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Last Updated :2024/07/25

Researcher Profile and Settings

Master

Affiliation (Master)

  • Faculty of Fisheries Sciences　Marine Bioresource and Environmental Science　Interdisciplinary Sustainability Studies

Affiliation (Master)

  • Faculty of Fisheries Sciences　Marine Bioresource and Environmental Science　Interdisciplinary Sustainability Studies

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Profile and Settings

Degree

  • Ph. D. (Fisheries Sciences)

Profile and Settings

  • Name (Japanese)

    Kudo

  • Name (Kana)

    Hideaki

  • Name

    200901002728919214

Alternate Names

Achievement

Research Interests

  • 魚類神経生理学   regional fisheries resources,   嗅覚   分子形態学   魚類生態生理学   魚類生理学   サケ生物学   Olfaction   Molecular Morphology   Fish Ecophysiology   Fish Physiology   Salmon Biology   

Research Areas

  • Life sciences / Aquaculture

Research Experience

  • 2019/11 - Today Faculty of Fisheries Sciences, Hokkaido Universuty Laboratory of Humans and the Ocean Professor
  • 2015/04 - 2019/10 Faculty of Fisheries Sciences, Hokkaido University Laboratory of Humans and the Ocean (Salmon Biology Group)
  • 2010/04 - 2015/03 - 北海道大学大学院水産科学研究院水圏生態系保全学領域 准教授
  • 2007/04 - 2010/03 Hokkaido University Faculty of Fisheries Sciences
  • 2006/04 - 2007/03 Hokkaido University Faculty of Fisheries Sciences
  • 2006 - 2007 Associate Professor
  • 1997/04 - 2006/03 産業医科大学医学部第２解剖学講座 講師 講師
  • 1997 - 2006 Lecturer
  • 1996/04 - 1997/03 産業医科大学医学部第２解剖学講座 助手 助手
  • 1996 - 1997 Research Associate
  • 1995/04 - 1996/03 日本学術振興会特別研究員 (DC2) 日本学術振興会特別研究員
  • 1995 - 1996 Postdoctoral Fellowships of Japan Society for the Promotion of Science

Education

  •        - 1996  Hokkaido University  Graduate School, Division of Fisheries
  •        - 1993  Hokkaido University
  •        - 1993  Hokkaido University  Graduate School, Division of Fisheries
  •        - 1991  Hokkaido University  School of Fisheries Sciences
  •        - 1991  Hokkaido University  Faculty of Fisheries

Awards

  • 2006 日本臨床分子形態学会論文賞
  • 2000 日本臨床電子顕微鏡学会論文賞

Published Papers

  • Atsushi Ogihara, Takashi Abe, Kazutaka Shimoda, Takafumi Sasaki, Hideaki Kudo
    Fish physiology and biochemistry 2024/05/22 
    Anadromous Pacific salmon (genus Oncorhynchus) are known for homing behavior to their natal rivers based on olfactory imprinted memories during seaward migration. The SNARE complex is a regulator of vesicle exocytosis from the presynaptic membrane. Our previous study suggested that its component genes (Snap25, Stx1, and Vamp2) are more highly expressed in the olfactory nervous system (ONS) during the migration stages associated with olfactory imprinting in the evolutionary species of Pacific salmon, such as chum (O. keta) and pink (O. gorbuscha) salmon. Masu salmon (O. masou) has a significantly different life history from these species, living longer in rivers and being a more primitive Pacific salmon species. In this study, the transcription of snare mRNAs in the ONS was analyzed using mainly male wild masu salmon. Five cDNAs encoding masu salmon SNAREs, which are well conserved among vertebrates, were isolated and sequenced. Each snare mRNA was highly expressed in age 1+ (yearling) parr prior to smoltification, particularly in the olfactory bulb. Their transcription status was significantly different from that of chum and pink salmon, which showed high expression in earlier under-yearling juveniles. The present results and our previous studies indicate that snare mRNAs are highly transcripted until the seaward migration, reflecting neural development and neuroplasticity of the ONS for olfactory imprinting.
  • Asumi Urushiyama, Mitsuru Torao, Takashi Abe, Tomoharu Watanabe, Yasuyuki Miyakoshi, Hiroshi Ueda, Hideaki Kudo
    Fisheries Science 0919-9268 2023/11/29
  • Junnosuke Konishi, Takashi Abe, Atsushi Ogihara, Daisuke Adachi, Takashi Denboh, Hideaki Kudo
    Journal of Fish Biology 101 (1) 269 - 275 0022-1112 2022/07 [Refereed]
  • Takashi Abe, Masaki Ichimura, Hideaki Kudo
    Fish Physiology and Biochemistry 48 (2) 461 - 469 0920-1742 2022/04 [Refereed]
  • Takashi Abe, Yosuke Koshino, Tomoharu Watanabe, Yasuyuki Miyakoshi, Yuji Yoshida, Hideaki Kudo
    Journal of Fish Biology 0022-1112 2020/09/13 [Refereed][Not invited]
     
    The expression of synaptic vesicle exocytosis-regulator SNARE complex component genes (snap25, stx1, and vamp2) was examined in the olfactory nervous system during seaward and homeward migration by pink salmon (Oncorhynchus gorbuscha). The expression levels of snares in the olfactory organ were higher in seaward fry than in feeding and homeward adults, reflecting the development of the olfactory nervous system. The expression of snap25a, b, and stx1a was up-regulated or stable in the adult olfactory bulb and telencephalon. This up-regulated expression suggested alterations in olfactory neuronal plasticity that may be related to the discrimination of natal rivers. The expression of stx1b was down-regulated in the adult olfactory bulb, but remained stable in the adult telencephalon. The expression of vamp2 was initially strong in seaward fry, but was down-regulated in adults in both the olfactory bulb and telencephalon. Pink salmon has the low diversity of maturation age, the largest population, and the most evolutional position in Pacific salmon (genus Oncorhynchus). The expression of snares in the olfactory center of pink salmon reflected the timing of sexual maturation and homeward migration. The present results and our previous studies indicate that snares show distinct expression patterns between two salmon species that depend on physiological and ecological features of migration. This article is protected by copyright. All rights reserved.
  • Jumpei OKADO, Yosuke KOSHINO, Hideaki KUDO, Yutaka WATANUKI
    Fisheries Research 222 (105415) 1 - 7 0165-7836 2020 [Refereed][Not invited]
     
    Juvenile mortality, a key factor determining the stock sizes of salmonids, may be increased by predation both in rivers and along shores. Information on predation at sea, however, is scarce. We analysed the diet of a pelagic seabird, the rhinoceros auklet Cerorhinca monocerata, breeding on an isolated island off eastern Hokkaido, Japan, and estimated their consumption of juvenile chum salmon Oncorhynchus keta. The auklets brought juvenile chum salmon and Japanese anchovy Engraulis japonicus for their chicks and, in addition, fed on squid themselves. The fork length of most of the juvenile chum salmon was over 80 mm, indicating that they were migrating to offshore nursery area, the Sea of Okhotsk. Using a simple bioenergetics model, the consumption of juvenile chum salmon by auklets during the first half of chick-rearing period (late June to middle July) was 316.6 t in 2014 (296.4 t by adults, 20.2 t by chicks) and 11.7 t in 2015 (0 t by adults, 11.7 t by chicks). The otoliths of six out of 66 juvenile salmon found in the diet for chicks had thermal markings and indicated that these fish were released from the rivers along Pacific coast of Hokkaido. Our study first demonstrates the extent of the auklets' consumption contributing to the reduction of the survival in the open coastal area of juvenile chum salmon with the known stock origins.
  • Abe T, Kudo H
    Comparative biochemistry and physiology. Part A, Molecular & integrative physiology 227 39 - 50 1095-6433 2019/01 [Refereed][Not invited]
  • Kudo H, Eto A, Abe T, Mochida K
    Heliyon 4 (8) e00744 - e00744 2405-8440 2018/08 [Refereed][Not invited]
  • Kudo H, Kimura T, Hasegawa Y, Abe T, Ichimura M, Ijiri S
    General and comparative endocrinology 260 41 - 50 0016-6480 2018/05 [Refereed][Not invited]
     
    Mature male Pacific salmon (Oncorhynchus spp.) develop a hooknose, as a secondary male sexual characteristic, during the spawning period. It is likely that androgens regulate hooknose formation. However, endocrinological and histochemical details about the relationship between androgens and hooknose formation are poorly understood. In this study, we performed assays of serum androgens, detection of androgen receptor (AR) in hooknose tissues, external morphological measurement of hooknose-related lengths, and microscopic observation of hooknose tissues of pink salmon (O. gorbuscha) at different stages of sexual maturation. Expression of the arβ gene was detected in hooknose tissues of males but not females. The elongation of these tissues was mediated directly via androgens. Serum 11-ketotestosterone (11-KT) concentrations indicated a significant positive correlation with both jaw lengths during sexual maturation of males. In the upper jaw, cartilage tissue developed during hooknose formation, and AR-immunoreactive chondrocytes were located in the rostal-vetral regions of hooknose cartilage in maturing male. The chondrocytes in maturing males before entering into rivers exhibited rich-cytoplasm with high cell activity than at other sexual development stages. On the other hand, in the lower jaw, the development of the spongiosa-like bone meshworks. AR-immunoreactivity was detected in a proportion of the osteocytes and osteoblast-like cells in the spongiosa-like bone meshworks. These results indicate that hooknose formation in pink salmon, which is associated with the buildup of a structure with sufficient strength that it can be used to attack other males on the spawning ground, is regulated by 11-KT.
  • Abe T, Minowa Y, Kudo H
    Comparative biochemistry and physiology. Part A, Molecular & integrative physiology 217 17 - 25 1095-6433 2018/03 [Refereed][Not invited]
     
    It is generally accepted that information about some of the odorants in the natal streams of anadromous Pacific salmon (Genus Oncorhynchus) is imprinted during their seaward migration, and that anadromous Pacific salmon use olfaction to identify their natal streams during the homeward migration. However, little is known about the molecular mechanisms of the various pre-synaptic functions that are important for olfactory imprinting and memory retrieval in the salmon brain. Synaptosome-associated protein-25 (SNAP-25) mediates pre-synaptic vesicle exocytosis and regulates synaptic transmission and neuronal plasticity. Despite the importance of synaptic plasticity for memorization, the expression of SNAP-25 in the salmon brain is not well understood. In this study, snap25 expression was detected in chum salmon (O. keta) brains using molecular biological techniques. Two cDNAs encoding salmon SNAP-25 were isolated and sequenced (SNAP-25a and SNAP-25b). These cDNAs encoded proteins with 204 amino acid residues, which showed marked homology with each other (97%). The protein and nucleotide sequences demonstrated a high level of homology between salmon SNAP-25s and those of other teleost species. By quantitative PCR, the expression of snap25a and snap25b was detected in all regions of the salmon brain, especially in the telencephalon. The expression levels of snap25a in the olfactory blub were higher during seaward migration than in upriver and post-upriver migrations, reflecting synaptogenesis in the olfactory nervous system, and snap25b in the telencephalon was increased during upriver period. Our results indicated that snap25s gene is involved in synaptic plasticity for olfactory imprinting and/or olfactory memory retrieval in Pacific salmon.
  • Ueda Shusuke, Abe Takashi, Koshino Yosuke, Kudo Hideaki
    NIPPON SUISAN GAKKAISHI 84 (1) 133 - 135 0021-5392 2018 [Refereed][Not invited]
  • Kenta Susuki, Masatoshi Ban, Masaki Ichimura, Hideaki Kudo
    JOURNAL OF MORPHOLOGY 278 (7) 948 - 959 0362-2525 2017/07 [Refereed][Not invited]
     
    Mature male Pacific salmon (Genus Oncorhynchus) demonstrate prominent morphological changes, such as the development of a dorsal hump. The degree of dorsal hump formation depends on the species in Pacific salmon. It is generally accepted that mature males of sockeye (O. nerka) and pink (O. gorbuscha) salmon develop most pronounced dorsal humps. The internal structure of the dorsal hump in pink salmon has been confirmed in detail. In this study, the dorsal hump morphologies were analyzed in four Pacific salmon species inhabiting Japan, masu (O. masou), sockeye, chum (O. keta), and pink salmon. The internal structure of the dorsal humps also depended on the species; sockeye and pink salmon showed conspicuous development of connective tissue and growth of bone tissues in the dorsal tissues. Masu and chum salmon exhibited less-pronounced increases in connective tissues and bone growth. Hyaluronic acid was clearly detected in dorsal hump connective tissue by histochemistry, except for in masu salmon. The lipid content in dorsal hump connective tissue was richer in masu and chum salmon than in sockeye and pink salmon. These results revealed that the patterns of dorsal hump formation differed among species, and especially sockeye and pink salmon develop pronounced dorsal humps through both increases in the amount of connective tissue and the growth of bone tissues. In contrast, masu and chum salmon develop their dorsal humps by the growth of bone tissues, rather than the development of connective tissue.
  • Hikari Izumi, Seishi Hagihara, Hiroaki Kurogi, Seinen Chow, Katsumi Tsukamoto, Hirohiko Kagawa, Hideaki Kudo, Shigeho Ijiri, Shinji Adachi
    FISHERIES SCIENCE 81 (2) 321 - 329 0919-9268 2015/03 [Refereed][Not invited]
     
