2022/01/05 更新

写真a

ヤマモト ユキ
山本 ゆき
YAMAMOTO Yuki
所属
環境生命科学学域 准教授
職名
准教授
外部リンク

学位

  • 博士 (獣医学) ( 岐阜大学 )

研究分野

  • ライフサイエンス / 動物生産科学

 

論文

  • Hyperthermia alters interleukin-6 production in response to lipopolysaccharide via endoplasmic reticulum stress in bovine endometrial cells. 国際誌

    Shunsuke Sakai, Yuki Inoue, Keisuke Tanaka, Yuki Yamamoto, Hisataka Iwata, Koji Kimura

    Journal of cellular physiology   2021年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    In the postpartum period, cows experience the uterine bacterial infection and develop the endometritis. To eliminate bacteria and recover from endometritis, endometrial epithelial and stromal cells secrete the cytokine and chemokine, such as interleukin 6 (IL-6), IL-8, and monocyte chemotactic protein 1 (MCP1), to recruit immune cells. Moreover, the symptom of endometritis is prolonged in summer and we have recently indicated that hyperthermia suppresses and enhances the IL-6 production in response to lipopolysaccharide (LPS) challenge in endometrial epithelial and stromal cells, respectively. However, the mechanisms for the opposite reaction of IL-6 secretion in response to LPS challenge in both types of endometrial cells under hyperthermia conditions were still unclear. To reveal these mechanisms, both types of endometrial cells were cultured with LPS under the control (38.5°C) or hyperthermia (40.5°C) conditions and comprehensively analyzed differential gene expressions of them by RNA-seq. In addition, based on these results, we examined the effect of endoplasmic reticulum (ER) stress on the IL-6 production in both types of endometrial cells cultured with LPS under hyperthermia conditions. In comprehensive analysis, hyperthermia induced the ER stress in the endometrial stromal cells but not in the endometrial epithelial cells. Actually, we confirmed that hyperthermia increased the gene expression of BiP, ATF4, and sXBP1 and protein expression of BiP and phosphorylated inositol requiring 1, ER stress marker, in the endometrial stromal cells but not in the endometrial epithelial cells. Moreover, in the endometrial stromal cells exposed to LPS, activation and inhibition of ER stress enhanced the IL-6 production under control conditions and suppressed it under hyperthermia conditions, respectively. In this study, we could uncover the one of causes for the disruption of IL-6 production in response to LPS challenge in the endometrial cells under hyperthermia conditions. This finding might be a clue for the improvement of the symptom of endometritis in cows during summer.

    DOI: 10.1002/jcp.30604

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  • Effects of cortisol on prostaglandin F2α secretion and expression of genes involved in the arachidonic acid metabolic pathway in equine endometrium - In vitro study. 国際誌

    Anna Z Szóstek-Mioduchowska, Haruki Shiotani, Yuki Yamamoto, Agnieszka Sadowska, Anna Wójtowicz, Keisuke Kozai, Takuo Hojo, Koji Kimura, Dariusz J Skarzynski, Kiyoshi Okuda

    Theriogenology   173   221 - 229   2021年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Glucocorticoids (GCs) are known to play an important role in maintaining basal and stress-related homeostasis by interacting with endocrine mediators and prostaglandins (PGs). Although a growing body of evidence shows that GCs exert their regulatory action at a multitude of sites in the reproductive axis through corticosteroid receptors, little is known about the direct role of cortisol, an active form of GCs, in the equine endometrium. Thus, the study aimed to determine the effect of cortisol on PGF2α synthesis in the endometrial tissue and cells in vitro. In Exp.1, the immunolocalization and the expression of the glucocorticoid receptor (GCR) in the endometrium throughout the estrous cycle were established. In Exp. 2 and 3, the effects of cortisol on PGF2α secretion and transcripts associated with the arachidonic acid (AA) cascade in endometrial tissues, and cells were defined. Endometrial tissues obtained from the early, mid, and late luteal phases and the follicular phase of the estrous cycle were exposed to cortisol (100, 200, and 400 nM) for 24 h. Endometrial epithelial and stromal cells (early phase of estrous cycle) were exposed to cortisol (100 nM) for 24 h. Then, PGF2α secretion and transcripts associated with the AA cascade (PLA2G2A, PLA2G4A, PTGS2, and PGFS) were assessed. GCR was expressed in the cytoplasm and the nucleus in the luminal and glandular epithelium as well as in the stroma. Endometrial GCR protein abundance was up-regulated at the late luteal phase compared to the mid-luteal phase of the estrous cycle. Cortisol dose-dependently decreased PGF2α secretion, PLA2G2A and PLA2G4A transcripts in endometrial tissues. Additionally, cortisol treatment decreased PGF2α secretion from endometrial epithelial and stromal cells. Moreover, it affected PLA2G2A, PLA2G4A, and PTGS2 transcripts in endometrial stromal cells. These findings suggest that cortisol suppresses the synthesis of PGF2α by affecting the AA cascade in the equine endometrium during the estrous cycle.

