード

  • シトクロムP450
  • 環境化学物質
  • エストロゲン
  • 野生動物
  • マイクロアレイ
  • アフリカ
  • ルシフェラーゼ
  • neonatal imprinting
  • レポーターアッセイ
  • アロマターゼ
  • レポーター
  • トランスジェニック
  • トキシコロジー
  • in vivoイメージング
  • ERE
  • インプリンティング
  • 視床下部
  • 環境汚染
  • ステロイドホルモン
  • 環境ホルモン
  • ビスフェノールA
  • ダイオキシン受容体
  • PPAR
  • フタル酸エステル
  • バイオマーカー
  • 環境汚染物質
  • ダイオキシン類
  • CYP1A
  • 海棲哺乳類
  • ドブネズミ

研究分野

  • 環境・農学, ランドスケープ科学
  • 環境・農学, 環境農学
  • 環境・農学, 化学物質影響
  • 環境・農学, 放射線影響
  • ライフサイエンス, 応用分子細胞生物学
  • ライフサイエンス, 衛生学、公衆衛生学分野:実験系を含まない
  • ライフサイエンス, 衛生学、公衆衛生学分野:実験系を含む
  • ライフサイエンス, 医療管理学、医療系社会学
  • ライフサイエンス, 獣医学

担当教育組織

■経歴

経歴

  • 2011年 - 2012年
    北海道大学 (連合)獣医学研究科, 教授

委員歴

  • 現在
    日本毒性学会, 評議員, 学協会
  • 現在
    食品安全委員会, 専門委員(動物用医薬品、添加物), 政府
  • 現在
    日本環境化学会, 理事, 学協会
  • 現在
    日本獣医学会, 理事, 学協会
  • 現在
    日本学術会議, 会員, 政府

学内役職歴

  • 教育改革室室員, 2019年4月1日 - 2020年9月30日
  • 教育改革室室員, 2020年10月12日 - 2022年3月31日
  • 教育改革室室員, 2022年4月1日 - 2024年3月31日
  • 教育改革室室員, 2024年4月1日 - 2026年3月31日
  • 教育研究評議会評議員, 2021年4月1日 - 2023年3月31日
  • 経営戦略室室員, 2017年10月26日 - 2019年3月31日
  • 経営戦略室室員, 2019年4月1日 - 2020年9月30日
  • 経営戦略室室員, 2020年10月12日 - 2021年3月31日
  • 総長補佐, 2017年4月1日 - 2019年3月31日
  • 総長補佐, 2019年4月1日 - 2020年9月30日
  • 総長補佐, 2020年10月12日 - 2022年3月31日
  • 総長補佐, 2022年4月1日 - 2024年3月31日
  • 総長補佐, 2024年4月1日 - 2024年12月31日
  • 大学院獣医学院長, 2021年4月1日 - 2023年3月31日
  • 大学院獣医学院長, 2023年4月1日 - 2025年3月31日
  • 大学院獣医学研究科副研究科長, 2013年4月1日 - 2015年3月31日
  • 大学院獣医学研究科副研究科長, 2015年4月1日 - 2017年3月31日
  • 副理事, 2025年1月1日 - 2026年3月31日

■研究活動情報

受賞

  • 2020年, 日本環境化学会, 学術賞               
  • 2015年, ソロプチミスト日本財団, 女性研究者賞               
    石塚真由美
  • 2015年, 北海道大学, 研究総長賞(優秀賞)               
    石塚真由美
  • 2009年, 文部科学省, 科学技術分野の文部科学大臣表彰・若手科学者賞               
    野生動物のシトクロムP450と汚染環境適応能力解明の研究
    石塚真由美
  • 2007年, 日本農学会, 日本農学進歩賞               
    環境化学物質が野生動物に引き起こす毒性と適応
    石塚真由美
  • 2007年, 日本トキシコロジー学会, 奨励賞               
    野生生物のシトクロムP450と汚染環境への適応機構に関する研究
    石塚真由美

論文

  • Exploration of functional cytochrome P450 4F enzymes in liver, intestine, and kidney from dogs, cats, pigs, and tree shrews and comparison of their metabolic capacities with human P450 4F2 and 4F12
    Yasuhiro Uno, Izumi Kawabata, Genki Ushirozako, Kyoko Tsukiyama-Kohara, Mayumi Ishizuka, Hazuki Mizukawa, Norie Murayama, Hiroshi Yamazaki
    Biochemical Pharmacology, 236, 116894, 116894, Elsevier BV, 2025年06月
    研究論文(学術雑誌)
  • Assessing the efficacy of phosphate and lime amendments in immobilizing three forms of lead in contaminated soil: An in vivo study on C57/BL6 mice simulating environmentally realistic exposure pathways.
    Nyein Chan Soe, Takashi Fujimori, Kenji Shiota, Rio Doya, Walubita Mufalo, Mayumi Ito, Tsutomu Sato, Toshifumi Igarashi, Yoshinori Ikenaka, Mayumi Ishizuka, Shouta M M Nakayama
    Chemosphere, 374, 144201, 144201, 2025年04月, [国際誌]
    英語, 研究論文(学術雑誌), Lead (Pb) bioavailability differs depending on the specific Pb species present in the area. Adding organic and inorganic soil amendments can ameliorate the mobility of Pb in the soil. However, there is a scarcity of in vivo studies investigating the impact of these amendments on mammals via environmentally realistic exposure pathways. We evaluated the accumulation of Pb in blood and tissues of mice living on soils spiked with one of three Pb species (hydrocerussite [2PbCO3·Pb(OH)2], lead sulfate [PbSO4], and lead sulfide [PbS]) and compared the efficacy of phosphate (triple super phosphate [TSP] or phosphoric acid) or liming (calcined dolomite) amendments in reducing Pb accumulation from these soils via realistic exposure pathways. The Pb species in the spiked soil were investigated via X-ray absorption near edge structures (XANES) spectroscopy. C57/BL6 mice (six per group) were exposed to both Pb-spiked and amended soils by housing them on the soil for three months and thus simulating realistic exposure pathways. XANES analysis revealed that Pb carbonates were the dominant phase in all Pb-spiked soils. The group exposed to 2PbCO3·Pb(OH)2 had the greatest Pb accumulation in brain, trachea, kidneys, liver, bone, and blood, but not lungs, whereas the PbS-exposed group accumulated more Pb in the lungs. TSP was the most effective chemical stabilizer of the three amendments, facilitating reductions in the 2PbCO3·Pb(OH)2, PbSO4, and PbS exposure groups of 68-88%, 44-62%, and 6-49%, respectively. This suggests that chemical remediation using phosphate sources may be effective for immobilizing various Pb species in soils.
  • Pollution and partitioning of neonicotinoid insecticides in free-grazing ducks and their eggs: Implications for human health.
    Collins Nimako, Kraisiri Khidkhan, Sittinee Kulprasertsri, Saranya Poapolathep, Paphatsara Khunlert, Yared B Yohannes, Yoshinori Ikenaka, Shouta M M Nakayama, Mayumi Ishizuka, Amnart Poapolathep
    Environmental pollution (Barking, Essex : 1987), 373, 126099, 126099, 2025年03月20日, [国際誌]
    英語, 研究論文(学術雑誌), Neonicotinoid insecticides are used extensively in many pest control schemes across the globe; but little is known about their impacts on free-grazing domestic birds and the quality of meat or eggs produced from such birds. This study assessed the pollution and partitioning of neonicotinoids in serum and eggs of free-grazing ducks from 5 provinces of Thailand and elucidated the associated human health implications. Biological samples (duck serum, egg albumins, and egg yolks) and environmental samples (soil, water, feed) were collected from 9 duck farms in Thailand and subjected to LC/MS/MS analysis. Out of 6 neonicotinoid compounds targeted, five were detected in duck serum. Imidacloprid had the greatest median concentration of 1.4 ng/mL and the highest detection frequency (df) of 85.8 % in the ducks' serum, followed by acetamiprid (median concentration = 0.4 ng/mL; df = 2.8 %), clothianidin (median concentration = 0.2 ng/mL; df = 9.4 %) or thiamethoxam (median concentration = 0.2 ng/mL; df = 7.5 %) and dinotefuran (only one sample was contaminated with 6.3 ng/mL of dinotefuran). The neonicotinoids were similarly detected in soil, water, and feed samples obtained from the duck farms, suggesting that the ducks were exposed to the insecticides from the nearby agricultural fields. The neonicotinoid compounds selectively accumulated in the albumin of duck eggs compared to yolk. The median concentration ratios of albumin to yolk obtained for imidacloprid, dinotefuran, thiamethoxam, clothianidin, and acetamiprid were 694, 463, 458, 382, and 263, respectively. However, upon human health risk analysis, levels of neonicotinoids detected in duck eggs were not found to present any appreciable risks to duck egg consumers.
  • Sex dependent intergenerational effects of lead in mouse model.
    Nelly Banda, Nyein Chan Soe, John Yabe, Rio Doya, Yared Beyene Yohannes, Yoshinori Ikenaka, Mayumi Ishizuka, Shouta M M Nakayama
    Scientific reports, 14, 1, 30233, 30233, 2024年12月04日, [国際誌]
    英語, 研究論文(学術雑誌), Lead (Pb) exposure negatively impacts fertility in both males and females, pregnancy outcomes, and child brain development. We investigated the reproductive and neurological effects of Pb exposure on male and female mice via Pb-contaminated soil for 4 weeks. Breeding was conducted after completion of exposure, in four groups; group 1 consisted of exposed dams and unexposed sires, group 2 consisted of exposed sires and unexposed dams, group 3 consisted of exposed sires and exposed dams and group 4 was the control. Generally, Pb exposure reduced observed conception rates, with a cumulative decrement observed when both males and females are exposed. Gene expression of the testes revealed oxidative stress as the cause of reduced conception rates. Neurological tests: Morris water maze and rotarod were conducted on F1 generation offspring. Maternally and paternally exposed F1 mice performed poorly in the Morris water maze when compared to the control. The severity of the neurological effects was also parent-dependent and sex-dependent. Paternal Pb exposure effects were more pronounced in female offspring. A comparison of gene expression changes of the hippocampus and prefrontal cortex showed paternal Pb-exposure resulted in more prefrontal cortex changes than in the hippocampus, a trend also recorded in the exposed sires. The pronounced effects in female offspring of paternal Pb exposure may suggest that Pb neurological effects may be X-chromosome-linked.
  • Habu vipers (Protobothrops flavoviridis) are an overlooked but important reservoir of the zoonotic tick Amblyomma testudinarium (Acari: Ixodidae) in subtropical Asia.
    Mackenzie L Kwak, Shintaro Nakagawa, So Shinya, Paula Andrea Jiménez, Greg Markowsky, Daniel McInnes, Yurie Taya, Shouta M M Nakayama, Mayumi Ishizuka, Nariaki Nonaka, Ryo Nakao
    Acta tropica, 260, 107472, 107472, 2024年11月17日, [国際誌]
    英語, 研究論文(学術雑誌), Subtropical Asia has a rich diversity of reptiles and ticks, though the role of reptiles in the sylvatic cycles of medically important ticks in the region is poorly known. Habu vipers (Protobothrops flavoviridis) are widespread and common in the Japanese subtropics but their role as hosts for ticks has not been carefully explored. For 15 months in 2023/24, habu vipers were screened for ticks and were found to be important hosts for immature stages of the tick Amblyomma testudinarium, with a 22 % infestation rate. Amblyomma testudinarium was found to have weak attachment site preferences on P. flavoviridis and host body length was found to have no relationship with either the risk of infestation or the tick load in infested snakes. The phenological profile of A. testudinarium was mapped for the first time in the subtropics based on mean tick loads on P. flavoviridis and historical flagging data. March-April were identified as the period of highest activity, May to July was a period of declining activity, August-September was a period of almost complete inactivity, and October to February was a periods of increasing activity. The role of habu vipers in the sylvatic cycle of A. testudinarium in subtropical Asia is discussion. Additionally, the potential of habu vipers to serve as reservoirs of pathogens or as dilution hosts is also explored.
  • Investigating drug residues in Mongolian milk using a newly developed method with high performance liquid chromatography and a photo diode array.
    Delgermurun Dugar, Kodai Motohira, Nyamsuren Purevdorj, Bolormaa Pelden, Shouta Mm Nakayama, Mayumi Ishizuka, Yoshinori Ikenaka
    The Journal of veterinary medical science, 2024年10月14日, [国内誌]
    英語, 研究論文(学術雑誌), Despite the beneficial impacts of using drugs in animal husbandry, the risks of drug residues in animal products are a concern worldwide. Therefore, most countries have developed systems and methods to detect and monitor drug residues in animal products using high performance liquid chromatography (HPLC) with mass spectrometry (MS). However, MS detectors are not available in all universities; thus, we developed a new method suitable for ultraviolet detection. We first validated a new method targeting tetracycline and albendazole in milk and evaluated these drug residues in 50 samples collected from farms and supermarkets in Mongolia. The practical limit of quantification (PQL) calculated in our newly developed method was suitable to detect the maximum residual limits defined in Codex Alimentarius, and the accuracy and precision of a new method were comparable to previous studies. In particular, inter-day analysis showed great precision, with albendazole showing a 99% recovery rate with ± 3.3 of relative standard deviation (RSD). In addition, we evaluated our drugs contamination, but targeted drugs residues were not detected in the current sample set. However, this may reflect the decreased use of tetracycline in the veterinary field and seasonal use of albendazole in Mongolia. Therefore, these drugs must be continuously monitored. To the best of our knowledge, this is the first report about drug residues in milk published in an international journal by a Mongolian domestic institution. Further investigations of drug residue in Mongolia are urgently needed.
  • Investigation of Functional Cytochrome P450 4A Enzymes in Liver and Kidney of Pigs, Cats, Tree Shrews, and Dogs in Comparison with the Metabolic Capacity of Human P450 4A11
    Yasuhiro Uno, Kyoko Tsukiyama-Kohara, Mayumi Ishizuka, Hazuki Mizukawa, Norie Murayama, Hiroshi Yamazaki
    Drug Metabolism and Disposition, 52, 9, 1009, 1019, 2024年09月01日
    研究論文(学術雑誌)
  • Characterization of Neonicotinoid Metabolites by Cytochrome P450-Mediated Metabolism in Poultry.
    Adisorn Dam-On, Collins Nimako, Sittinee Kulprasertsri, Yoshinori Ikenaka, Yared B Yohannes, Shouta M M Nakayama, Mayumi Ishizuka, Saranya Poapolathep, Amnart Poapolathep, Kraisiri Khidkhan
    Toxics, 12, 8, 2024年08月21日, [国際誌]
    英語, 研究論文(学術雑誌), Neonicotinoids, a neuro-effective class of insecticides, are heavily applied in agricultural activities worldwide. Poultry can be exposed to neonicotinoids by several routes, but the knowledge of neonicotinoid's metabolism in poultry and its associated interspecies differences is highly limited. Hence, this study aims to investigate the species differences in metabolite formations, as well as cytochrome P450 (CYP)-dependent metabolism of four major neonicotinoid compounds, acetamiprid, imidacloprid, clothianidin, and thiamethoxam, in poultry. In vitro biotransformation assays using hepatic microsomes of chicken, ducks, geese, quails, and rats were conducted. Metabolites of neonicotinoids were then screened by LC/Q-TOF and quantified by LC/MS/MS. The results revealed an existence of interspecies differences in the formations of N-[ (6-chloro-3-pyridyl) methyl] -N-methyl acetamidine (IM-1-5) of acetamiprid and dm-clothianidin of clothianidin between chicken and other species. In addition, the greatest CYP activities in the metabolism of most neonicotinoid substrates, such as acetamiprid to dm-acetamiprid, imidacloprid to hydroxylated-imidacloprid and imidacloprid-olefin, clothianidin to dm-clothianidin, and thiamethoxam to clothianidin, were found in chicken. These results suggested that the CYPs in chicken may have a greater capacity for metabolism of neonicotinoids compared to other poultry. This study further revealed that the maximum intrinsic clearance of dn-imidacloprid and dn-clothianidin in ducks may be superintended by CYP-mediated nitro-reductions of imidacloprid and clothianidin. Further studies employing CYP recombinant enzymes may be required to elucidate the specific CYP isoforms that may be involved in neonicotinoid metabolism in avian species.
  • Role of brain monoamines in acetamiprid-induced anxiety-like behavior.
    Anri Hirai, Chitoku Toda, Yared Beyene Yohannes, Nimako Collins, Mai Tamba, Kei Nomiyama, Akifumi Eguchi, Nobuhiko Hoshi, Tetsushi Hirano, Shouta M M Nakayama, Mayumi Ishizuka, Yoshinori Ikenaka
    Toxicology, 153839, 153839, 2024年05月21日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Neonicotinoid (NN) pesticides have been linked to increased brain dysfunction in mammals, such as anxiety-like behavior; this is thought to involve monoamines (MA), neurotransmitters that control behavior, memory, and learning. However, the mechanism by which NNs affect the central nervous system is not fully understood. In this study, we aimed to investigate whether MAs affect NNs-induced anxiety-like behavior. Mice were orally administered acetamiprid (ACE), an NN, at the no observed adverse effect level (NOAEL) of mouse (20mg/kg body mass) set by the Food Safety Commission of Japan, and the elevated zero-maze (EZM) test was performed 30min after administration. After behavioral analysis, levels of four MA (dopamine, 3-MT, serotonin, and histamine) in selected brain regions were determined by liquid chromatography mass spectrometry (LC/MS/MS). In the exposed group, a trend toward increased anxiety-like behavior was observed, and at least one MA concentration was significantly increased in each region. Further, significant correlations were found between behavioral test results and hippocampal serotonin and striatal dopamine concentrations, as well as between dopamine and serotonin concentrations, in the exposed group. As anxiety can influence activity in the behavioral tests, the activity of neurons in the raphe nuclei (RN), a brain region greatly involved in anxiety via the serotonergic system, was examined by staining with anti-serotonin antibodies, and increased serotonergic activity was observed. Taken together, these results suggest that ACE regulates MA levels, notably serotonin levels in the hippocampus and that RN plays an important role in ACE-induced anxiety-like behavior.
  • オオミズナギドリにおける血球と羽根の水銀濃度
    岩崎真由, 安積紗羅々, 石塚真由美, 池中良徳, 綿貫豊
    日本鳥学会誌, 73, 57, 65, 2024年05月, [査読有り]
    日本語
  • Exposure of Male Farmers and Nonfarmers to Neonicotinoid Pesticides in the South-West and Littoral Regions of Cameroon: A Comparative Study.
    Faustin Pascal Tsagué Manfo, Collins Nimako, Edouard Akono Nantia, Christian Fusi Suh, Shu Policap Chenwi, Fidelis Cho-Ngwa, Paul Fewou Moundipa, Shouta M M Nakayama, Mayumi Ishizuka, Yoshinori Ikenaka
    Environmental toxicology and chemistry, 43, 5, 952, 964, 2024年05月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Pesticides, especially the newly developed neonicotinoids, are increasingly used in many countries around the world, including Cameroon, to control pests involved in crop destruction or disease transmission. Unfortunately, the pesticides also pose tremendous environmental problems because a predominant amount of their residues enter environmental matrices to affect other nontargeted species including humans. This therefore calls for continuous biomonitoring of these insecticides in human populations. The present study sought to assess the neonicotinoid insecticide exposures in two agrarian regions of Cameroon, the South-West region and Littoral region. The study involved 188 men, including 125 farmers and 63 nonfarmers. Spot urine samples were obtained from these subjects and subjected to liquid chromatographic-tandem mass spectrometric analysis for concentrations of neonicotinoid compounds, including acetamiprid, clothianidin, dinotefuran, imidacloprid, thiacloprid, nitenpyram, thiamethoxam, and N-dm-acetamiprid. Neonicotinoid compounds were detected in all study participants, and residues of all the screened pesticides were detected among participants. N-dm-Acetamiprid and imidacloprid were the most prevalent among the subjects (100.0% and 93.1%, respectively), whereas nitenpyram was less common (3.2%). The median values of imidacloprid and total urinary neonicotinoid concentrations were elevated among farmers (0.258 vs. 0.126 µg/L and 0.829 vs. 0.312 µg/L, respectively). Altogether the findings showed that both the farmer and nonfarmer study populations of Cameroon were exposed to multiple residues of neonicotinoids, with relatively higher levels of pesticides generally recorded among farmers. Although exposure levels of the neonicotinoids were generally lower than their respective reference doses, these results warrant further research on the health risk evaluation of multiple residues of the pesticides and reinforcement of control measures to minimize the exposure risks, especially among farmers. Environ Toxicol Chem 2024;43:952-964. © 2024 SETAC.
  • Current situation of lead (Pb) exposure in raptors and waterfowl in Japan and difference in sensitivity to in vitro lead exposure among avian species.
    Mizuki Maruyama, Nana Ushine, Yukiko Watanabe, Chihiro Ishii, Keisuke Saito, Hidefumi Sakai, Takeshi Kuritani, Rio Doya, Kohei Ogasawara, Yoshinori Ikenaka, Yared Beyene Yohannes, Mayumi Ishizuka, Shouta M M Nakayama
    Environmental pollution (Barking, Essex : 1987), 123907, 123907, 2024年04月04日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Although lead (Pb) poisoning in wild birds has been considered a serious problem in Japan for over 30 years, there is little information about Pb exposure and its sources throughout Japan except for Hokkaido. Furthermore, to identify and effectively prioritize the conservation needs of highly vulnerable species, differences in sensitivity to Pb exposure among avian species need to be determined. Therefore, we investigated the current situation of Pb exposure in raptors (13 species, N = 82), waterfowl (eight species, N = 44) and crows (one species, N = 6) using concentration and isotope analysis. We employed blood or tissue samples collected in various Japanese facilities mainly in 2022 or 2023. We also carried out a comparative study of blood δ-ALAD sensitivity to in vitro Pb exposure using blood of nine avian species. Pb concentrations in the blood or tissues displayed increased levels (>0.1 μg/g blood) in two raptors (2.4%), ten waterfowl (23%) and one crow (17%). Among them, poisoning levels (>0.6 μg/g blood) were found in one black kite and one common teal. The sources of Pb isotope ratios in ten blood samples with high Pb levels were determined as deriving from shot pellets (N = 9) or rifle bullets (N = 1). In the δ-ALAD study, red-crowned crane showed the highest sensitivity among the nine tested avian species and was followed in order by five Accipitriformes species (including white-tailed and Steller's sea eagle), Blakiston's fish owl, Muscovy duck and chicken, suggesting a genetically driven variance in susceptibility. Further studies on contamination conditions and exposure sources are urgently needed to inform strict regulations on the usage of Pb ammunition. Furthermore, detailed examinations of δ-ALAD sensitivity, interspecific differences, and other factors involved in the variability in sensitivity to Pb are required to identify and prioritize highly sensitive species.
  • Effect of chicken manure amendment on lead burden in mice: exposure to lead-spiked soil
    Nyein Chan Soe, Yared Beyene Yohannes, Takamitsu Ohigashi, Hokuto Nakata, Chikae Tatsumi, Yoshitaka Uchida, Walubita Mufalo, Mayumi Ito, Tsutomu Sato, Toshifumi Igarashi, Yoshinori Ikenaka, Mayumi Ishizuka, Shouta M. M. Nakayama
    Journal of Soils and Sediments, Springer Science and Business Media LLC, 2024年03月13日, [査読有り]
    研究論文(学術雑誌)
  • Pesticide Contamination Levels in the Stomach Contents of Wild Raccoons (Procyon lotor) and Masked Palm Civets (Paguma larvata) in Japan
    So Shinya, Mariko Sashika, Miku Minamikawa, Tetsuji Itoh, Tsutomu Tanikawa, Kazuyuki D. Tanaka, Shouta M. M. Nakayama, Mayumi Ishizuka, Yoshinori Ikenaka
    Environmental Toxicology and Chemistry, Wiley, 2024年03月05日, [査読有り]
    研究論文(学術雑誌), Abstract