    To describe the histological characteristics of the oocyte chorion in wild adult and artificially matured Japanese eels, we investigated changes in chorion thickness during artificially induced oogenesis and compared the chorion thickness and ultrastructure between wild and artificially matured eels. In artificially maturing eels, the chorion thickness and volume increased significantly with increasing follicle diameter, peaking at approximately 450 A mu m; beyond this point, the chorion thinned significantly, whereas there were no significant changes in volume. A significant positive correlation was observed between the number of salmon pituitary extract (SPE) injections and chorion thickness. In wild post-spawning adult eels, chorion thickness varied among individuals, and two had chorions that were significantly thinner than those of artificially matured eels. Ultrastructural examination revealed electron-dense layers in the chorions of wild post-spawning adult eels, as was seen in artificially matured eels. This result is inconsistent with our hypothesis that the formation of an electron-dense layer is unique to artificially maturing eels due to repeated SPE injections. These results suggest that the formation cycle of the chorion might be affected by SPE injections in artificially maturing eels, whereas that of wild eels might be synchronized with behavioral and/or environmental fluctuations that occur during the oceanic spawning migration.
  • Sayaka Mino, Hideaki Kudo, Takayuki Arai, Tomoo Sawabe, Ken Takai, Satoshi Nakagawa
    INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY 64 (9) 3195 - 3201 1466-5026 2014/09 [Refereed][Not invited]
     
    A novel mesophilic, strictly hydrogen-oxidizing, sulfur-, nitrate- and thiosulfate-reducing bacterium, designated strain Monchim33(T), was isolated from a deep-sea hydrothermal vent chimney at the Central Indian Ridge. The non-motile, rod-shaped cells were Gram-stain-negative and non-sporulating. Growth was observed between 15 and 37 degrees C (optimum 33 degrees C; 3.2 h doubling time) and between pH 5.4 and 8.6 (optimum pH 6.0). The isolate was a strictly anaerobic chemolithoautotroph capable of using molecular hydrogen as the sole energy source and carbon dioxide as the sole carbon source. The G+C content of the genomic DNA was 42.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the novel isolate belonged to the genus Sulfurovum and was closely related to Sulfurovum sp. NBC37-1 and Sulfurovum lithotrophicum 42BK(T) (95.6 and 95.4% similarity, respectively). DNA DNA hybridization demonstrated that the novel isolate could be differentiated genotypically from Sulfurovum sp. NBC37-1 and Sulfurovum lithotrophicum. On the basis of the molecular and physiological traits of the new isolate, the name Sulfurovum aggregans sp. nov. is proposed, with the type strain Monchim33(T) (=JCM 19824(T)=DSM 27205(T)).
  • Kenta Susuki, Masaki Ichimura, Yosuke Koshino, Masahide Kaeriyama, Yasuaki Takagi, Shinji Adachi, Hideaki Kudo
    JOURNAL OF MORPHOLOGY 275 (5) 514 - 527 0362-2525 2014/05 [Refereed][Not invited]
     
    Mature male Pacific salmon (Genus Oncorhynchus) develop a dorsal hump, as a secondary male sexual characteristic, during the spawning period. Previous gross anatomical studies have indicated that the dorsal humps of salmon are mainly composed of cartilaginous tissue (Davidson [1935] J Morphol 57:169-183.) However, the histological and biochemical characteristics of such humps are poorly understood. In this study, the detailed microstructures and components of the dorsal humps of pink salmon were analyzed using histochemical techniques and electrophoresis. In mature males, free interneural spines and neural spines were located in a line near to the median septum of the dorsal hump. No cartilaginous tissue was detected within the dorsal hump. Fibrous and mucous connective tissues were mainly found in three regions of the dorsal hump: i) the median septum, ii) the distal region, and iii) the crescent-shaped region. Both the median septum and distal region consisted of connective tissue with a high water content, which contained elastic fibers and hyaluronic acid. It was also demonstrated that the lipid content of the dorsal hump connective tissue was markedly decreased in the mature males compared with the immature and maturing males. Although, the crescent-shaped region of the hump consisted of connective tissue, it did not contain elastic fibers, hyaluronic acid, or lipids. In an ultrastructural examination, it was found that all of the connective tissues in the dorsal hump were composed of collagen fibers. Gel electrophoresis of collagen extracts from these tissues found that the collagen in the dorsal hump is composed of Type I collagen, as is the case in salmon skin. These results indicate that in male pink salmon the dorsal hump is formed as a result of an increase in the amount of connective tissue, rather than cartilage, and the growth of free interneural spines and neural spines. J. Morphol. 275:514-527, 2014. (c) 2013 Wiley Periodicals, Inc.
  • Yuxue Qin, Airi Nagai, Hideaki Kudo, Masahide Kaeriyama
    Nippon Suisan Gakkaishi (Japanese Edition) 79 (5) 872 - 874 0021-5392 2013/12/03 [Refereed][Not invited]
  • Yosuke Koshino, Hideaki Kudo, Masahide Kaeriyama
    FRESHWATER BIOLOGY 58 (9) 1864 - 1877 0046-5070 2013/09 [Refereed][Not invited]
     
    1. Pacific salmon (Oncorhynchus spp.) transport marine-derived nutrients (MDN) and organic matter to freshwater ecosystems, which enhances the productivity of North Pacific ecosystems. Relatively few studies, however, have evaluated the MDN subsidy to both the aquatic system and the terrestrial catchment simultaneously. Using stable isotope analysis, we tested how the dynamics of MDN differed between the river and adjacent riparian forest in rivers of the Shiretoko World Natural Heritage Site in eastern Hokkaido (Japan). In addition, we accounted for temporal and spatial variations in the stable isotope signatures of freshwater organisms due to the presence or absence of spawning salmon. 2. We analysed carbon and nitrogen stable isotopes (C-13 and N-15) of biofilm, invertebrates, fish, riparian plants and brown bear (Ursus arctos) in the Rusha River during the pre-spawning and spawning periods and in the Akai River (where there are no salmon). Willow leaves were collected along the 50-m transects to evaluate how far MDN are incorporated within the riparian area. We counted the number of pink salmon (O.gorbuscha) carcasses in riparian areas and categorised their mode of transport. In addition, we examined the stomach contents of Dolly Varden (Salvelinus malma). 3. The C-13 and N-15 of aquatic organisms increased by 1-4 parts per thousand and 1-6 parts per thousand, respectively, with the arrival of salmon spawners. Aquatic organisms incorporated 23% of their nitrogen from salmon (range: 7-46%). The diet of Dolly Varden switched from aquatic invertebrates to salmon eggs during the salmon spawning run. 4. More salmon carcasses were transported from the stream to riparian areas by flooding than by brown bears. The C-13 and N-15 of blowflies (Calliphora spp.) and brown bears increased significantly during the spawning run. Riparian vegetation, with the exception of Manchurian alder (Alnus hirsuta), incorporated 25% of its nitrogen from salmon. The N-15 values of riparian willow (Salix spp.) were correlated negatively with distance from the stream. 5. The proportion of MDN incorporated in the freshwater biota was lower than that reported for North American rivers, potentially due to the influence of dams and modification of the river environment in this Japanese example. The riparian forest incorporated a relatively high fraction of MDN, however, mainly due to the transport of salmon carcasses from the channel by brown bears and, particularly, flooding. The dynamics of salmon-derived nutrients thus differed between river and adjacent riparian zones. These results suggested the importance of linkages between freshwater and riparian ecosystems for the extent of the marine nutrient subsidy.
  • Hirofumi Hayano, Yasuyuki Miyakoshi, Shuichi Mano, Ryouichi Tamura, Hideaki Kudo, Masahide Kaeriyama
    Nippon Suisan Gakkaishi (Japanese Edition) 79 (3) 372 - 382 0021-5392 2013/06/17 [Refereed][Not invited]
     
    We investigated the mechanism of temporal changes in yearly catches and resources of icefish Salangichthys microdon in Lake Abashiri from 1936 to 2007. Icefish have lived in Lake Abashiri since the early 1930s because of climate change and topographical features, and have been caught by commercial fisheries. Their population size fluctuated annually from 1 to 94 tons. The periodicity of one-year intervals relating to the life-history of icefish was observed in yearly catches. Population sizes at the beginning of each fishing season were estimated to be 36,763 × 103-487,590 × 103 individuals based on the daily CPUE and the density of juveniles. The icefish seem to be stimulated to migrate seaward by rising water and flooding, resulting in an abrupt decline in commercial catches and high spawner abundance in the following year. The relationship between the number of adults and recruitment fitted well to Ricker's reproduction model.
  • Hirofumi Hayano, Ryouichi Tamura, Nobuhisa Koide, Ki Baik Seong, Hideaki Kudo, Masahide Kaeriyama
    Nippon Suisan Gakkaishi (Japanese Edition) 79 (2) 166 - 174 0021-5392 2013/04/12 [Refereed][Not invited]
     
    To investigate the distribution of ice fish Salangichthys microdon eggs, lines for survey at 11 locations were set on the shore of Lake Abashiri. Sediment s were collected by water depth on each of the survey lines to analyze the grain size and density of icefish eggs. Icefish eggs were distributed on sediment comprised of sand and gravel, and the egg density tended to be higher in the large grain size rather than the ine sand. However, there was a survey point where there were no eggs even though the sediment was medium sand. This suggests that factors such as water temperature and lake water level affect the egg distribution in addition to the sediment. There were few iceish eggs on the sediment where silt clay was predominant.
  • Aya Yamada, Yosuke Koshino, Hideaki Kudo, Syuichi Abe, Katsutoshi Arai, Masahide Kaeriyama
    Nippon Suisan Gakkaishi (Japanese Edition) 78 (5) 973 - 975 0021-5392 2012/11/05 [Refereed][Not invited]
  • Hideaki Kudo, Yousuke Koshino, Akihiro Eto, Masaki Ichimura, Masahide Kaeriyama
    FISHERIES RESEARCH 119 94 - 98 0165-7836 2012/05 [Refereed][Not invited]
     
    This paper describes an attempt in 2008 to establish an aerial census of adult chum salmon using a small radio-controlled (RC) helicopter. The Moheji River, located in southern Hokkaido, was chosen because all the salmon in a stretch of the river between a weir and the estuary are seine-netted every morning for artificial propagation. Aerial photographs of the river were taken from a RC helicopter equipped with a digital single-lens reflex camera and polarized filter. To quantify salmon density within the census area, the number of salmon per aerial photograph was counted using image-processing software. Salmon could be clearly identified in photographs taken from an altitude of similar to 30 m. Salmon numbers estimated by aerial census and seine-netting were significantly related. The results indicate that a small RC helicopter can be used to generate adult salmon abundance data in Japanese rivers. (C) 2011 Elsevier B.V. All rights reserved.
  • Masahide Kaeriyama, Hyunju Seo, Hideaki Kudo, Mitsuhiro Nagata
    ENVIRONMENTAL BIOLOGY OF FISHES 94 (1) 165 - 177 0378-1909 2012/05 [Refereed][Not invited]
     
    Pacific salmon (Oncorhynchus spp.) play an important role as a keystone species and provider of ecosystem services in the North Pacific ecosystem. We review our studies on recent production trends, marine carrying capacity, climate effects and biological interactions between wild and hatchery origin populations of Pacific salmon in the open sea, with a particular focus on Japanese chum salmon (O. keta). Salmon catch data indicates that the abundance of Pacific salmon increased since the 1976/77 ocean regime shift. Chum and pink salmon (O. gorbuscha) maintained high abundances with a sharp increase in hatchery-released populations since the late 1980s. Since the 1990s, the biomass contribution of hatchery returns to the total catch amounts to 50% for chum salmon, more than 10% for pink salmon, and less than 10% for sockeye salmon (O. nerka). We show evidence of density-dependence of growth and survival at sea and how it might vary across spatial scales, and we provide some new information on foraging plasticity that may offer new insight into competitive interactions. The marine carrying capacity of these three species is synchronized with long-term patterns in climate change. At the present time, global warming has positively affected growth and survival of Hokkaido populations of chum salmon. In the future, however, global warming may decrease the marine carrying capacity and the area of suitable habitat for chum salmon in the North Pacific Ocean. We outline future challenges for salmon sustainable conservation management in Japan, and recommend fishery management reform to sustain the hatchery-supported salmon fishery while conserving natural spawning populations.
  • Yuichiro Kogura, James E. Seeb, Noriko Azuma, Hideaki Kudo, Syuiti Abe, Masahide Kaeriyama
    ENVIRONMENTAL BIOLOGY OF FISHES 92 (4) 539 - 550 0378-1909 2011/12 [Refereed][Not invited]
     
    Lacustrine sockeye salmon (Oncorhynchus nerka) are listed as an endangered species in Japan despite little genetic information on their population structure. In order to clarify the genetic diversity and structure of Japanese populations for evaluating on the bottleneck effect and an endangered species, we analyzed the ND5 region of mitochondrial DNA (mtDNA) and 45 single nucleotide polymorphisms (SNPs) in 640 lacustrine sockeye salmon in Japan and 80 anadromous sockeye salmon in Iliamna Lake of Alaska. The genetic diversity of the Japanese population in both mtDNA and SNPs was significantly less than that of the Iliamna Lake population. Moreover, all Japanese populations had SNP loci deviating from the HWE. In spite of low genetic diversity, the SNP analyses resulted that the Japanese population was significantly divided into three groups. These suggest that Japanese sockeye salmon populations should be protected as an endangered species and genetically disturbed by the hatchery program and transplantations.
  • Taku Endo, Takashi Todo, P. Mark Lokman, Hideaki Kudo, Shigeho Ijiri, Shinji Adachi, Kohei Yamauchi
    BIOLOGY OF REPRODUCTION 84 (4) 816 - 825 0006-3363 2011/04 [Refereed][Not invited]
     