    DOI: 10.1016/j.theriogenology.2021.08.009

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  • Heat stress influences the attenuation of prostaglandin synthesis by interferon tau in bovine endometrial cells. 査読 国際誌

    Shunsuke Sakai, Mami Yagi, Nao Fujime, Mariko Kuse, Ryosuke Sakumoto, Yuki Yamamoto, Kiyoshi Okuda, Koji Kimura

    Theriogenology   165   52 - 58   2021年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Heat stress (HS) reduces reproductive performance of cattle, possibly by disrupting endocrine regulation such as prostaglandin (PG) production from uterus and estradiol 17β production from the dominant follicle. Prostaglandin F2α (PGF2α) secretion from endometrium surges during the luteal phase due to tumor necrosis factor (TNF) α stimulation and a positive-feedback loop with oxytocin (OT) from the corpus luteum, ultimately triggering luteolysis, while interferon τ (IFNT) inhibits upregulation of PGF2α production by TNFα and OT, thereby preventing luteolysis and triggering recognition of pregnancy. In the present study, we investigated the effect of OT, TNFα, and IFNT on PGF2α production in both types of endometrial cells under HS conditions. Stimulation of PGF2α production in endometrial epithelial cells by OT was unaffected by HS, while stimulation of PGF2α production in endometrial stromal cells by TNFα was enhanced by HS, and this increased PGF2α production was not significantly suppressed by IFNT. These results suggest that HS disrupted the regulation of PGF2α production by TNFα and IFNT in bovine endometrial stromal cells and it might be one of causes for low conception rate of cattle in summer.

    DOI: 10.1016/j.theriogenology.2021.02.005

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  • Alteration of chemokine production in bovine endometrial epithelial and stromal cells under heat stress conditions 査読 国際誌

    Sakai S, Hatabu T, Yamamoto Y, Kimura K

    Physiological Reports   8 ( 22 )   e14640   2020年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    After parturition, cows frequently develop uterine bacterial infections, resulting in the onset of endometritis. To eliminate the bacteria, bovine endometrial cells secrete chemokines, such as IL-6 and MCP1, which attract macrophages (MΦs) to the subepithelial stroma. These attracted MΦs are not only involved in bacterial elimination but also the orchestration of inflammation and tissue repair. These immune responses aid in the recovery from endometritis; however, the recovery from endometritis takes longer in summer than in any other season. Based on these findings, we hypothesized that heat stress (HS) affects the chemokine production in endometrial cells. To confirm this hypothesis, we compared IL-6 and MCP1 production induced by lipopolysaccharide (LPS) in bovine endometrial epithelial and stromal cells under normal (38.5°C) and HS conditions (40.5°C). In the endometrial epithelial cells, IL-6 production stimulated by LPS was significantly (p < .05) suppressed under HS conditions. MCP1 production in endometrial epithelial cells was not detected under both the control and HS conditions regardless of the presence of LPS. Moreover, LPS significantly (p < .05) stimulated IL-6 and MCP1 production in endometrial stromal cells. Moreover, HS significantly (p < .05) enhanced their production compared to that under the control conditions. In addition, HS did not affect the migration ability of MΦs; however, the supernatant of the endometrial stromal cells cultured under the HS condition significantly (p < .05) attracted the MΦs when compared to the control condition. These results suggest that HS disrupts chemokine production in two types of endometrial cells and alters the distribution of MΦs in the endometrium during the summer.

    DOI: 10.14814/phy2.14640

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  • Involvement of activin signal pathway in cyclic apoptosis of the oviductal isthmic epithelium in cows. 査読 国際誌

    Yuki Yamamoto, Sayaka Ito, Kiyoshi Okuda, Koji Kimura

    Theriogenology   153   143 - 150   2020年9月

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    担当区分:筆頭著者, 責任著者   記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Activin (ACV) A induces various cellular functions via activin receptor type 2 (ACVR2A/2B)-activin receptor-like kinase (ALK) 4 -Smad 2/3 pathway. Although the production of ACVA is indicated in bovine oviducts, its role on the oviduct is unclear. Oviductal isthmus needs to change its function rapidly at peri-fertilization, however, the mechanism is unknown. This study was aimed to clarify the role of ACVA in the morphological changes of oviductal isthmus in cows. First, mRNA expressions of INHBA (ACVA component) and its receptors (ALK4, ACVR2A and ACVR2B) in the isthmic tissues were examined throughout the estrous cycle. INHBA was the highest, however, ACVR2A was the lowest on the day of ovulation, suggesting reduced ACV signal transduction in the isthmus just after ovulation. Proteins of ACVRs and Smad2/3 were clearly detected in the cultured epithelial cells. It is known that ACVA regulates cellular apoptosis. Our data showed that the number of cleaved caspase-3-positive epithelial cells was largest at 2-3 days after ovulation in the isthmus. Interestingly, our study demonstrated that follistatin (ACV/TGFB/BMP inhibitor) significantly decreased the BCL2/BAX ratio in the cultured isthmic epithelial cells. To clarify which ALK pathway is involved in the regulation of BCL2/BAX ratio, the effects of SB431542 (ACV signaling (ALK4) and TGFB signaling (ALK5) inhibitor), SB525334 (ALK5 inhibitor) and LDN193189 (BMP signaling (ALK2/3) inhibitor) were investigated in the next study. The results showed that only SB431542 significantly decreased BCL2/BAX and the others had no effects. These results suggest that decreased ACVA-ACVR2A-ALK4 signal at the post-ovulation induces cyclic apoptosis of isthmic epithelial cells in bovine oviducts.