    Pesticides, which are vital for agriculture, pose a significant threat to wildlife in transformed Japanese landscapes. Despite global reports of pesticide poisoning in animals, limited studies have examined current wildlife exposure in croplands or metropolitan areas in the region. Using liquid chromatography–tandem mass spectrometry (LC–MS/MS) and gas chromatography–tandem mass spectrometry (GC–MS/MS), our study aimed to assess the contamination status of 368 commonly used pesticides. The stomach contents of raccoons living in croplands contained 13 pesticides, including six herbicides and 11 fungicides. Neonicotinoid insecticides, some fungicides, and previously banned insecticides (benzene hexachloride and dichlofenthion) were most frequently detected and found at the highest concentrations, suggesting direct soil–plant transfer and direct consumption by crop‐eating species. In masked palm civets living in metropolitan areas, four insecticides and six fungicides were detected, indicating urban wildlife exposure from raided dustbins, urban gardens, and lumber from houses. Although the maximum measured concentrations of all pesticides were lower than the acceptable daily intake for humans, it remains unclear whether these concentrations may have toxic or adverse health effects on the species evaluated in these transformed landscapes. Our study is the first to examine recent pesticide exposures in wild mammals in Japan. Application of the method we developed will lay the foundation for the examination of pesticides in other wildlife species to assist conservation management efforts in the region. Environ Toxicol Chem 2024;00:1–9. © 2024 SETAC
  • Quantification of the tissue distribution and accumulation of the neonicotinoid pesticide clothianidin and its metabolites in maternal and fetal mice.
    Tetsushi Hirano, Shuji Ohno, Yoshinori Ikenaka, Kanoko Onaru, Shizuka Kubo, Yuka Miyata, Mizuki Maeda, Youhei Mantani, Toshifumi Yokoyama, Collins Nimako, Yared Beyene Yohannes, Shouta M M Nakayama, Mayumi Ishizuka, Nobuhiko Hoshi
    Toxicology and applied pharmacology, 116847, 116847, 2024年02月07日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Neonicotinoids (NNs) are commonly used pesticides that have a selective agonistic action on insect nicotinic acetylcholine receptors. Recent evidence has shown that NNs have adverse effects in the next generation of mammals, but it remains unclear how NNs transferred from dams to fetuses are distributed and accumulated in fetal tissues. Here, we aimed to clarify the tissue distribution and accumulation properties of the NN clothianidin (CLO) and its 6 metabolites in 7 tissues and blood in both dams and fetuses of mice administered CLO for a single day or for 9 consecutive days. The results showed that the total concentrations of CLO-related compounds in the brain and kidney were higher in fetuses than in dams, whereas in the liver, heart, and blood they were lower in fetuses. The multi-day administration increased the total levels in heart and blood only in the fetuses of the single administration group. In addition, dimethyl metabolites of CLO showed fetus/dam ratios >1 in some tissues, suggesting that fetuses have higher accumulation property and are thus at higher risks of exposure to CLO-related compounds than dams. These findings revealed differences in the tissue-specific distribution patterns of CLO and its metabolites between dams and fetuses, providing new insights into the assessment of the developmental toxicity of NNs.
  • Insights on hazardous metal bioaccessibility, and groundwater impacted by Zn residues from a legacy mine and risk evaluation of adjacent soils
    Walubita Mufalo, Takahiko Arima, Toshifumi Igarashi, Mayumi Ito, Tsutomu Sato, Shingo Tomiyama, Imasiku Nyambe, Carlito Baltazar Tabelin, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka
    Environmental Geochemistry and Health, 46, 2, Springer Science and Business Media LLC, 2024年02月06日, [査読有り]
    研究論文(学術雑誌)
  • Metals and arsenic distribution in stray dogs' tissues around a lead-zinc mine in Kabwe, Zambia.
    Nyein Chan Soe, Yared Beyene Yohannes, Andrew Kataba, Madalitso Tembo, John Yabe, Golden Zyambo, Kenneth Chawinga, Kaampwe Muzandu, Yoshinori Ikenaka, Mayumi Ishizuka, Shouta M M Nakayama
    Environmental science and pollution research international, 31, 8, 12083, 12093, 2024年02月, [国際誌]
    英語, 研究論文(学術雑誌), Metal contamination poses a threat to human, animal, and environmental health. The purpose of the current study was to assess the accumulation of toxic and trace metal concentrations in tissues of stray dogs in Kabwe, a town known for lead pollution due to a long history of lead and zinc mining. Brain, spleen, heart, stomach, stomach content, small intestine, kidney, liver, and bone samples were collected from 29 stray dogs (14 from locations within 3 km of the mine and 15 from sites 7 km away from the mine) after necropsy. Inductively coupled plasma mass spectrometry was used to analyze toxic metals, arsenic (As), cadmium (Cd), and lead (Pb), and trace elements, copper (Cu) and zinc (Zn). The lungs (0.117 ± 0.114 mg/kg dry weight), kidney (7.515 ± 8.830 mg/kg dry weight), and bone (41.68 ± 66.83 mg/kg dry weight) were found to have the highest concentrations of As, Cd, and Pb, respectively. In contrast, higher Cu and Zn concentrations were measured in the liver than in other tissues. In all tissues analyzed, tissues sampled from dogs near the mine had significantly higher mean concentrations of Cd and Pb than dogs far away. Neither sex nor age-related differences were observed in the distribution of metals in most tissues. There were significant associations among toxic (Pb and Cd) and trace metals (Cu and Zn). In the kidney, Cd positively correlated with Pb (ρ = 0.534) and Zn (ρ = 0.600), whereas in the liver, Cu correlated with Zn (ρ = 0.565). The current study's findings suggest that environmental pollution is still a problem in Kabwe, and environmental remediation is needed to address the pollution.
  • Brood patch size as a field indicator for feather mercury concentration, but not plastic ingestion, in a harvested seabird of the high Arctic: The little auk Alle alle
    Mayuko Otsuki, Monica Ogawa, Watanuki Yutaka, Yoko Mitani, Mayumi Ishizuka, Yoshinori Ikenaka, Jean-Baptiste Thiebot
    Polar Science, 2024年02月
    研究論文(学術雑誌)
  • Lead speciation in body tissues, gastrointestinal contents, and feces of lead-exposed wild rats (Rattus rattus)
    Takashi Fujimori, Haruya Toyomaki, Kenji Shiota, Hokuto Nakata, John Yabe, Kaampwe Muzandu, Kenneth Chawinga, Rio Doya, Nyein Chan Soe, Mayumi Ishizuka, Shouta M.M. Nakayama
    Science of The Total Environment, 908, 168297, 168297, Elsevier BV, 2024年01月
    研究論文(学術雑誌)
  • 半焼成ドロマイトおよびリン酸塩を用いたカブウェ鉱山鉱さい中の重金属不溶化特性
    Takahiko ARIMA, Kenta NOTO, Walubita MUFALO, Toshifumi IGARASHI, Mayumi ITO, Tsutomu SATO, Hokuto NAKATA, Shouta NAKAYAMA, Mayumi ISHIZUKA
    Resources Processing, 70, 3, 141, 150, The Resources Processing Society of Japan, 2024年
    研究論文(学術雑誌)
  • Assessment of Organohalogen Compounds Contamination in Pet Food and Associated Health Risks: A Case Study in Japan
    Kei NOMIYAMA, Fuka SATO, Makoto SHIMASAKI, Hazuki MIZUKAWA, Kraisiri KHIDKHAN, Yoshinori IKENAKA, Mayumi ISHIZUKA
    Environmental Monitoring and Contaminants Research, 4, 38, 54, Japan Society for Environmental Chemistry, 2024年, [査読有り]
    研究論文(学術雑誌)
  • Evaluation of anticoagulant rodenticide sensitivity by examining in vivo and in vitro responses in avian species, focusing on raptors
    Kraisiri Khidkhan, Fuyu Yasuhira, Aksorn Saengtienchai, Chaiyan Kasorndorkbua, Ratiwan Sitdhibutr, Kohei Ogasawara, Hikaru Adachi, Yukiko Watanabe, Keisuke Saito, Hidefumi Sakai, Kazuo Horikoshi, Hajime Suzuki, Yusuke K. Kawai, Kazuki Takeda, Yared B. Yohannes, Yoshinori Ikenaka, Barnett A. Rattner, Mayumi Ishizuka, Shouta M.M. Nakayama
    Environmental Pollution, 122837, 122837, Elsevier BV, 2023年11月, [査読有り]
    研究論文(学術雑誌)
  • Surveys of eleven species of wild and zoo birds and feeding experiments in white-tailed eagles reveal differences in the composition of the avian gut microbiome based on dietary habits between and within species.
    Kohei Ogasawara, Naoki Yamada, Shouta Mm Nakayama, Yukiko Watanabe, Keisuke Saito, Akane Chiba, Yoshitaka Uchida, Kaoru Ueda, Yasunori Takenaka, Kentaro Kazama, Mami Kazama, Junya Yamagishi, Hazuki Mizukawa, Yoshinori Ikenaka, Mayumi Ishizuka
    The Journal of veterinary medical science, 2023年10月31日, [査読有り], [国内誌]
    英語, 研究論文(学術雑誌), The composition of the gut microbiome varies due to dietary habits. We investigated influences of diet on the composition of the gut microbiome using the feces of 11 avian species, which consumed grain-, fish- and meat-based diets. We analyzed gut microbiome diversity and composition by next-generation sequencing (NGS) of 16S ribosomal RNA. The grain-diet group had higher gut microbiome diversity than the meat- and fish-diet group. The ratio of Bacteroidetes and Firmicutes phyla was higher in the grain-diet group than in the meat- and fish-diet groups. The grain-diet group had a higher ratio of Veillonellaceae than the meat-diet group and a higher ratio of Eubacteriaceae than the fish-diet habit group. To clarify the influence of diet within the same species, white-tailed eagles (Haliaeetus albicilla, n=6) were divided into two groups, and given only deer meat or fish for approximately one month. The composition of the gut microbiome of individuals in both groups were analyzed by NGS. There were indications of fluctuation in the levels of some bacteria (Lactobacillus, Coriobacteriales, etc.) in each diet group. Moreover, one individual for each group which switched each diet in last week changed to each feature of composition of bacterial flora. The above results show that the composition of the gut microbiome differ depending on diet, even within the same species.
  • A stable isotope analysis of the dietary patterns of the aquatic apex predator, the African tigerfish (Hydrocynus vittatus).
    Ruan Gerber, Lizaan de Necker, Johan H J van Vuren, Yoshinori Ikenaka, Shouta M M Nakayama, Mayumi Ishizuka, Victor Wepener, Nico J Smit
    Journal of fish biology, 2023年07月27日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Stable isotope analyses, specifically δ13 C and δ15 N, are useful tools increasingly used to understand ecosystem function, food web structures and consumer diets. Although the iconic tigerfish, Hydrocynus vittatus, is regarded as an apex predator in southern African freshwater systems, little information is available regarding their feeding behaviour and how this may change with growth or differ between ecosystems with most information stemming from stomach content analyses (SCA). The aim of the present study was to address this lack of information through a baseline study of the diet of large and small tigerfish in various lentic and lotic ecosystems in South Africa using stable isotope methods. Fish and various food web components and food sources were collected from two river and two lake ecosystems from the Lower Phongolo River floodplain, SA. The δ13 C and δ15 N values for all samples were determined and multivariate analyses and Bayesian analytical techniques applied to determine the feeding ecology of H. vittatus and how this may differ with size and habitat type. Analyses revealed a substantial difference in the type and abundance of food sources contributing to the diet of H. vittatus between ecosystems, most prominently between the lotic systems, where less dietary specialisation was observed, and lentic systems where more specialisation was observed. Furthermore, there was a distinct difference in diet between small and large tigerfish, especially in the lotic system, indicating an ontogenetic diet shift as tigerfish grow and further supporting previous SCA studies. This is the first study of its kind on the African continent for H. vittatus and the findings illustrate the value of stable isotope analysis in providing in-depth information into the feeding ecology of consumers and how this may differ between size classes and habitat types. This article is protected by copyright. All rights reserved.
  • Evaluation of the Effect of Pb Pollution on Avian Influenza Virus-Specific Antibody Production in Black-Headed Gulls (Chroicocephalus ridibundus)
    Nana, Makoto Ozawa, Shouta, Mayumi Ishizuka, Takuya Kato, Shin-ichi Hayama
    Animals, 2023年07月, [査読有り]
    研究論文(学術雑誌)
  • A Comparative Genomic and Phylogenetic Investigation of the Xenobiotic Metabolism Enzymes of Cytochrome P450 in Elephants Shows Loss in CYP2E and CYP4A.
    Kanami Watanabe, Mitsuki Kondo, Yoshinori Ikenaka, Shouta M M Nakayama, Mayumi Ishizuka
    Animals : an open access journal from MDPI, 13, 12, 2023年06月09日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Cytochrome P450 is an important enzyme that metabolizes a variety of chemicals, including exogenous substances, such as drugs and environmental chemicals, and endogenous substances, such as steroids, fatty acids, and cholesterol. Some CYPs show interspecific differences in terms of genetic variation. As little is known about the mechanisms of elephant metabolism, we carried out a comparative genomic and phylogenetic analysis of CYP in elephants. Our results suggest that elephant CYP genes have undergone independent duplication, particularly in the CYP2A, CYP2C, and CYP3A genes, a unique cluster specific to elephant species. However, while CYP2E and CYP4A were conserved in other Afrotheria taxa, their decay in elephants resulted in genetic dysfunction (pseudogene). These findings outline several remarkable characteristics of elephant CYP1-4 genes and provide new insights into elephant xenobiotic metabolism. Further functional investigations are necessary to characterize elephant CYP, including expression patterns and interactions with drugs and sensitivities to other chemicals.
  • Estimation of the relationship between Pb contamination and feeding history of black-headed gulls (Chroicocephalus ridibundus) using stable isotopes
    Nana Ushine, Shouta MM Nakayama, Mayumi Ishizuka, Takuya Kato, Shin-ichi Hayama
    Japanese Journal of Environmental Toxicology, 26, 25, 37, 2023年06月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Immobilization of Pb and Zn leached from mining residue materials in Kabwe, Zambia: Performance of calcined dolomite in column experiments
    Walubita Mufalo, Pawit Tangviroon, Takahiko Arima, Toshifumi Igarashi, Mayumi Ito, Tsutomu Sato, Kenta Noto, Takeshi Kawashima, Imasiku Nyambe, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka
    Journal of Geochemical Exploration, 249, 107209, 107209, Elsevier BV, 2023年06月, [査読有り]
    研究論文(学術雑誌)
  • Association between Chronic Environmental Lead (Pb) Exposure and Cytokines in Males and Females of Reproductive Age from Kabwe, Zambia.
    Andrew Kataba, Yared Beyene Yohannes, Hokuto Nakata, John Yabe, Haruya Toyomaki, Kaampwe Muzandu, Golden Zyambo, Yoshinori Ikenaka, Kennedy Choongo, Mayumi Ishizuka, Shouta M M Nakayama
    International journal of environmental research and public health, 20, 8, 2023年04月20日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Lead (Pb) poisoning remains a great public health challenge globally known to induce a wide range of ailments in both children and adults. The current study investigated the association of chronic environmental Pb exposure and immunomodulatory cytokines tumor necrosis factor alpha (TNF-α) and interleukin-8 (IL-8) in adult males and females living in Kabwe, Zambia. The standard human cytokine/chemokine Milliplex assay was used to quantify plasma cytokines from four groups categorized as low (<10 μg/dL) and high (>10 μg/dL) blood lead level (BLL) groups, namely, low BLL female (n = 47; BLL = 3.76 μg/dL), low BLL Male (n = 43; BLL = 4.13 μg/dL), high BLL female (n = 21; BLL = 23.5 μg/dL), and high BLL male (n = 18; BLL = 23.7 μg/dL), respectively. The low BLL group was associated with increased TNF-α levels, and the high BLL group was associated with reduced TNF-α levels in female subjects. No associations between BLL and the levels of IL-8 and TNF-α cytokines were observed in either females or males, respectively. A negative correlation between BLL and TNF-α was found in female subjects, suggesting that an increase in BLL accompanied by a reduction in TNF-α. The reduced levels of circulating TNF-α in female subjects suggest that chronic Pb exposure could predispose females to immune and inflammation-related disorders than their male counterparts. Further studies are recommended to ascertain the impact of chronic Pb exposure on immunomodulatory cytokines, especially in females.
  • X-ray analytic microscopy with CT-guided sample extraction to analyze potential projectile fragments in a dead serow.
    Yuko Kihara, Yohsuke Makino, Masaaki Yokoyama, Fumiko Chiba, Aki Tanaka, Shouta M M Nakayama, Shin-Ichi Hayama, Mayumi Ishizuka, Kurt B Nolte, Hirotaro Iwase
    Legal medicine (Tokyo, Japan), 63, 102257, 102257, 2023年04月11日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), In forensic pathology, it is important to detect and recover as evidence residual metal particles and projectiles when evaluating potential gunshot wounds. This process can be challenging when the bullets are fragmented. This report presents our experience using multiple modalities to analyze the wound of an illegally killed Japanese serow (Capricornis crispus) found in a mountainous region without its head and hind limbs. We performed postmortem computed tomography (PMCT) and necropsy that showed a distant-range gunshot wound of the neck likely created by a centerfire rifle. A postmortem cut through the neck and absent head precluded a complete evaluation. To determine the composition of the metal-like fragments in the neck, sampling and metal analysis were performed in two ways. Samples extracted from the exposed wound surface without CT guidance were analyzed directly using inductively coupled plasma mass spectrometry (ICP-MS). Samples from the bone, muscles, and cervical cord extracted under CT guidance were analyzed using x-ray analytic microscopy (XGT-9000, HORIBA, Kyoto, Japan). In wound surface samples, silicon and iron were detected as the main components on ICP-MS, suggesting that the materials were gravel. The samples taken under CT guidance and analyzed with XGT-9000 revealed that the high-density CT areas were mainly composed of lead. Combining CT-guided sample extraction and XGT-9000 can be useful for retrieving true projectile fragments and avoiding the confusion created by erroneously sampling non-projectile surface materials.
  • Effects of Diazinon Exposure on Urinary Shedding of Leptospira interrogans Serogroup Hebdomadis in Mice
    So Shinya, Devinda S. Muthusinghe, Nobuo Koizumi, Kumiko Yoshimatsu, Shouta M. M. Nakayama, Mayumi Ishizuka, Yoshinori Ikenaka
    Toxics, 11, 4, 2023年04月11日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Wild rodents are natural hosts of Leptospira spp. and are exposed to various pesticides, some of which are immunotoxic. Rodent urine is an important source of infection for humans and other animals. We evaluated the effects of pesticide exposure on Leptospira growth in mice. Diazinon, at doses of 0.2, 1, and 5 mg/kg/day, was orally administered continuously to mice infected with Leptospira interrogans serogroup Hebdomadis for 32 days. The numbers of L. interrogans in urine and kidney tissues were significantly lower in mice exposed to 5 mg/kg/day diazinon than in unexposed mice (p < 0.05). The urinary concentration of 2-isopropyl-6-methyl-4-pyrimidinol, the metabolite of diazinon, was comparable with the concentration at which viability of L. interrogans was decreased in in vitro assay, suggesting that it had toxic effects on L. interrogans in the proximal renal tubules. Diazinon exposure reinforced Leptospira-induced expression of inflammatory cytokine genes in kidney tissues, and an enhanced immune system might suppress Leptospira growth. These results suggest that diazinon exposure may not increase the risk of Leptospira transmission to humans through mice. This novel study evaluated the relationship between pesticide exposure and Leptospira infection in mice, and the results could be useful for risk assessment of leptospirosis.
  • Characteristics of tissue distribution, metabolism, effects on brain catecholamines, and environmental exposure of frogs to neonicotinoid insecticides.
    So Shinya, Fumiya Nishibe, Yared Beyene Yohannes, Mayumi Ishizuka, Shouta M Nakayama, Yoshinori Ikenaka
    Aquatic toxicology (Amsterdam, Netherlands), 257, 106437, 106437, 2023年04月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Pesticide exposure is considered to be one important factor responsible for declining amphibian populations worldwide. The usage of neonicotinoid insecticides (NNIs) has markedly increased in recent years, and there are concerns regarding the effects of NNI-induced toxicity on the development and behavior of amphibians. However, there have been few reports on the metabolism, distribution, and neurotoxicity of NNIs in amphibians. In this study, we exposed the Western clawed frog (Silurana tropicalis) to clothianidin (CLT) in water. After 24 h of exposure, the highest concentrations were detected in the skin, indicating that frogs are at a high risk of absorbing CLT through their skin along with water. Excretion of CLT was estimated based on the concentrations of CLT metabolites in the water until 48 h of exposure. The findings showed that frogs had higher CLT metabolic ability than zebrafish. Serotonin levels in the brain were lower in the high-concentration CLT exposure group than in the control group, although the difference was not statistically significant. This suggested that catecholamine-related effects of CLT on the brain cannot be disregarded. In addition, quantitative analyses of NNI residue in wild frogs, soil, and water in agricultural areas in Hokkaido, Japan, were performed and four NNIs were detected. These results indicated the possible risk of NNI-induced toxicity in frogs. This is the first report of the characteristics of tissue distribution and metabolism of NNIs in frogs, which may facilitate the design of appropriate conservation programs for amphibians.
  • Characteristics of cytochrome P450-dependent metabolism against acetamiprid in the musk shrew (Suncus murinus).
    So Shinya, Yusuke Kawai, Mitsuki Kondo, Shouta M M Nakayama, Mayumi Ishizuka, Yoshinori Ikenaka
    Comparative biochemistry and physiology. Toxicology & pharmacology : CBP, 265, 109537, 109537, 2023年03月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Soricidae spp. (shrews) play an essential role in soil ecosystems and, due to their habitat and behavior, are exposed to soil pollutants, such as pesticides. Still, toxicity risk in Soricidae spp. has not been appropriately assessed. In this study, the musk shrew (Suncus murinus) was used as a model organism for toxicity assessment in Soricidae. Considering their carnivorous diet, it is reasonable to assume that the musk shrew has unique metabolic traits that are different from those of other common experimental models. This study describes the cytochrome P450 (CYP)-dependent metabolism affected by acetamiprid (ACP), a neonicotinoid insecticide. Pharmacokinetics analysis, an in vitro metabolic assay, and genetic analysis of CYP were performed and compared with data from mice and rats. Through phylogenetic and syntenic analyses, three families of CYP were identified in the musk shrew. Pharmacokinetic analysis showed that the blood concentration of ACP decreased more quickly in musk shrews than in mice. Moreover, the in vitro metabolic assay suggested more efficient metabolic responses toward ACP in musk shrews than in mice or rats. One of the CYP2A isoforms in musk shrews might be linked to a better ACP metabolism. From the results above, we describe novel metabolic traits of the musk shrew. Future research on recombinant CYP enzymes is necessary to fully understand CYP-dependent metabolism of xenobiotics in musk shrews.
  • Social cost of mining-related lead (Pb) pollution in Kabwe, Zambia, and potential remediation measures
    Daichi Yamada, Masato Hiwatari, Daiju Narita, Peter Hangoma, Bona Chitah, Hokuto Nakata, Shouta M.M. Nakayama, John Yabe, Mayumi Ito, Toshifumi Igarashi, Mayumi Ishizuka, Golden Zyambo
    Science of The Total Environment, 865, 161281, 161281, Elsevier BV, 2023年03月, [査読有り]
    研究論文(学術雑誌)
  • Investigation of dichlorodiphenyltrichloroethane (DDT) on xenobiotic enzyme disruption and metabolomic bile acid biosynthesis in DDT-sprayed areas using wild rats.
    Kodai Motohira, Yared Beyene Yohannes, Yoshinori Ikenaka, Akifumi Eguchi, Shouta Mm Nakayama, Victor Wepener, Nico J Smit, Johan Hj VAN Vuren, Mayumi Ishizuka
    The Journal of veterinary medical science, 85, 2, 236, 243, 2023年01月02日, [査読有り], [国内誌]
    英語, 研究論文(学術雑誌), Dichlorodiphenyltrichloroethane (DDT) is an organochlorine insecticide used worldwide. Several studies have reported the toxic effects of DDT and its metabolites on steroid hormone biosynthesis; however, its environmental effects are not well understood. This study examined wild rats collected in DDT-sprayed areas of South Africa and quantified plasma metabolites using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS). Fold change analysis of the metabolome revealed the effect of DDT on bile acid biosynthesis. Gene expression of the related enzyme in rat liver samples was also quantified. Significant association was found between DDT and gene expression levels related to constitutive androstane receptor mediated enzymes, such as Cyp2b1 in rat livers. However, our results could not fully demonstrate that enzymes related to bile acid biosynthesis were strongly affected by DDT. The correlation between DDT concentration and gene expression involved in steroid hormone synthesis in testis was also evaluated; however, no significant correlation was found. The disturbance of metabolic enzymes occurred in rat liver in the target area. Our results suggest that DDT exposure affects gene expression in wild rats living in DDT-sprayed areas. Therefore, there is a need for DDT toxicity evaluation in mammals living in DDT-sprayed areas. We could not find an effective biomarker that could reflect the mechanism of DDT exposure; however, this approach can provide new insights for future research to evaluate DDT effects in sprayed areas.
  • Status Report on Neonicotinoid Pollution in Japan: Emphasis on Human, Animal, and Environmental Health
    NIMAKO Collins, NAKAYAMA Shouta M. M., YOHANNES Yared Beyene, IKENAKA Yoshinori, ISHIZUKA Mayumi
    Environmental Monitoring and Contaminants Research, 3, 69, 91, Japan Society for Environmental Chemistry, 2023年, [査読有り]
    英語, Neonicotinoid insecticides are exclusively used for insect control in many parts of the globe. Since early 1992, various neonicotinoid active compounds have been used for pest control in Japan. At present, all seven major neonicotinoid active compounds, imidacloprid, acetamiprid, dinotefuran, clothianidin, thiamethoxam, thiacloprid, and nitenpyram, are used in Japan, and the total shipment amount of these chemicals in the country was estimated 337.9 tons in 2022. Due to the massive neonicotinoid application in Japan, concerns have been raised about their potential infiltrations into nontarget ecosystems and their effects on human and ecological species. These concerns have inspired several studies, extensively investigating the environmental contamination levels and exposure tendencies in humans and several other invertebrate species. The current status report harmonized the up-to-date data on neonicotinoids in Japan and identified the incoherencies or knowledge gaps existing in the neonicotinoid literature reported in Japan. The report further summarized extensive neonicotinoid publications globally to illustrate the distributions of various neonicotinoid compounds in agricultural soils and surface waters and their exposures in humans and nontarget animal species. This report represents a few perspectives with detailed data from Japan into perspective.
  • Sensitivity Assessment of Diphacinone by Pharmacokinetic Analysis in Invasive Black Rats in the Bonin (Ogasawara) Archipelago, Japan
    Kazuki Takeda, Keita Shimizu, Miyu Sato, Masafumi Katayama, Shouta MM Nakayama, Kotaro Tanaka, Yoshinori Ikenaka, Takuma Hashimoto, Ryuichi Minato, Yusuke Oyamada, Kazuyuki D. Tanaka, Goro Kimura, Tsutomu Tanikawa, Keisuke Kato, Taichi Kusakabe, Mayumi Ishizuka, Ryo Kamata
    Elsevier BV, 2023年
  • Biological effects related to exposure to polychlorinated biphenyl (PCB) and decabromodiphenyl ether (BDE-209) on cats
    Khidkhan K, Mizukawa H, Ikenaka Y, Nakayama SMM, Nomiyama K, Yokoyama N, Ichii O, Takiguchi M, Tanabe S, Ishizuka M
    PLOS ONE, 18, 1, e0277689, 2023年01月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), As an animal familiar to humans, cats are considered to be sensitive to chemicals; cats may be exposed to polychlorinated biphenyls (PCBs) and decabromodiphenyl ether (BDE-209) from indoor dust, household products, and common pet food, leading to adverse endocrine effects, such as thyroid hormone dysfunction. To elucidate the general biological effects resulting from exposure of cats to PCBs and PBDEs, cats were treated with a single i.p. dose of a principal mixture of 12 PCBs and observed for a short-term period. Results revealed that the testis weight, serum albumin, and total protein of the treated group decrease statistically in comparison with those in the control group. The negative correlations suggested that the decrease in the total protein and albumin levels may be disturbed by 4'OH-CB18, 3'OH-CB28 and 3OH-CB101. Meanwhile, the serum albumin level and relative brain weight decreased significantly for cats subjected to 1-year continuous oral administration of BDE-209 in comparison to those of control cats. In addition, the subcutaneous fat as well as serum high-density lipoprotein (HDL) and triglycerides (TG) levels increased in cats treated with BDE-209 and down-regulation of stearoyl-CoA desaturase mRNA expression in the liver occurred. These results suggested that chronic BDE-209 treatment may restrain lipolysis in the liver, which is associated with lipogenesis in the subcutaneous fat. Evidence of liver and kidney cell damage was not observed as there was no significant difference in the liver enzymes, blood urea nitrogen and creatinine levels between the two groups of both experiments. To the best of our knowledge, this is the first study that provides information on the biochemical effects of organohalogen compounds in cats. Further investigations on risk assessment and other potential health effects of PCBs and PBDEs on the reproductive system, brain, and lipid metabolism in cats are required.
  • Sulfotransferases (SULTs), enzymatic and genetic variation in Carnivora: Limited sulfation capacity in pinnipeds.
    Mitsuki Kondo, Yoshinori Ikenaka, Shouta M M Nakayama, Yusuke K Kawai, Hazuki Mizukawa, Yoko Mitani, Kei Nomyama, Shinsuke Tanabe, Mayumi Ishizuka
    Comparative biochemistry and physiology. Toxicology & pharmacology : CBP, 263, 109476, 109476, 2023年01月, [国際誌]
    英語, 研究論文(学術雑誌), Wild carnivorans are one of the most important species due to their high positions in the food chain. They are also highly affected by numerous environmental contaminants through bioaccumulation and biomagnification. Xenobiotic metabolism is a significant chemical defense system from xenobiotics because it degrades the activity of a wide range of chemicals, generally into less active forms, resulting in their deactivation. Sulfotransferases (SULTs) are one of the most important xenobiotic metabolic enzymes, which catalyze the sulfonation of a variety of endogenous and exogenous chemicals, such as hormones, neurotransmitters, and a wide range of xenobiotic compounds. Although SULTs are of such high importance, little research has focused on these enzymes in wild carnivorans. In this study, we clarified the genetic properties of SULTs in a wide range of mammals, focusing on carnivorans, using in silico genetic analyses. We found genetic deficiencies of SULT1E1 and SULT1D1 isoforms in all pinnipeds analyzed and nonsense mutations in SULT1Cs in several carnivorans including pinnipeds. We further investigated the enzymatic activity of SULT1E1 in vitro using liver cytosols from pinnipeds. Using a SULT1E1 probe substrate, we found highly limited estradiol sulfonation in pinnipeds, whereas other mammals had relatively high sulfation. These results suggest that pinnipeds have severely or completely absent SULT1E1 activity, which importantly catalyzes the metabolism of estrogens, drugs, and environmental toxins. This further implies a high susceptibility to a wide range of xenobiotics in these carnivorans, which are constantly exposed to environmental chemicals throughout their lifetime.
  • Contamination Status of Pet Cats in Thailand with Organohalogen Compounds (OHCs) and Their Hydroxylated and Methoxylated Derivatives and Estimation of Sources of Exposure to These Contaminants
    Makoto Shimasaki, Hazuki Mizukawa, Kohki Takaguchi, Aksorn Saengtienchai, Araya Ngamchirttakul, Disdanai Pencharee, Kraisiri Khidkhan, Yoshinori Ikenaka, Shouta M. M. Nakayama, Mayumi Ishizuka, Kei Nomiyama
    Animals, 12, 24, 3520, 3520, MDPI AG, 2022年12月13日, [査読有り], [招待有り], [国際共著], [国際誌]
    英語, 研究論文(学術雑誌), In this study, we analyzed serum samples of pet cats from Thailand and estimated the contribution to organohalogen compounds (OHCs) exposure through cat food and house dust intake. BDE-209 was predominant in cat sera and accounted for 76% of all polybrominated diphenyl ethers (PBDEs). Decabromodiphenyl ether (BDE-209) is a major contaminant in dry cat food and house dust, which has been estimated to be a source of exposure for Thai pet cats. BDE-209 is a major contaminant of OHCs in dry cat food and house dust, which was estimated to be a source of exposure for Thai pet cats. On the other hand, the level of contamination by PCBs was lower than in other countries. Analysis of pet foods suggested that BDE-209 in pet cat serum was attributable to the consumption of dry cat food. On the other hand, house dust also contained high concentrations of BDE-209. Thus, high levels of BDE-209 in pet cat sera can be attributed to the consumption of dry cat food and house dust. These results suggest that pet cats are routinely exposed to non-negligible levels of OHCs.
  • Accumulation of Metals in the Environment and Grazing Livestock near A Mongolian Mining Area.
    Bayartogtokh Bataa, Kodai Motohira, Delgermurun Dugar, Tsend-Ayush Sainnokhoi, Lkhamjav Gendenpil, Tserenchimed Sainnokhoi, Bolormaa Pelden, Yared Beyene Yohannes, Sumiya Ganzorig, Shouta M M Nakayama, Mayumi Ishizuka, Yoshinori Ikenaka
    Toxics, 10, 12, 2022年12月10日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), The Mongolian economy is supported by rich deposits of natural resources, such as copper, coal, and gold. However, the risk of heavy metal pollution to livestock and human have been recently discussed. This research collected various samples from soil and animal (sheep, goat, horse, cow, and camel), blood and organs (kidney and liver) in the Mongolian countryside. These samples were processed, and the concentration of metals was quantified using inductively coupled plasma-mass spectrometry (ICP/MS). As previously reported, arsenic was found at high levels of accumulation in soil. Selenium is another concern, as median concentration in one area exceeded the maximum allowable level. Cadmium and selenium were found to be highly accumulated in animal kidney. This research revealed the current pollution level in Mongolia based on evaluation of soil and animals. The concentration in animals could not indicate that animals had severe effects because of heavy metal exposure. However, kidney is eaten in Mongolia, and so there is a direct connection to human health, and this research suggested the possible risks posed by each edible animal. In particular, evaluation of metals in livestock is rare in Mongolia. This result can contribute to animal and human health in Mongolian communities.
  • Methylation profiles of global LINE-1 DNA and the GSTP1 promoter region in children exposed to lead (Pb).
    Yared Beyene Yohannes, Shouta M M Nakayama, John Yabe, Haruya Toyomaki, Andrew Kataba, Hokuto Nakata, Kaampwe Muzandu, Chihiro Miyashita, Yoshinori Ikenaka, Kennedy Choongo, Mayumi Ishizuka
    Epigenetics, 17, 13, 2377, 2388, 2022年12月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Lead (Pb) exposure has adverse health effects and altered DNA methylation may contribute to Pb toxicity. LINE-1 is an interspersed repeated DNA that is used as a surrogate marker for estimating genomic DNA methylation levels, and GSTP1 is an isozyme that detoxifies xenobiotics like Pb, and its expression is inhibited by methylation. Thus, to assess the effects of Pb exposure on global hypomethylation and gene-specific promoter hypermethylation, we examined DNA methylation at LINE-1 repetitive elements and the GSTP1 promoter region. Blood samples were obtained from children (N = 123) living in Pb-polluted areas (as exposed children) and children (N = 63) living in Pb-unpolluted areas (as control children) in Kabwe, Zambia. ICP-MS was used to determine blood lead levels (BLLs), and pyrosequencing and a fluorescence-based polymerase chain reaction assay were used to determine levels of LINE-1 methylation and GSTP1 promoter methylation, respectively. Inverse association was found between BLLs and LINE-1 methylation (β = - 0.046, p = 0.006). The highest quartile of BLL had significant hypomethylation of LINE-1 (p for trend = 0.03), suggesting the higher the BLL, the lower LINE-1 methylation. GSTP1 methylation levels did not differ significantly between the two areas (p = 0.504), nor was it associated with Pb poisoning risk (OR = 1.03, p = 0.476), indicating GSTP1 methylation may not be a reliable biomarker of Pb exposure in healthy people. Therefore, Pb-related health problems could result from global DNA methylation changes due to high BLLs.
  • Detection of Changes in Monoamine Neurotransmitters by the Neonicotinoid Pesticide Imidacloprid Using Mass Spectrometry.
    Anri Hirai, Ryo Yamazaki, Atsushi Kobayashi, Takashi Kimura, Kei Nomiyama, Shuichi Shimma, Shouta M M Nakayama, Mayumi Ishizuka, Yoshinori Ikenaka
    Toxics, 10, 11, 2022年11月17日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Monoamine neurotransmitters (MAs), including dopamine (DA) and serotonin (5-HT), regulate brain functions such as behavior, memory, and learning. Neonicotinoids are pesticides that are being used more frequently. Neonicotinoid exposure has been observed to produce neurological symptoms, such as altered spontaneous movements and anxiety-like behaviors, which are suspected to be caused by altered MA levels. However, current neurotoxicity tests are not sufficiently sensitive enough to make these determinations. In this study, we performed some behavior tests, and derivatization reagents to improve the ionization efficiency, which was applied to liquid chromatography mass spectrometry (LC-MS/MS) to reveal the effect of neonicotinoid administration on MAs in the brain. We orally administered the neonicotinoid imidacloprid (0, 10, and 50 mg/kg body weight) to C57BL/6NCrSlc mice. In the behavior tests, a decrease in activity was observed. The LC-MS/MS quantification of MAs in various brain regions showed a decrease in some MA levels in the olfactory bulb and the striatum. These results showed, for the first time, that even a low dose of imidacloprid could alter MA levels in various parts of the brain.
  • Characteristics of cytochrome P450-dependent metabolism in the liver of the wild raccoon, Procyon lotor.
    So Shinya, Yared Beyene Yohannes, Yoshinori Ikenaka, Shouta Mm Nakayama, Mayumi Ishizuka, Shoichi Fujita
    The Journal of veterinary medical science, 84, 12, 1665, 1672, 2022年11月02日, [査読有り], [国内誌]
    英語, 研究論文(学術雑誌), Wildlife is exposed to a wide range of xenobiotics in the natural environment. In order to appropriately assess xenobiotic-induced toxicity in wildlife, it is necessary to understand metabolic capacities. Carnivores, in general, have low metabolic abilities, making them vulnerable to a variety of chemicals. Raccoons (Procyon lotor) in the wild have been found to have high levels of xenobiotics. However, little is known about the metabolic capacity of the cytochrome P450 (CYP) enzymes in this species. Thus, this study used liver samples to investigate the characteristics of CYP enzymes in wild raccoons. In 22 wild raccoons, CYP concentrations in hepatic microsomes were examined. To better understand the properties of CYP-dependent metabolism, in vitro metabolic activity studies were performed using ethoxyresorufin, pentoxyresorufin and testosterone as substrates. In addition, three raccoons were fed commercial dog food in the laboratory for one week, and the effects on CYP-dependent metabolism were investigated. In comparison to other mammalian species, raccoons had very low concentrations of CYP in their livers. In an in vitro enzymatic analysis, raccoons' ethoxyresorufin O-deethylase (EROD) and pentoxyresorufin O-depentylase (PROD) metabolic capacities were less than one-fifth and one-tenth of rats', respectively. These results indicate the possible high risk in raccoons if exposed to high levels of environmental xenobiotics because of their poor CYP activity. In this study, the features of CYP-dependent metabolism in wild raccoons are described for the first time.
  • Duplication, Loss, and Evolutionary Features of Specific UDP-Glucuronosyltransferase Genes in Carnivora (Mammalia, Laurasiatheria).
    Mitsuki Kondo, Yoshinori Ikenaka, Shouta M M Nakayama, Yusuke K Kawai, Mayumi Ishizuka
    Animals : an open access journal from MDPI, 12, 21, 2022年10月27日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), UDP-glucuronosyltransferases (UGTs) are one of the most important enzymes for xenobiotic metabolism or detoxification. Through duplication and loss of genes, mammals evolved the species-specific variety of UGT isoforms. Among mammals, Carnivora is one of the orders that includes various carnivorous species, yet there is huge variation of food habitat. Recently, lower activity of UGT1A and 2B were shown in Felidae and pinnipeds, suggesting evolutional loss of these isoforms. However, comprehensive analysis for genetic or evolutional features are still missing. This study was conducted to reveal evolutional history of UGTs in Carnivoran species. We found specific gene expansion of UGT1As in Canidae, brown bear and black bear. We also found similar genetic duplication in UGT2Bs in Canidae, and some Mustelidae and Ursidae. In addition, we discovered contraction or complete loss of UGT1A7-12 in phocids, some otariids, felids, and some Mustelids. These studies indicate that even closely related species have completely different evolution of UGTs and further imply the difficulty of extrapolation of the pharmacokinetics and toxicokinetic result of experimental animals into wildlife carnivorans.
  • Specific Gene Duplication and Loss of Cytochrome P450 in Families 1-3 in Carnivora (Mammalia, Laurasiatheria).
    Mitsuki Kondo, Yoshinori Ikenaka, Shouta M M Nakayama, Yusuke K Kawai, Mayumi Ishizuka
    Animals : an open access journal from MDPI, 12, 20, 2022年10月18日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Cytochrome P450s are among the most important xenobiotic metabolism enzymes that catalyze the metabolism of a wide range of chemicals. Through duplication and loss events, CYPs have created their original feature of detoxification in each mammal. We performed a comprehensive genomic analysis to reveal the evolutionary features of the main xenobiotic metabolizing family: the CYP1-3 families in Carnivora. We found specific gene expansion of CYP2Cs and CYP3As in omnivorous animals, such as the brown bear, the black bear, the dog, and the badger, revealing their daily phytochemical intake as providing the causes of their evolutionary adaptation. Further phylogenetic analysis of CYP2Cs revealed Carnivora CYP2Cs were divided into CYP2C21, 2C41, and 2C23 orthologs. Additionally, CYP3As phylogeny also revealed the 3As' evolution was completely different to that of the Caniformia and Feliformia taxa. These studies provide us with fundamental genetic and evolutionary information on CYPs in Carnivora, which is essential for the appropriate interpretation and extrapolation of pharmacokinetics or toxicokinetic data from experimental mammals to wild Carnivora.
  • Sex-specific behavioral effects of acute exposure to the neonicotinoid clothianidin in mice.
    Shizuka Kubo, Tetsushi Hirano, Yuka Miyata, Shuji Ohno, Kanoko Onaru, Yoshinori Ikenaka, Shouta M M Nakayama, Mayumi Ishizuka, Youhei Mantani, Toshifumi Yokoyama, Nobuhiko Hoshi
    Toxicology and applied pharmacology, 456, 116283, 116283, 2022年10月14日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Although neonicotinoids are among the major classes of pesticides that affect mammalian nervous systems, little is known about sex differences in their effects. This study aimed to examine whether the neurobehavioral effects of a neonicotinoid, clothianidin (CLO), differed between sexes. Male and female C57BL/6 N mice were orally administered CLO (5 or 50 mg/kg) at or below the chronic no-observed-adverse-effect-level (NOAEL) and subjected to behavioral tests of emotional and learning functions. Changes in neuroactivity in several brain regions and the concentrations of CLO and its metabolites in blood and urine were measured. Acute CLO exposure caused sex-related behavioral effects; decreases in locomotor activities and elevation of anxiety-like behaviors were more apparent in males than in females. In addition, male-specific impairment of short- and long-term learning memory by CLO exposure was observed in both the novel recognition test and the Barnes maze test. Male-dominant increases in the number of c-fos positive cells were observed in the paraventricular thalamic nucleus in the thalamus and in the dentate gyrus in the hippocampus, which are related to the stress response and learning function, respectively. The concentrations of CLO and most metabolites in blood and urine were higher in males. These results support the notion that male mice are more vulnerable than females to the neurobehavioral effects of CLO and provide novel insights into the risk assessment of neonicotinoids in mammalian neuronal function.
  • Does Moringa Oleifera affect element accumulation patterns and lead toxicity in Sprague–Dawley rats?
    Hokuto Nakata, Shouta M.M. Nakayama, Andrew Kataba, Haruya Toyomaki, Rio Doya, Yared Beyene Yohannes, Yoshinori Ikenaka, Mayumi Ishizuka
    Journal of Functional Foods, 97, 105242, Elsevier BV, 2022年10月
  • Toxicokinetic analysis of the anticoagulant rodenticides warfarin & diphacinone in Egyptian fruit bats (Rousettus aegyptiacus) as a comparative sensitivity assessment for Bonin fruit bats (Pteropus pselaphon)
    Kazuki Takeda, Kosuke Manago, Ayuko Morita, Yusuke K. Kawai, Nobuaki Yasuo, Masakazu Sekijima, Yoshinori Ikenaka, Takuma Hashimoto, Ryuichi Minato, Yusuke Oyamada, Kazuo Horikoshi, Hajime Suzuki, Mayumi Ishizuka, Shouta M.M. Nakayama
    Ecotoxicology and Environmental Safety, 243, 113971, 113971, Elsevier BV, 2022年09月, [査読有り]
    研究論文(学術雑誌)
  • Drought altered trophic dynamics of an important natural saline lake: A stable isotope approach.
    Lizaan de Necker, Luc Brendonck, Ruan Gerber, Pieter Lemmens, David X Soto, Yoshinori Ikenaka, Mayumi Ishizuka, Victor Wepener, Nico J Smit
    The Science of the total environment, 834, 155338, 155338, 2022年08月15日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Narrative review of lead poisoning in humans caused by industrial activities and measures compatible with sustainable industrial activities in Republic of Zambia
    Hokuto Nakata, Shouta M.M. Nakayama, John Yabe, Kaampwe Muzandu, Andrew Kataba, Atsuko Ikeda-Araki, Marie-Noel Brune Drisse, Lesley Jayne Onyon, Julia Gorman, Poudel Kritika, Hisanori Fukunaga, Yoshinori Ikenaka, Reiko Kishi, Mayumi Ishizuka
    Science of The Total Environment, 157833, 157833, Elsevier BV, 2022年08月, [査読有り]
    研究論文(学術雑誌)
  • Clarifying expression patterns by renal lesion using transcriptome analysis and vanin-1 as a potential novel biomarker for renal injury in chickens.
    Chihiro Ishii, Yusuke K Kawai, Yoshinori Ikenaka, Naoya Maekawa, Osamu Ichii, Shouta M M Nakayama, Mayumi Ishizuka
    Poultry science, 101, 9, 102011, 102011, 2022年06月16日, [国際誌]
    英語, 研究論文(学術雑誌), Bird death is often caused by renal lesions induced by chemicals. The avian kidney has a renal portal system with significant blood flow that is sensitive to many chemicals. However, early avian biomarkers for kidney injury are yet to be identified. This study aimed to identify novel renal biomarkers. Acute kidney injury (AKI) can be divided into acute interstitial nephritis (AIN) and acute tubular necrosis (ATN). A chicken model of kidney damage was created by an injection of diclofenac or cisplatin, which caused either AIN or ATN, respectively. Microarray analysis was performed to profile the gene expression patterns in the chickens with nephropathy. A gene enrichment analysis suggested that the genes related to responses to external stimuli showed expression changes in both AIN and ATN. However, hierarchical clustering analyses suggested that gene expression patterns differed between AIN and ATN, and the number of biomarkers relating to renal damage was low. To identify early biomarkers for nephropathy, we focused on genes that were induced at various levels of renal damage. The gene, vanin-1 (VNN1) was highly induced in the early stages of renal damage. A quantitative real-time PCR analysis supported this finding. These results suggest VNN1 could be a useful early biomarker of kidney injury in avian species.
  • Cytochrome P450 2J (CYP2J) Genes in Dogs, Cats, and Pigs Are Expressed and Encode Functional Drug-Metabolizing Enzymes.
    Yasuhiro Uno, Norie Murayama, Moe Ijiri, Hiroaki Kawaguchi, Osamu Yamato, Mitsuya Shiraishi, Atsushi Asano, Hiroki Teraoka, Hazuki Mizukawa, Shouta M M Nakayama, Yoshinori Ikenaka, Mayumi Ishizuka, Hiroshi Yamazaki
    Drug metabolism and disposition: the biological fate of chemicals, 50, 11, 1434, 1441, 2022年06月14日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Cytochromes P450 (P450 or CYP) have been identified and analyzed in dogs and pigs, species that are often used in preclinical drug studies. Moreover, P450s are clinically important for drug therapy not only in humans but also in species under veterinary care, including dogs and cats. In the present study, seven P450s homologous to human CYP2J2, namely, dog CYP2J2; cat CYP2J2; and pig CYP2J33, CYP2J34, CYP2J35, CYP2J91, and CYP2J93, were newly identified and characterized. The cDNAs of these CYP2Js contained open reading frames of 502 amino acids, except for CYP2J35 (498 amino acids), and shared high sequence identity (77-80%) with human CYP2J2. Phylogenetic analysis revealed that dog and cat CYP2J2 were closely related, whereas pig CYP2Js formed a cluster. All seven CYP2J genes contain nine coding exons and are located in corresponding genomic regions, with the pig CYP2J genes forming a gene cluster. These CYP2J2 mRNAs were predominantly expressed in small intestine with additional expression in kidney and brain for dog CYP2J2 and pig CYP2J91 mRNAs, respectively. All seven CYP2Js metabolized human CYP2J2 substrates terfenadine, ebastine, and astemizole, indicating that they are functional enzymes. Dog CYP2J2 and pig CYP2J34 and CYP2J35 efficiently catalyzed ebastine primary hydroxylation and secondary carebastine formation at low substrate concentrations, just as human CYP2J2 does. Velocity-versus-substate plots exhibited sigmoidal relationships for dog CYP2J2, cat CYP2J2, and pig CYP2J33, indicating allosteric interactions. These results suggest that dog, cat, and pig CYP2Js have similar functional characteristics to human CYP2J2, with slight differences in ebastine and astemizole oxidations. Significance Statement New dog cytochrome P450 2J2 (CYP2J2); cat CYP2J2; and pig CYP2J33, CYP2J34, CYP2J35, CYP2J91, and CYP2J93, homologous to human CYP2J2, were identified and characterized by sequence, phylogenetic, and genomic structure analyses. Intestinal expression patterns of CYP2J mRNAs were characteristic in dogs, cats, and pigs. Dog, cat, and pig CYP2Js likely play roles as drug-metabolizing enzymes in small intestine, similar to human CYP2J2.
  • Molecular and functional characterization of flavin-containing monooxygenases in pigs, dogs, and cats.
    Yasuhiro Uno, Makiko Shimizu, Yurie Ogawa, Miaki Makiguchi, Hiroaki Kawaguchi, Osamu Yamato, Mayumi Ishizuka, Hiroshi Yamazaki
    Biochemical pharmacology, 202, 115125, 115125, 2022年06月08日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Flavin-containing monooxygenases (FMOs) are drug-oxygenating enzymes that are present in the human genome as FMO1-5 and FMO6P. Among pig, dog, and cat FMOs, pig and dog FMO1 and FMO3 have been partly characterized, but other FMOs have not been systematically identified. In this study, orthologous FMO cDNAs were isolated from pig, dog, and cat livers and evaluated by sequence and phylogenetic analyses, tissue expression, and catalytic function. The amino acid sequences of pig, dog, and cat FMO1-5 shared high sequence identities (83-89%) with human FMO1-5 and were closely clustered in a phylogenetic tree. The gene structure and genomic organization of FMO1-5 were conserved across these species. Dog and pig FMO6P contained insertions of 1 and 83 bases, respectively, and are possibly pseudogenes similar to human FMO6P. Among the tissue types analyzed, pig FMO1 mRNA was abundant in liver, kidney, and lung; dog FMO3, FMO2, and FMO5 mRNAs were abundant in liver, lung, and kidney, respectively; cat FMO1 and FMO3 mRNAs were abundant in kidney and liver, respectively. Recombinant pig and dog FMO1-5 and cat FMO1-6 all mediated benzydamine and trimethylamine N-oxygenations and methyl p-tolyl sulfoxide S-oxygenation. The selective human FMO3 substrate trimethylamine was predominantly metabolized by pig FMO1, dog FMO3, and cat FMO3. Cat FMO6 was also active toward trimethylamine. These results suggest some similarities in the drug-metabolizing capabilities of FMO3 in dogs, cats, and humans and that dog and cat FMO3 generally have molecular and functional characteristics similar to human FMO3, being the major FMO in human liver.
  • Behavior and toxic effects of Pb in a waterfowl model with oral exposure to Pb shots: Investigating Pb exposure in wild birds.
    Hiroshi Sato, Chihiro Ishii, Shouta M M Nakayama, Takahiro Ichise, Keisuke Saito, Yukiko Watanabe, Kohei Ogasawara, Ryota Torimoto, Atsushi Kobayashi, Takashi Kimura, Yukiko Nakamura, Junya Yamagishi, Yoshinori Ikenaka, Mayumi Ishizuka
    Environmental pollution (Barking, Essex : 1987), 308, 119580, 119580, 2022年06月06日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Among wild birds, lead (Pb) exposure caused by ingestion of ammunition is a worldwide problem. We aimed to reveal the behavior and toxic effect of Pb caused by ingesting Pb shots in waterfowl. Four male, eight-week old Muscovy ducks (Cairina moschata) were given three Pb shots (approximately 240 mg in total) orally and then fed for 29 days after exposure, simulating a low-dose Pb exposure in wild waterfowl. During the breeding period, blood samples were collected 10 times, and fecal samples every day. Additionally, 22 fresh tissue and 6 bone samples were obtained from each duck through the dissection. Although there were no gross abnormalities, the maximum blood Pb concentration of each duck ranged from 0.6 to 3.7 mg/L, reaching a threshold concentration indicative of clinical symptoms (>0.5 mg/L). δ-aminolevulinic acid dehydratase declined one day after exposure and remained low throughout the feeding period. Hematocrit also tended to decrease, indicating signs of anemia. The highest Pb accumulation was observed in the bones, followed by the kidneys, intestinal tracts, and liver. High Pb accumulation in the bones, which are known to have a long Pb half-life, suggested that Pb would remain in the body and possibly affect bird health beyond 28 days after exposure. Gene expression analysis showed a significant increase in the expression of the toll-like receptor-3 gene, which is involved in virus discrimination in the liver, suggesting a disruption of the immune system. Microbiota analyses showed a correlation between the blood Pb concentration and the abundances of Lachnospiraceae and Ruminococcaceae, suggesting that Pb affects lipid metabolism. These results provide fundamental data on Pb exposure in wild birds and a new perspective on the damage such exposure causes.
  • メタボロミクスおよび甲状腺ホルモン分析による有機ハロゲン汚染物質への曝露によって引き起こされたペット猫(Felis silvestris catus)の健康影響評価
    野見山桂, 山本恭央, 江口哲史, 西川博之, 水川葉月, 横山望, 市居修, 滝口満喜, 中山翔太, 池中良徳, 石塚真由美, 国末達也
    環境ホルモン学会研究発表会プログラム・要旨集, 842, 156490, 156490, 2022年06月03日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Companion animals are in close contact with the human surroundings, and there is growing concern about the effects of harmful substances on the health of pet cats. In this study, we investigated the potential health effects of organohalogen compounds (OHCs) on thyroid hormone (TH) homeostasis and metabolomics in Japanese pet cats. There was a significant negative correlation between concentrations of several contaminants, such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), hydroxylated PCBs (OH-PCBs), hydroxylated PBDEs (OH-PBDEs), and THs in cat serum samples. These results suggested that exposure to OHCs causes a decrease in serum TH levels in pet cats. In this metabolomics study, each exposure level of parent compounds (PCBs and PBDEs) and their hydroxylated compounds (OH-PCBs and OH-PBDEs) were associated with their own unique primary metabolic pathways, suggesting that parent and phenolic compounds exhibit different mechanisms of action and biological effects. PCBs were associated with many metabolic pathways, including glutathione and purine metabolism, and the effects were replicated in in-vivo cat PCB administration studies. These results demonstrated that OHC exposure causes chronic oxidative stress in pet cats. PBDEs were positively associated with alanine, aspartate, and glutamate metabolism. Due to the chronic exposure of cats to mixtures of these contaminants, the combination of their respective metabolic pathways may have a synergistic effect.
  • Impacts of Surface Water on Windborne Lead Dispersion from the Zinc Plant Leach Residue in Kabwe, Zambia
    Shinsaku Nakamura, Toshifumi Igarashi, Yoshitaka Uchida, Mayumi Ito, Kazuyo Hirose, Tsutomu Sato, Walubita Mufalo, Meki Chirwa, Imasiku Nyambe, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka
    Minerals, 12, 5, 2022年05月, [査読有り]
    研究論文(学術雑誌)
  • Geospatial approach to investigate spatial clustering and hotspots of blood lead levels in children within Kabwe, Zambia.
    Given Moonga, Moses N Chisola, Ursula Berger, Dennis Nowak, John Yabe, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka, Stephan Bose-O'Reilly
    Environmental research, 207, 112646, 112646, 2022年05月01日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Estimation of the Effects of Neonicotinoid Insecticides on Wild Raccoon, Procyon lotor, in Hokkaido, Japan: Urinary Concentrations and Hepatic Metabolic Capability of Neonicotinoids.
    So Shinya, Mariko Sashika, Miku Minamikawa, Tetsuji Itoh, Yared Beyene Yohannes, Shouta M M Nakayama, Mayumi Ishizuka, Collins Nimako, Yoshinori Ikenaka
    Environmental toxicology and chemistry, 41, 8, 1865, 1874, 2022年04月22日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Human Health Risk Assessment from Lead Exposure through Consumption of Raw Cow Milk from Free-Range Cattle Reared in the Vicinity of a Lead-Zinc Mine in Kabwe.
    Golden Zyambo, John Yabe, Kaampwe Muzandu, Ethel M'kandawire, Kennedy Choongo, Andrew Kataba, Kenneth Chawinga, Allan Liazambi, Shouta M M Nakayama, Hokuto Nakata, Mayumi Ishizuka
    International journal of environmental research and public health, 19, 8, 2022年04月14日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Geochemical identification of particulate lead pollution in shallow groundwater in inhabited areas in Kabwe, Zambia
    Kazuhiro Toyoda, Shota Nakano, Shunitz Tanaka, Kawawa Banda, Imasiku A. Nyambe, Tsuyoshi Ishikawa, Shouta Nakayama, Mayumi Ishizuka
    Applied Geochemistry, 139, 2022年04月, [査読有り]
    研究論文(学術雑誌)
  • Alkaline Leaching and Concurrent Cementation of Dissolved Pb and Zn from Zinc Plant Leach Residues
    Marthias Silwamba, Mayumi Ito, Naoki Hiroyoshi, Carlito Baltazar Tabelin, Ryota Hashizume, Tomoki Fukushima, Ilhwan Park, Sanghee Jeon, Toshifumi Igarashi, Tsutomu Sato, Imasiku Nyambe, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka
    Minerals, 12, 4, 2022年04月, [査読有り]
    研究論文(学術雑誌)
  • Assessment of ameliorative effects of organic dietary interventions on neonicotinoid exposure rates in a Japanese population.
    Collins Nimako, Takahiro Ichise, Hiroshi Hasegawa, Osei Akoto, Nathaniel O Boadi, Kumiko Taira, Kazutoshi Fujioka, Norikazu Isoda, Shouta M M Nakayama, Mayumi Ishizuka, Yoshinori Ikenaka
    Environment international, 162, 107169, 107169, 2022年04月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Ca2+ imaging with two-photon microscopy to detect the disruption of brain function in mice administered neonicotinoid insecticides.
    Anri Hirai, Shouta Sugio, Collins Nimako, Shouta M M Nakayama, Keisuke Kato, Keisuke Takahashi, Koji Arizono, Tetsushi Hirano, Nobuhiko Hoshi, Kazutoshi Fujioka, Kumiko Taira, Mayumi Ishizuka, Hiroaki Wake, Yoshinori Ikenaka
    Scientific reports, 12, 1, 5114, 5114, 2022年03月24日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Foraging ecology of mature male Antarctic minke whales (Balaenoptera bonaerensis) revealed by stable isotope analysis of baleen plates
    Hiroshi Ishikawa, Mayuko Otsuki, Tsutomu Tamura, Kenji Konishi, Takaharu Bando, Mayumi Ishizuka, Yoshinori Ikenaka, Shouta M.M. Nakayama, Yoko Mitani
    Polar Science, 31, 2022年03月, [査読有り]
    研究論文(学術雑誌)
  • Environmentally relevant lead (Pb) water concentration induce toxicity in zebrafish (Danio rerio) larvae.
    Andrew Kataba, Tarryn L Botha, Shouta M M Nakayama, Yared B Yohannes, Yoshinori Ikenaka, Victor Wepener, Mayumi Ishizuka
    Comparative biochemistry and physiology. Toxicology & pharmacology : CBP, 252, 109215, 109215, 2022年02月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Metabolomic Alteration in the Plasma of Wild Rodents Environmentally Exposed to Lead: A Preliminary Study.
    Hokuto Nakata, Akifumi Eguchi, Shouta M M Nakayama, John Yabe, Kaampwe Muzandu, Yoshinori Ikenaka, Chisato Mori, Mayumi Ishizuka
    International journal of environmental research and public health, 19, 1, 2022年01月04日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • 土地利用方法に着目した野生トカゲの重金属汚染バイオモニタリング;ザンビア共和国の鉱山跡地を例として
    銅谷 理緒, 中山 翔太, 中田 北斗, 近藤 充希, Golden ZYAMBO, Kaampwe MUZANDU, John YABE, 池中 良徳, 石塚 真由美
    日本毒性学会学術年会, 49.1, P-133, 日本毒性学会, 2022年
    日本語, In Kabwe town in the Republic of Zambia, heavy metal pollution has been widespread due to lead and zinc mining activities since the early 20th, and it continues even after the official cessation of industrial operation in 1994. In addition to soil, high concentrations of lead have been detected in humans, domestic animals, and wild rodents (Yabe et al. 2015, Nakata et al. 2017, Nakayama et al. 2011).