    To investigate the regulation of lipid uptake into the eel oocyte in more detail, effects of 11-ketotestosterone (11-KT) and lipid transporters (lipoproteins) were determined in vitro. Ovarian explants from previtellogenic Japanese eels (Anguilla japonica) were incubated for 28 days with 11-KT and/or with very low density lipoproteins (Vldl), low density lipoproteins (Ldl), or high density lipoproteins (Hdl) purified from eel plasma. The androgen 11-KT induced notable increases in oocyte diameter, which were accompanied by the appearance of vacuoles rather than lipid. Ldl and Hdl increased oocyte diameters, whereas Vldl did not. However, coincubation of 11-KT and Vldl, but not of Ldl or Hdl, resulted in dramatic increases in oocyte size and lipid droplet surface area. Effects of both 11-KT (oocyte size) and Vldl (lipid droplet surface area) were dose-dependent between 1 and 100 ng/ml and between 0.5 and 5 mg/ml, respectively. Interestingly, abnormal oocyte cytology under conditions of coculture with 11-KT and Vldl could essentially be prevented if Vldl concentrations were high enough (>= 5 mg Vldl/ml medium). Unlike 11-KT, estradiol-17beta had no effect on oocyte diameter or lipid droplet surface area. We conclude that Vldl is a key transporter of neutral lipids that accumulate into the eel oocyte during oogenesis and that Vldl-dependent lipid uptake is stimulated by the androgen 11-KT.
  • Hyunju Seo, Hideaki Kudo, Masahide Kaeriyama
    ENVIRONMENTAL BIOLOGY OF FISHES 90 (2) 131 - 142 0378-1909 2011/02 [Refereed][Not invited]
     
    We used multiple regression and path analysis to examine the effects of regional and larger spatial scales of climatic/oceanic conditions on the growth, survival, and population dynamics of Hokkaido chum salmon (Oncorhynchus keta). Variability in the growth of chum salmon at ages 1 to 4 was estimated from scale analysis and the back-calculation method using scales of 4-year-old adults returning to the Ishikari River in Hokkaido, Japan, during 1943-2005. Growth of chum salmon at age 1 was less during the period from the 1940s to the mid-1970s compared to the period from the mid-1980s to the present. On the other hand, growth of chum salmon at ages 2, 3, and 4 has declined since the 1980s. Path analysis indicated that growth at age 1 in the Okhotsk Sea was directly affected by warmer sea surface temperatures associated with global warming. The increased growth at age 1 led directly to higher survival rates and indirectly to larger population sizes. Subsequently, in the Bering Sea, the larger population size was directly associated with decreased growth at age 3 and indirectly associated with shorter adult fork lengths despite the lack of relationships among sea surface temperature, zooplankton biomass, and growth at ages 2 to 4. Therefore, higher growth at age 1 related to global warming positively affected the survival rate of juvenile chum salmon in the Okhotsk Sea. The higher survival rates in turn appear to be causing a population density-dependent effect on growth at ages 2 to 4 and maturation in the Bering Sea due to limited carrying capacity.
  • Zhen-Lin Hao, Xiu-Mei Zhang, Hideaki Kudo, Masahide Kaeriyama
    JOURNAL OF SHELLFISH RESEARCH 29 (2) 463 - 470 0730-8000 2010/08 [Refereed][Not invited]
     
    To provide morphological bases for functional studies, the development of the photoreceptor cells in the retina of the cuttlefish Sepia esculenta from newly hatched juveniles to the adults was examined by light and electron microscopy. Four layers were distinguished in the retina: the rhabdomeric layer, subrhabdomeric layer, inner segmental layer, and plexifonn layer. With the development of the retina, the structure of the plexiform layer becomes stronger. Morphometric data on the rhabdomeric microvilli from the newly hatched to the adult retinas are presented. The thickness of the rhabdomeric layer and the total surface area of the rhabdomeric microvilli present beneath a unit surface area of the retina show an exponential increase with developmental days; the diameter of the lens shows a linear increase with days. The results of our research show that the visual acuity and sensitivity of S. esculenta continuously increased with development.
  • Yuya Yokoyama, Yosuke Koshino, Kota Miyamoto, Hideaki Kudo, Shuichi Kitada, Masahide Kaeriyama
    NIPPON SUISAN GAKKAISHI 76 (3) 383 - 391 0021-5392 2010/05 [Refereed][Not invited]
     
    Pacific salmon Oncorlynchus spp. plays a role in sustaining the biodiversity and production of the terrestrial ecosystem. Accurate estimation of the escapement and spawning dynamics is important for the quantifying the effect of salmon on the riparian ecosystem. The objective of this paper is to estimate accurately the escapement and spawning dynamics of wild pink salmon O. gorbuscha at the Rusha River in the Shiretoko World Natural Heritage area in 2006-2008. The escapement of pink salmon was estimated by the area-under-the-curve method (AUC) with the standard error based on the bootstrap method. The estimated escapement indicated appropriate results. The carrying capacity of spawning redds, however, was far lower than escapements in the available spawning area.
  • Yuya Yokoyama, Yosuke Koshino, Kota Miyamoto, Hideaki Kudo, Shuichi Kitada, Masahide Kaeriyama
    Nippon Suisan Gakkaishi (Japanese Edition) 76 (3) 383 - 391 0021-5392 2010 [Refereed][Not invited]
     
    Pacific salmon Oncorhynchus spp. plays a role in sustaining the biodiversity and production of the terrestrial ecosystem. Accurate estimation of the escapement and spawning dynamics is important for the quantifying the effect of salmon on the riparian ecosystem. The objective of this paper is to estimate accurately the escapement and spawning dynamics of wild pink salmon O. gorbuscha at the Rusha River in the Shiretoko World Natural Heritage area in 2006-2008. The escapement of pink salmon was estimated by the area-under-the-curve method (AUC) with the standard error based on the bootstrap method. The estimated escapement indicated appropriate results. The carrying capacity of spawning redds, however, was far lower than escapements in the available spawning area.
  • Hideaki Kudo, Yoshiaki Doi, Sunao Fujimoto
    NEUROSCIENCE LETTERS 468 (2) 98 - 101 0304-3940 2010/01 [Refereed][Not invited]
     
    The xenobiotic metabolizing system is considered to play important roles in the olfaction by the chemical homeostasis. Several phase I and phase II xenobiotic metabolizing enzymes are expressed in the olfactory epithelium in vertebrates. Multidrug resistance-related proteins (MRPs) are the phase III xenobiotic metabolizing pumps that eliminate some conjugated ligands from cells. However, the MRP-expressions in the olfactory epithelium have not been confirmed in the mammals. We investigated gene and protein expressions of MRP type 1 (MRP1) and type 2 (MRP2) isoforms in the adult rat olfactory epithelium in order to clarify the existence of phase III xenobiotic metabolizing pumps in the olfactory organs. Expressions of MRP1 mRNA were detected in the nasal cavity by reverse transcriptase polymerase chain reaction (RT-PCR). The nucleoside sequence of the RT-PCR products were completely identical to that found in other organs of rat. On the contrary, the analysis did not detect expressions of MRP2 mRNA in the nasal cavity. By in situ hybridization using a digoxigenin-labeled MRP1 cRNA probe, signals for MRP1 mRNA were observed preferentially in the perinuclear regions of supporting cells. However, the respiratory epithelial cells did not show the signals for MRP1 mRNA. By immunohistochemistry using a specific antibody to MRP1, MRP1-immunoreactivities were seen mainly on the supporting cells. These findings suggest that MRP1 is involved in olfaction as a part of the "olfactory signal termination" by the chemical homeostasis in the "perireceptor events" of the olfactory epithelium. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
  • YOKOTANI RYOTA, AZUMA NORIKO, KUDO HIDEAKI, ABE SYUITI, KAERIYAMA MASAHIDE
    水産育種 水産育種研究会 39 (1) 1 - 8 1343-7917 2009/10/20 [Refereed][Not invited]
  • Hideaki Kudo, Masakazu Shinto, Yasunori Sakurai, Masahide Kaeriyama
    CHEMICAL SENSES 34 (7) 617 - 624 0379-864X 2009/09 [Refereed][Not invited]
     
    It is generally accepted that anadromous Pacific salmon (genus Oncorhynchus) imprint to odorants in their natal streams during their seaward migration and use olfaction to identify these during their homeward migration. Despite the importance of the olfactory organ during olfactory imprinting, the development of this structure is not well understood in Pacific salmon. Olfactory cues from the environment are relayed to the brain by the olfactory receptor neurons (ORNs) in the olfactory organ. Thus, we analyzed morphometric changes in olfactory lamellae of the peripheral olfactory organ and in the quantity of ORNs during life history from alevin to mature in chum salmon (Oncorhynchus keta). The number of lamellae increased markedly during early development, reached 18 lamellae per unilateral peripheral olfactory organ in young salmon with a 200 mm in body size, and maintained this lamellar complement after young period. The number of ORNs per olfactory organ was about 180 000 and 14.2 million cells in fry and mature salmon, respectively. The relationship between the body size (fork length) and number of ORNs therefore revealed an allometric association. Our results represent the first quantitative analysis of the number of ORNs in Pacific salmon and suggest that the number of ORNs is synchronized with the fork length throughout its life history.
  • H. Kudo, Y. Doi, H. Ueda, M. Kaeriyama
    COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY 154 (1) 142 - 150 1095-6433 2009/09 [Refereed][Not invited]
     
    Despite the importance of olfactory receptor neurons (ORNs) for homing migration, the expression of olfactory marker protein (OMP) is not well understood in ORNs of Pacific salmon (genus Oncorhynchus). In this study, salmon OMP was characterized in the olfactory epithelia of lacustrine sockeye salmon (C. nerka) by molecular biological and histochemical techniques. Two cDNAs encoding salmon OMP were isolated and sequenced. These cDNAs both contained a coding region encoding 173 amino acid residues, and the molecular mass of the two proteins was calculated to be 19,581.17 and 19,387.11 Da, respectively. Both amino acid sequences showed marked homology (90%). The protein and nucleotide sequencing demonstrates the existence of high-level homology between salmon OMPs and those of other teleosts. By in situ hybridization using a digoxigenin-labeled salmon OMP cRNA probe, signals for salmon OMP mRNA were observed preferentially in the perinuclear regions of the ORNs. By immunohistochemistry using a specific antibody to salmon OMP, OMP-immunoreactivities were noted in the cytosol of those neurons. The present study is the first to describe cDNA cloning of OMP in salmon olfactory epithelium, and indicate that OMP is a useful molecular marker for the detection of the ORNs in Pacific salmon. (C) 2009 Elsevier Inc. All rights reserved.
  • Hyunju Seo, Hideaki Kudo, Masahide Kaeriyama
    FISHERIES SCIENCE 75 (4) 957 - 966 0919-9268 2009/07 [Refereed][Not invited]
     
    Spatiotemporal changes in growth patterns of chum salmon Oncorhynchus keta that returned to the Ishikari (Japan) and Namdae (Korea) rivers in 1984-1998 were investigated using scale analysis. Juvenile chum salmon from both populations left coastal marine areas after spring at a size of over 8 cm fork length (FL). In summer, juvenile salmon from the Namdae River entered the Okhotsk Sea at a larger FL than did Ishikari River juveniles. There were no significant differences in annual growth between populations of 1-, 2-, and 4-year-old fish. For 3-year-old fish, however, Namdae River salmon had significantly higher synchronous and sympatric growth than did Ishikari River salmon. Mean FL of adults was also larger in Namdae River salmon than in Ishikari River salmon. Analysis of covariance (ANCOVA) results showed (1) negative linear relations between FL and catch, (2) homogeneous slopes of those relations at regional and species levels, and (3) nonhomogeneous slopes at the population level, indicating that density-dependent effects on growth were most significant at this level. We concluded that growth of chum salmon was concurrently influenced by stronger effects of intrapopulation competition and weaker effects of inter- and intraspecific interactions in the Bering Sea.
  • Trends in run size and carrying capacity of Pacific salmon in the North Pacific Ocean
    Kaeriyama M, Seo H, Kudo H
    North Pacific Anadromous Fish Commission Bulletin 5 293 - 302 2009 [Not refereed]
  • IMAI Naotaka, KUDO Hideaki, KAERIYAMA Masahide
    Japanese journal of ichthyology 日本魚類学会 54 (2) 121 - 128 0021-5090 2007 [Refereed][Not invited]
  • H Tobata-Kudo, H Kudo, Tada, I
    PARASITOLOGY INTERNATIONAL 54 (2) 147 - 152 1383-5769 2005/06 [Refereed][Not invited]
     
    The infective third-stage larvae (Us) of Strongyloides ratti, a parasitic nematode in rodents, showed two types of chemokinesis on a gradient of sodium chloride (NaCl) in an in vitro agarose tracking assay. The types were a consistent directional avoidance behavior under unfavorable environmental conditions and a reduced avoidance behavior under favorable conditions. We examined the effects of treatments with glycolytic enzymes and lectins by analyzing the avoidance behavior. L-Fucose dehydrogenase, hyaluronidase, beta-glucosidase, alpha-mannosidase, beta-galactosidase, concanavalin A, wheat germ agglutinin and soybean agglutinin exhibited inhibitory or enhancive effects on chemokinesis. We also confirmed the sites of the amphids of Us aside from the mouth at the anterior end by scanning electron microscopy, and that concanavalin A-binding sites existed in the vicinity of the amphids using lectin-histochemistry. The carbohydrate moieties in the amphids of S. ratti Us may play an important role as chemosensors in perceiving environmental cues. (c) 2005 Elsevier Ireland Ltd. All rights reserved.
  • H Tobata-Kudo, H Kudo, Tada, I
    PARASITOLOGY RESEARCH 95 (5) 314 - 318 0932-0113 2005/03 [Refereed][Not invited]
     