    DOI: 10.1016/j.theriogenology.2020.05.009

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  • Analysis of ciliogenesis process in the bovine oviduct based on immunohistochemical classification. 査読 国際誌

    Ito S, Yamamoto Y, Kimura K

    Molecular biology reports   47 ( 2 )   1003 - 1012   2019年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1007/s11033-019-05192-w

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  • Prolonged luteal lifespan and pseudopregnancy in Asian elephants (Elephas maximus). 査読

    Lueders I, Niemuller C, Steinmetz HW, Bouts T, Gray C, Knauf-Witzens T, Taya K, Watanabe G, Yamamoto Y, Oerke AK

    Animal reproduction science   197   58 - 66   2018年10月

  • Different origins of two corpora lutea recovered from a pregnant African elephant (Loxodonta africana) 査読

    Y. Yamamoto, K. Nagaoka, Y. Kamite, G. Watanabe, T. Allen, F. Stansfield, K. Taya

    REPRODUCTION IN DOMESTIC ANIMALS   52 ( 6 )   1138 - 1141   2017年12月

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    担当区分:筆頭著者   記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY  

    Elephant ovaries contain multiple corpora lutea (CLs) throughout pregnancy. Two CLs (P-1 and P-2) collected from a pregnant African elephant were used to investigate their origin and physiological state in this study. The mRNA expressions of prolactin receptor, CYP11A and inhibin betaB subunit were higher in P-2 than in P-1, while LHCGR and inhibin betaA subunit mRNA were higher in P-1 than in P-2. Protein expression of cleaved caspase-3 was detected in P-1 but not in P-2. These results suggest different origins for the two CLs in this one pregnant elephant, and we also demonstrated the production of bioactive prolactin by the elephant placenta.

    DOI: 10.1111/rda.13010

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  • Adrenomedullin regulates the speed of oviductal fluid flow in cattle 査読

    Yuka Yoshimoto, Takumi Nishie, Sayaka Ito, Yoshihiko Kobayashi, Yuki Yamamoto, Kiyoshi Okuda, Koji Kimura

    MOLECULAR REPRODUCTION AND DEVELOPMENT   84 ( 8 )   712 - 718   2017年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY  

    Unidirectional flow of oviductal fluid from the ovarian to uterine side of the ampulla plays a significant role in successful pregnancy, and is produced by ciliary beating. Various systems regulate ciliary beating, such as paracrine, autocrine, and endocrine. We hypothesized that Adrenomedullin (ADM)-a peptide hormone that acts via its receptors, which are complexes of Calcitonin receptor-like receptor (CRLR) and Receptor activity-modifying protein (RAMP) 2 or 3-promotes oviductal fluid flow in the ampulla of bovine oviducts. First, we examined the expression of ADM, CRLR, RAMP2, and RAMP3 mRNAs in isolated epithelial cells throughout the estrous cycle, and the localization of ADM receptor protein constituents in the ampulla. RAMP2 expression was significantly higher in the follicular phase. Furthermore, RAMP2 protein was detected only in ciliated cells, whereas CRLR and RAMP3 were detected in all epithelial cells. The effects of ADM and an ADM antagonist on fluid-flow speed were examined using microbeads in ampullary tissue. ADM antagonist decreased bead transport speed, and this decrease was reversed by ADM. In addition, ADM recovered the bead transport speed that decreased in the absence of calcium. Overall, our results suggest that ADM contributes to the regulation of oviductal fluid flow in ampulla.

    DOI: 10.1002/mrd.22852

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  • Expressions of lipoprotein receptors and cholesterol efflux regulatory proteins during luteolysis in bovine corpus luteum 査読

    Kei Horihata, Shin Yoshioka, Masahiro Sano, Yuki Yamamoto, Koji Kimura, Dariusz J. Skarzynski, Kiyoshi Okuda

    REPRODUCTION FERTILITY AND DEVELOPMENT   29 ( 7 )   1280 - 1286   2017年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CSIRO PUBLISHING  

    The corpus luteum (CL) synthesises and secretes progesterone (P4), which is essential for the establishment and maintenance of pregnancy in mammals. P4 is synthesised from cholesterol. Cholesterol is internalised by low-density lipoprotein receptor (LDLR) and/or scavenger receptor B1 (SR-BI), and is effluxed by ATP-binding cassette (ABC) transporter A1 (ABCA1) and G1 (ABCG1). To test the hypothesis that lipoprotein receptors and ABC transporters are involved in functional luteolysis, we examined the expression of LDLR, SR-BI, ABCA1 and ABCG1 in bovine CL during the luteal stages and after injection of prostaglandin (PG) F(2 alpha)on Day 10 after ovulation. Expression of LDLR and SR-BI mRNA and protein was lower in the regressed luteal than late luteal stage. Injection of cows with a PGF(2 alpha) did not affect LDLR mRNA and protein levels in the CL. Although expression of SR-BI mRNA did not change, SR-BI protein expression decreased 12 and 24 h after PGF(2 alpha) injection. The overall findings of the present study suggest that the decreased expression of SR-BI induced by PGF(2 alpha) is one of the factors responsible for the continuous decrease in P4 production during functional luteolysis.