    We employed a species of wild lizards (Trachylepis wahlbergii) as a target organism for biomonitoring focusing on land use patterns. This species was considered to be suitable because they live in relatively small home ranges, they only prey on insects, and they are widely distributed from residential areas to grasslands.

    An initial field survey was conducted in 2017 to collect the lizards and soil of their habitat. Liver and other organs were collected from 224 lizards. Metal analysis of lizard and soil samples was performed by ICP-MS after acid digestion with a microwave system. The highest concentration in the liver was 200μg/g, which is much higher than the previous result in the same area using other animal species. Also, biological concentrations were relatively high in places near the mine and areas without vegetation. A follow-up survey was conducted in 2021 to further investigate the species-specificity of accumulation pattern, chronological shift, and relationship of these points with changes in land use pattern. The analytical results of 112 lizards are presented together with environmental parameters and geographical analysis.
  • Assessing the Net Benefits of Organic Farming interventions in Ecosystem Preservation against Emerging Pesticides
    Collins NIMAKO, Anri HIRAI, Takahiro ICHISE, Shouta M.M. NAKAYAMA, Mayumi ISHIZUKA, Yoshinori IKENAKA
    日本毒性学会学術年会, 49.1, P-108, 日本毒性学会, 2022年
    日本語, Organic farming practices are generally considered potential countermeasures against pesticide exposure in human populations. However, little is known if current organic interventional measures adopted in Japan can mitigate neonicotinoid (NNI) exposures or otherwise. The current validates the efficacies of organic dietary interventions in ameliorating NNIs exposures within the Japanese population. Firstly, 103 Japanese volunteers were recruited and fed strictly with either organic diets for 5 or 30 days or with conventional diets. Then the exposure rates of 8 NNIs were determined in the population, by LC-MS/MS analysis. After analysis, 8 NNIs were detected in the target population; but the detection rates were far lower in the organic diet consumers compared to conventional diet consumers. The organic dietary intervention drastically reduced the cumulative levels and the daily intake rates of NNIs in the Japanese population. Subsequently, the residual levels of NNIs were determined in organic and conventional green tea leaves produced in Japan. Seven NNIs compounds and one NNI metabolite were detected in tea leaves cultivated by strict organic farming methods. However, the detection rates of NNIs were relatively lower in organic tea leaves than conventional tea leaves. Moreover, the daily exposure rates of NNIs through green tea consumption were far lower for organic tea leaves than conventional tea leaves. These findings ultimately show that the adoption of organic farming interventions may offer optimum ameliorative outcomes on NNI exposure rates Japanese population.
  • Estimation of the reference lead (Pb) concentration levels affecting immune cells in the blood of Black-headed Gulls (Chroicocephalus ridibundus, Laridae)
    Nana Ushine, Osamu Kurata, Yoshikazu Tanaka, Shouta M.M Nakayama, Mayumi Ishizuka, Takuya Kato, Shin-Ichi Hayama
    Avian Conservation and Ecology, 17, 2, Resilience Alliance, Inc., 2022年
    研究論文(学術雑誌)
  • A GCDGC-specific DNA (cytosine-5) methyltransferase that methylates the GCWGC sequence on both strands and the GCSGC sequence on one strand.
    Yoshikazu Furuta, Fumihito Miura, Takahiro Ichise, Shouta M M Nakayama, Yoshinori Ikenaka, Tuvshinzaya Zorigt, Mai Tsujinouchi, Mayumi Ishizuka, Takashi Ito, Hideaki Higashi
    PloS one, 17, 3, e0265225, 2022年, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Editorial: Animal Poisoning and Biomarkers of Toxicity.
    Fernando Capela E Silva, Ana Catarina Sousa, Manuel Ramiro Pastorinho, Hazuki Mizukawa, Mayumi Ishizuka
    Frontiers in veterinary science, 9, 891483, 891483, 2022年, [査読有り], [国際誌]
    英語
  • Urinary concentrations of neonicotinoid insecticides were related to renal tubular dysfunction and neuropsychological complaints in Dry-zone of Sri Lanka.
    Kumiko Taira, Tomonori Kawakami, Sujithra Kaushaliya Weragoda, H M Ayala S Herath, Yoshinori Ikenaka, Kazutoshi Fujioka, Madhubhani Hemachandra, Nirmalie Pallewatta, Yoshiko Aoyama, Mayumi Ishizuka, Jean-Marc Bonmatin, Makiko Komori
    Scientific reports, 11, 1, 22484, 22484, 2021年11月18日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Solid-Phase Partitioning and Leaching Behavior of Pb and Zn from Playground Soils in Kabwe, Zambia.
    Walubita Mufalo, Pawit Tangviroon, Toshifumi Igarashi, Mayumi Ito, Tsutomu Sato, Meki Chirwa, Imasiku Nyambe, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka
    Toxics, 9, 10, 2021年10月04日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Genome-wide DNA methylation analysis of dogs with high lead exposure living near a lead mining area in Kabwe, Zambia
    Jumpei Yamazaki, Haruya Toyomaki, Shouta M.M. Nakayama, John Yabe, Kaampwe Muzandu, Jaroslav Jelinek, Shoko Yokoyama, Yoshinori Ikenaka, Mitsuyoshi Takiguchi, Mayumi Ishizuka
    Environmental Pollution, 286, 117229, 117229, 2021年10月01日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Lead concentrations and isotope ratios in blood, breastmilk and feces: contribution of both lactation and soil/dust exposure to infants in a lead mining area, Kabwe, Zambia
    Haruya Toyomaki, John Yabe, Shouta M.M. Nakayama, Yared B. Yohannes, Kaampwe Muzandu, Tiza Mufune, Hokuto Nakata, Yoshinori Ikenaka, Takeshi Kuritani, Mitsuhiro Nakagawa, Kennedy Choongo, Mayumi Ishizuka
    Environmental Pollution, 286, 117456, 117456, 2021年10月01日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Simultaneous steroids measurement in dogs with hyperadrenocorticism using a column-switching liquid chromatography-tandem mass spectrometry method.
    Noboru Sasaki, Thandar Oo, Yoshikazu Yasuda, Takahiro Ichise, Noriyuki Nagata, Nozomu Yokoyama, Kazuyoshi Sasaoka, Keitaro Morishita, Shouta Mm Nakayama, Mayumi Ishizuka, Kensuke Nakamura, Mitsuyoshi Takiguchi, Yoshinori Ikenaka
    The Journal of veterinary medical science, 83, 11, 1634, 1642, 2021年09月17日, [査読有り], [国内誌]
    英語, 研究論文(学術雑誌)
  • Effects of zinc on tissue uptake and toxicity of lead in Sprague Dawley rat.
    Andrew Kataba, Shouta M M Nakayama, Yared Beyene Yohannes, Haruya Toyomaki, Hokuto Nakata, Yoshinori Ikenaka, Mayumi Ishizuka
    The Journal of veterinary medical science, 83, 11, 1674, 1685, 2021年09月16日, [査読有り], [国内誌]
    英語, 研究論文(学術雑誌)
  • The impact of elevated blood lead levels in children on maternal health-related quality of life
    Hokuto Nakata, Harukazu Tohyama, Wakako Fujita, Shouta M.M. Nakayama, Mayumi Ishizuka, John Yabe, Nosiku S. Munyinda, Doreen Sakala, Kennedy Choongo, Shojiro Yamasaki, Natsumi Nagai, Takahiko Yoshida, Takeshi Saito
    Chemosphere, 279, 130490, 130490, 2021年09月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Geolocators link marine mercury with levels in wild seabirds throughout their annual cycle: Consequences for trans-ecosystem biotransport
    Akiko Shoji, Kyle H. Elliott, Yutaka Watanuki, Niladri Basu, Shannon Whelan, Joshua Cunningham, Scott Hatch, Hazuki Mizukawa, Shouta M.M. Nakayama, Yoshinori Ikenaka, Mayumi Ishizuka, Stéphane Aris-Brosou
    Environmental Pollution, 284, 117035, 117035, 2021年09月01日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Simultaneous quantification of imidacloprid and its metabolites in tissues of mice upon chronic low-dose administration of imidacloprid
    Collins Nimako, Yoshinori Ikenaka, Osei Akoto, Kazutoshi Fujioka, Kumiko Taira, Koji Arizono, Keisuke Kato, Keisuke Takahashi, Shouta M.M. Nakayama, Takahiro Ichise, Mayumi Ishizuka
    Journal of Chromatography A, 1652, 462350, 462350, 2021年08月30日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Glutathione S-transferase gene polymorphisms in association with susceptibility to lead toxicity in lead- and cadmium-exposed children near an abandoned lead-zinc mining area in Kabwe, Zambia.
    Yared Beyene Yohannes, Shouta M M Nakayama, John Yabe, Haruya Toyomaki, Andrew Kataba, Hokuto Nakata, Kaampwe Muzandu, Yoshinori Ikenaka, Kennedy Choongo, Mayumi Ishizuka
    Environmental science and pollution research international, 29, 5, 6622, 6632, 2021年08月28日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Effect of prenatal exposure to phthalates on epigenome-wide DNA methylations in cord blood and implications for fetal growth: The Hokkaido Study on Environment and Children's Health
    Ryu Miura, Atsuko Ikeda-Araki, Toru Ishihara, Kunio Miyake, Chihiro Miyashita, Tamie Nakajima, Sumitaka Kobayashi, Mayumi Ishizuka, Takeo Kubota, Reiko Kishi
    Science of the Total Environment, 783, 147035, 147035, 2021年08月20日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Analysis of lead distribution in avian organs by LA-ICP-MS: Study of experimentally lead-exposed ducks and kites
    Ryouta Torimoto, Chihiro Ishii, Hiroshi Sato, Keisuke Saito, Yukiko Watanabe, Kohei Ogasawara, Ayano Kubota, Takehisa Matsukawa, Kazuhito Yokoyama, Atsushi Kobayashi, Takashi Kimura, Shouta M.M. Nakayama, Yoshinori Ikenaka, Mayumi Ishizuka
    Environmental Pollution, 283, 117086, 117086, 2021年08月15日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Evaluation of dispersion of lead-bearing mine wastes in kabwe district, zambia
    Shinsaku Nakamura, Toshifumi Igarashi, Yoshitaka Uchida, Mayumi Ito, Kazuyo Hirose, Tsutomu Sato, Walubita Mufalo, Meki Chirwa, Imasiku Nyambe, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka
    Minerals, 11, 8, 2021年08月
    研究論文(学術雑誌)
  • Human Exposures to Neonicotinoids in Kumasi, Ghana
    Collins Nimako, Yoshinori Ikenaka, Osei Akoto, Nesta Bortey-Sam, Takahiro Ichise, Shouta M.M. Nakayama, Kwadwo A. Asante, Kazutoshi Fujioka, Kumiko Taira, Mayumi Ishizuka
    Environmental Toxicology and Chemistry, 40, 8, 2306, 2318, 2021年08月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • 二光子顕微鏡を用いた、ニコチン性アセチルコリン受容体アゴニストによる脳機能障害の検出               
    平井 杏梨, 杉尾 翔太, Nimako Collins, 中山 翔太, 加藤 恵介, 高橋 圭介, 有薗 幸司, 平野 哲史, 星 信彦, 藤岡 一俊, 平 久美子, 石塚 真由美, 和氣 弘明, 池中 良徳
    The Journal of Toxicological Sciences, 46, Suppl., S102, S103, (一社)日本毒性学会, 2021年07月
    英語
  • Bioaccumulation of DDT and other organochlorine pesticides in amphibians from two conservation areas within malaria risk regions of South Africa
    Nico J. Wolmarans, Lieven Bervoets, Ruan Gerber, Yared Beyene Yohannes, Shouta MM Nakayama, Yoshinori Ikenaka, Mayumi Ishizuka, Patrick Meire, Nico J. Smit, Victor Wepener
    Chemosphere, 274, 129956, 129956, 2021年07月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • The effects of fipronil on emotional and cognitive behaviors in mammals
    Tomohiro Suzuki, Anri Hirai, Kraisiri Khidkhan, Collins Nimako, Takahiro Ichise, Kazuki Takeda, Hazuki Mizukawa, Shouta M.M. Nakayama, Kei Nomiyama, Nobuhiko Hoshi, Mizuki Maeda, Tetsushi Hirano, Kazuyoshi Sasaoka, Noboru Sasaki, Mitsuyoshi Takiguchi, Mayumi Ishizuka, Yoshinori Ikenaka
    Pesticide Biochemistry and Physiology, 175, 104847, 104847, 2021年06月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Aging-related changes in the sensitivity of behavioral effects of the neonicotinoid pesticide clothianidin in male mice
    Tetsushi Hirano, Yuka Miyata, Shizuka Kubo, Shuji Ohno, Kanoko Onaru, Mizuki Maeda, Sayaka Kitauchi, Misaki Nishi, Yoshiaki Tabuchi, Yoshinori Ikenaka, Takahiro Ichise, Shouta M.M. Nakayama, Mayumi Ishizuka, Koji Arizono, Keisuke Takahashi, Keisuke Kato, Youhei Mantani, Toshifumi Yokoyama, Nobuhiko Hoshi
    Toxicology Letters, 342, 95, 103, 2021年05月15日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Assessment of LeadCare® II analysis for testing of a wide range of blood lead levels in comparison with ICP–MS analysis
    Hokuto Nakata, Shouta M.M. Nakayama, John Yabe, Kaampwe Muzandu, Haruya Toyomaki, Yared Beyene Yohannes, Andrew Kataba, Golden Zyambo, Yoshinori Ikenaka, Kennedy Choongo, Mayumi Ishizuka
    Chemosphere, 271, 129832, 129832, 2021年05月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Sensitivity of turtles to anticoagulant rodenticides: Risk assessment for green sea turtles (Chelonia mydas) in the Ogasawara Islands and comparison of warfarin sensitivity among turtle species
    Yoshiya Yamamura, Kazuki Takeda, Yusuke K. Kawai, Yoshinori Ikenaka, Chiyo Kitayama, Satomi Kondo, Chiho Kezuka, Mari Taniguchi, Mayumi Ishizuka, Shouta M.M. Nakayama
    Aquatic Toxicology, 233, 105792, 105792, 2021年04月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Estimation of the feeding record of pregnant Antarctic minke whales (Balaenoptera bonaerensis) using carbon and nitrogen stable isotope analysis of baleen plates
    Mayuka Uchida, Ippei Suzuki, Keizo Ito, Mayumi Ishizuka, Yoshinori Ikenaka, Shouta M.M. Nakayama, Tsutomu Tamura, Kenji Konishi, Takeharu Bando, Yoko Mitani
    Polar Biology, 44, 3, 621, 629, 2021年03月, [査読有り]
    研究論文(学術雑誌)
  • The VKORC1 ER-luminal loop mutation (Leu76Pro) leads to a significant resistance to warfarin in black rats (Rattus rattus)
    Kazuki Takeda, Yoshinori Ikenaka, Denis Fourches, Kazuyuki D. Tanaka, Shouta M.M. Nakayama, Dhoha Triki, Xinhao Li, Manabu Igarashi, Tsutomu Tanikawa, Mayumi Ishizuka
    Pesticide Biochemistry and Physiology, 173, 104774, 104774, 2021年03月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Evaluation of the ameliorative effect of Spirulina (Arthrospira platensis) supplementation on parameters relating to lead poisoning and obesity in C57BL/6J mice
    Hokuto Nakata, Shouta M.M. Nakayama, Andrew Kataba, Yared Beyene Yohannes, Yoshinori Ikenaka, Mayumi Ishizuka
    Journal of Functional Foods, 77, 2021年02月, [査読有り]
    研究論文(学術雑誌)
  • Delta-aminolevulinic acid dehydratase (ALAD) and vitamin D receptor (VDR) genes polymorphisms in children residing in an abandoned lead‑zinc mine area in Kabwe, Zambia
    Yared B. Yohannes, Shouta M.M. Nakayama, John Yabe, Haruya Toyomaki, Andrew Kataba, Hokuto Nakata, Kaampwe Muzandu, Yoshinori Ikenaka, Kennedy Choongo, Mayumi Ishizuka
    Meta Gene, 27, 2021年02月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Levels of DDTs and other organochlorine pesticides in healthy wild Nile crocodiles (Crocodylus niloticus) from a flagship conservation area
    Ruan Gerber, Hindrik Bouwman, Danny Govender, Mayumi Ishizuka, Yoshinori Ikenaka, Yared B. Yohannes, Nico J. Smit, Victor Wepener
    Chemosphere, 264, Pt 1, 128368, 128368, 2021年02月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • An investigation of the wild rat crown incisor as an indicator of lead (Pb) exposure using inductively couple plasma mass spectrometry (ICP-MS) and laser ablation ICP-MS
    Andrew Kataba, Shouta M.M. Nakayama, Hokuto Nakata, Haruya Toyomaki, Yared B. Yohannes, John Yabe, Kaampwe Muzandu, Golden Zyambo, Ayano Kubota, Takehisa Matsukawa, Kazuhito Yokoyama, Yoshinori Ikenaka, Mayumi Ishizuka
    International Journal of Environmental Research and Public Health, 18, 2, 1, 15, 2021年01月02日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Simultaneous Detection Technique and Chronic Low-dose Accumulation Trends of Imidacloprid and its Metabolites in Tissues of C57BL/6J Mice
    Collins NIMAKO, Yoshinori IKENAKA, Osei AKOTO, Kazutoshi FUJIOKA, Kumiko TAIRA, Koji ARIZONO, Keisuke KATO, Keisuke TAKAHASHI, Shouta M.M. NAKAYAMA, Takahiro ICHISE, Mayumi ISHIZUKA
    日本毒性学会学術年会, 48.1, P-154E, 日本毒性学会, 2021年
    日本語, The present study aimed to (i) develop a sensitive LC-MS/MS-based technique for simultaneous detection and quantification of Imidacloprid (IMI) and its metabolites in tissue specimens, and to (ii) determine the specific bioaccumulation trends of the IMI compounds in organs of C57BL/6J male mice; after exposure to 0.6 mg/kg bw/day of IMI (10% of NOAEL) through a powdered diet for 24 weeks. We successfully developed a method which was accurate (recoveries were ≥ 70% for most compounds), sensitive (LODs ≤ 0.47 ng/mL, LOQs ≤ 1.43 ng/mL and R2 ≥ 0.99) and precise (RSDs ≤ 20%) for routine analysis of IMI and seven of its metabolites in in blood and various tissues of mice. Upon biodistribution analysis, IMI and five of its metabolites were detected in various organs within mice. Blood, liver, mesenteric white adipose tissue and pancreas mainly accumulated IMI-olefin; brain, testis, inguinal white adipose tissue and gonadal white adipose tissue mainly accumulated IMI, whereas the kidney mainly accumulated 4-hydroxy-IMI. The N-desnitro-IMI metabolite showed unique accumulation in brain and testis by recording brain-blood and testis-blood detection ratios of 8.4 and 7.6, respectively. Cumulative levels of the six detected IMI compounds (Σ6 IMI compounds) were found in the decreasing order; blood > testis > iWAT > kidney > brain > gWAT > mWAT > pancreas > liver. The current study provides essential data needed for effective mechanistic elucidation of compound-specific adverse outcomes associated with chronic exposures to IMI in mammalian species.
  • 活動紹介:モンゴル生命科学大学との研究協力
    本平 航大, Dugar Delgermurun, 池中 良徳, 中山 翔太, Pelden Bolormaa, Gendenpil Lkhamjav, 石塚 真由美
    日本科学教育学会年会論文集, 45, 563, 564, 一般社団法人 日本科学教育学会, 2021年
    日本語, 発表者は北海道大学のJICAを通じたプロジェクトの一環で2019年に青年海外協力隊(獣医師)としてモンゴル生命科学大学獣医学部に短期派遣され、約1か月の研究支援を実施した。モンゴル国では残留抗生物質の検査体制の拡大が望まれており、発表者の活動により、日本から大学研究レベルの検査手法の開発とその研究プロセスの伝達、共有が実現された。帰国後も、現在に至るまでFacebook Messengerなどのツールを利用し、追加の検査手法開発に向けた継続的な研究協力関係を構築した。結果として、国際会議における科学的成果発表など、今回の活動により一定の進展があったことを社会に報告できた。しかし、専門性の高い研究レベルの支援を遠隔で実施する過程で双方、難点を抱える場面があった。本発表により発表者が実施した研究支援を踏まえ、開発途上国に対する大学研究レベルの支援の一例紹介、またその課題を共有する。
  • Neonicotinoid residues in commercial Japanese tea leaves produced by organic and conventional farming methods.
    Collins Nimako, Anri Hirai, Takahiro Ichise, Osei Akoto, Shouta M M Nakayama, Kumiko Taira, Kazutoshi Fujioka, Mayumi Ishizuka, Yoshinori Ikenaka
    Toxicology reports, 8, 1657, 1664, 2021年, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Chronic low-dose exposure to imidacloprid potentiates high fat diet-mediated liver steatosis in c57bl/6j male mice
    Collins Nimako, Yoshinori Ikenaka, Yuko Okamatsu-Ogura, Jussiaea V. Bariuan, Atsushi Kobayashi, Ryo Yamazaki, Kumiko Taira, Nobuhiko Hoshi, Tetsushi Hirano, Shouta M.M. Nakayama, Mayumi Ishizuka
    Journal of Veterinary Medical Science, 83, 3, 487, 500, 2021年, [査読有り], [国内誌]
    英語, 研究論文(学術雑誌)
  • Urinary free metanephrines measurement in dogs with adrenal gland diseases using a new simple liquid chromatography tandem mass spectrometry method
    Noboru Sasaki, Yoshinori Ikenaka, Yumiko Inoue, Takahiro Ichise, Noriyuki Nagata, Mayumi Ishizuka, Syouta M.M. Nakayama, Kensuke Nakamura, Mitsuyoshi Takiguchi
    Journal of Veterinary Medical Science, 83, 4, 648, 655, 2021年, [査読有り], [国内誌]
    英語, 研究論文(学術雑誌)
  • Interspecies differences in cytochrome P450-mediated metabolism of neonicotinoids among cats, dogs, rats, and humans
    Kraisiri Khidkhan, Yoshinori Ikenaka, Takahiro Ichise, Shouta M.M. Nakayama, Hazuki Mizukawa, Kei Nomiyama, Hisato Iwata, Koji Arizono, Keisuke Takahashi, Keisuke Kato, Mayumi Ishizuka
    Comparative Biochemistry and Physiology Part - C: Toxicology and Pharmacology, 239, 108898, 108898, 2021年01月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Clinical biochemical parameters associated with the exposure to multiple environmental metals in residents from Kabwe, Zambia
    Hokuto Nakata, Shouta M.M. Nakayama, John Yabe, Kaampwe Muzandu, Haruya Toyomaki, Yared Beyene Yohannes, Andrew Kataba, Golden Zyambo, Yoshinori Ikenaka, Kennedy Choongo, Mayumi Ishizuka
    Chemosphere, 262, 127788, 127788, 2021年01月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Assessing the population-wide exposure to lead pollution in Kabwe, Zambia: an econometric estimation based on survey data
    Daichi Yamada, Masato Hiwatari, Peter Hangoma, Daiju Narita, Chrispin Mphuka, Bona Chitah, John Yabe, Shouta M.M. Nakayama, Hokuto Nakata, Kennedy Choongo, Mayumi Ishizuka
    Scientific Reports, 10, 1, 15092, 15092, 2020年12月01日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Biosorption of Pb (II) and Zn (II) from aqueous solution by Oceanobacillus profundus isolated from an abandoned mine
    Wilson Mwandira, Kazunori Nakashima, Satoru Kawasaki, Allison Arabelo, Kawawa Banda, Imasiku Nyambe, Meki Chirwa, Mayumi Ito, Tsutomu Sato, Toshifumi Igarashi, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka
    Scientific Reports, 10, 1, 21189, 21189, 2020年12月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Lead, zinc and cadmium accumulation, and associated health risks, in maize grown near the kabwe mine in Zambia in response to organic and inorganic soil amendments
    Patricia N. Mwilola, Ikabongo Mukumbuta, Victor Shitumbanuma, Benson H. Chishala, Yoshitaka Uchida, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka
    International Journal of Environmental Research and Public Health, 17, 23, 1, 15, 2020年12月01日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Land Use in Habitats Affects Metal Concentrations in Wild Lizards around a Former Lead Mining Site
    Rio Doya, Shouta M.M. Nakayama, Hokuto Nakata, Haruya Toyomaki, John Yabe, Kaampwe Muzandu, Yared B. Yohannes, Andrew Kataba, Golden Zyambo, Takahiro Ogawa, Yoshitaka Uchida, Yoshinori Ikenaka, Mayumi Ishizuka
    Environmental Science and Technology, 54, 22, 14474, 14481, 2020年11月17日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Evaluation of phytoremediation effects of chicken manure, urea and lemongrass on remediating a lead contaminated soil in Kabwe, Zambia
    Yui Yoshii, Isabell von Rein, Kabenuka Munthali, Mukuka Mwansa, Hokuto Nakata, Shota Nakayama, Mayumi Ishizuka, Yoshitaka Uchida
    SOUTH AFRICAN JOURNAL OF PLANT AND SOIL, 37, 5, 351, 360, 2020年11月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Acute exposure to environmentally relevant lead levels induces oxidative stress and neurobehavioral alterations in larval zebrafish (Danio rerio)
    Andrew Kataba, Tarryn L. Botha, Shouta M.M. Nakayama, Yared B. Yohannes, Yoshinori Ikenaka, Victor Wepener, Mayumi Ishizuka
    Aquatic Toxicology, 227, 105607, 105607, 2020年10月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Immobilization of lead and zinc leached from mining residual materials in kabwe, zambia: Possibility of chemical immobilization by dolomite, calcined dolomite, and magnesium oxide
    Pawit Tangviroon, Kenta Noto, Toshifumi Igarashi, Takeshi Kawashima, Mayumi Ito, Tsutomu Sato, Walubita Mufalo, Meki Chirwa, Imasiku Nyambe, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka
    Minerals, 10, 9, 1, 16, 2020年09月, [査読有り]
    研究論文(学術雑誌)
  • Blood lead levels and aberrant DNA methylation of the ALAD and p16 gene promoters in children exposed to environmental-lead
    Yared B. Yohannes, Shouta MM Nakayama, John Yabe, Hokuto Nakata, Haruya Toyomaki, Andrew Kataba, Kaampwe Muzandu, Yoshinori Ikenaka, Kennedy Choongo, Mayumi Ishizuka
    Environmental Research, 188, 109759, 109759, 2020年09月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Relationship between blood test values and blood lead (Pb) levels in Black-headed gull (Chroicocephalus ridibundus: Laridae).
    Nana Ushine, Shouta M M Nakayama, Mayumi Ishizuka, Tatsuo Sato, Yoshihiro Kurahashi, Emu Wakayama, Natsuko Sugiura, Shin-Ichi Hayama
    The Journal of veterinary medical science, 82, 8, 1124, 1129, 2020年08月19日, [査読有り], [国内誌]
    英語, 研究論文(学術雑誌)
  • Current situation regarding lead exposure in birds in Japan (2015-2018); lead exposure is still occurring.
    Chihiro Ishii, Yoshinori Ikenaka, Shouta M M Nakayama, Takeshi Kuritani, Mitsuhiro Nakagawa, Keisuke Saito, Yukiko Watanabe, Kohei Ogasawara, Manabu Onuma, Atsushi Haga, Mayumi Ishizuka
    The Journal of veterinary medical science, 82, 8, 1118, 1123, 2020年08月19日, [査読有り], [国内誌]
    英語, 研究論文(学術雑誌)
  • Trophic transfer of pollutants within two intertidal rocky shore ecosystems in different biogeographic regions of South Africa
    Anja Erasmus, Yoshinori Ikenaka, Shouta M.M. Nakayama, Mayumi Ishizuka, Nico J. Smit, Victor Wepener
    Marine Pollution Bulletin, 157, 111309, 111309, 2020年08月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Detoxification of lead-bearing zinc plant leach residues from Kabwe, Zambia by coupled extraction-cementation method
    Marthias Silwamba, Mayumi Ito, Naoki Hiroyoshi, Carlito Baltazar Tabelin, Tomoki Fukushima, Ilhwan Park, Sanghee Jeon, Toshifumi Igarashi, Tsutomu Sato, Imasiku Nyambe, Meki Chirwa, Kawawa Banda, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka
    Journal of Environmental Chemical Engineering, 8, 4, 104197, 104197, Elsevier BV, 2020年08月, [査読有り]
    研究論文(学術雑誌)
  • Altered hepatic cytochrome p450 expression in cats after chronic exposure to decabromodiphenyl ether (Bde-209)
    Kraisiri Khidkhan, Hazuki Mizukawa, Yoshinori Ikenaka, Shouta M.M. Nakayama, Kei Nomiyama, Nozomu Yokoyama, Osamu Ichii, Mitsuyoshi Takiguchi, Shinsuke Tanabe, Mayumi Ishizuka
    Journal of Veterinary Medical Science, 82, 7, 978, 982, 2020年07月, [査読有り], [国内誌]
    英語, 研究論文(学術雑誌)
  • エジプシャンルーセットオオコウモリ(Rousettus aegyptiacus)における抗血液凝固系殺鼠剤の薬物動態学/薬力学的解析               
    武田 一貴, 真砂 皓大, 中山 翔太, 川合 佑典, 池中 良徳, 石塚 真由美
    The Journal of Toxicological Sciences, 45, Suppl., S181, S182, (一社)日本毒性学会, 2020年06月
    日本語
  • Comparison of two reducing agents dithiothreitol and tris(3-hydroxypropyl)phosphine for in vitro kinetic assay of vitamin K epoxide reductase
    Kazuki Takeda, Ayuko Morita, Yoshinori Ikenaka, Shouta M.M. Nakayama, Mayumi Ishizuka
    Veterinary and Animal Science, 9, 100095, 100095, 2020年06月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Using Stable Î13C and Î15N Isotopes to Assess Foodweb Structures in an African Subtropical Temporary Pool
    L. De Necker, A. Manfrin, Y. Ikenaka, M. Ishizuka, L. Brendonck, J. H.J. Van Vuren, B. Sures, V. Wepener, N. J. Smit
    African Zoology, 55, 1, 79, 92, 2020年05月, [査読有り]
    研究論文(学術雑誌)
  • Factors associated with lead (Pb) exposure on dogs around a Pb mining area, Kabwe, Zambia
    Haruya Toyomaki, John Yabe, Shouta M.M. Nakayama, Yared B. Yohannes, Kaampwe Muzandu, Allan Liazambi, Yoshinori Ikenaka, Takeshi Kuritani, Mitsuhiro Nakagawa, Mayumi Ishizuka
    Chemosphere, 247, 125884, 125884, 2020年05月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Recovery of lead and zinc from zinc plant leach residues by concurrent dissolution-cementation using zero-valent aluminum in chloride medium
    Marthias Silwamba, Mayumi Ito, Naoki Hiroyoshi, Carlito Baltazar Tabelin, Ryota Hashizume, Tomoki Fukushima, Ilhwan Park, Sanghee Jeon, Toshifumi Igarashi, Tsutomu Sato, Meki Chirwa, Kawawa Banda, Imasiku Nyambe, Hokuto Nakata, Shouta Nakayama, Mayumi Ishizuka
    Metals, 10, 4, 531, 531, MDPI AG, 2020年04月, [査読有り]
    研究論文(学術雑誌)
  • Quantitative elucidation of maternal-to-fetal transfer of neonicotinoid pesticide clothianidin and its metabolites in mice
    Shuji Ohno, Yoshinori Ikenaka, Kanoko Onaru, Shizuka Kubo, Nanami Sakata, Tetsushi Hirano, Youhei Mantani, Toshifumi Yokoyama, Keisuke Takahashi, Keisuke Kato, Koji Arizono, Takahiro Ichise, Shouta M.M. Nakayama, Mayumi Ishizuka, Nobuhiko Hoshi
    Toxicology Letters, 322, 32, 38, 2020年04月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Combined exposure to dinotefuran and chronic mild stress counteracts the change of the emotional and monoaminergic neuronal activity induced by either exposure singly despite corticosterone elevation in mice.
    Tadashi Takada, Naoki Yoneda, Tetsushi Hirano, Kanoko Onaru, Youhei Mantani, Toshifumi Yokoyama, Hiroshi Kitagawa, Yoshiaki Tabuchi, Collins Nimako, Mayumi Ishizuka, Yoshinori Ikenaka, Nobuhiko Hoshi
    The Journal of veterinary medical science, 82, 3, 350, 359, 2020年03月24日, [査読有り], [国内誌]
    英語, 研究論文(学術雑誌)
  • Current trends of blood lead levels, distribution patterns and exposure variations among household members in Kabwe, Zambia
    John Yabe, Shouta MM Nakayama, Hokuto Nakata, Haruya Toyomaki, Yared B. Yohannes, Kaampwe Muzandu, Andrew Kataba, Golden Zyambo, Masato Hiwatari, Daiju Narita, Daichi Yamada, Peter Hangoma, Nosiku Sipilanyambe Munyinda, Tiza Mufune, Yoshinori Ikenaka, Kennedy Choongo, Mayumi Ishizuka
    Chemosphere, 243, 125412, 125412, 2020年03月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • In Vivo Accumulation of Plastic-Derived Chemicals into Seabird Tissues.
    Kosuke Tanaka, Yutaka Watanuki, Hideshige Takada, Mayumi Ishizuka, Rei Yamashita, Mami Kazama, Nagako Hiki, Fumika Kashiwada, Kaoruko Mizukawa, Hazuki Mizukawa, David Hyrenbach, Michelle Hester, Yoshinori Ikenaka, Shouta M M Nakayama
    Current biology : CB, 30, 4, 723, 728, 2020年02月24日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Avian interspecific differences in VKOR activity and inhibition: Insights from amino acid sequence and mRNA expression ratio of VKORC1 and VKORC1L1.
    Shouta M M Nakayama, Ayuko Morita, Yoshinori Ikenaka, Yusuke K Kawai, Kensuke P Watanabe, Chihiro Ishii, Hazuki Mizukawa, Yared B Yohannes, Keisuke Saito, Yukiko Watanabe, Masaki Ito, Natsuo Ohsawa, Mayumi Ishizuka
    Comparative biochemistry and physiology. Toxicology & pharmacology : CBP, 228, 108635, 108635, 2020年02月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • ニコチン性アセチルコリン受容体アゴニストによるシグナル毒性と2光子顕微鏡を用いた検出手法の開発
    平井 杏梨, 杉尾 翔太, 池中 良徳, Nimako COLLINS, 中山 翔太, 星 信彦, 和氣 弘明, 石塚 真由美
    日本毒性学会学術年会, 47.1, P-4S, 日本毒性学会, 2020年
    日本語, 一部の化学物質は脳内の受容体に作用する事で細胞内、細胞間における情報伝達を攪乱する“シグナル毒性”を示し、予期せぬ影響を引き起こす。特に脳機能は神経細胞やグリア細胞間の複雑なシグナルネットワークが形成されており、このネットワークの攪乱は、シグナル毒性のクリティカルなエンドポイントになり得ると考えられる。しかし、シグナル毒性を起因とする“脳機能の攪乱”は、細胞死やそれに伴う脳組織変性を伴わない場合が多く、現行の神経毒性試験法では検出不可能である。そこで、本研究では、ニコチン性アセチルコリン受容体 (nAChR)のアゴニストであるネオニコチノイド(NNs)およびニコチンをモデル化合物とし、体性感覚野における神経細胞の活動変化を2光子顕微鏡で検出する事で、シグナル毒性に伴う脳機能の攪乱を検出する事を目的とした。

    まず、C57BL/6Nマウスを用い、アセタミプリド(ACE)をマウスの最小毒性量である20 mg/kgとなるように経口投与し、経時的に採血を行い、LC/MSを用いてACEおよびその代謝産物の血中濃度を定量した。また、ACEを20 mg/kgおよび7.1 mg/kgとなるように経口投与し、投与1時間後にオープンフィールド試験および高架式十字迷路試験をそれぞれ行った。さらに、C57BL/6JマウスにACEを30 mg/kgおよび典型的なnAChRアゴニストであるニコチンをLD50の半分の濃度(1.6 mg/kg)となるように経口投与し、2光子顕微鏡を用いて、体性感覚野における神経細胞の活動を経時的に観察した。