    The infective third-stage larvae (L3s) of a parasitic nematode of rodents, Strongyloides ratti, showed three types of thermokinesis on a temperature gradient using an in vitro agarose tracking assay method. These depended both on the pattern of gradient temperature and the prior culture temperature. Most L3s (>= 80%) isolated from rat feces cultured at 25 degrees C and placed on a gradient at temperatures between 30 degrees C and 37 degrees C showed no directional response, at 22-29 degrees C more than 50% of the L3s showed positive thermokinesis, at 21 degrees C L3s showed positive, negative and no directional responses in the same ratio, while at 18-20 degrees C, L3s showed negative thermokinesis (approx. 40%) or no directional response (approx. 60%) as in our previous study. The present study describes the effects of glycolytic enzyme- and lectin-treated positive thermokinesis of L3s. alpha-Glucosidase or concanavalin A significantly exhibited inhibitory effects on thermokinesis.
  • Takahisa Nagata, Hideaki Kudo, Tomoko Nishino, Yoshiaki Doi, Hideaki Itoh, Sunao Fujimoto
    Medical Molecular Morphology 38 (3) 161 - 172 1860-1480 2005 [Refereed][Not invited]
     
    The progression of rat liver fibrosis induced by intraperitoneal administration of thioacetamide (TAA) was evaluated by immunocytochemistry using anti-α-smooth muscle actin (α-SMA), antiendothelin-converting enzyme (ECE)-1, and anti-monocyte chemotactic protein (MCP)-1 antibodies. The fibrous septal spaces gradually increased after administration of TAA, and pseudolobules were established in the 7-week TAA-treated groups. Immunoreactivities against α-SMA were not detected in hepatic stellate cells (HSCs) of the control group without TAA treatment, although they were observed in the HSCs around the fibrous septal spaces in all TAA-treated groups, indicating that activation of HSCs occurs during the establishment of pseudolobules. Immunoreactivities against ECE-1 and MCP-1 were seen in such HSCs of the TAA-treated groups, but few or no immunoreactivities were detected in the HSCs of the control group. The most significant increase in the ECE-1 immunoreactivities was detected in the 1-week TAA-treated group, whereas that in MCP-1 was observed in the 7-week TAA-treated group. The present immunocytochemistry indicated a difference in the accelerated expression period between immunoreactivities against ECE-1 and MCP-1 in the HSCs during the progression of TAA-induced liver fibrosis, suggesting that ECE-1 is involved in the early phase of liver fibrosis and that MCP-1 plays a role during the later phase. © The Japanese Society for Clinical Molecular Morphology 2005.
  • Y Doi, H Kudo, T Nishino, T Nagata, S Fujimoto
    JOURNAL OF CARDIOVASCULAR PHARMACOLOGY 44 S207 - S210 0160-2446 2004/11 [Refereed][Not invited]
     
    Wistar rats were deeply anesthetized and perfused by Hanks' solution bubbled with either 95% air and 5% CO2 (normoxic group) or 95% N-2 and 5% CO2 (hypoxic group) from the thoracic aorta for 30 minutes. The isolated abdominal aortas were used for electron microscopy, immunocytochemistry of endothelin-1 (ET 1) and endothelin-converting enzyme-1 (ECE-1), and in situ hybridization of preproendothelin-1 mRNA. A remarkable increase in the number of Weibel-Palade bodies, storage sites of ET-1 and ECE-1, occurred in the hypoxic group when compared with the normoxic group. Immunoreactivities for ET-1 and ECE-1, and signals for preproendothelin-1 mRNA were seen along the endothelia of both groups, but the intensities were significantly elevated in the hypoxic group. The increase in the number of ECE-1 immunoreactive gold particles was noticed in Weibel-Palade bodies in the hypoxic group. These findings indicate the enhancement of preproendothelin-1 synthesis in the rat aortic endothelial cells and the acceleration of ET-1 processing in Weibel-Palade bodies of such cells in an acute hypoxic condition.
  • S Yanagi, H Kudo, Y Doi, K Yamauchi, H Ueda
    ANATOMY AND EMBRYOLOGY 208 (3) 231 - 238 0340-2061 2004/06 [Refereed][Not invited]
     
    In mammals, glutathione S-transferase (GST) in the olfactory epithelium is involved in assistance of the olfactory reception by the xenobiotic metabolism. We previously reported the protein and gene expressions of salmon olfactory GST class pi (soGST) in the olfactory receptor cells (ORCs) of the salmonid fish. However, the chronological appearances of soGST in ORCs during ontogeny and cell proliferation are still unknown in this species. In this study, we performed immunohistochemistry of soGST using an antibody specific to soGST in the olfactory system (olfactory placode, olfactory pit, olfactory epithelium, olfactory nerve and olfactory bulb) of lacustrine sockeye salmon (Oncorhynchus nerka) embryos and 5-bromo-2'-deoxyuridine (BrdU) experimental fish. The projection of olfactory nerve bundles from the olfactory pit to the presumptive olfactory bulb was identified at embryonic day 28 after fertilization. The olfactory cilia were first detected on the apical surface of ORCs at day 43. soGST-immunoreactivity was first detected within the olfactory pit cells at day 55. At 58 day, the number of soGST-immunoreactive cells increased markedly in the olfactory epithelia, and soGST-immunoreactive fibers were observed in the olfactory nerves and olfactory bulbs. By in vivo uptake of BrdU in 1-year-old fish, we observed for the first time at day 7 after labeling that the olfactory epithelia showed ORCs in which both soGST-immunoreactivity and BrdU coexisted. These results indicate that soGST is synthesized in the mature ORCs of lacustrine sockeye salmon after cell formation and differentiation.
  • T Hirano, H Kudo, Y Doi, T Nishino, S Fujimoto, Y Tsurudome, Y Ootsuyama, H Kasai
    CANCER SCIENCE 95 (2) 118 - 122 1347-9032 2004/02 [Refereed][Not invited]
     
    We previously reported that 3'-methyl-4-dimethylaminoazobenzene (3'-MeDAB) increased the 8-hydroxyguanine (8-OH-Gua) content in nuclear DNA and the base excision repair activity in mouse liver. However, to understand the mechanism of 3'-MeDAB carcinogenesis, a further investigation of the 8-OH-Gua repair systems was necessary. In this report, we examined the expression of the repair enzyme, 8-oxoguanine DNA glycosylase 1 (OGG1), in 3'-MeDAB-treated mouse liver. We prepared four kinds of anti-peptide polyclonal antibodies raised against mouse OGG1 (mOGG1). The sequences used as epitopes were designed from positions located close to the N-terminus, the nuclear localization signal (NILS), and the regions containing Lys(249) and Asp(267), which are involved in the catalytic mechanisms of mOGG1 (glycosylase and lyase, respectively). Immunoblotting, using all four antibodies, revealed a 32-kDa protein (mOGG1-32) in addition to the 38-kDa mOGG1 in the 3'-MeDAB-treated mouse liver. Moreover, immunostaining with mOGG1 antibody, yielded strong, positive signals in the 3'-MeDAB-treated mouse liver nuclei. However, we could not detect any difference in the Ogg1 mRNA expression pattern. Although the function of mOGG1-32 remains unclear, these findings suggest that 3'-MeDAB may alter the function of the DNA repair protein, and this action may be related to 3'-MeDAB carcinogenesis.
  • S Uchida, A Sakai, H Kudo, H Otomo, M Watanuki, M Tanaka, M Nagashima, T Nakamura
    BONE 32 (5) 491 - 501 8756-3282 2003/05 [Refereed][Not invited]
     
    In this study, we investigated the expression of vascular endothelial growth factor (VEGF) mRNA along with its receptors in the healing process following rat femoral drill-hole injury. The cellular events involved in the differential expression of VEGF were studied by reverse transcription-polymerase chain reaction, immunocytochemistry, and in situ hybridization. Abundant alkaline phosphatase-positive osteoprogenitor cells were present in the bone marrow cavity surrounding the wound region at day 3. Some of the cells were inummoreactive for Flk-1, a marker of angioblasts. At day 5, osteoblasts expressing osteocalcin mRNA actively participated in bone formation. After day 11, medullary bone gradually decreased and hematopoietic cells covered the wound region. The expressions of the VEGF splice variants VEGF120 and VEGF164 were detected at days 1 and 3, and VEGF188 mRNA began to appear from day 5. The expressions of the three VEGF splice variants gradually decreased after day 11. VEGF immunoreactivity and mRNA expression were strongly detected in angioblasts, osteoprogenitor cells, and osteoblasts between days 3 and 7, but gradually decreased, after day 11. Immunoreactivity for Flt-1 was also detected in endothelial cells, osteoprogenitor cells, and osteoblasts between days 3 and 7. However, immunoreactivity for Flk-1 was not detected on osteoblasts but rather on endothelial cells. These findings indicate that the differential expression of VEGF splicing isoforms along with its receptors may play an important role in the healing process after rat femoral drill-hole injury. (C) 2003 Elsevier Science (USA). All rights reserved.
  • M Morita, H Kudo, Y Doi, T Hirano, K Ikemura, S Fujimoto
    ANATOMICAL RECORD 268 (4) 371 - 380 0003-276X 2002/12 [Refereed][Not invited]
     
    In order to clarify the role of antioxidant enzymes in the male rat submandibular gland against short-term normobaric oxygenation, we performed immunocytochemical staining of manganese-containing superoxide dismutase (Mn-SOD), copper- and zinc-containing SOD (Cu/Zn-SOD), catalase (CAT), glutathione peroxidase, and glutathione S-transferases (GST alpha, GST mu., and GST pi) between days 1 and 7 after normobaric oxygenation. Ultrastructural alterations and immunoreactivities for malondialdehyde (MDA), a lipid peroxidation-related molecule, of the acinar and ductal cells after the oxygenation were also investigated. Immunoreactivity for MDA was exhibited in the acinar cells throughout the experiment. On the other hand, immunoreactivity for the SODs, CAT, and GSTs was not altered, when compared to that of controls, but was significantly elevated in the granular, striated, and excretory ductal cells. Since an increase of lipid peroxidation as indicated by enhanced immunoreactivity for MDA was detected in the acinar and intercalated ductal cells, the results indicate that the enhanced antioxidant enzymes in the granular, striated, and excretory ductal cells play a crucial role in the self-defense system of the male rat submandibular gland against normobaric oxygenation.
  • K Mochida, T Matsubara, H Kudo, T Andoh, H Ueda, S Adachi, K Yamauchi
    JOURNAL OF EXPERIMENTAL ZOOLOGY 293 (4) 368 - 383 0022-104X 2002/09 [Refereed][Not invited]
     
    We previously produced four monoclonal antibodies to testicular proteins of a teleost, the Nile tilapia. One of the monoclonal antibodies, TAT(Testicular Antigen of Tilapia)-10, recognizes a Mr=27,000 protein (27 kD protein), which is present in A and early B type spermatogonia, spermatids, and spermatozoa in testis. In order to clarify the function of this protein, molecular cloning was conducted. The cDNA for the 27 kD protein contains a complete open reading frame encoding 220 amino acid residues. The predicted amino acid sequence of the 27 kD protein was homologous to those of the ubiquitin carboxy-terminal hydrolases (UCH) reported in mammals. The measurement of the ubiquitin-releasing activity of the recombinant 27 kD protein revealed that the protein is the active form of UCH. Northern blot analysis showed that the UCH mRNA was expressed in ovary and brain in addition to the testis. Immunohistochemical study showed that, in brain, UCH was localized especially on the olfactory organ including the olfactory bulb and olfactory epithelium in olfactory rosetta, suggesting the involvement of the protein in chemoreceptive function. In the Tilapia ovary, UCH localized especially in pre-vitellogenic oocytes, suggesting that the enzyme activity could be important in oocyte growth. This is the first report for the cDNA cloning and cellular localization of UCH in fish. (C) 2002 Wiley-Liss, Inc.
  • Y Doi, H Kudo, O Yamamoto, K Hamasaki, M Yoshizuka, S Fujimoto
    VIRCHOWS ARCHIV 441 (2) 179 - 186 0945-6317 2002/08 [Refereed][Not invited]
     
    Male rats received daily intraperitoneal injections of cadmium sulfate (2.0 mg/kg) for 3, 6, and 8 days (cadmium-treated groups) or physiological saline for 8 days (control group). The thoracic aortae from both groups were used for electron microscopy and immunocytochemistry for big endothelin (ET)-1, ET-1 and ET-converting enzyme (ECE)-1,and the blood plasma and homogenized thoracic aortae were prepared for assays of big ET-1 and ET-1 concentrations. A remarkable increase in the number of Weibel-Palade (WP) bodies, enhanced immunoreactivities for ET-1 and ECE-1 along the endothelium, and elevated concentrations of ET-1 in the blood plasma as well as in homogenized thoracic aortae were observed in the cadmium-treated groups. However, immunoreactivity for big ET-1 and the plasma and aortic tissue concentrations of big ET-1 did not show any significant changes between the control and cadmium-treated groups. By immunoelectron microscopy, immunoreactivities for ET-1 and ECE-1 were much more pronounced in the increased WP bodies. Since WP bodies are involved in the extracellular release of ET-1 in the manner of a regulated pathway, these findings indicate that cadmium administration induces the enhanced re-lease of ET-1, which is actively processed by ECE-1 in the WP bodies.
  • T Ota, M Tamura, A Osajima, Y Doi, H Kudo, H Anai, M Miyazaki, T Nishino, Y Nakashima
    JOURNAL OF LABORATORY AND CLINICAL MEDICINE 140 (1) 43 - 51 0022-2143 2002/07 [Refereed][Not invited]
     