    DOI: 10.1071/RD15538

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  • Local effect of lysophosphatidic acid on prostaglandin production in the bovine oviduct 査読

    Yuka Yoshimoto, Yoshihiko Kobayashi, Izabela Woclawek-Potocka, Emilia Sinderewicz, Yuki Yamamoto, Koji Kimura, Kiyoshi Okuda

    REPRODUCTION FERTILITY AND DEVELOPMENT   29 ( 5 )   1021 - 1028   2017年4月

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    担当区分:責任著者   記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CSIRO PUBLISHING  

    The mammalian oviduct plays an important role in the fertilisation and transport of gametes and embryo. Prostaglandins (PGs) are local mediators of oviductal functions and are involved in fertilisation and the transport of gametes and embryo. Lysophosphatidic acid (LPA), a kind of phospholipid, is involved in various physiological actions. We hypothesised that LPA regulates PG production in the bovine oviduct. To test this hypothesis, we examined the mRNA expression of LPA receptors (LPAR1-6) and LPA-producing enzymes (ATX, PLA1, PLA1) in ampullary and isthmic tissues and in cultured epithelial and stromal cells isolated from the bovine oviduct. We also investigated the effects of LPA on PG synthase expression and PG production in cultured cells. The mRNA of LPAR1-4, 6, ATX and PLA1 were expressed in cultured epithelial and stromal cells. The expressions of LPAR1-3 were significantly lower and the expression of LPAR4 was significantly higher in the isthmic than in the ampullary tissues. Lysophosphatidic acid significantly stimulated PG production in the cultured isthmic stromal cells. The overall findings suggest that LPA stimulates PG production via LPAR4 in the bovine oviduct. Since PGs are important for fertilisation and the transport of gametes and embryo, these findings show that locally produced LPA regulates oviductal functions.

    DOI: 10.1071/RD15409

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  • Hypoxia-inducible factor 1 mediates hypoxia-enhanced synthesis of progesterone during luteinization of granulosa cells 査読

    Fadhillah, Shin Yoshioka, Ryo Nishimura, Yuki Yamamoto, Koji Kimura, Kiyoshi Okuda

    JOURNAL OF REPRODUCTION AND DEVELOPMENT   63 ( 1 )   75 - 85   2017年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SOCIETY REPRODUCTION & DEVELOPMENT-SRD  

    Hypoxia has been suggested to enhance progesterone (P4) synthesis in luteinizing granulosa cells (GCs), but the mechanism is unclear. The present study was designed to test the hypothesis that the hypoxia-induced increase in P4 synthesis during luteinization in bovine GCs is mediated by hypoxia-inducible factor 1 (HIF-1). GCs obtained from small antral follicles were cultured with 2 mu g/ml insulin in combination with 10 mu M forskolin for 24 h as a model of luteinizing GCs. To examine the influence of HIF-1 on P4 synthesis, we determined the effect of changes in protein expression of the alpha-subunit of HIF-1 (HIF1A) on P4 production and on the expression levels of StAR, P450scc, and 3 beta-HSD. CoCl2 (100 mu M), a hypoxia-mimicking chemical, increased HIF-l alpha protein expression in luteinizing GCs. After the upregulation of HIF-1 alpha, we observed an increase in P4 production and in the gene and protein expression levels of StAR in CoCl2-treated luteinizing GCs. In contrast, CoCl2 did not affect the expression of either P450scc or 3 beta-HSD. Echinomycin, a small-molecule inhibitor of HIF-1's DNA-binding activity, attenuated the effects of CoCl2 and of low oxygen tension (10% O-2) on P4 production and StAR. expression in luteinizing GCs. Overall, these findings suggest that HIF-1 is one of the factors that upregulate P4 in GCs during luteinization.

    DOI: 10.1262/jrd.2016-068

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  • Remodeling of bovine oviductal epithelium by mitosis of secretory cells 査読

    Sayaka Ito, Yoshihiko Kobayashi, Yuki Yamamoto, Koji Kimura, Kiyoshi Okuda

    CELL AND TISSUE RESEARCH   366 ( 2 )   403 - 410   2016年11月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SPRINGER  

    Two types of oviductal epithelial cells, secretory and ciliated, play crucial roles in the first days after fertilization in mammals. Secretory cells produce various molecules promoting embryo development, while ciliated cells facilitate transport of oocytes and zygotes by ciliary beating. The proportions of the two cell types change during the estrous cycle. The proportion of ciliated cells on the oviductal luminal surface is abundant at the follicular phase, whereas the proportion of secretory cells gradually increases with the formation of the corpus luteum. In the present study, we hypothesize that the proportions of ciliated and secretory epithelial cells are regulated by mitosis. The proportion of the cells being positive for FOXJ1 (a ciliated cell marker) or Ki67 (a mitosis marker) in epithelial cells during the estrous cycle were immunohistochemically examined. Ki67 and FOXJ1 or PAX8 (a secretory cell marker), were double-stained to clarify which types of epithelial cells undergo mitosis. In the ampulla, the percentage of FOXJ1-positive cells was highest at the day of ovulation (Day 0) and decreased by about 50 % by Days 8-12, while in the isthmus it did not change during the estrous cycle. The proportion of Ki67-positive cells was highest at around the time of ovulation in both the ampulla and isthmus. All the Ki67-positive cells were PAX8-positive and FOXJ1-negative in both the ampulla and isthmus. These findings suggest that epithelial remodeling, which is regulated by differentiation and/or proliferation of secretory cells of the oviduct, provides the optimal environment for gamete transport, fertilization and embryonic development.