    結果について、ACEのTmaxは約25分で、主要な代謝産物であるdm-ACEでは約150分であった。ACE投与の1時間後には、マウスの活動性は抑制され、不安様行動が増加した。また、体性感覚野において、ACE投与1時間後および2時間半後に神経細胞の発火頻度が減少し、同期発火が増加した。ニコチン投与直後および30分後には、発火頻度が減少傾向を示し、同期発火が増加した。本結果は、脳神経活動の変化が行動の変化の原因であることを示唆する結果であった。
  • Review on counter measures to coronavirus disease 2019 (COVID-19) pandemic, May 2020
    Taishi Kidaka, Sithumini M.W. Lokupathirage, Bungiriye Devinda Shameera Muthusinghe, Boniface Lombe Pongombo, Christida Estu Wastika, Zhouxing Wei, Shizuka Yoshioka, Mayumi Ishizuka, Yoshihiro Sakoda, Hiroaki Kariwa, Norikazu Isoda
    Japanese Journal of Veterinary Research, 68, 3, 133, 150, 2020年
    研究論文(学術雑誌)
  • Bioimaging of Pb and STIM1 in mice liver, kidney and brain using Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) and immunohistochemistry.
    Masao Togao, Shouta M M Nakayama, Yoshinori Ikenaka, Hazuki Mizukawa, Yoshiki Makino, Ayano Kubota, Takehisa Matsukawa, Kazuhito Yokoyama, Takafumi Hirata, Mayumi Ishizuka
    Chemosphere, 238, 124581, 124581, 2020年01月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Occurrence and concentrations of chemical additives in plastic fragments on a beach on the island of Kauai, Hawaii.
    Kosuke Tanaka, Hideshige Takada, Yoshinori Ikenaka, Shouta M M Nakayama, Mayumi Ishizuka
    Marine pollution bulletin, 150, 110732, 110732, 2020年01月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • ペット動物から見る室内化学物質汚染の実態解明とリスク評価
    水川 葉月, 野見山 桂, 池中 良徳, 中山 翔太, 石塚 真由美, 高橋 真
    環境ホルモン学会研究発表会要旨集, 22回, 45, 45, 環境ホルモン学会(日本内分泌撹乱化学物質学会), 2019年12月
    日本語
  • Tissue distribution and characterization of feline cytochrome P450 genes related to polychlorinated biphenyl exposure.
    Kraisiri Khidkhan, Hazuki Mizukawa, Yoshinori Ikenaka, Shouta M M Nakayama, Kei Nomiyama, Nozomu Yokoyama, Osamu Ichii, Wageh Sobhy Darwish, Mitsuyoshi Takiguchi, Shinsuke Tanabe, Mayumi Ishizuka
    Comparative biochemistry and physiology. Toxicology & pharmacology : CBP, 226, 108613, 108613, 2019年12月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Dichlorodiphenyltrichloroethane (DDT) levels in rat livers collected from a malaria vector control region.
    Kodai Motohira, Yoshinori Ikenaka, Yared Beyene Yohannes, Shouta M M Nakayama, Victor Wepener, Nico J Smit, Johan H J VAN Vuren, Ana Catarina Sousa, Alex Ajeh Enuneku, Emmanuel Temiotan Ogbomida, Mayumi Ishizuka
    The Journal of veterinary medical science, 81, 11, 1575, 1579, 2019年11月14日, [査読有り], [国内誌]
    英語, 研究論文(学術雑誌)
  • Effects of the organochlorine p,p'-DDT on MCF-7 cells: Investigating metabolic and immune modulatory transcriptomic changes.
    Lesa A Thompson, Yoshinori Ikenaka, Wageh Sobhy Darwish, Shouta M M Nakayama, Hazuki Mizukawa, Mayumi Ishizuka
    Environmental toxicology and pharmacology, 72, 103249, 103249, 2019年11月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Effects of PCB exposure on serum thyroid hormone levels in dogs and cats.
    Kohki Takaguchi, Hiroyuki Nishikawa, Hazuki Mizukawa, Rumi Tanoue, Nozomu Yokoyama, Osamu Ichii, Mitsuyoshi Takiguchi, Shouta M M Nakayama, Yoshinori Ikenaka, Tatsuya Kunisue, Mayumi Ishizuka, Shinsuke Tanabe, Hisato Iwata, Kei Nomiyama
    The Science of the total environment, 688, 1172, 1183, 2019年10月20日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Bioaccumulation of persistent organic pollutants and their trophic transfer through the food web: Human health risks to the rural communities reliant on fish from South Africa's largest floodplain
    C.M. Volschenk, R. Gerber, M.T. Mkhonto, Y. Ikenaka, Y.B. Yohannes, S. Nakayama, M. Ishizuka, J.H.J. van Vuren, V. Wepener, N.J. Smit
    Science of The Total Environment, 685, 1116, 1126, Elsevier BV, 2019年10月
    研究論文(学術雑誌)
  • How toxic is a non-toxic nanomaterial: Behaviour as an indicator of effect in Danio rerio exposed to nanogold.
    Tarryn L Botha, Sarel J Brand, Yoshinori Ikenaka, Shouta M M Nakayama, Mayumi Ishizuka, Victor Wepener
    Aquatic toxicology (Amsterdam, Netherlands), 215, 105287, 105287, 2019年10月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • One year exposure to Cd- and Pb-contaminated soil causes metal accumulation and alteration of global DNA methylation in rats.
    Shouta M M Nakayama, Hokuto Nakata, Yoshinori Ikenaka, John Yabe, Balazs Oroszlany, Yared B Yohannes, Nesta Bortey-Sam, Kaampwe Muzandu, Kennedy Choongo, Takeshi Kuritani, Mitsuhiro Nakagawa, Mayumi Ishizuka
    Environmental pollution (Barking, Essex : 1987), 252, Pt B, 1267, 1276, 2019年09月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • An epigenome-wide analysis of cord blood DNA methylation reveals sex-specific effect of exposure to bisphenol A.
    Ryu Miura, Atsuko Araki, Machiko Minatoya, Kunio Miyake, Mei-Lien Chen, Sumitaka Kobayashi, Chihiro Miyashita, Jun Yamamoto, Toru Matsumura, Mayumi Ishizuka, Takeo Kubota, Reiko Kishi
    Scientific reports, 9, 1, 12369, 12369, 2019年08月26日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Solidification of sand by Pb(II)-tolerant bacteria for capping mine waste to control metallic dust: Case of the abandoned Kabwe Mine, Zambia.
    Wilson Mwandira, Kazunori Nakashima, Satoru Kawasaki, Mayumi Ito, Tsutomu Sato, Toshifumi Igarashi, Meki Chirwa, Kawawa Banda, Imasiku Nyambe, Shouta Nakayama, Hokuto Nakata, Mayumi Ishizuka
    Chemosphere, 228, 17, 25, 2019年08月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Zinc and Lead Biosorption by Oceanobacillus Profundus Kbz 3-2: a Bacterial Strain Resistant to Metals Isolated from Metal polluted Soils in Kabwe, Zambia               
    Wilson Mwandira, Kazunori Nakashima, Satoru Kawasaki, Mayumi Ito, Tsutomu Sato, Toshifumi Igarashi, Meki Chirwa, Kawawa Banda, Imasiku Nyambe, Shouta Nakayama, Mayumi Ishizuka
    Proceedings of the 14th Asian Congress on Biotechnology (ACB2019), 2019年07月, [査読有り]
    英語, 研究論文(国際会議プロシーディングス)
  • ネオニコチノイド系殺虫剤と農薬の現状と今後の展望〜毒性学・農学・行政の視点から〜 ネオニコチノイド系殺虫剤の曝露実態の解明と毒性評価               
    池中 良徳, 一瀬 貴大, Nimako Collins, 中山 翔太, 平野 哲史, 市川 剛, 加藤 恵介, 高橋 圭介, 長谷川 浩, 平 久美子, 有薗 幸司, 星 信彦, 藤岡 一俊, 石塚 真由美
    The Journal of Toxicological Sciences, 44, Suppl., S53, S53, (一社)日本毒性学会, 2019年06月
    日本語
  • Evidence of impacts from DDT in pelican, cormorant, stork, and egret eggs from KwaZulu-Natal, South Africa.
    H Bouwman, Y B Yohannes, S M M Nakayama, K Motohira, M Ishizuka, M S Humphries, V van der Schyff, M du Preez, A Dinkelmann, Y Ikenaka
    Chemosphere, 225, 647, 658, 2019年06月, [国際誌]
    英語, 研究論文(学術雑誌)
  • Baseline bio-accumulation concentrations and resulting oxidative stress in Synodontis zambezensis after an acute laboratory exposure to 4,4'-DDT.
    C M Volschenk, Y Ikenaka, Y B Yohannes, S M Nakayama, M Ishizuka, E Smit, J H J van Vuren, R Greenfield
    Pesticide biochemistry and physiology, 156, 44, 55, 2019年05月, [国際誌]
    英語, 研究論文(学術雑誌)
  • Functional and molecular characterization of UDP-glucuronosyltransferase 2 family in cynomolgus macaques.
    Yasuhiro Uno, Rika Takahira, Norie Murayama, Shunsuke Onozeki, Shu Kawamura, Shotaro Uehara, Yoshinori Ikenaka, Mayumi Ishizuka, Shinichi Ikushiro, Hiroshi Yamazaki
    Biochemical pharmacology, 163, 335, 344, 2019年05月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Efficacy of biocementation of lead mine waste from the Kabwe Mine site evaluated using Pararhodobacter sp.
    Wilson Mwandira, Kazunori Nakashima, Satoru Kawasaki, Mayumi Ito, Tsutomu Sato, Toshifumi Igarashi, Kawawa Banda, Meki Chirwa, Imasiku Nyambe, Shouta Nakayama, Mayumi Ishizuka
    Environmental science and pollution research international, 26, 15, 15653, 15664, 2019年05月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Characterization of function and genetic feature of UDP-glucuronosyltransferase in avian species.
    Yusuke K Kawai, So Shinya, Yoshinori Ikenaka, Aksorn Saengtienchai, Takamitsu Kondo, Wageh Sobhy Darwish, Shota M M Nakayama, Hazuki Mizukawa, Mayumi Ishizuka
    Comparative biochemistry and physiology. Toxicology & pharmacology : CBP, 217, 5, 14, 2019年03月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • A review: poisoning by anticoagulant rodenticides in non-target animals globally.
    Shouta M M Nakayama, Ayuko Morita, Yoshinori Ikenaka, Hazuki Mizukawa, Mayumi Ishizuka
    The Journal of veterinary medical science, 81, 2, 298, 313, 2019年02月28日, [査読有り], [国内誌]
    英語, 研究論文(学術雑誌)
  • Biotransport of metallic trace elements from marine to terrestrial ecosystems by seabirds.
    Shoji A, Elliott KH, Aris-Brosou S, Mizukawa H, Nakayama SMM, Ikenaka Y, Ishizuka M, Kuwae T, Watanabe K, Escoruela Gonzalez J, Watanuki Y
    Environmental toxicology and chemistry, 38, 1, 106, 114, 2019年01月, [査読有り]
    研究論文(学術雑誌)
  • Exposures of children to neonicotinoids in pine wilt disease control areas.
    Yoshinori Ikenaka, Yuichi Miyabara, Takahiro Ichise, Shouta Nakayama, Collins Nimako, Mayumi Ishizuka, Chiharu Tohyama
    Environmental toxicology and chemistry, 38, 1, 71, 79, 2019年01月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • LC-ESI/MS/MS analysis of neonicotinoids in urine of very low birth weight infants at birth.
    Go Ichikawa, Ryota Kuribayashi, Yoshinori Ikenaka, Takahiro Ichise, Shouta M M Nakayama, Mayumi Ishizuka, Kumiko Taira, Kazutoshi Fujioka, Toshimi Sairenchi, Gen Kobashi, Jean-Marc Bonmatin, Shigemi Yoshihara
    PloS one, 14, 7, e0219208, 2019年, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Comparison of xenobiotic metabolism in phase I oxidation and phase II conjugation between rats and bird species.
    Aksorn Saengtienchai, Yoshinori Ikenaka, Minami Kawata, Yusuke Kawai, Kazuki Takeda, Takamitsu Kondo, Nesta Bortey-Sam, Shouta M M Nakayama, Hazuki Mizukawa, Mayumi Ishizuka
    Comparative biochemistry and physiology. Toxicology & pharmacology : CBP, 214, 28, 35, 2018年12月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Characterization and imaging of lead distribution in bones of lead-exposed birds by ICP-MS and LA-ICP-MS.
    Chihiro Ishii, Shouta M M Nakayama, Andrew Kataba, Yoshinori Ikenaka, Keisuke Saito, Yukiko Watanabe, Yoshiki Makino, Takehisa Matsukawa, Ayano Kubota, Kazuhito Yokoyama, Hazuki Mizukawa, Takafumi Hirata, Mayumi Ishizuka
    Chemosphere, 212, 994, 1001, 2018年12月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Linking organochlorine exposure to biomarker response patterns in Anurans: a case study of Müller's clawed frog (Xenopus muelleri) from a tropical malaria vector control region.
    Wolmarans NJ, Du Preez LH, Yohannes YB, Ikenaka Y, Ishizuka M, Smit NJ, Wepener V
    Ecotoxicology (London, England), 27, 9, 1203, 1216, 2018年11月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Molecular and functional characterization of UDP-glucuronosyltransferase 1A in cynomolgus macaques.
    Yasuhiro Uno, Rika Takahira, Norie Murayama, Yu Ishii, Yoshinori Ikenaka, Mayumi Ishizuka, Hiroshi Yamazaki, Shinichi Ikushiro
    Biochemical pharmacology, 155, 172, 181, 2018年09月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Characterization, Spatial Variation and Risk Assessment of Heavy Metals and a Metalloid in Surface Soils in Obuasi, Ghana.
    Osei Akoto, Nesta Bortey-Sam, Shouta M M Nakayama, Yoshinori Ikenaka, Elvis Baidoo, Joseph Apau, Jemima Tiwaa Marfo, Mayumi Ishizuka
    Journal of health & pollution, 8, 19, 180902, 180902, 2018年09月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Fish consumption from urban impoundments: What are the health risks associated with DDTs and other organochlorine pesticides in fish to township residents of a major inland city.
    Wihan Pheiffer, Nico J Wolmarans, Ruan Gerber, Yared B Yohannes, Yoshinori Ikenaka, Mayumi Ishizuka, Nico J Smit, Victor Wepener, Rialet Pieters
    The Science of the total environment, 628-629, 517, 527, 2018年07月01日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Lead and cadmium excretion in feces and urine of children from polluted townships near a lead-zinc mine in Kabwe, Zambia
    John Yabe, Shouta M. M. Nakayama, Yoshinori Ikenaka, Yared B. Yohannes, Nesta Bortey-Sam, Abel Nketani Kabalo, John Ntapisha, Hazuki Mizukawa, Takashi Umemura, Mayumi Ishizuka
    CHEMOSPHERE, 202, 48, 55, 2018年07月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Serologic Evidence of Tick-Borne Encephalitis Virus Infection in a Patient with Suspected Lyme Disease in Japan.
    Yoshii K, Sato K, Ishizuka M, Kobayashi S, Kariwa H, Kawabata H
    The American journal of tropical medicine and hygiene, 99, 1, 180, 181, 2018年07月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌), Tick-borne encephalitis (TBE) is widely prevalent on the Eurasian continent, including Japan, but four cases of TBE have been reported in Japan. To inspect unconfirmed TBE cases in Japan, we conducted a retrospective seroepidemiological study of a total of 158 samples from 81 meningoencephalitis patients suspected as Lyme disease. Two serum samples from one patient showed neutralizing antibodies against TBE virus. The patient with severe and progressive encephalitis had a history of tick bite in Hokkaido in 2012. These results demonstrated that tick-borne encephalitis virus (TBEV) case was actually unconfirmed in Japan. Further seroepidemiological surveys are required to identify unconfirmed TBEV infections to consider the pros and cons of introducing specific countermeasures including vaccination in Japan.
  • An epigenome-wide study of cord blood DNA methylations in relation to prenatal perfluoroalkyl substance exposure: The Hokkaido study
    Ryu Miura, Atsuko Araki, Chihiro Miyashita, Sumitaka Kobayashi, Sachiko Kobayashi, Shu-Li Wang, Chung-Hsing Chen, Kunio Miyake, Mayumi Ishizuka, Yusuke Iwasaki, Yoichi M. Ito, Takeo Kubota, Reiko Kishi
    Environment International, 115, 21, 28, Elsevier Ltd, 2018年06月01日, [査読有り]
    英語, 研究論文(学術雑誌)
  • Investigation of hepatic warfarin metabolism activity in rodenticide-resistant black rats (Rattus rattus) in Tokyo by in situ liver perfusion.
    Kazuki Takeda, Yoshinori Ikenaka, Kazuyuki D Tanaka, Shouta M M Nakayama, Tsutomu Tanikawa, Hazuki Mizukawa, Mayumi Ishizuka
    Pesticide biochemistry and physiology, 148, 42, 49, 2018年06月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • A glycomics approach to discover novel renal biomarkers in birds by administration of cisplatin and diclofenac to chickens.
    Ishii C, Ikenaka Y, Ichii O, Nakayama SMM, Nishimura SI, Ohashi T, Tanaka M, Mizukawa H, Ishizuka M
    Poultry science, 97, 5, 1722, 1729, 2018年05月, [査読有り]
    研究論文(学術雑誌)
  • Accumulation patterns and risk assessment of metals and metalloid in muscle and offal of free-range chickens, cattle and goat in Benin City, Nigeria.
    Emmanuel Temiotan Ogbomida, Shouta M M Nakayama, Nesta Bortey-Sam, Balazs Oroszlany, Isioma Tongo, Alex Ajeh Enuneku, Ogbeide Ozekeke, Martins Oshioriamhe Ainerua, Iriagbonse Priscillia Fasipe, Lawrence Ikechukwu Ezemonye, Hazuki Mizukawa, Yoshinori Ikenaka, Mayumi Ishizuka
    Ecotoxicology and environmental safety, 151, 98, 108, 2018年04月30日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Association between human exposure to heavy metals/metalloid and occurrences of respiratory diseases, lipid peroxidation and DNA damage in Kumasi, Ghana.
    Nesta Bortey-Sam, Yoshinori Ikenaka, Osei Akoto, Shouta M M Nakayama, Kwadwo A Asante, Elvis Baidoo, Christian Obirikorang, Hazuki Mizukawa, Mayumi Ishizuka
    Environmental pollution (Barking, Essex : 1987), 235, 163, 170, 2018年04月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Sex and site differences in urinary excretion of conjugated pyrene metabolites in the West African Shorthorn cattle.
    Nesta Bortey-Sam, Yoshinori Ikenaka, Osei Akoto, Shouta M M Nakayama, Jemima T Marfo, Aksorn Saengtienchai, Hazuki Mizukawa, Mayumi Ishizuka
    The Journal of veterinary medical science, 80, 2, 375, 381, 2018年03月02日, [査読有り], [国内誌]
    英語, 研究論文(学術雑誌)
  • β-carotene and retinol reduce benzo[a]pyrene-induced mutagenicity and oxidative stress via transcriptional modulation of xenobiotic metabolizing enzymes in human HepG2 cell line.
    Darwish WS, Ikenaka Y, Nakayama S, Mizukawa H, Thompson LA, Ishizuka M
    Environmental science and pollution research international, 25, 7, 6320, 6328, 2018年03月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Evaluation of mitochondrial redox status and energy metabolism of X-irradiated HeLa cells by LC/UV, LC/MS/MS and ESR
    Kumiko Yamamoto, Yoshinori Ikenaka, Takahiro Ichise, Tomoki Bo, Mayumi Ishizuka, Hironobu Yasui, Wakako Hiraoka, Tohru Yamamori, Osamu Inanami
    FREE RADICAL RESEARCH, 52, 6, 648, 660, 2018年, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Contamination by neonicotinoid insecticides and their metabolites in Sri Lankan black tea leaves and Japanese green tea leaves.
    Yoshinori Ikenaka, Kazutoshi Fujioka, Tomonori Kawakami, Takahiro Ichise, Nesta Bortey-Sam, Shouta M M Nakayama, Hazuki Mizukawa, Kumiko Taira, Keisuke Takahashi, Keisuke Kato, Koji Arizono, Mayumi Ishizuka
    Toxicology reports, 5, 744, 749, 2018年, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Investigation of mRNA expression changes associated with field exposure to DDTs in chickens from KwaZulu-Natal, South Africa.
    Lesa A Thompson, Yoshinori Ikenaka, Wageh S Darwish, Yared B Yohannes, Johan J van Vuren, Victor Wepener, Nico J Smit, Atnafu G Assefa, Ahmed Tharwat, Walaa Fathy Saad Eldin, Shouta M M Nakayama, Hazuki Mizukawa, Mayumi Ishizuka
    PloS one, 13, 10, e0204400, 2018年, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • ポリ塩化ビフェニル曝露によるイヌ・ネコの甲状腺ホルモン恒常性への影響
    高口倖暉, 野見山桂, 西川博之, 水川葉月, 田上瑠美, 草木桃子, 横山望, 市居修, 滝口満喜, 中山翔太, 池中良徳, 石塚真由美, 岩田久人, 国末達也, 田辺信介
    Journal of Toxicological Sciences, 43, Supplement, S245, S245, (一社)日本毒性学会, 2018年, [査読有り]
    日本語
  • Regulatory Science on AI-based Medical Devices and Systems
    Chinzei Kiyoyuki, Shimizu Akinobu, Mori Kensaku, Harada Kanako, Takeda Hideaki, Hashizume Makoto, Ishizuka Mayumi, Kato Nobumasa, Kawamori Ryuzo, Kyo Shunei, Nagata Kyosuke, Yamane Takashi, Sakuma Ichiro, Ohe Kazuhiko, Mitsuishi Mamoru
    ADVANCED BIOMEDICAL ENGINEERING, 7, 118, 123, 2018年
  • The evolution of UDP-glycosyl/glucuronosyltransferase 1E (UGT1E) genes in bird lineages is linked to feeding habits but UGT2 genes is not.
    Yusuke K Kawai, Yoshinori Ikenaka, Mayumi Ishizuka, Akira Kubota
    PloS one, 13, 10, e0205266, 2018年, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Lead exposure in raptors from Japan and source identification using Pb stable isotope ratios
    Chihiro Ishii, Shouta M. M. Nakayama, Yoshinori Ikenaka, Hokuto Nakata, Keisuke Saito, Yukiko Watanabe, Hazuki Mizukawa, Shinsuke Tanabe, Kei Nomiyama, Terutake Hayashi, Mayumi Ishizuka
    CHEMOSPHERE, 186, 367, 373, 2017年11月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Spatial and temporal profile of cisplatin delivery by ultrasound-assisted intravesical chemotherapy in a bladder cancer model
    Noboru Sasaki, Kazuhiro Ishi, Nobuki Kudo, Shouta M. M. Nakayama, Kensuke Nakamura, Keitaro Morishita, Hiroshi Ohta, Mayumi Ishizuka, Mitsuyoshi Takiguchi
    PLOS ONE, 12, 11, e0188093, 2017年11月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Anthropogenic and Naturally Produced Brominated Phenols in Pet Blood and Pet Food in Japan
    Hazuki Mizukawa, Kei Nomiyama, Susumu Nakatsu, Miyuki Yamamoto, Mayumi Ishizuka, Yoshinori Ikenaka, Shouta M. M. Nakayama, Shinsuke Tanabe
    ENVIRONMENTAL SCIENCE & TECHNOLOGY, 51, 19, 11354, 11362, 2017年10月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Assessment of DDT contamination in house rat as a possible bioindicator in DDT-sprayed areas from Ethiopia and South Africa
    Yared Beyene Yohannes, Yoshinori Ikenaka, Gengo Ito, Shouta M. M. Nakayama, Hazuki Mizukawa, Victor Wepener, Nico J. Smit, Johan H. J. Van Vuren, Mayumi Ishizuka
    ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH, 24, 30, 23763, 23770, 2017年10月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Oxidative stress and respiratory symptoms due to human exposure to polycyclic aromatic hydrocarbons (PAHs) in Kumasi, Ghana
    Nesta Bortey-Sam, Yoshinori Ikenaka, Osei Akoto, Shouta M. M. Nakayama, Kwadwo A. Asante, Elvis Baidoo, Christian Obirikorang, Aksorn Saengtienchai, Norikazu Isoda, Collins Nimako, Hazuki Mizukawa, Mayumi Ishizuka
    ENVIRONMENTAL POLLUTION, 228, 311, 320, 2017年09月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Gender-specific association of exposure to non-dioxin-like polychlorinated biphenyls during pregnancy with methylation levels of H19 and long interspersed nuclear element-1 in cord blood in the Hokkaido study
    Sumitaka Kobayashi, Fumihiro Sata, Chihiro Miyashita, Ryu Miura, Kaoru Azumi, Sachiko Kobayashi, Houman Goudarzi, Atsuko Araki, Mayumi Ishizuka, Takashi Todaka, Jumboku Kajiwara, Tsuguhide Hori, Reiko Kishi
    TOXICOLOGY, 390, 135, 145, 2017年09月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Contamination Levels and Sources of Heavy Metals and a Metalloid in Surface Soils in the Kumasi Metropolis, Ghana.
    Osei Akoto, Nesta Bortey-Sam, Yoshinori Ikenaka, Shouta M M Nakayama, Elvis Baidoo, Yared Beyene Yohannes, Mayumi Ishizuka
    Journal of health & pollution, 7, 15, 28, 39, 2017年09月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Uridine Diphosphate-Glucuronosyltransferase (UGT) 2B Subfamily Interspecies Differences in Carnivores
    Takamitsu Kondo, Yoshinori Ikenaka, Shouta M. M. Nakayama, Yusuke K. Kawai, Hazuki Mizukawa, Yoko Mitani, Kei Nomiyama, Shinsuke Tanabe, Mayumi Ishizuka
    TOXICOLOGICAL SCIENCES, 158, 1, 90, 100, 2017年07月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Effects of prenatal perfluoroalkyl acid exposure on cord blood IGF2/H19 methylation and ponderal index: The Hokkaido Study
    Sachiko Kobayashi, Kaoru Azumi, Houman Goudarzi, Atsuko Araki, Chihiro Miyashita, Sumitaka Kobayashi, Sachiko Itoh, Seiko Sasaki, Mayumi Ishizuka, Hiroyuki Nakazawa, Tamiko Ikeno, Reiko Kishi
    JOURNAL OF EXPOSURE SCIENCE AND ENVIRONMENTAL EPIDEMIOLOGY, 27, 3, 251, 259, 2017年05月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Organochlorine pesticide contamination of foods in Africa: incidence and public health significance
    Lesa A. Thompson, Wageh Sobhy Darwish, Yoshinori Ikenaka, Shouta M. M. Nakayama, Hazuki Mizukawa, Mayumi Ishizuka
    JOURNAL OF VETERINARY MEDICAL SCIENCE, 79, 4, 751, 764, 2017年04月, [査読有り]
    英語
  • Contamination status and accumulation characteristics of heavy metals and arsenic in five seabird species from the central Bering Sea
    Chihiro Ishii, Yoshinori Ikenaka, Shouta M. M. Nakayama, Hazuki Mizukawa, Yared Beyene Yohannes, Yutaka Watanuki, Masaaki Fukuwaka, Mayumi Ishizuka
    JOURNAL OF VETERINARY MEDICAL SCIENCE, 79, 4, 807, 814, 2017年04月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Characterization of Species Differences in Xenobiotic Metabolism in Non-experimental Animals
    Hazuki Mizukawa, Yoshinori Ikenaka, Mayu Kakehi, Shouta Nakayama, Mayumi Ishizuka
    YAKUGAKU ZASSHI-JOURNAL OF THE PHARMACEUTICAL SOCIETY OF JAPAN, 137, 3, 257, 263, 2017年03月, [査読有り]
    中国語
  • Trace Element Contamination in Tissues of Four Bird Species from the Rift Valley Region, Ethiopia
    Yared Beyene Yohannes, Yoshinori Ikenaka, Shouta M. M. Nakayama, Hazuki Mizukawa, Mayumi Ishizuka
    BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY, 98, 2, 172, 177, 2017年02月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Monitoring Lead (Pb) Pollution and Identifying Pb Pollution Sources in Japan Using Stable Pb Isotope Analysis with Kidneys of Wild Rats.
    Hokuto Nakata, Shouta M M Nakayama, Balazs Oroszlany, Yoshinori Ikenaka, Hazuki Mizukawa, Kazuyuki Tanaka, Tsunehito Harunari, Tsutomu Tanikawa, Wageh Sobhy Darwish, Yared B Yohannes, Aksorn Saengtienchai, Mayumi Ishizuka
    International journal of environmental research and public health, 14, 1, 2017年01月10日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • The Hokkaido birth cohort study on environment and children's health: Cohort profile-updated 2017
    Reiko Kishi, Atsuko Araki, Machiko Minatoya, Tomoyuki Hanaoka, Chihiro Miyashita, Sachiko Itoh, Sumitaka Kobayashi, Yu Ait Bamai, Keiko Yamazaki, Ryu Miura, Naomi Tamura, Kumiko Ito, Houman Goudarzi, S. Sasaki, T. Ikeno, E. Okada, S. Nishihara, R. M. Ketema, T. Kita, I. Kashino, T. Baba, T. S. Braimoh, S. Minakami, K. Cho, N. Shinohara, K. Moriya, T. Mitsui, T. Saito, S. Suyama, T. Nomura, S. Konno, H. Matsuura, M. Ishizuka, T. Endo, T. Baba, F. Sata, K. Sengoku, Y. Saijo, E. Yoshioka, T. Miyamoto, M. Yuasa, J. Kajiwara, T. Hori, Y. Chisaki, T. Matsumura, F. Mizutani, J. Yamamoto, Y. Onoda, T. Kawai, T. Tsuboi
    Environmental Health and Preventive Medicine, 22, 1, 2017年
    研究論文(学術雑誌)
  • ネコの甲状腺機能に対するポリ塩化ビフェニル(PCBs)の影響評価~甲状腺ホルモンの脱ヨード化と代謝能の解析~
    水川葉月, 高居名菜, 横山望, 市居修, 滝口満喜, 野見山桂, 高口倖暉, 西川博之, 池中良徳, 池中良徳, 中山翔太, SAINNOXOI Tsend-Ayush, 田辺信介, 石塚真由美
    Journal of Toxicological Sciences, 42, Supplement, S236, S236, (一社)日本毒性学会, 2017年, [査読有り]
    日本語
  • Monitoring Lead (Pb) Pollution and Identifying Pb Pollution Sources in Japan Using Stable Pb Isotope Analysis with Kidneys of Wild Rats
    Hokuto Nakata, Shouta M. M. Nakayama, Balazs Oroszlany, Yoshinori Ikenaka, Hazuki Mizukawa, Kazuyuki Tanaka, Tsunehito Harunari, Tsutomu Tanikawa, Wageh Sobhy Darwish, Yared B. Yohannes, Aksorn Saengtienchai, Mayumi Ishizuka
    INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH, 14, 1, 2017年01月, [査読有り]
    英語, 研究論文(学術雑誌)
  • DDTs and other organochlorine pesticides in tissues of four bird species from the Rift Valley region, Ethiopia
    Yared Beyene Yohannes, Yoshinori Ikenaka, Shouta M. M. Nakayama, Hazuki Mizukawa, Mayumi Ishizuka
    SCIENCE OF THE TOTAL ENVIRONMENT, 574, 1389, 1395, 2017年01月, [査読有り]
    英語, 研究論文(学術雑誌)
  • The African hedgehog (Atelerix albiventris): Low phase I and phase II metabolism activities
    Aksorn Saengtienchai, Yoshinori Ikenaka, Nesta Bortey-Sam, Usuma Jermnark, Hazuki Mizukawa, Yusuke K. Kawai, Shouta M. M. Nakayama, Mayumi Ishizuka
    COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY C-TOXICOLOGY & PHARMACOLOGY, 190, 38, 47, 2016年12月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Excretion of polycyclic aromatic hydrocarbon metabolites (OH-PAHs) in cattle urine in Ghana
    Nesta Bortey-Sam, Yoshinori Ikenaka, Osei Akoto, Shouta M. M. Nakayama, Jemima Marfo, Aksorn Saengtienchai, Hazuki Mizukawa, Mayumi Ishizuka
    ENVIRONMENTAL POLLUTION, 218, 331, 337, 2016年11月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Novel revelation of warfarin resistant mechanism in roof rats (Rattus rattus) using pharmacokinetic/pharmacodynamic analysis
    Kazuki Takeda, Yoshinori Ikenaka, Tsutomu Tanikawa, Kazuyuki D. Tanaka, Shouta M. M. Nakayama, Hazuki Mizukawa, Mayumi Ishizuka
    PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY, 134, 1, 7, 2016年11月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Heavy metals and metalloid accumulation in livers and kidneys of wild rats around gold-mining communities in Tarkwa, Ghana
    Bortey Sam Nesta, M M Nakayama Shouta, Ikenaka Yoshinori, Akoto Osei, Baidoo Elvis, Mizukawa Hazuki, Ishizuka Mayumi
    Journal of Environmental Chemistry and Ecotoxicology, 8, 7, 58, 68, Academic Journals, 2016年07月31日
    研究論文(学術雑誌)
  • Strain differences in cytochrome P450 mRNA and protein expression, and enzymatic activity among Sprague Dawley, Wistar, Brown Norway and Dark Agouti rats
    Yoshihiro Nishiyama, Shouta M. M. Nakayama, Kensuke P. Watanabe, Yusuke K. Kawai, Marumi Ohno, Yoshinori Ikenaka, Mayumi Ishizuka
    JOURNAL OF VETERINARY MEDICAL SCIENCE, 78, 4, 675, 680, 2016年04月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Bioaccumulation and human health risk assessment of DDT and other organochlorine pesticides in an apex aquatic predator from a premier conservation area
    Ruan Gerber, Nico J. Smit, Johan H. J. Van Vuren, Shouta M. M. Nakayama, Yared B. Yohannes, Yoshinori Ikenaka, Mayumi Ishizuka, Victor Wepener
    SCIENCE OF THE TOTAL ENVIRONMENT, 550, 522, 533, 2016年04月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Characterization of equine cytochrome P450: role of CYP3A in the metabolism of diazepam.
    Nakayama SM, Ikenaka Y, Hayami A, Mizukawa H, Darwish WS, Watanabe KP, Kawai YK, Ishizuka M
    Journal of veterinary pharmacology and therapeutics, 39, 5, 478, 487, 2016年03月, [査読有り]
    研究論文(学術雑誌)
  • Distribution and health risk assessment of organochlorine pesticides (OCPs) residue in edible cattle tissues from northeastern part of Egypt: High accumulation level of OCPs in tongue
    Abdallah Fikry A. Mahmoud, Yoshinori Ikenaka, Yared B. Yohannes, Wageh S. Darwish, Elsaid A. Eldaly, Alaa Eldin M. A. Morshdy, Shouta M. M. Nakayama, Hazuki Mizukawa, Mayumi Ishizuka
    CHEMOSPHERE, 144, 1365, 1371, 2016年02月, [査読有り]
    英語, 研究論文(学術雑誌)
  • β-carotene and retinol contents in the meat of herbivorous ungulates with a special reference to their public health importance.
    Darwish WS, Ikenaka Y, Morshdy AE, Eldesoky KI, Nakayama S, Mizukawa H, Ishizuka M
    The Journal of veterinary medical science, 78, 2, 351, 354, 2016年02月, [査読有り]
    英語, 研究論文(学術雑誌)
  • ポリ塩化ビフェニル(PCBs)のin vivo暴露によるネコの異物代謝解明と甲状腺ホルモンへの影響評価
    水川葉月, 前原美咲, 横山望, 市居修, 滝口満喜, 野見山桂, 西川博之, 池中良徳, 中山翔太, 高口倖暉, 田辺信介, 石塚真由美
    Journal of Toxicological Sciences, 41, Supplement, S215, S215, (一社)日本毒性学会, 2016年, [査読有り]
    日本語
  • Reliability of stable Pb isotopes to identify Pb sources and verifying biological fractionation of Pb isotopes in goats and chickens
    Hokuto Nakata, Shouta M. M. Nakayama, John Yabe, Allan Liazambi, Hazuki Mizukawa, Wageh Sobhy Darwish, Yoshinori Ikenaka, Mayumi Ishizuka