    Impairment of kidney function in various types of glomerular disease is associated with tubulointerstitial changes. Monocyte chemoattractant protein-1 (MCP-1) is up-regulated in the tubulointerstitium and in the glomeruli in many human and experimental kidney disorders. We investigated the localization of MCP-1 expression in a rat model of progressive kidney failure. Male Wistar rats were subjected to subtotal nephrectomy (n = 30) or sham surgery (n = 30). Immunohistochemistry with immunoelectron microscopy and in situ hybridization were used to examine the expression of MCP-1 protein and messenger ribonucleic acid (mRNA) in the kidney, respectively. MCP-1 protein and mRNA were hardly detected in both glomeruli and tubulointerstitium of control rats. However, in the rats subjected to nephrectomy, MCP-1 expression was increased in the tubular cells of the remnant kidney, accompanied by significant macrophage infiltration. MCP-1 was observed mainly in the proximal tubular cells and only weakly in distal tubular cells. No significant expression of MCP-1 protein or mRNA was noted in the glomeruli. Immunoelectron microscopy showed the presence of MCP-1 in the rough endoplasmic reticulum of proximal tubular cells, confirming that MCP-1 is produced in proximal tubular cells. MCP-1 was also observed in endocytic vesicles adjacent to the brush border of proximal tubular cells, suggesting incorporation of MCP-1 from the tubular lumen. Our findings indicate localized expression of MCP-1 in proximal tubular cells in the remnant kidney and suggest that MCP-1 in proximal tubular cells is involved in tubulointerstitial damage in chronic kidney failure associated with glomerular hypertension.
  • S Nara, K Hachisuka, H Furukawa, Y Doi, H Kudo, S Fujimoto
    HISTOLOGY AND HISTOPATHOLOGY 17 (2) 427 - 436 0213-3911 2002/04 [Refereed][Not invited]
     
    Immunoreactivity for desmin, plectin and alpha-actinin was investigated in rat atrophic soleus muscle fibers induced by hindlimb suspension between 1 and 4 weeks (hindlimb suspension group, HSG), and compared with that of the control group (CG). Some of the HSG for 4 weeks were allowed unrestricted cage activity for 2 weeks as the recovery group (RG). In the cross-sectioned muscle fibers of the CG, desmin and plectin showed honey-comb immunoreactive patterns extending throughout the sarcoplasm. Superimposed images by double immunofluorescence labeling showed overlapping of both immunoreactivities. In the longitudinally sectioned profiles, superimposed images of alpha-actinin and desmin were overlapped at the level of Z-discs. The focal disorganization of the above honeycomb immunoreactive patterns, followed by the reduction of the cross-sectional area (CSA) of atrophic soleus muscle fibers and the appearance of Z-streaming, uniquely arose in the HSG from the first week and extended throughout the sarcoplasm in proportion to the suspension period. Such honey-comb patterns of both desmin and plectin were already restored in the RG at 2 weeks, followed by the disappearance of Z-streaming, prior to the recovery of the CSA. These findings indicate that the disorganization of topological and structural relationships of desmin and plectin with Z-discs surrounding individual myofibrils is primarily evoked, which leads to Z-streaming of atrophic soleus muscle fibers, and that the restoration of the muscle activity results in an early arrangement recovery of desmin and plectin around myofibrils.
  • Y Doi, H Kudo, T Nishino, O Yamamoto, T Nagata, S Nara, M Morita, S Fujimoto
    HISTOLOGY AND HISTOPATHOLOGY 17 (1) 97 - 105 0213-3911 2002 [Refereed][Not invited]
     
    Deeply anesthetized male Wistar rats were perfused by Hanks' balanced salt solution bubbled with either 95%air and 5%CO2 (normoxic group) or 95%N-2 and 5%CO2 (hypoxic group) from the thoracic aorta for 30 min, and the isolated abdominal aortae from both groups were used for electron microscopy, immunocytochemistry of endothelin (ET)-1 and ET-converting enzyme (ECE)-1, and in situ hybridization of preproET-1 mRNA. A remarkable increase in the number of Weibel-Palade (WP) bodies, storage sites of ET-1 and ECE-1, occurred in the hypoxic group when compared to the normoxic group. Immunoreactivities for ET-1 and ECE-1, and signals for preproET-1 mRNA were seen along the endothelia of both groups, but the intensities were significantly elevated in the hypoxic group. The increase in the number of ECE-1 immunoreactive gold particles was noticed especially in WP bodies in the hypoxic group. These findings indicate the enhancement of preproET-1 synthesis in the aortic endothelial cells as well as the acceleration of ET-1 processing in increased WP bodies in such cells in an experimentally hypoxic condition of the rat aortae.
  • Y Doi, H Kudo, T Nishino, K Kayashima, H Kiyonaga, T Nagata, S Nara, M Morita, S Fujimoto
    HISTOLOGY AND HISTOPATHOLOGY 16 (4) 1073 - 1079 0213-3911 2001/10 [Refereed][Not invited]
     
    We investigated the protein and mRNA expression of calcitonin gene-related peptide (CGRP) in endothelial cells of the rat thoracic aorta and femoral artery. Light microscopic immunocytochemistry revealed that immunoreactivity for CGRP was preferentially located in the endothelium of both vessels. Immunoelectron microscopy showed that CGRP-immunoreactive gold particles were preferentially localized on cisterns of the rough endoplasmic reticulum and on the Weibel-Palade (WP) bodies in the endothelial cells. Prepro CGRP mRNA signals were also detected on the endothelium. Our results are the first to demonstrate that endothelial cells of both elastic and large muscular arteries synthesize CGRP and store it, in part, in WP bodies, implying that CGRP may act as an endothelium-derived relaxing factor in these vessels.
  • Tomoko Nishino, Tomoko Nishino, Hideaki Kudo, Yoshiaki Doi, Masanobu Maeda, Masanobu Maeda, Kunshige Hamasaki, Miyako Morita, Sunao Fujimoto
    Chemical Senses 26 (2) 179 - 188 0379-864X 2001 [Refereed][Not invited]
     
    Immunocytochemistry was used to investigate the distribution of cells reacting with specific antibodies against glutathione S-transferase (GST) μ and π in rat circumvallate and foliate taste buds; the findings were confirmed by Western blotting. Double immunofluorescence staining for protein gene product (PGP) 9.5 and GST subunits allowed the classification of taste bud cells of both papillae into: (i) cells immunoreactive to either PGP 9.5 or GST subunit antibody; (ii) cells immunoreactive to both antibodies; and (iii) cells that did not react with either of these antibodies. Immunoelectron microscopy revealed that most GST subunit-immunoreactive cells seemed to be either type II or type III cells based on their ultrastructure. Since PGP 9.5 is now widely used as a marker for type III cells in mammalian taste buds, it seems reasonable to believe that most GST subunit-immunoreactive cells are type II cells. Whether cells immunoreactive for both PGP 9.5 and GST subunits consitute a small subpopulation of type III cells or whether they are intermediate forms between type II and III cells is under investigation. No type I cells reacted with antibodies against GST subunits in the present study. GST subunits in taste bud cells may participate in xenobiotic metabolism of certain substances exposed to taste pits, as already shown for olfactory epithelium.
  • O Yamamoto, Y Doi, H Kudo, M Yoshizuka, S Fujimoto
    ARCHIVES OF TOXICOLOGY 74 (10) 627 - 631 0340-5761 2000/12 [Refereed][Not invited]
     
    Acute toxicity of bis (tributyltin) oxide in the sweat glands in the rat footpad was investigated by electron microscopy and an energy-dispersive X-ray microanalyzer. Male Wistar rats received an intramuscular injection of 0.5 ml/kg bis (tributyltin) oxide. After 6-8 h, swelling of mitochondria appeared in the secretory cells of the sweat glands. After 12 h, the secretory cells began to show intracytoplasmic edema. After 16-20 h, secretory cells in some sweat glands showed marked hydropic degeneration with swollen cytoplasm. Using X-ray microanalysis, tin peaks were preferentially obtained from the swollen mitochondria of the affected secretory cells. Mitochondria dysfunction due to the toxic effects of bis (tributyltin) oxide induced changes in the secretory cells of rat sweat glands. After 24-48 h, the secretory portion of the sweat glands contained three types of cells: degenerating dark cells, regenerating cells carrying injured mitochondria, and light cells which were morphologically very similar to the cells in the transitional portion of the sweat gland. These light cells appeared to differentiate into active secretory cells after settling down in the secretory portion. Based on these observations, we concluded that the cells in the transitional portion could play an important role at least as reserve cells against secretory cell toxicity. In association with the regenerating process of the damaged secretory portions, increased mitotic activities were seen in different areas of all the dermal sweat ducts. The above-mentioned morphological observations for cell damage and subsequent regeneration and renewal of secretory cells in sweat gland intoxication have not been reported so far.
  • H Fukushige, Y Doi, H Kudo, K Kayashima, H Kiyonaga, T Nagata, H Itoh, S Fujimoto
    ANATOMICAL RECORD 259 (4) 437 - 445 0003-276X 2000/08 [Refereed][Not invited]
     
    Immunocytochemical localization of big endothelin-1 (big ET-1), ET-1, and ET receptor A and B (ETA and ETB), and gene expression of prepro ET-1 mRNA were examined on the rat liver vasculature. Immunoreactivities for big ET-1 and ET-1 were preferentially seen along the endothelium of interlobular veins (IV) and artery (IA), although the staining intensity was more pronounced in IV. Expression of preproET-1 mRNA was detected in both vascular endothelia and the signal intensity was more prevalent in IV. Immunoelectron microscopy showed that rough endoplasmic cisterns were immunoreactive for big ET-1, while Weibel-Palade (WP) bodies, a storage site for ET-1, were immunoreactive for ET-1 in endothelial cells of IV. These results indicate that endothelial cells of IV are the major site of synthesis of ET-1, which is extracellularly secreted by degranulation and/or exocytosis of WP bodies. Hepatic stellate cells (HSCs), especially of the plasma membrane of perisinusoidal and interhepatocellular processes, were immunoreactive for both ETA and ETB receptor antibodies. These findings suggest that ET-1 receptor-mediated HSC contraction is involved in the regulation of hepatic sinusoidal blood flow as previously cited in mammalian liver cirrhosis. We also showed that sarcolemma and caveoles in the smooth muscle cells of the media of IV, ana its branches before reaching the hepatic sinusoids, were immunoreactive for ETA receptor antibody. The results suggest that such vessels, which contains a large amount of hepatic blood inflow, participate in pump mechanism toward hepatic sinusoidal circulation in a receptor-mediated paracrine fashion. Anat Rec 259:437-445, 2000. (C) 2000 Wiley-Liss, Inc.
  • S Uchida, Y Doi, H Kudo, H Furukawa, T Nakamura, S Fujimoto
    BONE 27 (1) 81 - 90 8756-3282 2000/07 [Refereed][Not invited]
     
    We investigated the expression of activin beta A on osteoprogenitor cells in the regenerating bone and bone marrow of the rat femur after drill-hole injury, by immunocytochemistry and in situ hybridization. The periosteum and endosteum adjacent to the wound region showed marked thickening at day 3 and abundant osteoprogenitor cells, which were immunoreactive for proliferating cell nuclear antigen and showed positive reactions for alkaline phosphatase activity, and existed in the inner layer of the periosteum as well as in the endosteum, During the same period, these osteoprogenitor cells began to exhibit activin beta A immunoreactivity and mRNA expression. However, the latter expression gradually reduced the intensity as the cells started to express osteocalcin mRNA during their differentiation to osteoblasts participating in the periosteal and medullary bone formation from day 5. Immunoreactivity for activin type IB and II receptors was also found on activin beta A-immunoreactive cells between days 3 and 7, The above findings suggest that proliferating osteoprogenitor cells, before their transformation to osteoblasts, transiently produce and release activin A, which may play crucial roles in bone and bone marrow regeneration in a receptor-mediated, autocrine and paracrine fashion. (Bone 27:81-90; 2000) (C) 2000 by Elsevier Science Inc. All rights reserved.
  • Y Doi, H Peng, H Kudo, K Hamasaki, S Fujimoto
    NEUROSCIENCE LETTERS 285 (1) 33 - 36 0304-3940 2000/05 [Refereed][Not invited]
     
    We first detected ol-calcitonin gene-related peptide (alpha-CGRP) precursor mRNA in the enteric nervous system (ENS) of rat small intestine by reverse transcriptase polymerase chain reaction (RT-PCR). The nucleotide sequence of the RT-PCR product was completely identical to that found in other organs. fly in situ hybridization using digoxygenin-labeled alpha-CORP precursor cRNA probe, we found that antisense probes detected a signal on nerve cell bodies of both submucosal and myenteric plexuses. Our findings indicate that the rat ENS participates in synthesis of alpha-CGRP precursor. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.
  • M Tamura, H Tanaka, A Yashiro, A Osajima, M Okazaki, H Kudo, Y Doi, S Fujimoto, K Higashi, Y Nakashima, H Hirano
    JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY 11 (3) 423 - 433 1046-6673 2000/03 [Refereed][Not invited]
     