    DOI: 10.1007/s00441-016-2432-8

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  • Lysophosphatidic Acid Synthesis and its Receptors' Expression in the Bovine Oviduct During the Oestrous Cycle 査読

    E. Sinderewicz, K. Grycmacher, D. Boruszewska, I. Kowalczyk-Zieba, Y. Yamamoto, Y. Yoshimoto, I. Woclawek-Potocka

    REPRODUCTION IN DOMESTIC ANIMALS   51 ( 4 )   541 - 549   2016年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY  

    Contents Lysophosphatidic acid (LPA) is a naturally occurring simple phospholipid which in the bovine reproductive system can be produced in the endometrium, corpus luteum, ovarian follicle and embryo. In this study, we examined the possibility that LPA receptors are expressed, and LPA synthesized, in the bovine oviduct. We found that the concentration of LPA was highest in infundibulum in the follicular phase of the oestrous cycle and was relatively high during the early-luteal phase in all examined parts of the oviduct. We also documented that LPA synthesis engages both available pathways for LPA production. The autotaxin (ATX) protein expression was significantly higher in the infundibulum compared to the isthmus during the follicular phase of the oestrous cycle. During the early-luteal phase of the oestrous cycle, ATX and phospholipase A2 (PLA2) protein expression was highest in ampulla, although the expression of LPARs was not as dynamic as LPA concentration in the oviduct tissue, and we presume that in the bovine oviduct, the most abundantly expressed receptor is LPAR2. In conclusion, our results indicate that the bovine oviduct is a site of LPA synthesis and a target for LPA action in the bovine reproductive tract. We documented that LPAR2 is the most abundantly expressed in the bovine oviduct. We hypothesize that in the bovine oviduct, LPA may be involved in the transport of gametes, fertilization and cellular signalling between the oviduct and cumulus-oocyte complex.

    DOI: 10.1111/rda.12717

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  • Possible Contribution of Alpha2,6-Sialylation to Luteolysis in Cows by Inhibiting the Luteotropic Effects of Galectin-1 査読

    Kazuhisa Hashiba, Junko Nio-Kobayashi, Masahiro Sano, Megumi Maeda, Yoshinobu Kimura, Yuki Yamamoto, Koji Kimura, Kiyoshi Okuda

    BIOLOGY OF REPRODUCTION   95 ( 1 )   17   2016年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SOC STUDY REPRODUCTION  

    The corpus luteum (CL) is essential for establishing pregnancy. If pregnancy does not occur during the estrous cycle, luteolysis is induced by prostaglandin (PG) F2alpha secreted from the uterus. Galectin-1, a beta-galactose-binding protein, is expressed in the functional CL of cows and increases the viability of bovine luteal steroidogenic cells (LSCs) by modifying the functions of membrane glycoproteins. The binding of galectin-1 to glycoproteins is blocked by alpha2,6-sialylation of the terminal galactose residues of glycoconjugates, which is catalyzed by a sialyltransferase (ST6Gal-I). However, the physiological role of alpha2,6-sialic acid in bovine CL is unclear. The level of alpha2,6-sialylation of the bovine CL was higher during the regressed-luteal stage than in other luteal stages. Lectin histochemistry revealed that alpha2,6-sialylated glycoconjugates were localized to luteal endothelial cells throughout the estrous cycle. In addition, alpha2,6-sialylated glycoconjugates concentrated to the membrane of LSCs during the regressed-luteal stage. PGF2alpha treatment for 72 h enhanced the expression of ST6Gal-I mRNA and the level of alpha2,6-sialylated glycoproteins in mid-LSCs. The level of alpha2,6-sialylated glycoproteins of late-stage LSCs (Days 15-17 after ovulation) was higher than that of mid-stage LSCs (Days 8-12 after ovulation), and galectin-1 increased the viability of mid-LSCs but not that of late-stage LSCs. Furthermore, galectin-1 increased the viability of late-LSCs when alpha2,6-sialic acid residues were removed by neuraminidase. The overall findings suggest that alpha2,6-sialylation stimulated by PGF2alpha contributes to luteolysis by inhibiting the luteotropic effects of galectin-1 in bovine CL.

    DOI: 10.1095/biolreprod.116.140194

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  • IMMUNOLOCALIZATION OF INHIBIN/ACTIVIN SUBUNITS AND STEROIDOGENIC ENZYMES IN THE TESTES OF AN ADULT AFRICAN ELEPHANT (LOXODONTA AFRICANA) 査読

    Qinglin Li, Lu Lu, Qiang Weng, Shigehisa Kawakami, Eriko Saito, Tatsuya Yamamoto, Yuki Yamamoto, Saroch Kaewmanee, Kentaro Nagaoka, Gen Watanabe, Kazuyoshi Taya

    JOURNAL OF ZOO AND WILDLIFE MEDICINE   47 ( 2 )   419 - 422   2016年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:AMER ASSOC ZOO VETERINARIANS  

    In this case report, the authors investigated immunolocalization of inhibin alpha and inhibin/activin beta A and beta B subunits, as well as steroidogenic enzymes, in the testes of an African elephant. Testes were collected from a reproductively active male African elephant (24 yr old) at autopsy. Histologically, all types of spermatogenic cells including mature-phase spermatozoa were found in the seminiferous tubules. Positive immunostaining for inhibin alpha and inhibin/activin beta A and beta B subunits was observed in Sertoli and Leydig cells. In addition, P450scc, 3 beta HSD, P450c17, and P450arom were also detected in the cytoplasm of Leydig cells. These results suggested that Leydig cells of adult African elephant testes have the ability to synthesize progestin, androgen, and estrogen, whereas both Sertoli and Leydig cells appear as a major source of inhibin secretion in the male African elephant.