    ENVIRONMENTAL POLLUTION, 208, Pt B, 395, 403, 2016年01月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Constitutive Effects of Lead on Aryl Hydrocarbon Receptor Gene Battery and Protection by β-carotene and Ascorbic Acid in Human HepG2 Cells.
    Darwish WS, Ikenaka Y, Nakayama SM, Mizukawa H, Ishizuka M
    Journal of food science, 81, 1, T275, T281, 2016年01月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Organohalogen Compounds in Pet Dog and Cat: Do Pets Biotransform Natural Brominated Products in Food to Harmful Hydroxlated Substances?
    Hazuki Mizukawa, Kei Nomiyama, Susumu Nakatsu, Hisato Iwata, Jean Yoo, Akira Kubota, Miyuki Yamamoto, Mayumi Ishizuka, Yoshinori Ikenaka, Shouta M. M. Nakayama, Tatsuya Kunisue, Shinsuke Tanabe
    ENVIRONMENTAL SCIENCE & TECHNOLOGY, 50, 1, 444, 452, 2016年01月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Application of a Sediment Quality Index for the assessment and monitoring of metals and organochlorines in a premier conservation area
    Ruan Gerber, Nico J. Smit, Johan H. J. van Vuren, Shouta M. M. Nakayama, Yared B. Yohannes, Yoshinori Ikenaka, Mayumi Ishizuka, Victor Wepener
    ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH, 22, 24, 19971, 19989, 2015年12月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Accumulation properties of inorganic mercury and organic mercury in the red-crowned crane Grus japonensis in east Hokkaido, Japan
    Hiroki Teraoka, Erika Okamoto, Moe Kudo, Shouta M. M. Nakayama, Yoshinori Ikenaka, Mayumi Ishizuka, Tetsuya Endo, Takio Kitazawa, Takeo Hiraga
    ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY, 122, 557, 564, 2015年12月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Relationship between Urinary N-Desmethyl-Acetamiprid and Typical Symptoms including Neurological Findings: A Prevalence Case-Control Study
    Jemima Tiwaa Mario, Kazutoshi Fujioka, Yoshinori Ikenaka, Shouta M. M. Nakayama, Hazuki Mizukawa, Yoshiko Aoyama, Mayumi Ishizuka, Kumiko Taira
    PLOS ONE, 10, 11, e0142172, 2015年11月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Mutagenicity of modelled-heat-treated meat extracts: Mutagenicity assay, analysis and mechanism of mutagenesis
    Wageh Sobhy Darwish, Yoshinori Ikenaka, Shouta Nakayama, Hazuki Mizukawa, Mayumi Ishizuka
    JAPANESE JOURNAL OF VETERINARY RESEARCH, 63, 4, 173, 182, 2015年11月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Cytochrome P450-mediated warfarin metabolic ability is not a critical determinant of warfarin sensitivity in avian species: In vitro assays in several birds and in vivo assays in chicken
    Kensuke P. Watanabe, Minami Kawata, Yoshinori Ikenaka, Shouta M. M. Nakayama, Chihiro Ishii, Wageh Sobhi Darwish, Aksorn Saengtienchai, Hazuki Mizukawa, Mayumi Ishizuka
    ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY, 34, 10, 2328, 2334, 2015年10月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Metal extent in blood of livestock from Dandora dumping site, Kenya: Source identification of Pb exposure by stable isotope analysis
    Hokuto Nakata, Shouta M. M. Nakayama, Yoshinori Ikenaka, Hazuki Mizukawa, Chihiro Ishii, Yared B. Yohannes, Satoru Konnai, Wageh Sobhy Darwish, Mayumi Ishizuka
    ENVIRONMENTAL POLLUTION, 205, 8, 15, 2015年10月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Characterization and tissue distribution of conjugated metabolites of pyrene in the rat
    Aksorn Saengtienchai, Yoshinori Ikenaka, Wageh Sobhy Darwish, Shouta M. M. Nakayama, Hazuki Mizukawa, Mayumi Ishizuka
    JOURNAL OF VETERINARY MEDICAL SCIENCE, 77, 10, 1261, 1267, 2015年10月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Uridine Diphosphate-Glucuronosyltransferase (UGT) Xenobiotic Metabolizing Activity and Genetic Evolution in Pinniped Species
    Mayu Kakehi, Yoshinori Ikenaka, Shouta M. M. Nakayama, Yusuke K. Kawai, Kensuke P. Watanabe, Hazuki Mizukawa, Kei Nomiyama, Shinsuke Tanabe, Mayumi Ishizuka
    TOXICOLOGICAL SCIENCES, 147, 2, 360, 369, 2015年10月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Ecological Risk of Heavy Metals and a Metalloid in Agricultural Soils in Tarkwa, Ghana.
    Nesta Bortey-Sam, Shouta M M Nakayama, Osei Akoto, Yoshinori Ikenaka, Elvis Baidoo, Hazuki Mizukawa, Mayumi Ishizuka
    International journal of environmental research and public health, 12, 9, 11448, 65, 2015年09月11日, [査読有り], [国際誌]
    英語, Heavy metals and a metalloid in agricultural soils in 19 communities in Tarkwa were analyzed to assess the potential ecological risk. A total of 147 soil samples were collected in June, 2012 and analyzed for As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn. Mean concentrations (mg/kg dw) of heavy metals in the communities decreased in order of Zn (39) ˃ Cr (21) ˃ Pb (7.2) ˃ Cu (6.2) ˃ As (4.4) ˃ Ni (3.7) ˃ Co (1.8) ˃ Hg (0.32) ˃ Cd (0.050). Correlations among heavy metals and soil properties indicated that soil organic matter could have substantial influence on the total contents of these metals in soil. From the results, integrated pollution (C(deg)) in some communities such as, Wangarakrom (11), Badukrom (13) and T-Tamso (17) indicated high pollution with toxic metals, especially from As and Hg. Potential ecological risk (RI) indices indicated low (Mile 7) to high risks (Wangarakrom; Badukrom) of metals. Based on pollution coefficient (C(i)(f)), C(deg), monomial ecological risk (E(i)(r)) and RI, the investigated soils fall within low to high contamination and risk of heavy metals to the ecological system especially plants, soil invertebrates and/or mammalian wildlife. This represented moderate potential ecological risk in the study area, and mining activities have played a significant role.
  • Ecological Risk of Heavy Metals and a Metalloid in Agricultural Soils in Tarkwa, Ghana
    Nesta Bortey-Sam, Shouta M. M. Nakayama, Osei Akoto, Yoshinori Ikenaka, Elvis Baidoo, Hazuki Mizukawa, Mayumi Ishizuka
    INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH, 12, 9, 11448, 11465, 2015年09月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Accumulation of Heavy Metals and Metalloid in Foodstuffs from Agricultural Soils around Tarkwa Area in Ghana, and Associated Human Health Risks
    Nesta Bortey-Sam, Shouta M. M. Nakayama, Osei Akoto, Yoshinori Ikenaka, Julius N. Fobil, Elvis Baidoo, Hazuki Mizukawa, Mayumi Ishizuka
    INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH, 12, 8, 8811, 8827, 2015年08月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Accumulation of Heavy Metals and Metalloid in Foodstuffs from Agricultural Soils around Tarkwa Area in Ghana, and Associated Human Health Risks.
    Nesta Bortey-Sam, Shouta M M Nakayama, Osei Akoto, Yoshinori Ikenaka, Julius N Fobil, Elvis Baidoo, Hazuki Mizukawa, Mayumi Ishizuka
    International journal of environmental research and public health, 12, 8, 8811, 27, 2015年07月28日, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Mercury concentrations in primary feathers reflect pollutant exposure in discrete non-breeding grounds used by Short-tailed Shearwaters
    Yutaka Watanuki, Takashi Yamamoto, Ai Yamashita, Chihiro Ishii, Yoshinori Ikenaka, Shouta M. M. Nakayama, Mayumi Ishizuka, Yuya Suzuki, Yasuaki Niizuma, C. E. Meathrel, R. A. Phillips
    JOURNAL OF ORNITHOLOGY, 156, 3, 847, 850, 2015年07月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Levels, potential sources and human health risk of polycyclic aromatic hydrocarbons (PAHs) in particulate matter (PM10) in Kumasi, Ghana
    Nesta Bortey-Sam, Yoshinori Ikenaka, Osei Akoto, Shouta M. M. Nakayama, Yared Beyene Yohannes, Elvis Baidoo, Hazuki Mizukawa, Mayumi Ishizuka
    ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH, 22, 13, 9658, 9667, 2015年07月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Health risk assessment of heavy metals and metalloid in drinking water from communities near gold mines in Tarkwa, Ghana
    Nesta Bortey-Sam, Shouta M. M. Nakayama, Yoshinori Ikenaka, Osei Akoto, Elvis Baidoo, Hazuki Mizukawa, Mayumi Ishizuka
    ENVIRONMENTAL MONITORING AND ASSESSMENT, 187, 7, 397, 12, 2015年07月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Metabolic Activation of Heterocyclic Amines and Expression of Xenobiotic-Metabolizing Enzymes in the Gastrointestinal Tract of Rats
    Wageh S. Darwish, Shouta M. M. Nakayama, Yuumi Itotani, Marumi Ohno, Yoshinori Ikenaka, Mayumi Ishizuka
    JOURNAL OF FOOD SCIENCE, 80, 7, T1627, T1632, 2015年07月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Are red gourami (Colisa labiosa) low xenobiotic metabolizers? Elucidation of in vivo pharmacokinetics of pyrene as a model substrate
    Yoshinori Ikenaka, Shouta M. M. Nakayama, Mami Oguri, Aksorn Saengtienchai, Hazuki Mizukawa, Jun Kobayashi, Wageh Sobhy Darwish, Mayumi Ishizuka
    ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY, 39, 3, 1148, 1153, 2015年05月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Partial cloning of CYP2C23a genes and hepatic protein expression in eight representative avian species
    K. P. Watanabe, Y. K. Kawai, S. M.M. Nakayama, Y. Ikenaka, H. Mizukawa, N. Takaesu, M. Ito, S. I. Ikushiro, T. Sakaki, M. Ishizuka
    Journal of Veterinary Pharmacology and Therapeutics, 38, 2, 190, 195, Blackwell Publishing Ltd, 2015年04月01日, [査読有り]
    英語, 研究論文(学術雑誌)
  • Organohalogens and their hydroxylated metabolites in the blood of pigs from an open waste dumping site in south India: Association with hepatic cytochrome P450
    Hazuki Mizukawa, Kei Nomiyama, Tatsuya Kunisue, Michio X. Watanabe, Annamalai Subramanian, Hisato Iwata, Mayumi Ishizuka, Shinsuke Tanabe
    ENVIRONMENTAL RESEARCH, 138, 255, 263, 2015年04月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Lead poisoning in children from townships in the vicinity of a lead-zinc mine in Kabwe, Zambia
    John Yabe, Shouta M. M. Nakayama, Yoshinori Ikenaka, Yared B. Yohannes, Nesta Bortey-Sam, Balazs Oroszlany, Kaampwe Muzandu, Kennedy Choongo, Abel Nketani Kabalo, John Ntapisha, Aaron Mweene, Takashi Umemura, Mayumi Ishizuka
    CHEMOSPHERE, 119, 941, 947, 2015年01月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Human health risks from metals and metalloid via consumption of food animals near gold mines in Tarkwa, Ghana: Estimation of the daily intakes and target hazard quotients (THQs)
    Nesta Bortey-Sam, Shouta M. M. Nakayama, Yoshinori Ikenaka, Osei Akoto, Elvis Baidoo, Yared Beyene Yohannes, Hazuki Mizukawa, Mayumi Ishizuka
    ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY, 111, 160, 167, 2015年01月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Occurrence, distribution, sources and toxic potential of polycyclic aromatic hydrocarbons (PAHs) in surface soils from the Kumasi Metropolis, Ghana
    Nesta Bortey-Sam, Yoshinori Ikenaka, Shouta M. M. Nakayama, Osei Akoto, Yared Beyene Yohannes, Elvis Baidoo, Hazuki Mizukawa, Mayumi Ishizuka
    SCIENCE OF THE TOTAL ENVIRONMENT, 496, 471, 478, 2014年10月, [査読有り]
    英語, 研究論文(学術雑誌)
  • TCDD‑induced chick cardiotoxicity is abolished by a selective cyclooxygenase‑2 (COX‑2) inhibitor NS398.
    Fujisawa N, Nakayama SM, Ikenaka Y, Ishizuka M
    Archives of toxicology, 88, 9, 1739, 1748, 2014年09月, [査読有り]
    英語, 研究論文(学術雑誌)
  • IDENTIFICATION OF INTERSPECIFIC DIFFERENCES IN PHASE II REACTIONS: DETERMINATION OF METABOLITES IN THE URINE OF 16 MAMMALIAN SPECIES EXPOSED TO ENVIRONMENTAL PYRENE
    Aksorn Saengtienchai, Yoshinori Ikenaka, Shouta M. M. Nakayama, Hazuki Mizukawa, Mayu Kakehi, Nesta Bortey-Sam, Wageh Sobhy Darwish, Toshio Tsubota, Masanori Terasaki, Amnart Poapolathep, Mayumi Ishizuka
    ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY, 33, 9, 2062, 2069, 2014年09月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Organochlorine pesticides in bird species and their prey (fish) from the Ethiopian Rift Valley region, Ethiopia
    Yared Beyene Yohannes, Yoshinori Ikenaka, Shouta M. M. Nakayama, Mayumi Ishizuka
    ENVIRONMENTAL POLLUTION, 192, 121, 128, 2014年09月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Clofibric acid induces hepatic CYP 2B1/2 via constitutive androstane receptor not via peroxisome proliferator activated receptor alpha in rat
    Zein Shaban Ibrahim, Mohamed Mohamed Ahmed, Samir Ahmed El-Shazly, Mayumi Ishizuka, Shoichi Fujita
    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, 78, 9, 1550, 1559, 2014年09月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Repression of Hepatic Cytochrome P450 2D Expression in Mice during Babesia microti Infection
    Yoshinori Shimamoto, Kensuke Watanabe, Hiromi Ikadai, Masashi Okamura, Mayumi Ishizuka
    JOURNAL OF VETERINARY MEDICAL SCIENCE, 76, 8, 1147, 1151, 2014年08月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Concentrations and human health risk assessment of organochlorine pesticides in edible fish species from a Rift Valley lake-Lake Ziway, Ethiopia
    Yared B. Yohannes, Yoshinori Ikenaka, Aksorn Saengtienchai, Kensuke P. Watanabe, Shouta M. M. Nakayam, Mayumi Ishizuka
    ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY, 106, 95, 101, 2014年08月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Apoptosis and gene expression in the developing mouse brain of fusarenon-X-treated pregnant mice
    Samak Sutjarit, Shota M. M. Nakayama, Yoshinori Ikenaka, Mayumi Ishizuka, Wijit Banlunara, Worawut Rerkamnuaychoke, Susumu Kumagai, Amnart Poapolathep
    TOXICOLOGY LETTERS, 229, 1, 292, 302, 2014年08月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Contamination status and possibility of toxic effects of co-planar polychlorinated biphenyls, polycyclic aromatic hydrocarbons, and dichlorodiphenyltrichloroethane in large Japanese field mouse (Apodemus speciosus) collected from Hokkaido and Aomori
    Hazuki Mizukawa, Yoshinori Ikenaka, Shouta M. M. Nakayama, Kentaro Q. Sakamoto, Shoichi Fujita, Mayumi Ishizuka
    JAPANESE JOURNAL OF VETERINARY RESEARCH, 62, 3, 107, 115, 2014年08月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Contamination status and accumulation characteristics of metals and a metalloid in birds on Teuri Island, Hokkaido, Japan
    Chihiro Ishii, Yoshinori Ikenaka, Shouta M. M. Nakayama, Yuya Suzuki, Yutaka Watanuki, Yuji Watanabe, Yared Beyene Yohannes, Hazuki Mizukawa, Mayumi Ishizuka
    JAPANESE JOURNAL OF VETERINARY RESEARCH, 62, 3, 143, 149, 2014年08月, [査読有り]
    英語, 研究論文(学術雑誌)
  • An Overview on Mycotoxin Contamination of Foods in Africa
    Wageh Sobhy Darwish, Yoshinori Ikenaka, Shouta M. M. Nakayama, Mayumi Ishizuka
    JOURNAL OF VETERINARY MEDICAL SCIENCE, 76, 6, 789, 797, 2014年06月, [査読有り]
    英語
  • The Effect of Copper on the mRNA Expression Profile of Xenobiotic-Metabolizing Enzymes in Cultured Rat H4-II-E Cells
    Wageh Sobhy Darwish, Yoshinori Ikenaka, Shouta Nakayama, Mayumi Ishizuka
    BIOLOGICAL TRACE ELEMENT RESEARCH, 158, 2, 243, 248, 2014年05月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Toxicokinetics and tissue depletion of Fusarenon-X and its metabolite nivalenol in piglets
    Thanit Saengtienchai, Saranya Poapolathep, Supaporn Isariyodom, Yoshinori Ikenaka, Mayumi Ishizuka, Amnart Poapolathep
    FOOD AND CHEMICAL TOXICOLOGY, 66, 307, 312, 2014年04月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Molecular Characterization and mRNA Expression of Cytochrome P450 1A1 and Cytochrome P450 3A in Liver of Kafue Lechwe (Kobus leche kafuensis) as Potential Biomarkers of Pollution of the Kafue River Basin, Zambia               
    M'kandawire, Ethel, Syakalima, Michelo, Muzandu, Kaampwe, Pandey, Girja, Simuunza, Martin, Nakayama, Shouta M. M, Kawai, Yusuke K, Ikenaka, Yoshinori, Ishizuka, Mayumi
    Engineering, 6, 2, 51, 58, 2014年02月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Heavy metal contamination of soil and sediment in Zambia
    Yoshinori Ikenaka, Shouta M.M. Nakayama, Kaampwe Muzandu, Kennedy Choongo, Hiroki Teraoka, Naoharu Mizuno, Mayumi Ishizuka
    Heavy Metal Contamination of Water and Soil: Analysis, Assessment, and Remediation Strategies, 109, 128, 2014年01月01日
    論文集(書籍)内論文
  • SPECIES DIFFERENCE OF WARFARIN SENSITIVITY AMONG BIRDS CAN BE EXPLAINED BY THE TWO ENZYMES, CYTOCHROME P450 AND VITAMIN K EPOXIDE REDUCTASE
    Watanabe Kensuke P, Kawai Yusuke K, Kawata Minami, Nakayama Shouta M. M, Ikenaka Yoshinori, Ishizuka Mayumi
    DRUG METABOLISM REVIEWS, 45, 92, 2014年01月, [査読有り]
  • Ubiquitin-specific protease 2-69 in macrophages potentially modulates metainflammation
    Hiroshi Kitamura, Shunsuke Kimura, Yoshinori Shimamoto, Jun Okabe, Masatoshi Ito, Tomomi Miyamoto, Yoshinori Naoe, Chisato Kikuguchi, Bob Meek, Chitoku Toda, Shiki Okamoto, Katsushi Kanehira, Koji Hase, Hiroshi Watarai, Mayumi Ishizuka, Assam El-Osta, Osamu Ohara, Ichiro Miyoshi
    FASEB Journal, 27, 12, 4940, 4953, 2013年12月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Occurrence, distribution, and ecological risk assessment of DDTs and heavy metals in surface sediments from Lake Awassa-Ethiopian Rift Valley Lake
    Yared Beyene Yohannes, Yoshinori Ikenaka, Aksorn Saengtienchai, Kensuke P. Watanabe, Shouta M. M. Nakayama, Mayumi Ishizuka
    ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH, 20, 12, 8663, 8671, 2013年12月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Dioxin Sensitivity-Related Two Critical Amino Acids of Arylhydrocarbon Receptor May Not Correlate with the Taxonomy or Phylogeny in Avian Species
    Nozomi Fujisawa, Yusuke K. Kawai, Shouta M. M. Nakayama, Yoshinori Ikenaka, Hideaki Yamamoto, Mayumi Ishizuka
    JOURNAL OF VETERINARY MEDICAL SCIENCE, 75, 12, 1577, 1583, 2013年12月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Ubiquitin-specific protease 2-69 in macrophages potentially modulates metainflammation
    Hiroshi Kitamura, Shunsuke Kimura, Yoshinori Shimamoto, Jun Okabe, Masatoshi Ito, Tomomi Miyamoto, Yoshinori Naoe, Chisato Kikuguchi, Bob Meek, Chitoku Toda, Shiki Okamoto, Katsushi Kanehira, Koji Hase, Hiroshi Watarai, Mayumi Ishizuka, Assam El-Osta, Osamu Ohara, Ichiro Miyoshi
    FASEB JOURNAL, 27, 12, 4940, 4953, 2013年12月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Selection of suitable reference genes for mRNA quantification studies using common marmoset tissues
    Yoshinori Shimamoto, Hiroshi Kitamura, Kimie Niimi, Yasunaga Yoshikawa, Fumio Hoshi, Mayumi Ishizuka, Eiki Takahashi
    MOLECULAR BIOLOGY REPORTS, 40, 12, 6747, 6755, 2013年12月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Repeated Treatment with Furazolidone Induces Multiple Cytochrome P450-Related Activities in Chicken Liver, but Not in Rat Liver
    Nobuo Sasaki, Tomoyuki Matumoto, Yoshinori Ikenaka, Shouta M. M. Nakayama, Mayumi Ishizuka, Akio Kazusaka, Shoichi Fujita
    JOURNAL OF VETERINARY MEDICAL SCIENCE, 75, 11, 1497, 1502, 2013年11月, [査読有り]
    英語, 研究論文(学術雑誌)
  • De novo sequence analysis of cytochrome P450 1-3 genes expressed in ostrich liver with highest expression of CYP2G19
    Yusuke K. Kawai, Kensuke P. Watanabe, Akihiro Ishii, Aiko Ohnuma, Hirofumi Sawa, Yoshinori Ikenaka, Mayumi Ishizuka
    COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS, 8, 3, 201, 208, 2013年09月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Characterization of phase-II conjugation reaction of polycyclic aromatic hydrocarbons in fish species: unique pyrene metabolism and species specificity observed in fish species.
    Yoshinori Ikenaka, Mami Oguri, Aksorn Saengtienchai, Shouta M M Nakayama, Shigeho Ijiri, Mayumi Ishizuka
    Environmental toxicology and pharmacology, 36, 2, 567, 578, 2013年09月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Avian Cytochrome P450 (CYP) 1-3 Family Genes: Isoforms, Evolutionary Relationships, and mRNA Expression in Chicken Liver
    Kensuke P. Watanabe, Yusuke K. Kawai, Yoshinori Ikenaka, Minami Kawata, Shin-Ichi Ikushiro, Toshiyuki Sakaki, Mayumi Ishizuka
    PLOS ONE, 8, 9, e75689, 2013年09月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Accumulation and biological effects of metals in wild rats in mining areas of Zambia
    Shouta M. M. Nakayama, Yoshinori Ikenaka, Kyohei Hamada, Kaampwe Muzandu, Kennedy Choongo, John Yabe, Takashi Umemura, Mayumi Ishizuka
    ENVIRONMENTAL MONITORING AND ASSESSMENT, 185, 6, 4907, 4918, 2013年06月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Organochlorine pesticides and heavy metals in fish from Lake Awassa, Ethiopia: Insights from stable isotope analysis
    Yared Beyene Yohannes, Yoshinori Ikenaka, Shouta M. M. Nakayama, Aksorn Saengtienchai, Kensuke Watanabe, Mayumi Ishizuka
    CHEMOSPHERE, 91, 6, 857, 863, 2013年05月, [査読有り]
    英語, 研究論文(学術雑誌)
  • A Novel Mutation in VKORC1 and Its Effect on Enzymatic Activity in Japanese Warfarin-Resistant Rats
    Kazuyuki D. Tanaka, Yusuke K. Kawai, Yoshinori Ikenaka, Tsunehito Harunari, Tsutomu Tanikawa, Shoichi Fujita, Mayumi Ishizuka
    JOURNAL OF VETERINARY MEDICAL SCIENCE, 75, 2, 135, 139, 2013年02月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Effects of polycyclic aromatic hydrocarbons (PAHs) on an aquatic ecosystem: acute toxicity and community-level toxic impact tests of benzo[a]pyrene using lake zooplankton community
    Yoshinori Ikenaka, Masaki Sakamoto, Takamaru Nagata, Hirokazu Takahashi, Yuichi Miyabara, Takayuki Hanazato, Mayumi Ishizuka, Tomohiko Isobe, Jun-Woo Kim, Kwang-Hyeon Chang
    JOURNAL OF TOXICOLOGICAL SCIENCES, 38, 1, 131, 136, 2013年02月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Antibiotic residues in food: the African scenario
    Wageh Sobhy Darwish, Elsaid A. Eldaly, Mohamed Tharwat E-Abbasy, Yoshinori Ikenaka, Shouta Nakayama, Mayumi Ishizuka
    JAPANESE JOURNAL OF VETERINARY RESEARCH, 61, SUPPL., S13, S22, 2013年02月, [査読有り]
    英語
  • Biological responses of xenobiotic metabolizing enzymes to lead exposure in cultured H4IIE rat cells.
    Wageh Sobhy Darwish, Yoshinori Ikenaka, Mayumi Ishizuka
    The Japanese journal of veterinary research, 61 Suppl, SUPPL., S48-53, 53, 2013年02月, [査読有り], [国内誌]
    英語
  • Determination of organochlorine pesticides (OCPs) in the edible offal of Egyptian buffalo.
    Abdallah Fikry A Mahmoud, Wageh Sobhy Darwish, Alaa Eldin M A Morshdy, Elsaid A Eldaly, Yoshinori Ikenaka, Mayumi Ishizuka
    The Japanese journal of veterinary research, 61 Suppl, SUPPL., S58-63, 63, 2013年02月, [査読有り], [国内誌]
    英語
  • Distribution of metals in organs of Clarias gariepinus, Heterobranchus bidorsalis, and Chrysichthys nigrodigitatus from the Offin River at Dunkwa-on-Offin, Ghana.
    Jemima T Marfo, Osei Akoto, Shouta M M Nakayama, Elvis Baidoo, Yoshinori Ikenaka, Mayumi Ishizuka
    The Japanese journal of veterinary research, 61 Suppl, SUPPL., S69-71, 71, 2013年02月, [査読有り], [国内誌]
    英語
  • Determination of benzo[a]pyrene levels in ambient air and the source of polycyclic aromatic hydrocarbons using a diagnostic ratio method in Ghana
    Nesta Bortey-Sam, Osei Akoto, Yoshinori Ikenaka, Shouta M. M. Nakayama, Mayumi Ishizuka
    JAPANESE JOURNAL OF VETERINARY RESEARCH, 61, SUPPL., S72, S74, 2013年02月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Heavy metal pollution in Japanese seabirds
    Chihiro Ishii, Yoshinori Ikenaka, Shouta M. M. Nakayama, Yuya Suzuki, Yutaka Watanuki, Yuji Watanabe, Masa-aki Fukuwaka, Yared B. Yohannes, Yusuke K. Kawai, Mayumi Ishizuka
    JAPANESE JOURNAL OF VETERINARY RESEARCH, 61, SUPPL., S75, S76, 2013年02月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Metabolism of pyrene, a polycyclic aromatic hydrocarbon in freshwater turtles
    Balazs Oroszlany, Yoshinori Ikenaka, Aksorn Saengtiengchan, Mami Oguri, Shouta M. M. Nakayama, Mayumi Ishizuka
    JAPANESE JOURNAL OF VETERINARY RESEARCH, 61, SUPPL., S77, S78, 2013年02月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Metal contaminated soil from mining area caused metal accumulation and biological responses in rats
    Shouta M. M. Nakayama, Yoshinori Ikenaka, Kaampwe Muzandu, Kennedy Choongo, John Yabe, Takashi Umemura, Mayumi Ishizuka
    JAPANESE JOURNAL OF VETERINARY RESEARCH, 61, SUPPL., S79, S81, 2013年02月, [査読有り]
    英語, 研究論文(学術雑誌)
  • In vitro diazepam metabolism in horses
    Aki Hayami, Wageh Sobhy Darwish, Yoshinori Ikenaka, Shouta M. M. Nakayama, Mayumi Ishizuka
    JAPANESE JOURNAL OF VETERINARY RESEARCH, 61, SUPPL., S82, S84, 2013年02月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Geographic information system-based source estimation of copper pollution in Lake Itezhi-tezhi and metal-accumulation profiles in Oreochromis spp. from both field and laboratory studies.
    Shouta M M Nakayama, Yoshinori Ikenaka, Kaampwe Muzandu, Kennedy Choongo, John Yabe, Taro Muroya, Shigeho Ijiri, Masao Minagawa, Takashi Umemura, Mayumi Ishizuka
    Archives of environmental contamination and toxicology, 64, 1, 119, 29, 2013年01月, [査読有り], [国際誌]
    英語, 研究論文(学術雑誌)
  • Metal distribution in tissues of free-range chickens near a lead-zinc mine in Kabwe, Zambia
    John Yabe, Shouta M. M. Nakayama, Yoshinori Ikenaka, Kaampwe Muzandu, Kennedy Choongo, Geoffrey Mainda, Matthew Kabeta, Mayumi Ishizuka, Takashi Umemura
    ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY, 32, 1, 189, 192, 2013年01月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Cytochrome P450 3A mRNA expression along goat and rat gastrointestinal tracts
    Dominic Mureithi, Wageh Sobhy Darwish, Yoshinori Ikenaka, Laetitia Kanja, Mayumi Ishizuka
    JAPANESE JOURNAL OF VETERINARY RESEARCH, 60, 4, 205, 210, 2012年11月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Accumulation of Metals in the Liver and Kidneys of Cattle from Agricultural Areas in Lusaka, Zambia
    John Yabe, Shouta M. M. Nakayama, Yoshinori Ikenaka, Kaampwe Muzandu, Mayumi Ishizuka, Takashi Umemura
    JOURNAL OF VETERINARY MEDICAL SCIENCE, 74, 10, 1345, 1347, 2012年10月, [査読有り]
    英語, 研究論文(学術雑誌)
  • EFFECTS OF ENVIRONMENTAL LEAD CONTAMINATION ON CATTLE IN A LEAD/ZINC MINING AREA: CHANGES IN CATTLE IMMUNE SYSTEMS ON EXPOSURE TO LEAD IN VIVO AND IN VITRO
    Yoshinori Ikenaka, Shouta M. M. Nakayama, Taro Muroya, John Yabe, Satoru Konnai, Wageh Sobhy Darwish, Kaampwe Muzandu, Kennedy Choongo, Geoffrey Mainda, Hiroki Teraoka, Takashi Umemura, Mayumi Ishizuka
    ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY, 31, 10, 2300, 2305, 2012年10月, [査読有り]
    英語, 研究論文(学術雑誌)
  • The nucleotide sequence of metallothioneins (MT) in liver of the Kafue lechwe (Kobus leche kafuensis) and their potential as biomarkers of heavy metal pollution of the Kafue River
    Ethel M'kandawire, Michelo Syakalima, Kaampwe Muzandu, Girja Pandey, Martin Simuunza, Shouta M. M. Nakayama, Yusuke K. Kawai, Yoshinori Ikenaka, Mayumi Ishizuka
    GENE, 506, 2, 310, 316, 2012年09月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Transcriptional profiling of inflammatory cytokine genes in African, buffaloes (Syncerus caffer) infected with Theileria parva
    Tomohiro Okagawa, Satoru Konnai, Hirohisa Mekata, Naftaly Githaka, Saori Suzuki, Edward Kariuki, Francis Gakuya, Esther Kanduma, Tatsuya Shirai, Ryoyo Ikebuchi, Yoshinori Ikenaka, Mayumi Ishizuka, Shiro Murata, Kazuhiko Ohashi
    VETERINARY IMMUNOLOGY AND IMMUNOPATHOLOGY, 148, 3-4, 373, 379, 2012年08月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Cytochrome P450 (CYP) in fish
    Tomohide Uno, Mayumi Ishizuka, Takao Itakura
    ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY, 34, 1, 1, 13, 2012年07月, [査読有り]
    英語
  • Metal and metalloid levels and bio-accumulation characteristics in soil, sediment, land plants and hippopotami (Hippopotamus amphibius L) from the South Luangwa National Park, Zambia
    Shouta M. M. Nakayama, Yoshinori Ikenaka, Kaampwe Muzandu, Kennedy Choongo, Ethel M'kandawire, Jun Yasuda, Mayumi Ishizuka
    ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY, 80, 333, 338, 2012年06月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Inhibitory effects of dopamine on spinal synaptic transmission via dopamine D 1-like receptors in neonatal rats
    K. Kawamoto, K. Otsuguro, M. Ishizuka, S. Ito
    British Journal of Pharmacology, 166, 2, 788, 800, 2012年05月
    研究論文(学術雑誌)
  • Expressional repression of hepatic cytochrome P450 2d in ICR mice infected with Babesia microti
    Shimamoto Yoshinori, Watanabe Kensuke, Sasaki Mizuki, Ikadai Hiromi, Ishizuka Mayumi, Hoshi Fumio, Yokoyama Naoaki, Igarashi Ikuo, Kitamura Hiroshi
    FASEB JOURNAL, 26, 2012年04月, [査読有り]
  • Molecular cloning and characterization of Th1 and Th2 cytokines of African buffalo (Syncerus caffer)
    Suzuki S, Konnai S, Okagawa T, Githaka NW, Kariuki E, Gakuya F, Kanduma E, Shirai T, Ikebuchi R, Ikenaka Y, Ishizuka M, Murata S, Ohashi K
    Int J Immunogenet., 39, 2, 170, 82, 2012年04月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Downregulation of Hepatic Cytochrome P450 3A in Mice Infected with Babesia microti
    Yoshinori Shimamoto, Mizuki Sasaki, Hiromi Ikadai, Mayumi Ishizuka, Naoaki Yokoyama, Ikuo Igarashi, Fumio Hoshi, Hiroshi Kitamura
    JOURNAL OF VETERINARY MEDICAL SCIENCE, 74, 2, 241, 245, 2012年02月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Cross-talks between heavy metals and xenobiotics metabolizing enzymes
    DARWISH Wageh S., IKENAKA Yoshinori, ISHIZUKA Mayumi
    日本毒性学会学術年会, 39, O, 6, 日本毒性学会, 2012年