    Profilin binds to actin monomer to regulate actin polymerization, and to phosphatidylinositol 4,5-bisphosphate to inhibit hydrolysis by phospholipase C gamma 1. This study investigated the expression of profilin in rat anti-Thy-1.1 mesangial proliferative glomerulonephritis (GN) and examined the effect of growth factors on its expression in cultured rat mesangial cells. Profilin mRNA was constitutively expressed in isolated glomeruli of untreated rats. However, in glomeruli of anti-Thy-1.1 GN rats, its expression was upregulated beginning on day 1, reaching a peak level on day 4 (3.9-fold versus control glomeruli), and decreased on day 14, as determined by competitive reverse transcription-PCR. Increased expression of profilin protein was confirmed using immunoblotting and immunohistochemistry. Immunoelectron microscopy revealed the presence of profilin in plasma membrane and the rough endoplasmic reticulum of mesangial cells, indicating that profilin was produced in mesangial cells. In cultured rat mesangial cells, expression of profilin mRNA and protein was upregulated by basic fibroblast growth factor but not by platelet-derived growth factor or transforming growth factor-beta. Suppression of profilin expression using an antisense oligonucleotide against profilin inhibited [H-3]thymidine uptake. These findings indicated the involvement of profilin in anti-Thy-1.1 GN and suggest that the upregulation of profilin might be involved in the progression of anti-Thy-1.1 GN possibly by affecting cell growth.
  • H Kudo, Y Doi, T Nishino, S Nara, K Hamasaki, S Fujimoto
    JOURNAL OF NUTRITION 130 (1) 38 - 44 0022-3166 2000/01 [Refereed][Not invited]
     
    Zinc deficiency leads to olfactory and gustatory dysfunction, but little is known about the underlying molecular mechanism of this phenomenon. We examined the effect of dietary zinc deficiency on the rat olfactory epithelium. Immunoreactivities of glutathione S-transferase (GST) mu, neuron-specific enolase (NSE) and proliferating cell nuclear antigen (PCNA), and in situ hybridization of GST mu mRNA in the olfactory epithelia were examined under different dietary zinc intake conditions. Adult male rats were fed a zinc-deficient (ZD) diet (0.5 mg zinc/kg diet), whereas control rats, including pair-fed (PF) and zinc-adequate (ad libitum consumption, AL) groups, were fed a zinc-adequate diet (58 mg zinc/kg diet) for 7 wk. We also examined the effect of zinc replacement (ZR) by subsequently feeding half of the ZD group a zinc-adequate diet for 5 wk after the initial 7-wk deprivation. No significant differences in immunoreactivity for NSE in olfactory epithelial receptor cells or for PCNA in basal cells were noted among groups. Intense GST mu immunoreactivity and hybridization signals were observed in olfactory supporting cells of AL, PF and ZR groups, but very minimal or no such signal was noted in ZD rats. Our findings indicated that zinc deficiency reduces GST mu expression in the supporting cells of rat olfactory epithelia but does not affect receptor cell proliferation or maintenance.
  • M Maeda, H Hirano, H Kudo, Y Doi, K Higashi, S Fujimoto
    NEUROREPORT 10 (9) 1957 - 1960 0959-4965 1999/06 [Refereed][Not invited]
     
    WE investigated the cardiovascular effects of bilateral microinjection of antisense oligodeoxynucleotides (oligos) into the nucleus tractus solitarii (NTS) to neuronal nitric oxide synthase (nNOS) to suppress the expression of nNOS molecular biologically. In urethane-anesthetized, paralyzed Wistar-Kyoto rats, bilateral microinjection of nNOS antisense oligos (20 pmol in a 50 nl volume) into the NTS produced a significant increase in mean arterial blood pressure at 30-60 min after injection, compared with rats injected with nNOS sense or scrambled oligos. Immunohistochemical study demonstrated that nNOS immunoreactivity in the rat NTS was suppressed by nNOS antisense oligos. These results indicate that suppression of the nNOS gene using antisense in the NTS increases blood pressure. NeuroReport 10:1957-1960 (C) 1999 Lippincott Williams & Wilkins.
  • H Kudo, H Ueda, K Mochida, S Adachi, A Hara, H Nagasawa, Y Doi, S Fujimoto, K Yamauchi
    JOURNAL OF NEUROCHEMISTRY 72 (4) 1344 - 1352 0022-3042 1999/04 [Refereed][Not invited]
     
    A salmonid olfactory system-specific protein (N24) that has been identified in lacustrine sockeye salmon (Oncorhynchus nerka) was characterized by biochemical and molecular biological techniques. N24 is a homodimer, and the intact molecular mass is estimated as similar to 43.3 kDa by gel filtration. Furthermore, N24 was located only in the cytosolic fraction of the olfactory tissues as determined by subcellular fractionation, cDNA encoding the lacustrine sockeye salmon N24 was isolated and sequenced. This cDNA contained a coding region encoding 216 amino acid residues and the molecular mass of this protein is calculated to be 242,224.77. The protein and nucleotide sequencing demonstrates the existence of a remarkable homology between N24 and glutathione S-transferase (GST; EC 2.5.1.18) class pi enzymes. Northern analysis showed that N24 mRNA with a length of 950 bases is expressed in lacustrine sockeye salmon olfactory epithelium. Olfactory receptor cells showed strong hybridization signals for N24 mRNA in the olfactory epithelium. N24 demonstrated glutathione binding activity in affinity-purified GST column experiments. The present study describes for the first time cDNA cloning of GST in fish olfactory epithelium.
  • K. Kayashima, Y. Doi, H. Kudo, H. Kiyonaga, S. Fujimoto
    Medical Electron Microscopy 32 (1) 36 - 42 0918-4287 1999 [Refereed][Not invited]
     
    Vasoactivity after treatment with endothelin (ET)-1 and immunoreactivity for ET-1 and its receptors were investigated in the rat superior mesenteric vasculature (SMV). By measurements of corrosion cast images of the SMVs, it was seen that ET-1 induces remarkable vasocontraction of the distal arterial branches, consisting of small arteries and arterioles, and localized vasoconstriction throughout the venous branches which possess localized medial thickenings. Immunoreactivity for ET-1 was preferentially seen along the endothelia of the proximal arterial branches. Cisterns of the rough endoplasmic reticulum and Weibel-Palade (WP) bodies of the endothelial cells were immunoreacted. Immunoreactivity for the ET(A) receptor was preferentially seen on the media of the distal arterial branches. These findings indicate that endothelial cells of the proximal arterial branches synthesize ET-1 and store it in the WP bodies. Because WP bodies are involved in the release of ET-1, this suggests that this endogenous ET-1, which is released from the proximal arterial branches, may be involved in the regulation of blood flow through the distal arterial branches by mediation of the ET(A) receptor. In addition, it seems likely that ET-1-induced vasoconstriction of the venous branches may act to impel the portal blood flow.
  • H Ueda, M Kaeriyama, K Mukasa, A Urano, H Kudo, T Shoji, Y Tokumitsu, K Yamauchi, K Kurihara
    CHEMICAL SENSES 23 (2) 207 - 212 0379-864X 1998/04 [Refereed][Not invited]
     
    Mechanisms of the amazing ability of salmon to migrate a long distance from open water ro natal streams for spawning are still unknown. Lacustrine sockeye salmon (Oncorhynchus nerka) in Lake Toya offers an excellent model system for studying the orientation mechanism in open water, because mature fish return to the natal area with a high degree of accuracy. First we examined the percentage of fish returning to the natal area after they were released 7 km south of the natal area. Forty percent of control male mature fish and 25% of the fish blinded by injection of a mixture of carbon toner and corn oil into the eyeball were captured in the natal area within 5 days. Forty-four percent of fish with brass rings (control) and 31% of fish with NdFe magnetic rings which interfere with the magnetic cue were captured in the natal area within 3 days. These experiments suggested that, although the number of blinded fish captured in the natal area was less than that of the controls, the difference was not statistically significant. In the fish captured in the natal area within 3 or 5 days, fish which found the natal area using their olfactory cue after random swimming for a long time and returned to that area may be included. Hence we tracked fish telemetrically using an ultrasonic tracking system, and found that mature males released at a long distance (3.6 or 6.8 km) from the natal area swam straight to the vicinity of the natal area. Interference of the magnetic cue by the attachment of a magnetic ring did not affect their direct return. Blockage of the visual cue caused them to move randomly. These data suggest that lacustrine sockeye salmon return straight to the vicinity of the natal area using their visual cue and finally reach the exact homing point using their olfactory cue.
  • T Nomiyama, Y Doi, H Kudo, H Furukawa, K Hamasaki, S Fujimoto
    ACTA ANATOMICA 162 (1) 23 - 32 0001-5180 1998 [Refereed][Not invited]
     
    The differentiating cavernous body (CB) of postnatal rabbit penises was examined with a special reference to immunolocalizations for fibronectin (FN) and endothelin-1 (ET-1). At postnatal day 1, the CBs were embedded by an abundance of mesenchymal cells (MCs), and some of them were closely associated with endothelial cells of preexisting capillaries. Our electron micrographs indicated that such MCs are successively incorporated into the capillary endothelium as vasoformative cells. At this period, vascular sprouts of the helicine artery (HA), which were associated with the MCs, arose from the deep penile artery, and the transformation of such cells to endothelial and medial muscle ones was also indicated, and some MCs appeared to differentiate to epithelioid cells in the media. Immunoreactions for FN were preferentially localized in the rough endoplasmic reticulum (rER) and along the plasma membrane of such vasoformative MCs, and on the extracellular matrix components which connect these MCs with sprouts of both growing capillaries and HA. These findings suggest that FN, which is produced in the rER of the MCs, plays a crucial role in the mechanical linkage during the incorporation of vasoformative MCs into these penile vessels. Immunoreactions for ET-1 were preferentially localized on Weibel-Palade bodies in endothelial cells of the HA, implying the involvement of this peptide in the regulation of the local blood flow in this vessel.
  • Y Kanazawa, Y Doi, H Kudo, S Fujimoto
    JOURNAL OF ELECTRON MICROSCOPY 47 (1) 87 - 92 0022-0744 1998 [Refereed][Not invited]
     
    In the rat hind limb bud aged between prenatal days 14 and 16, immunoreactions of fibronectin in the apical ectodermal ridge were localized on the plasma membranes of epidermal cells and cytoplasmic projections of the underlying mesenchymal cells, which are in contact with the basal lamina. Those of integrin alpha(3) and alpha(5) subunits also appeared on such areas. Definite immunoreactions of fibronectin and both integrin subunits were seen in cell to cell contact areas of mesenchymal cells which are associated with the marginal vein, or with each other forming solid cell cords, and appeared on the basal plasma membrane of endothelial cells of the growing capillaries arising from the marginal vein. These findings suggest that fibronectin may work as a ligand for alpha(3) beta(1) and/or alpha(5) beta(1) integrins expressed by the mesenchymal and vasoformative cells in developing limb bud.
  • E Toyama, Y Doi, H Kudo, T Fujimura
    ARCHIVES OF HISTOLOGY AND CYTOLOGY 60 (3) 235 - 244 0914-9465 1997/08 [Refereed][Not invited]
     
    The differentiating choroid plexus in rats at ages ranging from prenatal day 16 to postnatal day 3 was investigated with a special emphasis on the immunolocalization of Na+. K(+)ATPase in the choroid epithelium and neocapillarization of the choroid stroma. Immunoreactions for Na+. K(+)ATPase were localized on the apical plasma membrane of the simple choroid epithelium throughout the stages examined, but it also appeared on the basolateral plasma membrane till prenatal day 18, prior to the formation of the tight junctions as seen from both a marker experiment using lanthanum chloride and immunoreactions for tight junction-associated protein (ZO-1). This suggests that a polarity of the enzyme localization to the apical plasma membrane may take place after the establishment of the blood-cerebrospinal fluid barrier. Mesenchymal cells in the choroid stroma immunoreacted to the laminin antibody and occasionally contacted each other-forming solid cell cords-or endothelial cells of the preexisting capillaries. The contact areas immunoreacted to this antibody. Since there were few or no mitotic figures of the endothelial cells, the involvement of laminin in a mechanical linkage between the adjacent vasoformative mesenchymal cells as well as the endothelial lining in a manner suggestive of vasculogenesis was indicated.
  • H Kudo, H Ueda, K Yamauchi
    ZOOLOGICAL SCIENCE 13 (5) 647 - 653 0289-0003 1996/10 [Refereed][Not invited]
     
    Immunocytochemical and immunoelectron microscopic localizations of a salmonid olfactory system-specific protein (N24) were investigated in the olfactory system (the olfactory epithelium, the olfactory nerve and the olfactory bulb) of kokanee salmon (Oncorhynchus nerka) by using a specific antiserum to N24. N24 immunoreactivities were observed in the cytoplasm of ciliated and microvillous olfactory receptor cells but were not observed in the supporting and the basal cells in the olfactory epithelium. Gold particles showing immunoreactivities for N24 were scattered in the cytoplasm of the dendrites of olfactory receptor cells. Some particles were concentrated on vesicular structures, but none were observed in the membrane of olfactory receptor cells. N24 immunoreactive axons were terminated at the glomerular layer near the mitral cells in the olfactory bulb. In an olfactory rosettectomy experiment, N24 immunoreactivity in the olfactory bulb vanished fifteenth day after the excision of the olfactory rosette. These results reveal that the olfactory receptor cells produce N24 which exists in both dendrites and axons of the olfactory receptor cells, and suggest that N24 may participate in neuromodulation in the olfactory system of kokanee salmon.
  • H Kudo, S Hyodo, H Ueda, O Hiroi, K Aida, A Urano, K Yamauchi
    CELL AND TISSUE RESEARCH 284 (2) 261 - 267 0302-766X 1996/05 [Refereed][Not invited]
     