    DOI: 10.1638/2015-0091.1

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  • Regulation of bovine oviductal NO synthesis by follicular steroids and prostaglandins 査読

    Yoshihiko Kobayashi, Yuki Yamamoto, Soichi Kageyama, Hiroki Hirayama, Koji Kimura, Kiyoshi Okuda

    REPRODUCTION   151 ( 6 )   577 - 587   2016年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:BIOSCIENTIFICA LTD  

    Nitric oxide (NO) is a regulator of sperm motility, oocyte/embryo survival, and waves of contraction/relaxation in mammalian oviducts. As follicles control oviductal functions by two routes at least, (1) a systemic way via blood vessels before ovulation, (2) a direct way by entering of follicular fluid through fimbria at ovulation, we hypothesized that NO synthesis in the bovine oviduct is regulated by follicular steroids and prostaglandins (PGs). Quantification of mRNA expressions in the ampullary tissues showed that inducible NO synthase (NOS2) mRNA expression was highest on the day of ovulation (day 0). By contrast, NOS2 mRNA expression in the isthmus was highest on days 5-6 and lowest on days 19-21. Endothelial NOS (NOS3) mRNA expressions in either the ampulla or the isthmus did not change during the estrous cycle. PGE2 and PGF2 alpha. increased NOS2 mRNA expressions in cultured ampullary oviductal epithelial cells after 1-h incubation. These increases were suppressed by an antagonist of E-prostanoid receptor type 2, one of the PGE2 receptor. Estradio1-17 beta decreased the expression of NOS2 mRNA expression in cultured isthmic epithelial cells 24h after treatment. This effect was suppressed by an antagonist of estrogen receptor a (ESR1). Expression of ESR1 was highest on days 19-21 in the isthmic tissues. The overall findings indicate region-specific difference of NO synthesis in the oviduct. PGs flowed from ruptured follicle may up-regulate NO synthesis in the oviductal epithelium, whereas circulating E2 seems to inhibit NO synthesis via ESR1 in the isthmus at the follicular stage.

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  • Roles of EDNs in regulating oviductal NO synthesis and smooth muscle motility in cows 査読

    Yoshihiko Kobayashi, Yuka Yoshimoto, Yuki Yamamoto, Koji Kimura, Kiyoshi Okuda

    REPRODUCTION   151 ( 6 )   615 - 622   2016年6月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:BIOSCIENTIFICA LTD  

    Endothelins (EDNs) participate in various physiological events including smooth muscle contraction, nitric oxide (NO) synthesis, and embryonic development. In this study, we investigated the regional roles of EDNs produced by bovine oviductal epithelial cells in NO synthesis and smooth muscle motility. Quantification of mRNA expressions indicated that expression of EDN receptor B (EDNRB) in the ampullary region was higher after ovulation than before ovulation, whereas expression of FONRA in the isthmic region was higher after ovulation than before ovulation. Immunohistochemistry revealed that the EDN receptors (EDNRA and EDNRB) were expressed in the epithelium, whereas smooth muscle showed positive staining only for EDNRA. The expressions of inducible NO synthase (i NOS) protein and its mRNA (NOS2) in cultured epithelial cells isolated from the ampulla were stimulated by EDN1, but not by EDN2 or EDN3, after 1 h of incubation. In isthmic epithelial cells, none of the EDNs affected the expression of NOS2. Isometric contraction tests indicated that spontaneous waves were strong in the isthmic region but weak in the ampullary region. EDN1 modulated smooth muscle motility in both the regions. The overall findings suggest that EDN1 plays region-specific roles in smooth muscle motility and epithelial NO synthesis, providing an optimal oviductal microenvironment for transport of gametes, fertilization, and development/transport of early embryo.

    DOI: 10.1530/REP-15-0586

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  • Evidence for a PGF2α auto-amplification system in the endometrium in mares. 査読

    Kozai K, Tokuyama S, Szóstek AZ, Toishi Y, Tsunoda N, Taya K, Sakatani M, Takahashi M, Nambo Y, Skarzynski DJ, Yamamoto Y, Kimura K, Okuda K

    Reproduction (Cambridge, England)   151 ( 5 )   517 - 526   2016年5月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)  

    DOI: 10.1530/REP-15-0617

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  • Endothelin as a local regulating factor in the bovine oviduct 査読

    Yuki Yamamoto, Misa Kohka, Yoshihiko Kobayashi, Izabela Woclawek-Potocka, Kiyoshi Okuda

    REPRODUCTION FERTILITY AND DEVELOPMENT   28 ( 6 )   673 - 681   2016年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CSIRO PUBLISHING  

    Endothelin (EDN) is a possible regulating factor of oviductal motility, which is important for the transport of gametes and embryo. To clarify the factors that control the secretion of EDN in the bovine oviduct, the expression of EDNs, EDN-converting enzymes (ECEs) and EDN receptors (EDNRs) were investigated. All isoforms of EDN (EDN1-3), ECE (ECE1 and ECE2) and EDNR (EDNRA and EDNRB) were immunolocalised in the epithelial cells of the ampulla and the isthmus. EDNRs were also immunolocalised in smooth-muscle cells. ThemRNAexpression of EDN2 and ECE2 was higher in cultured ampullary oviductal epithelial cells than in isthmic cells. The expression of EDN1, EDN2 and ECE2 in the ampullary tissue was highest on the day of ovulation. Oestradiol-17 beta increased EDN2 and ECE1 expression, while progesterone increased only ECE1 expression in cultured ampullary epithelial cells. These results indicate that EDNs are produced by epithelial cells and their target site is smooth-muscle and epithelial cells, and suggest that ovarian steroids are regulators of endothelin synthesis in ampullary oviductal epithelial cells.