    日本語, [Introduction] The growing exposure of the human and animals to heavy metal pollution generates modulation in xenobiotics-metabolizing enzymes (XMEs) response. In this study, the modulation of Ahr ligand-dependent toxicities by heavy metals and the molecular basis of this modulation were investigated.[Materials and Methods] Samples were collected from different edible offal of cattle slaughtered at Zagazig abattoir, Egypt. Different heavy metals were measured using atomic absorption spectrophotometer. Human and rat liver hepatoma cell lines (HEPG2 and H4IIE) were treated with Lead and Copper under different concentrations ranged between permissible and toxic doses. The effects of these treatments on various XMEs and regulatory elements were screened using the methods of qPCR and Western Blotting.[Results and Discussion] Liver, kidney and tongue showed the highest contents of the various heavy metal residues compared to other tissues. Lead, copper, cadmium, zinc and nickel exceeded the maximum permissible limits of Egyptian Standards and WHO. Interestingly, both copper and lead could induce CYP1A1 mRNA expression under low doses in the treated cell cultures. This expression level was markedly decreased under high concentrations. Effects of copper and lead on CYP1A1 expression was parallel to their effects on Ahr suggesting that those effects were in response to Ahr. All tested phase II enzymes were severely down regulated by exposure to lead in a concentration dependent manner. In conclusion, there were clear cross-talks between copper, lead and pase I, II enzymes and regulatory elements in the cultured cells.
  • The identification of the important CYP isoforms in avian xenobiotic metabolism and its species difference among bird species
    WATANABE Kensuke P, KAWATA Minami, KAWAI Yusuke, IKENAKA Yoshinori, ISHIZUKA Mayumi
    日本毒性学会学術年会, 39, AP, 223, 日本毒性学会, 2012年
    日本語, [Background and aim]In wild bird species, the metabolic activity of warfarin by cytochrome P450 (CYP) was reported to be much lower compared to chicken. However, even the important CYP isoforms in avian xenobiotic metabolism have not been clarified due to the lack of information about the expression level and the function of each isoforms. Thus, the reported species difference of metabolic ability cannot be attributed to any isoform. In this study, we aimed to identify the isoform dominant in avian xenobiotic metabolism and to characterize the species difference of the isoform.[Method and result]We compared the mRNA copy number among CYP isoforms in chicken liver. CYP1A5, 2C23 and 2C45 were highly expressed in liver, while CYP3A37, which has been well studied in poultry species, showed lower expression level. Therefore, we focused on CYP2C23 of avian species. Partial sequences of CYP2C23 from 8 avian species were cloned and the anti-peptide antibody was synthesized against the conserved amino acid sequence among them. In immunoblot with the antibody and the microsomes of the avian species, we could detect CYP2C23s from all the avian species.[Discussion]With mRNA expression, CYP2C subfamily was assumed to be important isoforms in chicken xenobiotics metabolism. The expression levels of CYP2C23 proteins showed not as much difference among bird species as the metabolic activity. With all results above, the species difference of metabolic ability among bird species cannot be attributed to the protein expression levels, but the functional difference.
  • The study of polycyclic aromatic hydrocarbons (PAHs) and its metabolite as a biomarker for PAH exposures in wildlife animals
    SAENGTIENCAHI Aksorn, IKENAKA Yoshinori, LEE Kyunglee, TSUBOTA Toshio, ISHIZUKA Mayumi
    日本毒性学会学術年会, 39, P, 125, 日本毒性学会, 2012年
    日本語, [Introduction] Polycyclic aromatic hydrocarbons (PAHs) distribute ubiquitously as complex mixtures in the environment. Pyrene is one of PAHs that is widely used as model of PAH contamination in environment. Pyrene is metabolized by cytochrome P450s in phase I reaction then conjugated in phase II metabolism, and excreted into urine and feces. Although their metabolites are available for use in human as indicator for PAH exposure, there are still less information in wildlife. In present study, we focus on the elucidation of pyrene metabolites in wild animals. [Materials and Methods] Urine of 10 male sika deer (Cervus nippon), 1 to 5 year olds were collected from Hokkaido, Japan. All samples were extracted by Oasis WAX cartridge and they were analyzed by High performance liquid chromatography with fluorescence detector. [Results and Discussions] We could detect pyrene-1-glucuronide largely in urine. Moreover, pyrene-1-sulfate, and 1-hydroxypyrene also detected. When we compared this results with other ruminant as cattle, pyrene-1-glucuronide was main metabolites same as sika deer. Pyrene conjugate compounds were easily detected in urine. Due to observe the amount of polluted chemical as PAHs in environment, we could suggest that not only elucidate PAH concentration, but also its metabolite as 1-hydroxypyrene, pyrene 1-glucuronide, and sulfate conjugates were important to establish the appropriate biomarker for the assessment for PAH exposures in various wildlife animal species in environment.
  • All-trans retinoic acid inhibits the recruitment of ARNT to DNA, resulting in the decrease of CYP1A1 mRNA expression in HepG2 cells
    Marumi Ohno, Yoshinori Ikenaka, Mayumi Ishizuka
    BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 417, 1, 484, 489, 2012年01月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Sudan III dye strongly induces CYP1A1 mRNA expression in HepG2 cells
    Marumi Ohno, Yoshinori Ikenaka, Mayumi Ishizuka
    JOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, 26, 1, 16, 22, 2012年01月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Phase-II conjugation ability for PAH metabolism in amphibians: Characteristics and inter-species differences
    Haruki Ueda, Yoshinori Ikenaka, Shouta M. M. Nakayama, Tomoko Tanaka-Ueno, Mayumi Ishizuka
    AQUATIC TOXICOLOGY, 105, 3-4, 337, 343, 2011年10月, [査読有り]
    英語, 研究論文(学術雑誌)
  • UPTAKE OF LEAD, CADMIUM, AND OTHER METALS IN THE LIVER AND KIDNEYS OF CATTLE NEAR A LEAD-ZINC MINE IN KABWE, ZAMBIA
    John Yabe, Shouta M. M. Nakayama, Yoshinori Ikenaka, Kaampwe Muzandu, Mayumi Ishizuka, Takashi Umemura
    ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY, 30, 8, 1892, 1897, 2011年08月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Astaxanthin can alter CYP1A-dependent activities via two different mechanisms: Induction of protein expression and inhibition of NADPH P450 reductase dependent electron transfer
    Marumi Ohno, Wageh S. Darwish, Yoshinori Ikenaka, Wataru Miki, Mayumi Ishizuka
    FOOD AND CHEMICAL TOXICOLOGY, 49, 6, 1285, 1291, 2011年06月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Metal and metalloid contamination in roadside soil and wild rats around a Pb-Zn mine in Kabwe, Zambia
    Shouta M. M. Nakayama, Yoshinori Ikenaka, Kyohei Hamada, Kaampwe Muzandu, Kennedy Choongo, Hiroki Teraoka, Naoharu Mizuno, Mayumi Ishizuka
    ENVIRONMENTAL POLLUTION, 159, 1, 175, 181, 2011年01月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Carotenoids as regulators for inter-species difference in cytochrome P450 1A expression and activity in ungulates and rats
    Wageh S. Darwish, Yoshinori Ikenaka, Marumi Ohno, Elsaid A. Eldaly, Mayumi Ishizuka
    FOOD AND CHEMICAL TOXICOLOGY, 48, 11, 3201, 3208, 2010年11月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Current levels of heavy metal pollution in Africa
    John Yabe, Mayuni Ishizuka, Takashi Umemura
    Journal of Veterinary Medical Science, 72, 10, 1257, 1263, 2010年10月
  • Identification and Phylogenetic Analysis of Novel Cytochrome P450 1A Genes from Ungulate Species
    Wageh Sobhy Darwish, Yusuke Kawai, Yoshinori Ikenaka, Hideaki Yamamoto, Tarou Muroya, Mayumi Ishizuka
    JOURNAL OF VETERINARY MEDICAL SCIENCE, 72, 9, 1237, 1241, 2010年09月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Genetic polymorphisms of 17 β-hydroxysteroid dehydrogenase 3 and the risk of hypospadias.
    Sata F, Kurahashi N, Ban S, Moriya K, Tanaka KD, Ishizuka M, Nakao H, Yahata Y, Imai H, Kakizaki H, Nonomura K, Kishi R
    The journal of sexual medicine, 7, 8, 2729, 2738, 2010年08月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Heavy Metal Accumulation in Lake Sediments, Fish (Oreochromis niloticus and Serranochromis thumbergi), and Crayfish (Cherax quadricarinatus) in Lake Itezhi-tezhi and Lake Kariba, Zambia
    Shouta M. M. Nakayama, Yoshinori Ikenaka, Kaampwe Muzandu, Kennedy Choongo, Balazs Oroszlany, Hiroki Teraoka, Naoharu Mizuno, Mayumi Ishizuka
    ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY, 59, 2, 291, 300, 2010年08月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Metabolic Activation of Heterocyclic Amines and Expression of CYP1A1 in the Tongue
    Mami Takiguchi, Wageh S. Darwish, Yoshinori Ikenaka, Marumi Ohno, Mayumi Ishizuka
    TOXICOLOGICAL SCIENCES, 116, 1, 79, 91, 2010年07月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Comparison of warfarin sensitivity between rat and bird species
    Kensuke P. Watanabe, Aksorn Saengtienchai, Kazuyuki D. Tanaka, Yoshinori Ikenaka, Mayumi Ishizuka
    COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY C-TOXICOLOGY & PHARMACOLOGY, 152, 1, 114, 119, 2010年06月, [査読有り]
    英語, 研究論文(学術雑誌)
  • The CYP1D subfamily of genes in mammals and other vertebrates
    Yusuke K. Kawai, Yoshinori Ikenaka, Shoichi Fujita, Mayumi Ishizuka
    MAMMALIAN GENOME, 21, 5-6, 320, 329, 2010年06月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Sodium 2-propenyl thiosulfate derived from garlic induces phase II detoxification enzymes in rat hepatoma H4IIE cells
    Hye-Sook Chang, Miyan Ko, Mayumi Ishizuka, Shoichi Fujita, Akira Yabuki, Mohammad Alamgir Hossain, Osamu Yamato
    NUTRITION RESEARCH, 30, 6, 435, 440, 2010年06月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Cytochrome P450 1A-Dependent Activities in Deer, Cattle and Horses
    Wageh Sobhy Darwish, Yoshinori Ikenaka, Elsaid Abozeid Eldaly, Marumi Ohno, Kentaro Q. Sakamoto, Shoichi Fujita, Mayumi Ishizuka
    JOURNAL OF VETERINARY MEDICAL SCIENCE, 72, 5, 561, 566, 2010年05月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Metabolic alkalosis due to feeding chicks in breeding Adélie penguins Pygoscelis adeliae under natural conditions.
    Sakamoto KQ, Sato K, Kato A, Fukui D, Bando G, Naito Y, Habara Y, Ishizuka M, Fujita S
    Physiological and biochemical zoology : PBZ, 83, 2, 232, 238, 2010年03月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Expression and Sequence of CYP1A1 in the Camel
    Wageh Sobhy Darwish, Alaa Eldin Morshdy, Yoshinori Ikenaka, Zein Shaban Ibrahim, Shoichi Fujita, Mayumi Ishizuka
    JOURNAL OF VETERINARY MEDICAL SCIENCE, 72, 2, 221, 224, 2010年02月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Diazepam Metabolism in the Kidneys of Male and Female Rats of Various Strains
    Hyung-Sub Kim, Noriaki Sakai, Konomu Saito, Shoichi Fujita, Mayumi Ishizuka
    JOURNAL OF VETERINARY MEDICAL SCIENCE, 72, 1, 7, 11, 2010年01月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Impact of rat P450 genetic polymorphism on diazepam metabolism
    Noriaki Sakai, Mayumi Ishizuka
    EXPERT OPINION ON DRUG METABOLISM & TOXICOLOGY, 5, 11, 1421, 1433, 2009年11月, [査読有り]
    英語
  • Molecular Cloning of Novel Cytochrome P450 1A Genes from Nine Japanese Amphibian Species
    Shouta M. M. Nakayama, Tomoko Tanaka-Ueno, Kentaro Q. Sakamoto, Shoichi Fujita, Mayumi Ishizuka
    JOURNAL OF VETERINARY MEDICAL SCIENCE, 71, 10, 1407, 1411, 2009年10月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Crude Cacao Theobroma cacao Extract Reduces Mutagenicity Induced by Benzo[a]pyrene Through Inhibition of CYP1A Activity In Vitro
    Marumi Ohno, Kentaro Q. Sakamoto, Mayumi Ishizuka, Shoichi Fujita
    PHYTOTHERAPY RESEARCH, 23, 8, 1134, 1139, 2009年08月, [査読有り]
    英語, 研究論文(学術雑誌)
  • The Importance of Heterogeneous Nuclear Ribonucleoprotein K on Cytochrome P450 2D2 Gene Regulation: Its Binding Is Reduced in Dark Agouti Rats
    Noriaki Sakai, Kentaro Q. Sakamoto, Shoichi Fujita, Mayumi Ishizuka
    DRUG METABOLISM AND DISPOSITION, 37, 8, 1703, 1710, 2009年08月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Protective effect of Pleurotus cornucopiae mushroom extract on carbon tetrachloride-induced hepatotoxicity
    Khlood M. El Bohi, Yoshiharu Hashimoto, Kaampwe Muzandu, Yoshinori Ikenaka, Zein Shaban Ibrahim, Akio Kazusaka, Shoichi Fujita, Mayumi Ishizuka
    JAPANESE JOURNAL OF VETERINARY RESEARCH, 57, 2, 109, 118, 2009年08月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Absolute requirement for iron in the development of chemically induced uroporphyria in mice treated with 3-methylcholanthrene and 5-aminolevulinate
    Kenzi Nakano, Mayumi Ishizuka, Kentaro Q. Sakamoto, Shoichi Fujita
    BIOMETALS, 22, 2, 345, 351, 2009年04月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Can Ethograms Be Automatically Generated Using Body Acceleration Data from Free-Ranging Birds?
    Kentaro Q. Sakamoto, Katsufumi Sato, Mayumi Ishizuka, Yutaka Watanuki, Akinori Takahashi, Francis Daunt, Sarah Wanless
    PLOS ONE, 4, 4, e5379, 2009年04月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Morphological Features and Blood Parameters of Weddell Seal (Leptonychotes weddellii) Mothers and Pups during the Breeding Season
    Kentaro Q. Sakamoto, Katsufumi Sato, Yasuhiko Naito, Yoshiaki Habara, Mayumi Ishizuka, Shoichi Fujita
    JOURNAL OF VETERINARY MEDICAL SCIENCE, 71, 3, 341, 344, 2009年03月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Genetic Basis of Inter- and Intrastrain Differences in Diazepam p-Hydroxylation in Rats
    Noriaki Sakai, Konomu Saito, Kentaro Q. Sakamoto, Mayumi Ishizuka, Shoichi Fujita
    DRUG METABOLISM AND DISPOSITION, 37, 2, 268, 271, 2009年02月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Protection by Nigella sativa against carbon tetrachloride-induced downregulation of hepatic cytochrome P450 isozymes in rats
    Zein S. Ibrahim, Mayumi Ishizuka, Mohamed Soliman, Khlood ElBohi, Wageh Sobhy, Kaampwe Muzandu, Azza M. Elkattawy, Kentaro Q. Sakamoto, Shoichi Fujita
    JAPANESE JOURNAL OF VETERINARY RESEARCH, 56, 3, 119, 128, 2008年11月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Genetic and antigenic analyses of a Puumala virus isolate as a potential vaccine strain.
    Abu Daude NH, Kariwa H, Tkachenko E, Dzagurnova T, Medvedkina O, Tkachenko P, Ishizuka M, Seto T, Miyashita D, Sanada T, Nakauchi M, Yoshii K, Maeda A, Yoshimatsu K, Arikawa J, Takashima I
    The Japanese journal of veterinary research, 56, 3, 151, 165, 3, 2008年11月, [査読有り]
    英語, Puumala virus (PUUV), a causative agent of hemorrhagic fever with renal syndrome (HFRS), is prevalent in Europe and European Russia. No vaccine has been developed for PUUVassociated HFRS, primarily because of the low viral yield in cultured cells. A PUUV strain known as DTK/Ufa-97 was isolated in Russia and adapted for growth in Vero E6 cells maintained in serum-free medium. The DTK/Ufa-97 strain produced a higher viral titer in serumfreemedium, suggesting that it may prove useful in the development of an HFRS vaccine.When PUUV-infected Vero E6 cells were grown in serum-free medium, the DTK/Ufa-97 strain yielded more copies of intracellular viral RNA and a higher viral titer in the culture fluid than did the Sotkamo strain. Phylogenetic analysis revealed that PUUVs can be classified into multiple lineages according to geographical origin, and that the DTK/Ufa-97 strain is a member of the Bashkiria-Saratov lineage. The deduced amino acid sequences of the small, medium, and large segments of the DTK/Ufa-97 strain were 99.2% to 100%, 99.3% to 99.8%, and 99.8% identical, respectively, to those of the Bashkirian PUUV strains and 96.9%, 92.6%, and 97.4% identical, respectively, to those of the Sotkamo strain, indicating that the PUUVs are genetically diverse. However, DTK/Ufa-97 and other strains of PUUV exhibited similar patterns of binding to a panel of monoclonal antibodies against Hantaan virus. In addition, diluted antisera (i.e., ranging from 1:160 to 1:640) specific to three strains of PUUV neutralized both homologous and heterologous viruses. These results suggest that the DTK/Ufa-97 strain is capable of extensive growth and is antigenically similar to genetically distant strains of PUUV.
  • Analysis of acrylamide in a complex matrix of polyacrylamide solutions treated by heat and ultraviolet light
    Mayumi Ishizuka, Kazutoshi Fujioka, Takayuki Shibamoto
    JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, 56, 15, 6093, 6096, 2008年08月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Pesticide resistance in wild mammals - Mechanisms of anticoagulant resistance in wild rodents
    Mayumi Ishizuka, Tsutomu Tanikawa, Kazuyuki D. Tanaka, Min Heewon, Fumie Okajima, Kentaro Q. Sakamoto, Shoichi Fujita
    JOURNAL OF TOXICOLOGICAL SCIENCES, 33, 3, 283, 291, 2008年08月, [査読有り]
    英語
  • Downregulation of male-specific cytochrome P450 by profenofos
    Gihan G. Moustafa, Zein S. Ibrahim, Mohamed M. Ahmed, Mervat H. Ghoneim, Kentaro Q. Sakamoto, Mayumi Ishizuka, Shoichi Fujita
    JAPANESE JOURNAL OF VETERINARY RESEARCH, 56, 2, 109, 118, 2008年08月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Adverse birth outcomes associated with maternal smoking and polymorphisms in the N-nitrosamine-metabolizing enzyme genes NQO1 and CYP2E1
    Seiko Sasaki, Fumihiro Sata, Shizue Katoh, Yasuaki Saijo, Sonomi Nakajima, Noriaki Washino, Kanae Konishi, Susumu Ban, Mayumi Ishizuka, Reiko Kishi
    AMERICAN JOURNAL OF EPIDEMIOLOGY, 167, 6, 719, 726, 2008年03月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Antibiotic furazolidone induces CYP1A but not CYP2E1 subfamily in rat liver
    Nobuo Sasaki, Noriaki Sakai, Yoshinori Ikenaka, Tomomi Kamiya, Min Heewon, Kentaro Q. Sakamotoo, Mayumi Ishizuka, Shoichi Fujita
    JOURNAL OF VETERINARY MEDICAL SCIENCE, 70, 3, 223, 226, 2008年03月, [査読有り]
    英語, 研究論文(学術雑誌)
  • The induction of cytochrome P450 1A1 by sudan dyes
    Nahla A. G. Ahmed Refat, Zein Shaban Ibrahim, Gihan Gamal Moustafa, Kentaro Q. Sakamoto, Mayumi Ishizuka, Shoichi Fujita
    JOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, 22, 2, 77, 84, 2008年, [査読有り]
    英語, 研究論文(学術雑誌)
  • Testicular toxicity of profenofos in matured male rats
    Gihan Gamal Moustafa, Zein Shaban Ibrahim, Yoshiharu Hashimoto, M. Alkelch Alkelch, Kentaro Q. Sakamoto, Mayumi Ishizuka, Shoichi Fujita
    ARCHIVES OF TOXICOLOGY, 81, 12, 875, 881, 2007年12月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Using microarray analysis to evaluate genetic polymorphisms involved in the metabolism of environmental chemicals.
    Ban S, Kondo T, Ishizuka M, Sasaki S, Konishi K, Washino N, Fujita S, Kishi R
    Fukuoka igaku zasshi = Hukuoka acta medica, 98, 5, 208, 214, 5, 2007年05月, [査読有り]
    研究論文(学術雑誌)
  • Elevated warfarin metabolism in warfarin-resistant roof rats (Rattus rattus) in Tokyo
    Mayumi Ishizuka, Fumie Okajima, Tsutomu Tanikawa, Heewon Min, Kazuyuki D. Tanaka, Kentaro Q. Sakamoto, Shoichi Fujita
    DRUG METABOLISM AND DISPOSITION, 35, 1, 62, 66, 2007年01月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Plasma pharmacokinetics and CYP3A12-dependent metabolism of c-kit inhibitor imatinib in dogs
    M. Ishizuka, S. Nagai, K. Q. Sakamoto, S. Fujita
    XENOBIOTICA, 37, 5, 503, 513, 2007年, [査読有り]
    英語, 研究論文(学術雑誌)
  • Effect of lycopene and beta-carotene on peroxynitrite-mediated cellular modifications
    Kaampwe Muzandu, Mayumi Ishizuka, Kentaro Q. Sakamoto, Zein Shaban, Khlood El Bohi, Akio Kazusaka, Shoichi Fujita
    TOXICOLOGY AND APPLIED PHARMACOLOGY, 215, 3, 330, 340, 2006年09月, [査読有り]
    英語, 研究論文(学術雑誌)
  • CYP2D-related metabolism in animals of the Canoidea superfamily - Species differences
    M. Ishizuka, J. J. Lee, M. Masuda, F. Akahori, A. Kazusaka, S. Fujita
    Veterinary Research Communications, 30, 5, 505, 512, 2006年07月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Maternal smoking during pregnancy and genetic polymorphisms in the Ah receptor, CYP1A1 and GSTM1 affect infant birth size in Japanese subjects
    S Sasaki, T Kondo, F Sata, Y Saijo, S Katoh, S Nakajima, M Ishizuka, S Fujita, R Kishi
    MOLECULAR HUMAN REPRODUCTION, 12, 2, 77, 83, 2006年02月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Induction of cytochrome P450-1A by the equine estrogen equilenin, a new endogenous aryl hydrocarbon receptor ligand
    A Jinno, Y Maruyama, M Ishizuka, A Kazusaka, A Nakamura, S Fujita
    JOURNAL OF STEROID BIOCHEMISTRY AND MOLECULAR BIOLOGY, 98, 1, 48, 55, 2006年01月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Importance of CYP2D3 in polymorphism of diazepam P-hydroxylation in rats
    N Sakai, K Saito, HS Kim, A Kazusaka, M Ishizuka, Y Funae, S Fujita
    DRUG METABOLISM AND DISPOSITION, 33, 11, 1657, 1660, 2005年11月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Nitric oxide enhances catechol estrogen-induced oxidative stress in LNCaP cells
    K Muzandu, Z Shaban, M Ishizuka, A Kazusaka, S Fujita
    FREE RADICAL RESEARCH, 39, 4, 389, 398, 2005年04月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Antigenotoxic effect of Pleurotus cornucopiae extracts on the mutagenesis of Salmonella typhimurium TA98 elicited by benzo [a] pyrene and oxidative DNA lesions in V79 hamster lung cells
    KM El Bohi, L Sabik, K Muzandu, Z Shaban, M Soliman, M Ishizuka, A Kazusaka, S Fujita
    JAPANESE JOURNAL OF VETERINARY RESEARCH, 52, 4, 163, 172, 2005年02月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Lycopene and beta-carotene ameliorate catechol estrogen-mediated DNA damage
    K Muzandu, K El Bohi, Z Shaban, M Ishizuka, A Kazusaka, S Fujita
    JAPANESE JOURNAL OF VETERINARY RESEARCH, 52, 4, 173, 184, 2005年02月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Effect of components of green tea extracts, caffeine and catechins on hepatic drug metabolizing enzyme activities and mutagenic transformation of carcinogens
    S Nikaidou, M Ishizuka, Y Maeda, Y Hara, A Kazusaka, S Fujita
    JAPANESE JOURNAL OF VETERINARY RESEARCH, 52, 4, 185, 192, 2005年02月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Effect of catechins on mutagenesis of Salmonella typhimurium TA 102 elicited by tert-butyl hydroperoxide (t-BuOOH)
    S Nikaidou, M Ishizuka, Y Maeda, Y Hara, A Kazusaka, S Fujita
    JOURNAL OF VETERINARY MEDICAL SCIENCE, 67, 1, 137, 138, 2005年01月, [査読有り]
    英語, 研究論文(学術雑誌)
  • AhR and PPAR alpha: antagonistic effects on CYP2B and CYP3A, and additive inhibitory effects on CYP2C11
    Z Shaban, M Soliman, S El-Shazly, K El-Bohi, A Abdelazeez, K Kehelo, HS Kim, K Muzandu, M Ishizuka, A Kazusaka, S Fujita
    XENOBIOTICA, 35, 1, 51, 68, 2005年01月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Down regulation of hepatic PPAR alpha function by AhR ligand
    Z Shaban, S El-Shazly, S Abdelhady, Fattouh, I, K Muzandu, M Ishizuka, K Kimura, A Kazusaka, S Fujita
    JOURNAL OF VETERINARY MEDICAL SCIENCE, 66, 11, 1377, 1386, 2004年11月, [査読有り]
    英語, 研究論文(学術雑誌)
  • PPAR alpha-dependent modulation of hepatic CYP1A by clofibric acid in rats
    Z Shaban, S El-Shazly, M Ishizuka, K Kimura, A Kazusaka, S Fujita
    ARCHIVES OF TOXICOLOGY, 78, 9, 496, 507, 2004年09月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Strain differences in diazepam metabolism at its three metabolic sites in Sprague-Dawley, Brown Norway, Dark Agouti, and Wistar strain rats
    K Saito, N Sakai, HS Kim, M Ishizuka, A Kazusaka, S Fujita
    DRUG METABOLISM AND DISPOSITION, 32, 9, 959, 965, 2004年09月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Alterations of activities of cytosolic phospholipase A(2) and arachidonic acid-metabolizing enzymes in Di-(2-ethylhexyl)phthalate-induced testicular atrophy
    HS Kim, M Ishizuka, A Kazusaka, S Fujita
    JOURNAL OF VETERINARY MEDICAL SCIENCE, 66, 9, 1119, 1124, 2004年09月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Iodine intake as a possible cause of discontinuous decline in sperm counts: A re-evaluation of historical and geographic variation in semen quality
    KQ Sakamoto, M Ishizuka, A Kazusaka, S Fujita
    JAPANESE JOURNAL OF VETERINARY RESEARCH, 52, 2, 85, 94, 2004年08月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Polymorphism in diazepam metabolism in Wistar rats
    K Saito, HS Kim, N Sakai, M Ishizuka, A Kazusaka, S Fujita
    JOURNAL OF PHARMACEUTICAL SCIENCES, 93, 5, 1271, 1278, 2004年05月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Cytochrome P450 induction and gonadal status alteration in common carp (Cyprinus carpio) associated with the discharge of dioxin contaminated effluent to the Hikiji River, Kanagawa Prefecture, Japan
    KQ Sakamoto, K Nakai, T Aoto, A Yokoyama, R Ushikoshi, H Hirose, M Ishizuka, A Kazusaka, S Fujita
    CHEMOSPHERE, 51, 6, 491, 500, 2003年05月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Short period exposure to di-(2-ethylhexyl) phthalate regulates testosterone metabolism in testis of prepubertal rats
    HS Kim, K Saito, M Ishizuka, A Kazusaka, S Fujita
    ARCHIVES OF TOXICOLOGY, 77, 8, 446, 451, 2003年, [査読有り]
    英語, 研究論文(学術雑誌)
  • Perinatal exposure to low doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin alters sex-dependent expression of hepatic CYP2C11
    M Ishizuka, J Yonemoto, H Zaha, C Tohyama, H Sone
    JOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, 17, 5, 278, 285, 2003年, [査読有り]
    英語, 研究論文(学術雑誌)
  • Organochlorine compound accumulation in Steller sea lion Eumetopias jubatus migrating along the coast of Hokkaido in northern Japan.
    Hoshino, H, Fujita, S, Goto, Y, Isono, T, Ishinazaka, T, Sakurai, Y, Iwata, H, Kazusaka, A, Ishizuka, M, Tanabe, S
    Japanese Journal of Environmental Toxicology, 6, 1, 1, 10, 2003年, [査読有り]
  • Hepatic microsomal cytochrome P450S and chlorinated hydrocarbons in largha and ribbon seals from Hokkaido, Japan: Differential response of seal species to AH receptor agonist exposure
    Chiba, I, A Sakakibara, H Iwata, M Ishizuka, S Tanabe, F Akahori, A Kazusaka, S Fujita
    ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY, 21, 4, 794, 806, 2002年04月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Accumulation patterns of polychlorinated biphenyl congeners and organochlorine pesticides in Steller's sea eagles and white-tailed sea eagles, threatened species, in Hokkaido, Japan
    KQ Sakamoto, T Kunisue, M Watanabe, Y Masuda, H Iwata, S Tanabe, F Akahori, M Ishizuka, A Kazusaka, S Fujita
    ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY, 21, 4, 842, 847, 2002年04月, [査読有り]
    英語, 研究論文(学術雑誌)
  • The loss of enzyme activities by a single amino acid substitution of a newly cloned rabbit CYP2D isozyme, CYP2D24
    Mayumi Ishizuka, Yukio Yamamoto, Ayato Takada, Akio Kazusaka, Shoichi Fujita
    International Congress Series, 1233, C, 121, 126, 2002年, [査読有り]
    英語, 研究論文(学術雑誌)
  • P450 in wild animals as biomarker of environmental impact
    Shoichi Fujita, Issei Chiba, Mayumi Ishizuka, Hidenobu Hoshi, Hisato Iwata, Akihito Sakakibara, Shinsuke Tanabe, Akio Kazusaka, Makihiko Masuda, Yasushi Masuda, Hajime Nakagawa
    Biomarkers, 6, 1, 6(1): 19-25, 25, 2001年02月03日, [査読有り]
    研究論文(学術雑誌)
  • Increased mutant frequency and altered mutation spectrum of the lacI transgene in Wilson disease rats with hepatitis
    H. Sone, Ying Jie Li, M. Ishizuka, Y. Aoki, M. Nagao
    Cancer Research, 60, 18, 5080, 5086, 2000年09月15日, [査読有り]
    英語, 研究論文(学術雑誌)
  • Comparative effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on MCF-7, RL95-2, and LNCaP cells: Role of target steroid hormones in cellular responsiveness to CYP1A1 induction
    Nihar Ranjan Jana, Shubhashishi Sarkar, Mayumi Ishizuka, Junzo Yonemoto, Chiharu Tohyama, Hideko Sone
    Molecular Cell Biology Research Communications, 4, 3, 174, 180, Academic Press Inc., 2000年, [査読有り]
    英語, 研究論文(学術雑誌)
  • Role of estradiol receptor-alpha in differential expression of 2,3,7,8-tetrachlorodibenzo-p-dioxin-inducible genes in the RL95-2 and KLE human endometrial cancer cell lines
    NR Jana, S Sarkar, M Ishizuka, J Yonemoto, C Tohyama, H Sone
    ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS, 368, 1, 31, 39, 1999年08月, [査読有り]
    英語, 研究論文(学術雑誌)
  • Accumulation of halogenated aromatic hydrocarbons and activities of cytochrome P450 and glutathione S-transferase in crabs from Japanese rivers.
    ISHIZUKA M, SAKIYAMA T, IWATA H, FUKUSHIMA M, KAZUSAKA A, FUJITA S
    Environ. Toxicol. Chem., 17, 8, 1490, 1498, 1998年08月24日, [査読有り]
    研究論文(学術雑誌)
  • Cloning, tissue distribution, and functional expression of two novel rabbit cytochrome P450 isozymes, CYP2D23 and CYP2D24
    Yukio Yamamoto, Mayumi Ishizuka, Ayato Takada, Shoichi Fujita
    Journal of Biochemistry, 124, 3, 503, 508, Japanese Biochemical Society, 1998年, [査読有り]
    英語, 研究論文(学術雑誌)
  • Effects of the agrochemicals butachlor, pretilachlor and isoprothiolane on rat liver xenobiotic-metabolizing enzymes.
    ISHIZUKA M, IWATA H, KAZUSAKA A, HATAKEYAMA S, FUJITA S
    Xenobiotica, 28, 11, 1029, 1039, 1998年01月01日
    研究論文(学術雑誌)
  • Isozyme selective alterations of the expression of cytochrome P450 during regeneration of male rat liver following partial hepatectomy.
    ISHIZUKA M, YOSHINO S, YAMAMOTO Y, YAMAMOTO H, IMAOKA S, FUNAE Y, MASUDA M, IWATA H, FUJITA S
    Xenobiotica, 27, 9, 923, 931, 1997年09月29日, [査読有り]
    研究論文(学術雑誌)
  • Alterations of cytochrome p450-dependent monooxygenase activities in Eriocheir japonicus in response to water pollution
    Mayumi Ishizuka, Hidenobu Hoshi, Nobuyuki Minamoto, Makihiko Masuda, Akio Kazusaka, Shoichi Fujita
    Environmental Health Perspectives, 104, 7, 774, 778, Public Health Services, US Dept of Health and Human Services, 1996年, [査読有り]
    英語, 研究論文(学術雑誌)