    Cytophysiology of gonadotropin-releasing-hormone neurons in chum salmon (Oncorhynchus keta) was examined before and after upstream migration by an immunocytochemical technique with a specific antiserum to salmon gonadotropin-releasing hormone and an in situ hybridization technique with an Oligonucleotide encoding salmon gonadotropin-releasing-hormone precursor (pro-salmon gonadotropin-releasing hormone). In the forebrain (olfactory nerve, olfactory bulb, telencephalon, and preoptic area), salmon gonadotropin-releasing hormone-immunoreactive neurons and neurons showing signals for pro-salmon gonadotropin-releasing-hormone mRNA were compared between fish from the coastal sea and those from the spawning ground, Neurons in the dorsal region of the olfactory nerve and in the ventral region of the transitional area between olfactory nerve and olfactory bulb showed strong salmon gonadotropin-re leasing-hormone immunoreactivity and strong hybridization signals in fish from the coastal sea, but these activities and signals were not observed or were decreased in number in fish from the spawning ground. The neurons in the olfactory bulb, telencephalon, and preoptic area consistently revealed salmon gonadotropin-releasing-hormone immunoreactivity and hybridization signals, and the hybridization signals of salmon gonadotropin-releasing hormone in the telencephalon and the preoptic area were stronger in fish from the spawning ground than in those from the coastal sea. These findings suggest that salmon gonadotropin-releasing-hormone neurons in the olfactory nerve and the transitional area between olfactory nerve and olfactory bulb have different patterns of hormone production than those in the telencephalon and the preoptic area.
  • H UEDA, M SHIMIZU, H KUDO, A HARA, O HIROI, M KAERIYAMA, H TANAKA, H KAWAMURA, K YAMAUCHI
    FISHERIES SCIENCE 60 (2) 239 - 240 0919-9268 1994/04 [Refereed][Not invited]
  • Kudo H., Tsuneyoshi Y., Nagae M., Adachi S., Yamauchi K., Ueda H., Kawamura H.
    Aquaculture and Fisheries Management Blackwell Publishing 25 (Supplement 2) 171 - 182 1355-557X 1994 [Refereed][Not invited]
     
    Thyroid hormone regulates a number of physiological functions during smolting in salmonids. However, the target sites and roles of thyroid hormone in the central nervous system (CNS) are not known in detail. We detected thyroid hormone-specific binding sites (i.e. thyroid hormone receptors) in the olfactory epithelium and the brain (the olfactory bulb, the telencephalon, the mid-brain and the cerebellum) of wild masu salmon, Oncorhynchus masou (Brevoort), during smolting by means of in vitro autoradiography with frozen sections. A saturation experiment with the brain indicated the presence of a single class of binding sites of high affinity. T3-specific binding was detected in the olfactory epithelium and in all regions of the brain except the olfactory bulb. The T3-specific binding value in the olfactory epithelium was higher than in all other regions of the brain. This binding value in the olfactory epithelium increased at the full-smolt stage. The presence of thyroid hormone receptors in various regions of the CNS suggests that thyroid hormone plays an important role in the functional change in the brain and the olfactory epithelium during smolting.
  • H KUDO, H UEDA, H KAWAMURA, K AIDA, K YAMAUCHI
    NEUROSCIENCE LETTERS 166 (2) 187 - 190 0304-3940 1994/01 [Refereed][Not invited]
     
    Immunocytochemical and immunoelectron microscopic localization of salmon-type gonadotropin-releasing hormone (sGnRH) were observed in the olfactory system (olfactory epithelium, olfactory nerve and olfactory bulb) of masu salmon (Oncorhynchus masou) to investigate its possible involvement in the olfactory functions. sGnRH-immunoreactive (ir) bipolar neuron, which might be related to the terminal nerve, was located in dorsal portion of the olfactory nerve. sGnRH-ir gold particles were concentrated on electron-dense granule-like structures of 50 nm in diameter in fibers of the olfactory nerve close both to the olfactory epithelium and to the olfactory bulb. These findings suggest that sGnRH might participate in neurotransmisson and/or neuromodulation in the olfactory system of masu salmon. sGnRH would become a useful molecular marker for studying the olfactory imprinting and homing mechanisms in salmonids.
  • H UEDA, H KUDO, M SHIMIZU, K MOCHIDA, S ADACHI, K YAMAUCHI
    ZOOLOGICAL SCIENCE 10 (4) 685 - 690 0289-0003 1993/08 [Refereed][Not invited]
     
    An olfactory system-specific protein (N24; molecular weight 24 kDa) was examined for immunological similarity to proteins from various organs (heart, intestine, kidney, muscle, ovary and testis) of mature kokanee salmon (Oncorhynchus nerka) by means of Western blotting analysis using a polyclonal antibody to N24. The antibody recognized one 24 kDa protein in the testis but none in the other organs examined. Immunoelectron microscopic analysis revealed that immunoreactive gold particles were mainly concentrated on the nuclei of spermatids and spermatozoa, while no specific gold particles were observed on the nuclei and the cytoplasm of spermatogonia, spermatocytes, Sertoli, Leydig and peritubular cells in maturing and mature testes of kokanee salmon. This is the first description of an antigenic similarity between an olfactory system-specific protein and a testicular germ cell protein in the animal kingdom. This corresponding protein may prove to be a useful molecular marker for studying the mechanism of sperm chemotaxis during fertilization.
  • M SHIMIZU, H KUDO, H UEDA, A HARA, K SHIMAZAKI, K YAMAUCHI
    ZOOLOGICAL SCIENCE 10 (2) 287 - 294 0289-0003 1993/04 [Refereed][Not invited]
     
    An olfactory system-specific protein of 24 kDa (N24) was identified in kokanee salmon (Oncorhynchus nerka) by the comparison of proteins restricted to the olfactory system (olfactory epithelium, olfactory nerve and olfactory bulb) with those found in other parts of the brain (telencephalon, optic tectum, cerebellum, hypothalamus) and hypophysis. A polyclonal antibody to N24 was raised in a rabbit, and the specificity of the antiserum was examined by Western blotting analysis; the antiserum recognized only one 24 kDa band in the olfactory system but not in other parts of the brain in kokanee salmon, sockeye salmon (O. nerka), masu salmon (O. masou) and chum salmon (O. keta). Immunocytochemical analysis revealed that positive immunoreactivity occurred exclusively in the olfactory nerve and in some olfactory neuroepithelial cells. Both at the time of imprinting of maternal stream odorants and at the time of homing to the maternal stream, the immunoreactivity of N24 in fish in the maternal stream was stronger than that in seawater fish. The present study indicates that an olfactory system-specific protein may be importantly related to both imprinting and homing mechanisms in salmonids.

MISC

  • Olfactory nerve system and olfactory imprinting-related molecules in anadromous Pacific salmon
    KUDO Hideaki  Aroma Research  19-  (2)  3  -8  2018/05  [Not refereed][Invited]
  • 大門純平, 綿貫豊, 工藤秀明, 越野陽介  日本水産学会大会講演要旨集  2017-  2017
  • Takashi Abe, Yui Minowa, Masaki Kobayashi, Hideaki Kudo  CHEMICAL SENSES  41-  (9)  E140  -E140  2016/11  [Not refereed][Not invited]
  • Yui Minowa, Seishi Hagihara, Takashi Abe, Shigeho Ijiri, Shinji Adachi, Hideaki Kudo  CHEMICAL SENSES  41-  (9)  E145  -E145  2016/11  [Not refereed][Not invited]
  • KUDO Hideaki  Aroma Research  16-  (3)  14  -18  2015/08  [Not refereed][Invited]
  • Koshino Yousuke, Kudo Hideaki, Kaeriyama Masahide  North Pacific Anadromous Fish Commission technical report  8-  147  -149  2012
  • 小倉優一郎, SEEB J. E, 東典子, 工藤秀明, 阿部周一, 帰山雅秀  日本水産学会大会講演要旨集  2010-  53  2010/09/22  [Not refereed][Not invited]
  • 越野陽介, 横山雄哉, 宮本幸太, 吉原啓太, 工藤秀明, 帰山雅秀  日本水産学会大会講演要旨集  2009-  56  2009/03/27  [Not refereed][Not invited]
  • KUDO HIDEAKI, HIDEAKI KUDO  日本水産学会誌 = Bulletin of the Japanese Society of Scientific Fisheries  74-  (6)  1139  -1141  2008/11/15
  • Hideaki Kudo, Yoshiaki Doi, Hiroshi Ueda, Masahide Kaeriyama  CHEMICAL SENSES  33-  (8)  S62  -S62  2008/10  [Not refereed][Not invited]
  • 帰山 雅秀, 工藤 秀明  Kaiyo monthly  39-  (5)  314  -316  2007/05
  • 宮本幸太, 川合範明, 秋山信彦, 工藤秀明, 帰山雅秀  日本水産学会大会講演要旨集  2007-  72  2007/03/28  [Not refereed][Not invited]
  • Where, when, and how does mortality occur for juvenile chum salmon Oncorhynchus keta in their first ocean year?
    North Pacific Anadromous Fish Commission Technical Report  7-  52  -55  2007  [Not refereed][Not invited]
  • A comparison of secondary sexual characters and age composition of wild and hatchery chum salmon (Oncorhynchus keta) in the Yurappu River, Southern Hokkaido in Japan
    Imai N, Sagawa Y, Kudo H, Kaeriyama M  North Pacific Anadromous Fish Commission Technical Report  7-  115  -116  2007  [Not refereed][Not invited]
  • Comparison of feeding pattern of Pacific salmon between the Western subarctic gyre and the Gulf of Alaska in Summer 2005
    Sagawa Y, Imai N, Kudo H, Kaeriyama M  North Pacific Anadromous Fish Commission Technical Report  7-  85  -87  2007  [Not refereed][Not invited]
  • Yoshiaki Doi, Hideaki Kudo, Tomoko Nishino, Sunao Fujimoto  Journal of UOEH  25-  (4)  409  -417  2003/12/01  [Not refereed][Not invited]
     
    Vasculogenesis is defined as a neovascularization manner by which endothelial progenitor cells are successively incorporated into the growing capillaries, whereas angiogenesis is another neovascularization manner which includes mitotic proliferations of endothelial cells of the preexisting capillaries and their migration to the vascular tips forming so called "vascular sprouts" or "endothelial buds". Although angiogenesis had been considered to be more prevalent during organogenesis as well as during a wound healing process of adult mammals, recent findings that endothelial progenitor cells were isolated from human peripheral blood and incorporated into sites of active neovascularization have led many researchers to recognize the significance of vasculogenesis in a phenomenon of neovascularization. This paper mainly deals with the history of morphological approaches to clarify the crucial roles of vasculogenesis during organogenesis and a wound healing process.
  • S Uchida, H Kudo, A Sakai, K Narusawa, M Tanaka, M Watanuki, T Nakamura  JOURNAL OF BONE AND MINERAL RESEARCH  16-  S176  -S176  2001/09  [Not refereed][Not invited]
  • S Fujimoto, Y Doi, H Kudo, T Nishino  7TH WORLD CONGRESS FOR MICROCIRCULATION  347  -351  2001  [Refereed][Not invited]
     
    In neovascularization during organogenesis and wound healing, mesenchymal cells under mitotic proliferation were occasionally associated with growing capillaries, or in contact with the endothelium by expressing immunoreactivities for VEGF/flk-1 and von Willebrand factor. Immunoreactivities for fibronectin and/or laminin in the rough endoplasmic cisterns of such cells, and those for integrin alpha(3) and alpha(5) subunits in addition to the above glycoproteins in the cell areas were noticed. In cultured mesenchymal cells of rabbit phalli, the cell proliferation and cell to cell contact accelerated in bFGF-containing media. These findings indicated the involvement of mesenchymal cells as endothelial precursor cells in neovascularization in a manner of vasculogenesis. The roles of bFGF, and fibronectin and/or laminin in the promotion of vasculogenesis by a receptor-mediated manner were also indicated.
  • Y Doi, H Kudo, S Nara, T Nishino, S Fujimoto  7TH WORLD CONGRESS FOR MICROCIRCULATION  323  -327  2001  [Refereed][Not invited]
     
    By perfusion of the superior mesenteric artery of male Wistar rat either with normoxic or hypoxic Hanks' balanced salt solution (HBSS), the hypoxic group induced a severe vasocontraction of the distal arterial branches as revealed by the corrosion cast image. Immunoreactivities for endothelin (ET)-1 as well as for endothelial nitric oxide synthase (eNOS) were seen along the endothelium in both groups, but immunoreactive intensity for eNOS significantly decreased in the hypoxic group. The aggregation of Weibel-Palade (WP) bodies, which are immunoreacted with ET-1, to the apical portion of endothelial cells uniquely occurred in the proximal arterial branch of the hypoxic group. These findings indicate that synergic actions of enhanced ET-1 release from the endothelial cells via WP bodies and of decreased endothelial NO synthesis are involved in the hypoxic vasocontraction.
  • S Uchida, K Narusawa, W Makoto, H Kudo, S Fujimoto, T Nakamura  JOURNAL OF BONE AND MINERAL RESEARCH  15-  S548  -S548  2000/09  [Not refereed][Not invited]
  • Mochida K., Matsubara T., Kudo H., Adachi S., Ueda H., Yamauchi K.  Zoological science  17-  58  -58  2000
  • S Fujimoto, Y Doi, H Fukushige, H Kudo, T Nishino  21ST EUROPEAN CONFERENCE ON MICROCIRCULATION  33  -37  2000  [Refereed][Not invited]
     