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  • Purified Culture Systems for Bovine Oviductal Stromal Cells 査読

    Yuki Yamamoto, Yoshihiko Kobayashi, Kiyoshi Okuda

    JOURNAL OF REPRODUCTION AND DEVELOPMENT   60 ( 1 )   73 - 77   2014年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SOCIETY REPRODUCTION & DEVELOPMENT-SRD  

    Isolated stromal cells from the ampullary and isthmic parts of bovine oviductal tissues were cultured in monolayer and spheroid (cell aggregate) systems. Prostaglandin F2 alpha (PGF) plays a crucial role in oviductal contraction and is produced by oviductal epithelial cells in cattle. Since stromal cells of many organs produce PGF, PGF production by bovine oviductal stromal cells was investigated. After PGF synthesis was confirmed, the utility of isolation and culture methods for oviductal stromal cells was evaluated by PGF production in the present study. The homogeneity of the cells was > 99%. PGF production of the cells was increased by tumor necrosis factor-a. The stromal cells aggregated and farmed a spheroid by the treatments with several reagents. PGF production was higher in the spheroid culture than in the monolayer culture. The isolation and culture methods described here will facilitate studies of the physiological function of bovine oviductal stromal cells.

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  • Summer heat stress affects prostaglandin synthesis in the bovine oviduct 査読

    Yoshihiko Kobayashi, Kaori Wakamiya, Misa Kohka, Yuki Yamamoto, Kiyoshi Okuda

    REPRODUCTION   146 ( 2 )   103 - 110   2013年8月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:BIOSCIENTIFICA LTD  

    Summer heat stress (HS) negatively affects reproductive functions, including prostaglandin (PG) F-2 alpha secretion in the endometrium, and decreases fertility in cattle. In the present study, we examined the effects of elevated temperatures on PG synthesis in oviductal epithelial cells. The epithelial cells obtained from the ampulla and isthmus of the oviduct were incubated at various temperatures (38.5, 39.5, 40.0, and 40.5 degrees C) for 24 h. In the ampulla, PGE(2) concentration was higher at 40.5 degrees C than at 38.5 degrees C, while PGF(2 alpha) production was not affected by the temperatures in this range. The expressions of microsomal PGE synthase 1 (PTGES (mPGES1)), cytosolic PGES (PTGES3 (cPGES)), and heat shock protein 90 (HSP90AA1 (HSP90)) mRNAs and proteins were higher at 40.5 degrees C than at 38.5 degrees C in the ampullary epithelial cells. Seasonal changes in the expressions of PGES and HSP90AA1 mRNAs in oviductal tissues were also investigated. The expressions of PTGES3 and HSP90AA1 mRNAs were higher in the ampullary tissues in summer than in winter. In summary, elevated temperatures stimulated PGE(2) production in the ampullary oviduct by increasing the expressions of PGESs and HSP90AA1, which can activate cPGES. The overall results suggest that HS upsets PG secretions and reduces oviductal smooth muscle motility, which in turn could decrease gamete/embryo transport through the oviduct.

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  • Secretory Pattern of Inhibin During Estrous Cycle and Pregnancy in African (Loxodonta africana) and Asian (Elephas maximus) Elephants 査読

    Yuki Yamamoto, Natsuki Yuto, Tatsuya Yamamoto, Saroch Kaewmanee, Osamu Shiina, Yasushi Mouri, Etsuo Narushima, Masayuki Katayanagi, Keisuke Sugimura, Kentaro Nagaoka, Gen Watanabe, Kazuyoshi Taya

    ZOO BIOLOGY   31 ( 5 )   511 - 522   2012年9月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:WILEY  

    The ovary of female elephants has multiple corpora lutea (CL) during the estrous cycle and gestation. The previous reports clearly demonstrated that inhibin was secreted from lutein cells as well as granulosa cells of antral follicles in cyclic Asian elephants. The aim of this study is to investigate the inhibin secretion during the pregnancy in African and Asian elephants. Two African elephants and two Asian elephants were subjected to this study. Circulating levels of immunoreactive (ir-) inhibin and progesterone were measured by radioimmunoassay. Four pregnant periods of an African elephant and three pregnant periods of an Asian elephant were analyzed in this study. Circulating levels of ir-inhibin started to increase at 1 or 2 week before the ovulation and reached the peak level 3 or 4 weeks earlier than progesterone during the estrous cycle in both African and Asian elephants. After last luteal phase, the serum levels of ir-inhibin remained low throughout pregnancy in both an African and an Asian elephant. The mean levels of ir-inhibin during the pregnancy were lower than the luteal phase in the estrous cycle despite high progesterone levels were maintained throughout the pregnancy. These results strongly suggest that CL secrete a large amount of progesterone but not inhibin during the pregnancy in elephants. Zoo Biol 31:511-522, 2012. (c) 2011 Wiley Periodicals, Inc.