その他活動・業績

書籍等出版物

所属学協会

  • 日本野生動物医学会               
  • 環境ホルモン学会 [正式名称;日本内分泌撹乱化学物質学会]               
  • 日本環境化学会               
  • 日本獣医学会               
  • 日本毒性学会               

共同研究・競争的資金等の研究課題

  • 金属分析技術を応用した野生動物のナノプラスチック・添加剤の地球規模モニタリング
    科学研究費助成事業
    2025年06月27日 - 2028年03月31日
    石塚 真由美, 田中 厚資, 中山 翔太
    日本学術振興会, 挑戦的研究(開拓), 北海道大学, 25K21816
  • 脳機能撹乱検出法・診断法の開発を起点としたシグナル毒性評価プラットフォームの創設
    科学研究費助成事業
    2023年04月01日 - 2027年03月31日
    池中 良徳, 星 信彦, 野見山 桂, 杉尾 翔太, 石塚 真由美, 戸田 知得, 江口 哲史, 池中 建介, 平野 哲史
    日本学術振興会, 基盤研究(A), 北海道大学, 23H00512
  • アフリカの環境汚染によるヒトと動物の毒性学的影響とそのメカニズム解析
    科学研究費助成事業 国際共同研究加速基金(国際共同研究強化(B))
    2022年10月07日 - 2026年03月31日
    石塚 真由美, 武田 一貴, 池中 良徳, 江口 哲史, 中山 翔太
    日本学術振興会, 国際共同研究加速基金(国際共同研究強化(B)), 北海道大学, 22KK0163
  • 外来性の化学物質(xenobiotics)に対する哺乳類の適応進化/変化
    科学研究費助成事業 基盤研究(A)
    2021年04月05日 - 2026年03月31日
    石塚 真由美
    我々はこれまでの研究により、高次の動物が外来性の化学物質(Xenobiotics)への「適応」ために、化学物質の代謝や排泄など、解毒のカスケードに沿って薬物代謝酵素などの一連の多様性を発展させてきたとの仮説を立てた。化学物質感受性には多様性があり、解毒代謝酵素の解析から、この多様性獲得の主要因は食餌由来の化学物質である可能性を報告した。本研究では食性の観点および重度環境汚染域に棲息する動物を中心に、哺乳類が日常的に曝露される化学物質にどのように適応してきたのか、多様な種を用いてその進化を機能面から明らかにする。これまでの研究で構築してきた多様な動物試料を用いた研究体制を生かし、食性のユニークな動物種を対象としたウェットな実験や、データベースを用いた網羅的解析により、外来性の化学物質に対する動物の「適応」と「共存」メカニズムを明らかにする。


    今年度は、食肉目クマ科、スカベンジャー種(腐肉食類)等について、ゲノムデータベースを用いた遺伝子解析を行った。外来化学物質の代謝を担う第I相反応酵素シトクロムP450、第II相反応のグルクロン酸転移酵素や硫酸転移酵素について、種間比較を行い、食性との関連性について解析した。特に硫酸転移酵素についてはこれまで分子進化と食性に関するデータは少なく、研究成果については、現在論文を作成している。野生げっ歯類、トカゲ、一部の食肉性哺乳類について、次世代シークエンサーを用いて、エクソーム解析およびトランスクリプトームを行っている。また農薬や重金属の環境汚染地域に生活・棲息している野生げっ歯類及びヒトについてメタボローム解析を行った。現在データを解析中であるが、野生げっ歯類についてはDDT高濃度汚染域に棲息している野生げっ歯類のステロイド代謝への影響が認められた。現在、野生げっ歯類をDDT環境汚染レベル下で世代飼育し、フィールドデータの検証を行っている。
    日本学術振興会, 基盤研究(A), 北海道大学, 21H04919
  • 毒性試験の高感度化・効率化を目指したMITAシステムの構築と実践
    科学研究費助成事業 挑戦的研究(開拓)
    2022年06月30日 - 2025年03月31日
    池中 良徳, 野見山 桂, 新間 秀一, 杉尾 翔太, 石塚 真由美, 江口 哲史, 中山 翔太, 星 信彦, 平野 哲史
    日本学術振興会, 挑戦的研究(開拓), 北海道大学, 22K18425
  • 海鳥を標準デバイスとした海洋汚染リスクの広域マッピング法の開発
    科学研究費助成事業 基盤研究(A)
    2019年04月01日 - 2024年03月31日
    綿貫 豊, 依田 憲, 石塚 真由美, 力石 嘉人, 高田 秀重
    本研究では,海鳥をデバイスとする新しいアイデアで,生物多様性・資源保全に資する,広域スケールの汚染マップを作る。そのため,北太平洋西部において,①バイオロギング(動物装着型データロガー)により多数の外洋性海鳥(オオミズナギドリ)個体の移動を通年追跡して,集中度が高いホットスポットを抽出する,②全個体の血液・羽根など体組織の汚染物質濃度を,栄養段階に対して標準化し,体組織形成時期に対応する各個体の利用場所に関連付けることで,汚染度を地図化する,そして③体組織中のストレスマーカーで汚染物質の生体影響を知り,ホットスポットのリスクを評価する,の3つを達成する汎用性の高い手法を開発することを目的としている。R1年度は,新潟県粟島において、雛を育てている40個体のオオミズナギドリに追跡装置(ジオロケーター:光強度を記録することで日の出日の入り時刻を知り、1年間の毎日の位置を推定する、超小型記録装置)を足輪にて装着した。一方で、繁殖期間中の採食場所と行動を調べるために、GPS・加速度データロガーを装着回収し、回収時にその胃内容を採取した。また,オオミズナギドリを中心とした既存の海鳥体組織標本(一部はes-BANKより資料提供)をつかって,さまざまな部位の羽や血液、体脂肪などの窒素・炭素安定同位体比、酸化ストレス指標やストレス関連ステロイドや汚染物質などの予備的化学分析を実施し、問題点について検討し、追跡個体の体組織の分析に備えた。
    日本学術振興会, 基盤研究(A), 北海道大学, 19H01157
  • アフリカにおける新興・再興の環境汚染のフィールドベースの毒性メカニズム解析
    科学研究費助成事業 国際共同研究加速基金(国際共同研究強化(B))
    2018年10月09日 - 2022年03月31日
    石塚 真由美, 池中 良徳, 中山 翔太, 中田 北斗
    近年、アフリカ諸国では急速な資源開発がすすめられている。そのため急激な環境の汚染が顕在化しており、一部の国では生態 系や家畜・ヒトにおける健康被 害が報告されるようになった。化学物質は、食糧生産や感染症制圧には必要不可欠であるが、途上国では化学物質汚染によるリスクを度外視して使用している現 状がある。2018年度に発表された大気汚染度を国別で分析した データでは世界ワースト10のうち7か国はアフリカで占められている。化学物質による脅威(ケミ カルハザード)については、 目に見えにくい潜在的な性質のため、対策が後手に回される傾向が強い。本研究では、アフリカでもっとも問題となっている金属、農薬についてその現状を明ら かにすること、およびフィールドトキシコ ロジーの概念により、そのメカニズムと現象を結 びつけることを目的としてい る。当該研究では、ザンビア大学(金属)および南アフリカのノースウェスト大学(再興農薬)、ガーナのクワメエンクルマ科学技術大学(KNUST 、新興農薬)と共 同研究を計画した。