    Immunoreactivities for big endothelin (ET)-1 and ET-1, and gene expressions for preproET-1mRNA were preferentially seen along the endothelium of interlobular vein (IV) in rat liver vasculature. Rough endoplasmic cisterns and Weibel-Palade (WP) bodies in endothelial cells of IV were immunoreactive for big ET-I and ET-1, respectively. These indicate the involvement of the endothelial cells in synthesis of ET-1, which is in part stored in WP bodies. Since hepatic stellate cells (HSCs) were immunoreactive for ET receptor A and B (ETA and ETB), it is thought that ET-1 receptor-mediated HSC contraction regulates hepatic sinusoidal blood flow. The sarcolemma of smooth muscle cells in IV was also immunoreactive for ETA. This implies that IV, receiving a large amount of the portal blood inflow, participates in pump mechanism toward hepatic sinusoidal circulation in a receptor-mediated paracrine fashion.
  • T Ozaka, Y Doi, H Kudo, S Fujimoto  CONTROL MECHANISMS OF STRESS AND EMOTION: NEUROENDOCRINE-BASED STUDIES  1185-  259  -261  1999  [Refereed][Not invited]
     
    The rat carotid body under hypoxic conditions was investigated by electron microscopy, immunocytochemistry and in situ hybridization A remarkable increase in the number of Weibel-Palade (WP) bodies, which occasionally undergo degranulation and exocytosis, occurred in endothelial cells of the hypoxic carotid body artery (CBA). The degree of immunoreactivities and gene expressions of calcitonin gene-related peptide (CGRP) and endothelin (ET)-1 was significantly enhanced in the hypoxic samples when compared to the normoxic ones. Since WP bodies are involved in the storage and release of these peptides, the present findings indicate that CGRP and ET-I, which are actively synthesized and released from endothelial cells, play a crucial role in the regulation of blood flow through the CBA in hypoxic conditions.
  • M Maeda, H Hirano, H Kudo, Y Doi, K Higashi, S Fujimoto  CONTROL MECHANISMS OF STRESS AND EMOTION: NEUROENDOCRINE-BASED STUDIES  1185-  293  -295  1999  [Refereed][Not invited]
     
    In the present study, we investigated the cardiovascular effects of bilateral microinjection of an antisense nNOS (neuronal nitric oxide synthase) oligonucleotide into the nucleus tractus solitarii (NTS). The antisense was designed to target a region of the rat nNOS mRNA that contains the initiation codon, with a sequence of 5'-CTTCCATGGTATCTGTG-3'; and its corresponding sense sequence (5'-CACAGATACCATGGAAG-3') and scrambled sequence (5'-CGTAGTAGGCATACGTA-3') were designed. The oligonucleotide was diluted in artificial cerebrospinal fluid and mixed with cationic lipids for transfection. Bilateral microinjection of antisense nNOS oligonucleotide (20 pmol/50 nl) into the NTS in urethane-anesthetized, paralyzed Wistar-Kyoto rats (n = 7) produced a significant increase in arterial blood pressure 30-60 min after the microinjection as compared with the changes produced by bilateral microinjection of sense nNOS oligonucleotide (n = 5) or scrambled oligonucleotide (n = 5) into the NTS. Bilateral microinjection of the antisense nNOS produced a significant increase in heart rate 30 min after the microinjection as compared with the change produced by bilateral microinjection of the sense nNOS. Immunohistochemical study showed that nNOS in the NTS was inhibited by the microinjection of the antisense. These results suggest that expression of the nNOS gene in the NTS may regulate circulation.
  • K Kayashima, H Kudo, Y Doio, S Fujimoto  JOURNAL OF CARDIOVASCULAR PHARMACOLOGY  31-  S126  -S127  1998  [Refereed][Not invited]
     
    Immunocytochemistry of endothelin-1 (ET-1) and the ETA receptor, and scanning electron microscopy using cast resin after treatment with ET-1, were carried out in the rat mesenteric microvasculature. Immunoreaction of ET-1 was preferentially seen along the endothelium of the proximal portion of the anterior mesenteric artery, the endothelial cells of which contain abundant Weibel-Palade (WP) bodies. However, the arterioles and small veins distal to the artery showed Little immunoreactivity but showed heavy immunoreaction of ETA receptors in the media. By scanning electron microscopy after treatment with ET-1, the mesenteric micro vasculature became slightly narrower compared to the control exhibited of localized constricted areas, especially in the region of the small veins. Light microscopy of such areas revealed localized thickening of the medial muscle cells. Because the release of ET-1 from endothelial cells depends in part on extracellular discharge of the WP bodies, the results indicate that ET-1, discharged from the proximal portion of the anterior mesenteric artery, induces vasoconstriction of the arterioles and small veins, mediated by ETA receptors. The localized thickening in areas in the media of the small veins may participate in the maintenance of blood flow through the portal circulation.
  • Hideaki Kudo, Susumu Hyodo, Hiroshi Ueda, Osamu Hiroi, Katsumi Aida, Akihisa Urano, Kohei Yamauchi  Cell and Tissue Research  284, 261-267-  261  -267  1996/05/21  [Not refereed][Not invited]
     
    Cytophysiology of gonadotropin-releasing-hormone neurons in chum salmon (Oncorhynchus keta) was examined before and after upstream migration by an immunocytochemical technique with a specific antiserum to salmon gonadotropin-releasing hormone and an in situ hybridization technique with an oligonucleotide encoding salmon gonadotropin-releasing-hormone precursor (pro-salmon gonadotropin-releasing hormone). In the forebrain (olfactory nerve, olfactory bulb, telencephalon, and preoptic area), salmon gonadotropin-releasing hormone-immunoreactive neurons and neurons showing signals for pro-salmon gonadotropin-releasing-hormone mRNA were compared between fish from the coastal sea and those from the spawning ground. Neurons in the dorsal region of the olfactory nerve and in the ventral region of the transitional area between olfactory nerve and olfactory bulb showed strong salmon gonadotropin-releasing-hormone immunoreactivity and strong hybridization signals in fish from the coastal sea, but these activities and signals were not observed or were decreased in number in fish from the spawning ground. The neurons in the olfactory bulb, telencephalon, and preoptic area consistently revealed salmon gonadotropin-releasing-hormone immunoreactivity and hybridization signals, and the hybridization signals of salmon gonadotropin-releasing hormone in the telencephalon and the preoptic area were stronger in fish from the spawning ground than in those from the coastal sea. These findings suggest that salmon gonadotropin-releasing-hormone neurons in the olfactory nerve and the transitional area between olfactory nerve and olfactory bulb have different patterns of hormone production than those in the telencephalon and the preoptic area.

Books etc

  • 魚に魅せられた北大の研究者たち (Contributor)
    海文堂出版 2023/10 (ISBN: 9784303800116) 97p
  • 北海道大学水産学部練習船教科書編纂委員会 (Contributor)
    海文堂出版 2019/08 (ISBN: 9784303115005) vii, 242p
  • 日本魚類学会 (Contributor)
    丸善出版 2018/10 (ISBN: 9784621303177) xxv, 718p, 図版 [8] p
  • 海をまるごとサイエンス
    工藤 秀明 (Contributor叫びたくなるサケの凄技！ 母川刷込の解明を目指す)
    海文堂 2018
  • フィールドから考える地球の未来 −地域と研究者の対話
    工藤 秀明 (Contributorpp 162-178 津軽海峡がつなぎ、もたらすもの 〜青森県大間町と北海道函館市を歩く（秋道智彌・家田 修・工藤秀明）)
    昭和堂 2016
  • 練習船による水産科学・海洋環境科学実習
    工藤 秀明 (Contributorpp 12-23 魚類 (サケ・マス))
    五稜出版社 2016
  • サケ学大全
    工藤 秀明 (Contributorpp 103-108 サケの第二次性徴 背中の盛り上がりの中身は？)
    北海道大学出版会 2013

Association Memberships

  • 日本味と匂学会   日本水産学会   

Research Projects

  • サケの興奮嗅細胞分析と網羅的河川水有機化合物分析による母川刷込ニオイ分子の探索
    日本学術振興会：科学研究費補助金 基盤研究C
    Date (from‐to) : 2017/04 -2021/03 
    Author : 工藤 秀明
  • 日本学術振興会：科学研究費補助金 基盤研究C
    Date (from‐to) : 2014/04 -2017/03 
    Author : 工藤 秀明
  • 北海道の自然産卵サケ類における回遊履歴情報の資源管理への応用
    公益財団法人 北水協会：北水協会水産学術研究補助事業
    Date (from‐to) : 2013/04 -2016/03 
    Author : 工藤 秀明
  • サケ類における母川刷込関連脳領域の解明：嗅神経一次投射領域の神経解剖学的解析
    日本学術振興会：科学研究費補助金 基盤研究C
    Date (from‐to) : 2011/04 -2014/03 
    Author : 工藤 秀明
  • 我が国の野生サケの保全を目指した環境生物学的研究
    公益財団法人 住友財団：住友財団環境研究助成（一般）
    Date (from‐to) : 2011/04 -2013/03 
    Author : 工藤 秀明
  • ラジコンヘリコプターを用いた航空センサスによる野生シロザケ産卵遡上動態の解析
    公益財団法人 北水協会：北水協会水産学術研究補助事業
    Date (from‐to) : 2010/04 -2013/03 
    Author : 工藤 秀明
  • カラフトマスの性成熟に伴う背部隆起の解明：海洋由来コラーゲンの有効利用を目指して
    公益財団法人 秋山記念生命科学振興財団：秋山記念生命科学振興財団 研究助成（一般）
    Date (from‐to) : 2011/04 -2012/03 
    Author : 工藤 秀明
  • 母川刷込関連時期におけるサケ類嗅上皮の細胞動態と甲状腺ホルモンレセプター発現
    日本学術振興会：科学研究費補助金 基盤研究C
    Date (from‐to) : 2008/04 -2011/03 
    Author : 工藤 秀明
  • 環境変動に対するベーリング海・チャクチ海の海洋生態系の応答
    日本学術振興会：科学研究費補助金 基盤研究B
    Date (from‐to) : 2007/04 -2010/03 
    Author : 平譯 亨
  • 知床世界自然遺産エリアの保全と順応的管理:海域-陸域生態系の相互作用
    日本学術振興会：科学研究費補助金 基盤研究A
    Date (from‐to) : 2006/04 -2010/03 
    Author : 斎藤 誠一
  • 野生サケ類の産卵遡上動態解析のための航空センサス無人飛行システムの開発
    日本学術振興会：科学研究費補助金 萌芽研究
    Date (from‐to) : 2007/04 -2009/03 
    Author : 帰山 雅秀
  • サケ属魚類嗅上皮における薬物代謝関連分子による化学的恒常性維持に関する研究
    公益財団法人 秋山記念生命科学振興財団：秋山記念生命科学振興財団 研究助成（奨励）
    Date (from‐to) : 2007/04 -2008/03 
    Author : 工藤 秀明
  • ゼブラフィッシュ嗅上皮における薬物代謝関連分子検出系の水質汚染評価への応用
    日本学術振興会：科学研究費補助金 若手研究B
    Date (from‐to) : 2005/04 -2008/03 
    Author : 工藤 秀明
  • 線維芽細胞に由来する血管内皮前駆細胞の同定
    日本学術振興会：科学研究費補助金 基盤研究C
    Date (from‐to) : 2003/04 -2006/03 
    Author : 土肥 良秋
  • 嗅上皮における薬物代謝第三相（多剤耐性関連タンパク）による異物排出機構
    日本学術振興会：科学研究費補助金 若手研究B
    Date (from‐to) : 2002/04 -2005/03 
    Author : 工藤 秀明
  • 延髄孤束核での一酸化窒素合成酵素の単一分子の動きの観察
    日本学術振興会：科学研究費補助金 基盤研究C
    Date (from‐to) : 2000/04 -2002/03 
    Author : 前田 正信
  • ラット嗅上皮における嗅覚障害誘発因子の検索
    日本学術振興会：奨励研究A
    Date (from‐to) : 1999/04 -2001/03 
    Author : 工藤 秀明
  • 血管内皮細胞ワイベル・パラーデ小体のエンドセリン-1生合成・修飾過程に果たす役割
    日本学術振興会：科学研究費補助金 基盤研究C
    Date (from‐to) : 1999/04 -2001/03 
    Author : 藤本 淳
  • nNOSアンチセンスDNAを延髄孤束核へ導入した時の循環への効果
    ファイザー：第3回ファイザー循環器病研究助成
    Date (from‐to) : 1998/04 -1999/03 
    Author : 前田 正信
  • 循環調節ペプチドとその受容体の免疫細胞化学と分子組織化学
    日本学術振興会：科学研究費補助金 基盤研究C
    Date (from‐to) : 1997/04 -1999/03 
    Author : 藤本 淳

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