    ザンビアでは鉛による環境汚染がヒトおよび動物に及ぼす毒性学的影響について調査を行った。特に、イヌを歩哨動物とした汚染モニタリング方法について報告した。また、乳児における鉛汚染の状況について調査を行った。ガーナではヒト試料の最終に向けた準備を行うとともに、ネオニコチノイドが神経系や脂肪代謝等に及ぼす影響について動物を用いた実験を行った。南アフリカではDDTが引き起こす毒性学的影響について、家畜や野生動物を用いてオミクス解析を行い、バイオマーカーの探索を行った。
    日本学術振興会, 国際共同研究加速基金(国際共同研究強化(B)), 北海道大学, 18KK0287
  • mlAOPコンセプトによる化学物質感受性多様性評価と殺虫剤中毒解明に向けた応用
    科学研究費助成事業 基盤研究(A)
    2018年04月01日 - 2022年03月31日
    池中 良徳, 星 信彦, 川合 佑典, 石塚 真由美, 小林 篤史, 久保田 彰, 水川 葉月, 有薗 幸司, 平野 哲史, 加藤 恵介, 宮原 裕一, 市川 剛, 岡松 優子, 中山 翔太
    本年度は昨年度に引き続き、研究実施計画通り、以下の項目について、実施した。
    ・mlAOPの基礎データ取得に向けた、げっ歯類およびゼブラフィッシュを用いた各種行動試験の実施:個体レベルでの評価として、様々な系統及び種の動物でオープンフィールドテストや高架式十字迷路等の行動試験を実施した。特に、マウスでは、神経毒性試験の新たな評価法として、2光子顕微鏡を用いた実験および解析を導入し、in vivoにおける化学物質の脳神経系への影響の可視化にチャレンジした。
    ・組織レベルでの評価のための、イメージング解析を実施:組織レベルでの評価として、昨年度に引き続き、特にイメージング技術を駆使して実施した。特に超高分解能質量顕微鏡(MALDI-FT-ICR-MS 型;Bruker Solarix XR)によるネオニコチノイドおよびその代謝産物の組織分布のイメージング解析を試みた。カテコールアミンに着目した解析では、DPPによる誘導体化により、ドパミンの検出に成功した。一方、現在は再現性の評価や他のニューロトランスミッターへの応用を検討している。
    ・細胞・分子レベルでの評価:昨年度に引き続き、SH-SY5Y細胞をモデル神経細胞として用い、細胞増殖パラメーターなどの各種項目についてデータを取得した。また、マイクロアレイを実施し、投与により変動する遺伝子群を明らかにした。また、標的分子のリン酸化状態についても解析を実施した。
    ・ヒト尿試料を用いたバイオモニタリング:昨年度に引き続き、ボランティアを募り、一般市民延べ約1000人から尿試料の採取を実施し、尿中のネオニコチノイド濃度を測定した。また、有機野菜を食べてもらう事による尿中ネオニコチノイド低減効果についても明らかにした。
    日本学術振興会, 基盤研究(A), 北海道大学, 18H04132
  • ザンビアにおける鉛汚染のメカニズムの解明と健康・経済リスク評価手法および予防・修復技術の開発
    国際的な科学技術共同研究などの推進 SATREPS
    2015年 - 2021年
    石塚 真由美
    汚染除去法を最適化し、健康リスク評価に基づく経済効果を定量化 鉛汚染が深刻なザンビアにおいて生態系および人への汚染メカニズムとリスクを解明し、経済的損失を可視化することで、汚染防御対策や環境修復へと結びつける。リモートセンシングによる調査、地上調査による土壌や植物のキャラクテリゼーション、人の鉛汚染のメカニズム、健康ハザードと経済リスクの可視化、環境修復技術の確立と同時に、モニタリングシステムの構築とキャパシティビルディングによる各専門家の持続的育成を行う。 環境修復、健康・経済リスク評価をもとに、汚染低減に貢献! ザンビアの未来を担う人(特に幼児)の鉛レベルに低下が見られる。ザンビアにおける環境修復、健康リスク評価の新規プロトコルなどの政策に採用される。将来的には、アフリカを中心とした世界的に主要なハザードである金属汚染対策に貢献する。
    科学技術振興機構, 北海道大学
  • 「カクテル型」コンセプトによる「猛禽類対応型」新世代殺鼠剤の開発
    科学研究費助成事業 挑戦的研究(萌芽)
    2018年06月29日 - 2020年03月31日
    石塚 真由美, 池中 良徳, 中山 翔太
    現在、殺鼠剤による猛禽類への二次被害が頻発している。このため、殺鼠剤抵抗性ラットに有効かつ安全な駆除方策は存在しない。これは抵抗獲得機序に対する研究の不足と野生動物における感受性評価法の欠如が原因である。本研究では、殺鼠剤抵抗性の獲得の原因を明らかにし、殺鼠剤の開発や非対象生物種への保全に資するデータを得ることを目的とした。本研究により、野生齧歯類の殺鼠剤への抵抗性の原因として、ビタミンKエポキシド還元酵素の結合ポケット内外の変異が抵抗性獲得に寄与する事を実証した他、NADPH産生の向上とそれに伴うシトクロムP450による殺鼠剤代謝能の活性化という新しい抵抗性獲得機序が明らかとなった。
    日本学術振興会, 挑戦的研究(萌芽), 北海道大学, 18K19847
  • 高次の動物種における化学物質感受性の種差と適応進化の解明
    科学研究費助成事業 基盤研究(A)
    2016年04月01日 - 2020年03月31日
    石塚 真由美, 池中 良徳, 中山 翔太, 水川 葉月
    哺乳類および鳥類について、肝臓における異物代謝の主要経路となるシトクロムP450(P450)、グルクロン酸転移酵素(UGT)、硫酸転移酵素(ST)についてクローニングを行い、その酵素学的特徴を明らかにした。UGTやSTが欠損もしくは極めて活性が低い動物種とその原因を明らかにした。また、現在、世界的に外来性の小型哺乳類の駆除には主に抗血液凝固系の殺鼠剤が使用されている。そこで、広範の動物種についての殺鼠剤感受性評価を行い、P450、UGTによる代謝能について、その種差を明らかにした。
    日本学術振興会, 基盤研究(A), 北海道大学, 16H01779
  • 野生動物iHep細胞の作成とトッププレデターのMetabolism評価法の開発
    科学研究費助成事業 挑戦的研究(萌芽)
    2017年06月30日 - 2019年03月31日
    池中 良徳, 川合 佑典, 鈴木 淳史, 三谷 曜子, 石塚 真由美, 水川 葉月, 中山 翔太
    本研究では、化学物質感受性のキーであるMetabolismの評価法を開発し、希少野生動物の感受性を明らかにする事である。この評価のためには、新鮮肝が必要であるが、希少種ではその入手が困難である。そこで、皮膚線維芽細胞からダイレクトリプログラミングにより肝臓様(iHep)細胞への誘導を試みた。先ずiHep作成に先立ち、本研究では数種のトッププレデターの線維芽細胞を入手し、その培養に成功した。培養した線維芽細胞を用い、iHep細胞への誘導を試みた結果、特定の因子を導入する事でアルブミンを発現する上皮細胞に変化する事を見出した。本研究を通じて、初めて野生動物iHep細胞の作成に成功した可能性が高い。
    日本学術振興会, 挑戦的研究(萌芽), 北海道大学, 17K20038
  • オミックス解析によるイエネコの毒性発現機構の解明
    科学研究費助成事業 基盤研究(B)
    2016年04月01日 - 2019年03月31日
    野見山 桂, 水川 葉月, 国末 達也, 石塚 真由美, 岩田 久人
    ネコを対象にPCBs12異性体混合物の曝露試験を実施し、血液・肝臓・脳を対象にトランスクリプトームおよびメタボローム解析を実施した。
    トランスクリプトームでは、21890遺伝子のうちPCBs曝露群で531遺伝子が有意に変動した。パスウェイ解析の結果、炎症や感染症関連経路への影響が認められ、PCBsによる免疫系への影響が示唆された。
    血清を対象としたメタボローム解析では、122種のメタボロームが有意な変動を示した。パスウェイ解析の結果、ペントースリン酸回路、ヒスチジン代謝系等の中心炭素代謝に関連するメタボロームが減少しており、PCBs曝露に伴うこれらの代謝経路の抑制が示唆された。
    日本学術振興会, 基盤研究(B), 愛媛大学, 16H02989
  • 次世代型殺鼠剤開発を目的とした殺鼠剤抵抗性ラットの抵抗性獲得機序の解明
    科学研究費助成事業 挑戦的萌芽研究
    2016年04月01日 - 2018年03月31日
    石塚 真由美, 池中 良徳, 中山 翔太, 水川 葉月
    野生齧歯類は様々な感染症を媒介するため駆除する必要がある。駆除には殺鼠剤が用いられたがこれらに抵抗性を有す個体群が出現し駆除を困難にしている。従来抵抗性群は殺鼠剤の標的分子が変異し殺鼠剤が結合しにくい形になるのが原因と考えられてきた。本研究では殺鼠剤の解毒代謝機能を評価した。その結果、抵抗性群では肝で殺鼠剤を代謝し排泄する能力が向上しており、標的分子の変異と代謝能の向上という二つの機構を併せ持つことが判明した。
    日本学術振興会, 挑戦的萌芽研究, 北海道大学, 16K15034
  • 統合的メタロミクスによる鉛汚染源推定に有用な家畜・家禽の探索と種差の分子基盤解明
    科学研究費助成事業 若手研究(B)
    2016年04月01日 - 2018年03月31日
    中山 翔太, 石塚 真由美, 池中 良徳, 水川 葉月, 平田 岳史
    年間23万人が主に鉱床由来の鉛中毒により死亡し、60万人以上の子供の知的発達に影響を及ぼしているが、汚染源推定に有用な手法は確立されていない。本研究では鉛汚染源推定に有用な家畜・家禽種を解明することを目的とした。高精度鉛同位体比解析より、アフリカを含めた発展途上国で流通し、またヒトの食糧源としても用いられるヤギやニワトリを用いることで、鉛汚染源の推定が可能であることを明らかにした。LA-ICP-MS(レーザー照射型 誘導結合プラズマ質量分析法)により、マウスにおける鉛の臓器内局所分布を解析した。脳の海馬領域の高濃度蓄積や、特に、腎臓の髄質において皮質よりも高濃度の鉛蓄積が確認された。
    日本学術振興会, 若手研究(B), 北海道大学, 16K16197
  • ベクターコントロールが及ぼす希少野生動物への影響評価と新規感受性評価法の開発
    科学研究費助成事業 基盤研究(B)
    2015年04月01日 - 2018年03月31日
    池中 良徳, 石塚 真由美, 水川 葉月, 中山 翔太
    本研究では、アフリカのベクターコントロール地域である南アフリカのKwaZulu-Natal州に注目し、その汚染状況の調査および生息する生物に対する毒性影響評価を実施した。
    家禽に着目した調査の結果、肝臓中DDT濃度は中央値として920 ng/g ww、最大濃度で14,400 ng/g wwと非常に高い値を示した。リアルタイムRT-PCR法により遺伝子発現解析を実施した結果、脂質代謝や合成や性ステロイドホルモン合成に関与する遺伝子群に影響を与えている事が明らかになった。本研究結果は、DDTが生体に一定の影響を与えている事を示しており、今後より適切なベクターコントロールを実施する必要性を示唆する。
    日本学術振興会, 基盤研究(B), 北海道大学, 15H02825
  • ネコにおける有機ハロゲン化合物の代謝機構解明と甲状腺機能の影響評価
    科学研究費助成事業 若手研究(B)
    2015年04月01日 - 2018年03月31日
    水川 葉月, 石塚 真由美, 池中 良徳, 中山 翔太, 滝口 満善, 野見山 桂
    ネコにおけるPCBs短期投与試験およびBDE209長期投与試験を実施し、ネコにおける有機ハロゲン化合物の生体内動態(吸収、分布、代謝、排泄)の解明、甲状腺機能への影響評価、遺伝子解析やオミクス解析による毒性発現メカニズムの解明を目的とし、調査・研究を実施した。その結果、PCBsおよびBDE209曝露によって、甲状腺機能への影響のみならず酸化ストレスの増大やNADPHの生産の撹乱、脂質代謝機能や免疫機能のかく乱なども予想された。
    日本学術振興会, 若手研究(B), 北海道大学, 15K16132
  • ベクターコントロールのための薬剤散布の生態系およびヒト健康に与える影響評価
    科学研究費助成事業 基盤研究(B)
    2014年04月01日 - 2017年03月31日
    池中 良徳, 石塚 真由美, 中山 翔太, 水川 葉月, 櫻井 達也, 宮原 裕一, 下鶴 倫人, 中山 翔太, 水川 葉月
    WHOはハマダラカの駆除のためDDTの使用を推進しており、アフリカ等の途上国を中心に、室内残留散布として使用されている。一方、DDTは難分解性で環境中の長期間残留が知られ、発がんや内分泌撹乱などの生体影響も疑われている。当該研究では、南アフリカ共和国・クワズルナタール州をベクターコントロールモデル地域とし、DDT・IRSの潜在的な毒性リスク評価を行った。
    ニワトリ、ラット、野生鳥類の卵のを採取し、その分析を行った結果、いずれの試料からも極めて高濃度のDDT蓄積が観察された。本研究結果は、環境負荷が小さいとされるDDT・IRSにおける、潜在的な毒性影響および環境リスクの存在を示唆していた。
    日本学術振興会, 基盤研究(B), 北海道大学, 26304043
  • ペットのネコにおける有機ハロゲン代謝物の分析法開発と代謝機構解明およびリスク評価
    科学研究費助成事業 研究活動スタート支援
    2013年08月30日 - 2015年03月31日
    水川 葉月, 石塚 真由美, 池中 良徳, 中山 翔太, 滝口 満善, 野見山 桂
    ペットのネコに着目し、研究報告例の少ない液体クロマトグラフタンデム質量分析計(LC-MS/MS)を用いた有機ハロゲン化合物であるポリ塩化ビフェニル(PCBs)およびポリ臭素化ジフェニルエーテル(PBDEs)の代謝物の分析法を開発した。さらに、第I相、第II相代謝活性を測定しネコにおける有機ハロゲン化合物に対する代謝能評価を試みた。
    日本学術振興会, 研究活動スタート支援, 北海道大学, 25892001
  • カロテノイド/レチノイド類による有蹄類の異物代謝の新たな調節機構の解明
    科学研究費助成事業 特別研究員奨励費
    2011年 - 2013年
    石塚 真由美, DARWISH Abdallah, DARWISH ABDALLAH
    シトクロムP450の分子種のひとつCYPIA1は様々な発がん物質や変異原物質を代謝的に活性化し、化学物質の毒性を決定する重要な異物代謝酵素である。CYPIA1はAhR(アリルハイドロカーボン受容体)によって転写調節を受けており、CYPIA1の上流域のXRE (Xenobiotic Response Element)に結合してその転写を活性化することが知られている。最近、我々はカロテノイド類がAhRの機能に影響を及ぼすことを見出しており、カロテノイドがCYPIA1の生理的な動態の決定因子の一つである可能性を見出している。そこで、本研究では、カロテノイド類がAhRに及ぼす影響、およびその他のシトクロムP450分子種を制御する転写調節因子とのクロストークを明らかにし、カロテノイド類の新たな機能を明らかにすることを目的とする。
    本年度は、実際に産業動物などがどの程度の重金属類を蓄積しているのかを明らかにし、実施に環境中で人や動物が暴露されている範囲での金属暴露を細胞を用いて行った。H4IIE細胞、およびHepG2細胞を用いて実際に動物が暴露される可能性のある濃度で金属類及びカロテノイドの暴露が異物代謝酵素群にどのような影響を及ぼすのかについて調べた。金属類の曝露によりシトクロムP450、グルクロン酸抱合酵素等の発現量が減少した。メカニズムとして酸化ストレスの介在が考えられたが、同時に転写調節因子の発現量も減少していた。
    日本学術振興会, 特別研究員奨励費, 北海道大学, 11F01097
  • 環境汚染と希少野生プレデターにおける化学発癌
    科学研究費助成事業 基盤研究(A)
    2007年 - 2010年
    藤田 正一, 池中 良徳, 石塚 真由美, 坂本 健太郎, 石塚 真由美, 坂本 健太郎
    当該研究では、希少動物を含む生態系高次の動物について発がん物質の影響を調べるために、癌原物質を代謝的に活性化するシトクロムP450(CYP)1A1、及びその転写調節因子アリルハイドロカーボン受容体、活性代謝中間体を抱合する抱合酵素の種差を中心に調べ、その基質との親和性や分子進化について明らかにした。また、野生動物における発がん物質など環境汚染物質の蓄積とその影響について、野生げっ歯類を中心とした歩哨動物を用いて分析した。
    日本学術振興会, 基盤研究(A), 北海道大学, 19208028
  • 出生コホート研究による環境化学物質の次世代影響ならびに遺伝環境交互作用の解明
    科学研究費助成事業 基盤研究(A)
    2007年 - 2009年
    岸 玲子, 佐田 文宏, 吉岡 英治, 坂 晋, 中島 そのみ, 佐々木 成子, 室橋 春光, 神尾 陽子, 仙石 泰仁, 花岡 知之, 西條 泰明, 藤田 正一, 中澤 裕之, 梶原 淳睦, 湯浅 資之, 石塚 真由美
    妊婦514名とその児を対象とした1産院ベースコホートで、ベースライン時、1歳6ヵ月時、3歳6ヵ月時、7歳時の両親または児の食習慣・生活習慣・職業歴・居住環境・育児環境等を詳細に調べた。環境化学物質として母体血中ダイオキシン・PCB異性体類、母乳中ダイオキシン・PCB異性体類、母体血中PFOS/PFOAの測定した。小児の神経行動発達検査は、生後6ヵ月、1歳6ヵ月時にBSID-II、3歳6ヵ月時に日本語版K-ABC3歳7ヵ月時に日本版CBCLを終了した。
    日本学術振興会, 基盤研究(A), 北海道大学, 19209024
  • ホルムアルデヒドはパーキンソン氏病の原因となりえるか?
    科学研究費助成事業 萌芽研究
    2007年 - 2008年
    藤田 正一, 石塚 真由美, 坂本 健太郎
    ホルムアルデヒドはシックハウス症候群の1原因物質としてその詳細が調べられてきた。しかし、長期曝露による神経毒性は、「神経変性」という観点からは不明であり、さらに、ホルムアルデヒドとドパミンの縮合によって合成されるノルサルソリノールに着目してその毒性やパーキンソン氏病との関連を研究した報告は殆どない。そこで、本研究では、上記仮説の検証を含め、ホルムアルデヒドの内因性の発生や消去能の低下、ホルムアルデヒドを発生させる環境化学物質への曝露が弧発性パーキンソン氏病の原因となりえるのかを究明することを目的とする。
    本年度は、脳におけるホルムアルデヒドの解毒に重要なADH3のノックアウト(KO)マウスの繁殖を行い、材料採集と受容体発現の変化について調べた。また、行動を詳細に解析するために、データロガーを用いた毒性学的な行動解析方法を確立した。
    一方、シトクロムP450の分子種のひとつCYP2Dの遺伝的多型がパーキンソン氏病の発症とかかわりがあるとの報告があることから、ドパミンの代謝へのCYP2Dの関与について同定を行った。CYP2Dを欠損するDAラットを用いてカテコールアミン濃度や代謝に対し、P450がどのように関与するのか、明らかにした。また、その過程ではDAラットにおけるCYP2D2mRNAの低発現は、CYP2D2遺伝子の転写調節領域内の一塩基置換により、hnRNP K蛋白質のDNA結合が低下する事が原因である事を初めて明らかにした。
    日本学術振興会, 萌芽研究, 北海道大学, 19658111
  • 凍結ケナガマンモスのチトクロームP450を用いた更新世の古環境復元
    科学研究費助成事業 萌芽研究
    2006年 - 2007年
    坂本 健太郎, 藤田 正一, 石塚 真由美
    チトクロームP450(CYP)は外来異物を主な基質とする事を特徴とする酵素である。天然物質としては植物性アルカロイドなどが基質として知られている。これは植物側が捕食されないための防衛手段として毒性のあるアルカロイドを産生し、草食動物がそれを解毒するための酵素を進化させたと考える事が出来る。従って、解素酵素を解析することによって、餌生物に関する情報を得る事が出来るのではないかと考えた。本研究の最終的な目標は、既に絶滅してしまったケナガマンモスのCYPの解析を通して、その種が生息していた環境に関する情報を得ることである。本年度は下記の成果を得た。
    CYPの種間差を比較検討するために、哺乳類の12目、38種の試料採集を行った。このサンプルを元に、CYP1AのcDNAをクローニングし、その塩基配列について比較検討を行った。また、酵素活性と基質特異性について調べた。
    哺乳動物目間の比較では、食肉目内で塩基配列の種差が比較的少ない傾向が明らかとなった。また、酵素活性を調べたところ、草食獣では他の食性をもつ動物種に比べ、酵素活性が高いことが明らかとなった。これらの草食獣では、肝臓におけるCYP1Aの発現レベルも高かったことから、草食性の動物ではCYPをより多く発現させることで酵素活性を高く保っていると考えられた。食性の違いで代謝の動物種差があることから、これらの傾向は動物の生息状況を反映している可能性が示唆された。
    日本学術振興会, 萌芽研究, 北海道大学, 18658129
  • 次世代環境汚染生体影響評価システムの開発
    科学研究費助成事業 基盤研究(A)
    2003年 - 2006年
    藤田 正一, 石塚 真由美, 坂本 健太郎, 数坂 昭夫
    DNAマイクロアレイは多くの遺伝子変動を短時間でスクリーニングできる有効なツールである。しかし、塩基配列の違いから幅広い生物種間に応用することは極めて難しく、この手技を様々な階層の野生生物に用いる為には、各々の生物特有のアレイの開発が必要である。そこで、より簡便に広範囲の野生生物に対応する次世代環境影響評価システムを開発することを目的として基礎的研究を行った。
    これまでに、マイクロアレイ法で野生動物を用いた研究報告はほとんどない。野生動物では、系統差や複合汚染の影響、生理的条件の差により、通常の実験動物や細胞を用いた網羅的解析が難しいことが考えられる。そこで、野生げっ歯類を捕獲し、体内に蓄積している汚染物質を同定し、濃度を調べ、それらの動物への影響を既存のマイクロアレイを用いた解析が可能かどうかについて検討し、解析方法として、マイクロアレイ法が有効であることを報告した。また、ヒトのサンプルを用いて、マイクロアレイを作成し、従来の各遺伝子の解析とマイクロアレイ法について、比較検討した。さらに、簡便な生態影響評価用DNAマイクロアレイの開発のために、アレイ上にのせるべきDNAを検討し、ダイオキシン類など、残留性有機汚染物質の汚染亢進域で捕獲したネズミから、肝臓で変動の大きいバイオマーカーとなり得る遺伝子群を抽出した。また、広範囲の野生動物の試料を採集し、異物代謝酵素を中心にその塩基配列や基質特異性などを同定した。100種類以上の野生動物や動物園飼育動物のサンプルを採集し、これまでに報告のない動物種を中心に解析を進め、そのホモロジーから、マイクロアレイでの解析がどの動物種間で可能か検討した。
    さらに、生体機能を利用した生体影響スクリーニング用アレイ開発の為に、受容体への環境化学物質の結合および受容体活性化を利用したスクリーニングを検討した。環境汚染物質の中でも発がん性を持つ化学物質の受容体となるAhR(arylhydrocarbon receptor)と生体内の各核内受容体のクロストークを検討した。
    日本学術振興会, 基盤研究(A), 北海道大学, 15201009
  • 狂牛病原因物質プリオン・モデルペプチドの変成機序に関する分光学的研究
    科学研究費助成事業 萌芽研究
    2002年 - 2003年
    数坂 昭夫, 佐々木 一正, 石塚 真由美, 藤田 正一
    狂牛病を始めとするプリオン病研究において、PrPcからPrPScへの変性機序の解明と、それに基ずく発病機序の解明が重要と考え、幾つかの検討を行ってきた。その後、諸外国での研究成果の蓄積が多く重ねられている。それらの成果を考慮し本年は以下の研究を進めてきた。幾つかの成果を得た。
    1.生体中で、変性によって生ずる異常タンパク質を高選択・高感度に検出するバイオセンサーの開発を試みた。
    2.研究分担者が従来行ってきた、光ファイバセンシング・システムの改良を行い、目的達成を試みた。本システムでは、従来の蛍光発光の測定に加え、光屈折を利用する表面プラズモン測定を検出系とするシステム開発を継続中である。
    3.光ファイバに先端にPrPScに特異的に反応する抗体を固定化し、高選択バイオセンサの作成を試みている。光ファイバ先端を金微粒子を含む高分子で加工することにより抗体を安定に固定化することが可能であることが明らかになった。金微粒子の調製と高分子の選択が現在の課題である。
    4.タンパク質変性状態をより詳しく調べることを目的として、捕捉されたタンパク質のラマンスペクトル観測の有効性が期待される。その時、タンパク質に銀微粒子等を加えることにより、Surface enhanced ramanスペクトルの観測も期待され、高感度バイオセンサーへの拡張を今後の検討課題と考えている。
    日本学術振興会, 萌芽研究, 北海道大学, 14657091
  • 哺乳類の生殖および行動異常の現状と汚染の関係
    科学研究費助成事業 特定領域研究
    2001年 - 2003年
    藤田 正一, 昆 泰寛, 石塚 真由美, 数坂 昭夫
    環境汚染による野生動物への影響として、野生生物における個体数の減少、奇形の発生、性比のバランスの変化、繁殖能低下や行動異常が懸念されている。特に、PCBなどの有機塩素系化合物は、環境中において安定で脂溶性に富むため、食物連鎖の上位に立つ生物に高濃度の濃縮されることが知られている。当該研究では、アザラシやイルカ等の海棲哺乳類に、生物濃縮によって高濃度の有機塩素系化合物が蓄積されていることや、それらが内分泌系を撹乱している可能性を報告した。
    前述の海棲哺乳類については残留性の高い環境汚染物質が高濃度に蓄積しているため、他にも多くの毒性学的データが得られている。しかし、一方で、陸棲哺乳類については、魚食性の海棲哺乳類に比べると汚染レベルも低いため、環境汚染物質曝露がこれらの生物にもたらす影響については報告が少ない。そこで、我々は本研究において、陸生野生げっ歯類(アカネズミ、エゾヤチネズミ、ドブネズミ)に関し、生体に蓄積する環境汚染物質(ダイオキシン類、そのほかの有機塩素系化合物、臭素系難燃剤)や、土壌など棲息環境の汚染(PCB、DDTなどの有機塩素系化合物、多環芳香族)の分析を行い、また、生殖行動を調節するステロイドホルモンに関して、生合成・代謝を行う代謝酵素シトクロムP450(P450、CYP)の発現や活性、生殖器の発現遺伝子プロファイルや病理的変化との関係について調べた。また、野生げっ歯類のモデルとして、ラットを用いて、環境化学物質がどのような影響をもたらす可能性があるのかについて明らかにした。
    日本学術振興会, 特定領域研究, 北海道大学, 13027201
  • ヒト生殖毒性および次世代影響のバイオマーカーとしての神経内分泌動態の有効性
    科学研究費助成事業 萌芽研究
    2001年 - 2002年
    岸 玲子, 佐田 文宏, 小橋 元, 本間 研一, 石塚 真由美
    「目的」近年、内分泌かく乱物質に関する問題が重要視され、スチレン、2-ブロモプロパンなどの有機溶剤曝露労働者での無月経、不正月経周期、不正出血、受精率の減少が報告されている。その作用機序を解明するために、内分泌かく乱物質も含めた環境化学物質曝露による神経内分泌物質の動態と、生殖毒性の発現について知見を得ることを目的とした。
    「方法」産業分野での用途の広さ、また、日常的にも食品容器としての使用頻度の高さに伴い、取り扱い作業者の数も多いことから、内分泌かく乱作用の疑いのある有機溶剤スチレンモノマーを使用した。8週令オスラットに150ppm吸入曝露8時間/日で12日間行い、血漿中プロラクチン、成長ホルモン、甲状腺刺激ホルモンレベルをELISAにより測定した。また、精巣、血液を採取し、リアルタイムPCRによる精巣ステロイド合成酵素mRNAの定量と組織学的検討、RIAによる血中テストステロン濃度の検討を行った。
    「結果と考察」曝露により、血漿中のプロラクチンがメスで、甲状腺刺激ホルモンがオスで有意に増加していた。精巣毒性の検討で、血漿中テストステロン濃度、精巣組織への曝露影響は見られなかった。また、ステロイド合成酵素であるP450scc,3-beta-hydroxysteroid dehydrogenase, CYP17,CYP19 mRNAの発現には、どれも有意な差は見られなかった。プロラクチンに関しては、労働者で有意に増加するという報告があることから、疫学的報告を裏付ける結果を得た。また、結果の雌雄差については、血中スチレン濃度に雌雄差があったことから、代謝能力の違いによるものと考えられる。生殖毒性に関しては、短期間曝露であったため影響が見られなかったと考えられるため、今後より高濃度、長期間曝露の検討が必要である。
    日本学術振興会, 萌芽研究, 北海道大学, 13877057
  • 「環境ホルモン」の野生動物に対する影響とその作用機序の解明
    科学研究費助成事業 基盤研究(A)
    1999年 - 2002年
    藤田 正一, 星 英之, 石塚 真由美, 数坂 昭夫
    本研究では、様々な生物層から生物を採集して環境汚染およびその生体影響についての実態を把握し、そのメカニズムの解明することを目的とした。本研究では特に、魚食性生物に着目し、魚類、魚食性哺乳類、魚食性鳥類について、蓄積する環境汚染物質の化学分析を行い、P450発現やその他の生体影響について調べた。この過程で、北海道沿岸のゴマフアザラシに表層海水の一億倍の濃度のPCB、10億倍の濃度のDDTが蓄積していることを見出した。また、PCB蓄積レベルに相関してP450分子種であるCYP1ファミリーの発現量が増加していることも明らかにした。さらに、甲状腺ホルモンへの影響について検討したところ、PCB170やPCB180と血中の甲状腺ホルモンレベルは負の相関を示し、PCBによる野生生物の汚染が内分泌系を撹乱している可能性が考えられた。また、同じ魚食性生物で食物連鎖の頂点に立つオジロワシ、オオワシについて、その成長過程と生体に蓄積する環境汚染物質の残量パターンを解析し、PCB類、DDT類が高濃度で蓄積していることを示した。これらの烏獣の下位に立つ魚類については、ダイオキシン類汚染域棲息の雌コイでは、非汚染域棲息群に比べて、P450量、CYP1A発現量、CYP1A依存の代謝活性が増加していることや生殖腺重量や血中エストロゲン量が減少していることを見出した。一方で、海洋汚染物質の一つ、有機スズをラットに投与し、その影響を調べた。実際の汚染物質は低濃度で環境に存在するため、低濃度のトリブチルスズ(TBT)を妊娠ラットに曝露し、次世代への影響について調べたところ、胎仔・新生仔の脳グリア細胞のマーカー蛋白や細胞骨格蛋白の発現量を変動させ、さらに小脳の発達遅延を起こすことを初めて報告した。TBTの胎仔期・新生仔期曝露は、性成熟後も視床下部において神経細胞の分化・局在に影響することを明らかにした。他の重金属についても野生動物に高濃度で蓄積している事を明らかにした。
    日本学術振興会, 基盤研究(A), 北海道大学, 11306021
  • 内分泌攪乱物質汚染の評価と浄化:酵素P450を利用した生体影響評価法及び汚染環境のバイオリメディエーション法の開発
    科学研究費助成事業 基盤研究(A)
    1999年 - 2002年
    藤田 正一, 星 英之, 石塚 真由美, 数坂 昭夫
    本研究では、P450のバイオマーカーとしての有用性を確立し、これを利用した評価法の確立、環境浄化への利用を目的とした。対象生物として、食物連鎖の頂点にたち、海洋汚染の影響を受けやすい海生哺乳類に着目した。我々は、北海道沿岸の魚類を捕食するゴマフアザラシに表層海水の一億倍の濃度のPCB、10億倍の濃度のDDTが蓄積し、このPCB蓄積レベルに相関してP450分子種であるCYP1ファミリーの発現量が増加していることを明らかにした。そこで、P450のバイオマーカーとしての利用のために、海棲哺乳類からP450をクローニングし、その酵素の基質特異性などについて研究を行った。アザラシ2種、トド、イルカ2種、ミンククジラより、P450分子種であるCYP1A、CYP3AのcDNAを世界で初めて単離することに成功した。また、食物連鎖下位生物の魚類について、ダイオキシン類による汚染が問題となった藤沢市の引地川水域に棲息するコイを、環境省の安全宣言後に採集し、肝膵臓における異物代謝能や生殖腺への影響の有無を汚染水域の上流に棲息するコイとの比較から検討した。化学分析から、引地川の藤沢工場下流域より採集したコイではダイオキシン類が生体に高濃度に蓄積されていることが明らかとなった。汚染域棲息の雌コイでは、上流域棲息群に比べて、P450量、CYP1A発現量、CYP1A依存の代謝活性が増加していた。また、雌個体においては、生殖腺重量や血中エストロゲン量について、下流域のコイでは減少が見られた。エストロゲン及びCYP1A誘導の関係については、培養細胞を用いた研究から共役因子の関与などを明らかにした。以上の環境汚染物質の蓄積とP450との関係に関する研究は世界的にも高い評価を受け、1999年にNZで開かれたバイオマーカーシンポジウム、2000年に仙台で開かれた国際P450シンポジウム、2001年東京の日本獣医学会においてそれぞれ講演に招待された。
    日本学術振興会, 基盤研究(A), 北海道大学, 11358009