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  • The Secretory Pattern and Source of Immunoreactive Prolactin in Pregnant African (Loxodonta africana) and Asian (Elephas maximus) Elephants 査読

    Yuki Yamamoto, Tatsuya Yamamoto, Natsuki Yuto, Thomas B. Hildebrandt, Imke Lueders, Gudrun Wibbelt, Osamu Shiina, Yasushi Mouri, Keisuke Sugimura, Sayuri Sakamoto, Saroch Kaewmanee, Kentaro Nagaoka, Gen Watanabe, Kazuyoshi Taya

    JOURNAL OF REPRODUCTION AND DEVELOPMENT   58 ( 1 )   105 - 111   2012年2月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:SOCIETY REPRODUCTION & DEVELOPMENT-SRD  

    The objective of the present study was to define the secretion of prolactin (PRL) in pregnant African and Asian elephants. Levels of immunoreactive (ir-) PRL in serum and placental homogenates were measured by a heterologous radioimmunoassay (RIA) based on an ovine and human RIA system, and the localization of ir-PRL in the placenta was detected by immunohistochemistry using anti-human PRL. Circulating ir-PRL clearly showed a biphasic pattern during pregnancy in African and Asian elephants. Serum levels of ir-PRL started to increase from the 4-6th month of gestation and reached the first peak level around the 11-14th month. A second peak of circulating ir-PRL levels was observed around the 18-20th month of gestation followed by an abrupt decline after parturition. In contrast, in a case of abortion of an African elephant, the second peak of ir-PRL was not observed, and the levels remained low for about four months until parturition. The weight of the fetus delivered at the 17th month of gestation was 23.5 kg, which was quite small compared with normal fetuses in previous reports. Ir-PRL was detected in placental homogenates, and immunolocalization was observed in trophoblasts in both the African and Asian elephants, indicating that the placenta is the source of ir-PRL during pregnancy in elephants. The present results clearly demonstrated that circulating ir-PRL shows a biphasic pattern during normal pregnancy and that the placenta appears to be an important source of circulating ir-PRL during pregnancy in both African and Asian elephants.

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  • Role of the Double Luteinizing Hormone Peak, Luteinizing Follicles, and the Secretion of Inhibin for Dominant Follicle Selection in Asian Elephants (Elephas maximus) 査読

    Imke Lueders, Kazuyoshi Taya, Gen Watanabe, Yuki Yamamoto, Tatsuya Yamamoto, Saroch Kaewmanee, Cheryl Niemuller, Charlie Gray, Wolf Juergen Streich, Thomas B. Hildebrandt

    BIOLOGY OF REPRODUCTION   85 ( 4 )   714 - 720   2011年10月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:OXFORD UNIV PRESS INC  

    Elephants express two luteinizing hormone (LH) peaks timed 3 wk apart during the follicular phase. This is in marked contrast with the classic mammalian estrous cycle model with its single, ovulation-inducing LH peak. It is not clear why ovulation and a rise in progesterone only occur after the second LH peak in elephants. However, by combining ovarian ultrasound and hormone measurements in five Asian elephants (Elephas maximus), we have found a novel strategy for dominant follicle selection and luteal tissue accumulation. Two distinct waves of follicles develop during the follicular phase, each of which is terminated by an LH peak. At the first (anovulatory) LH surge, the largest follicles measure between 10 and 19.0 mm. At 7 +/- 2.4 days before the second (ovulatory) LH surge, luteinization of these large follicles occurs. Simultaneously with luteinized follicle (LUF) formation, immunoreactive (ir) inhibin concentrations rise and stay elevated for 41.8 +/- 5.8 days after ovulation and the subsequent rise in progesterone. We have found a significant relationship between LUF diameter and serum ir-inhibin level (r(2) = 0.82, P &lt; 0.001). The results indicate that circulating ir-inhibin concentrations are derived from the luteinized granulosa cells of LUFs. Therefore, it appears that the development of LUFs is a precondition for inhibin secretion, which in turn impacts the selection of the ovulatory follicle. Only now, a single dominant follicle may deviate from the second follicular wave and ovulate after the second LH peak. Thus, elephants have evolved a different strategy for corpus luteum formation and selection of the ovulatory follicle as compared with other mammals.

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  • Placentation in the African elephant (Loxodonta africana). V. the trophoblast secretes placental lactogen 査読

    Y. Yamamoto, T. Yamamoto, K. Taya, G. Watanabe, F. J. Stansfield, W. R. Allen

    Placenta   32 ( 7 )   506 - 510   2011年7月

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    担当区分:筆頭著者   記述言語:英語   掲載種別:研究論文(学術雑誌)  

    Objectives: To determine if elephant placenta secretes a lactogenic hormone which may function as the principal luteotrophin to maintain ovarian luteal function throughout gestation. Study design and main outcome measures: To label biopsies of endometrium and placenta recovered from African elephant culled professionally throughout gestation with an anti-human prolactin polyclonal antibody in a conventional immunocytochemical staining technique. Results: All trophoblast cells covering the placental villi and forming 'plugs' in the apical endometrial glands stained strongly and precisely with the anti-human prolactin antiserum throughout gestation. Conclusions: Elephant trophoblast secretes a placental lactogen (elPL) which may stimulate both the development and secretory function of the large accessory corpora lutea of elephant pregnancy and provide the mitogenic stimulus for placental differentiation and development. © 2011 Elsevier Ltd. All rights reserved.

    DOI: 10.1016/j.placenta.2011.04.012

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  • A Surge-Like Increase in Luteinizing Hormone Preceding Musth in a Captive Bull African Elephant (Loxodonta africana) 査読

    Saroch Kaewmanee, Gen Watanabe, Megumi Keio, Yuki Yamamoto, Tatsuya Yamamoto, Miori Kishimoto, Kentaro Nagaoka, Etsuo Narushima, Masayuki Katayanagi, Risa Nakao, Yuko Sakurai, Shu Morikubo, Mikako Kaneko, Masato Yoshihara, Tomoko Yabe, Kazuyoshi Taya

    JOURNAL OF VETERINARY MEDICAL SCIENCE   73 ( 3 )   379 - 383   2011年3月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:JAPAN SOC VET SCI  

    This study was conducted to determine the correlation between reproductive hormones and musth in a male African elephant. Changes in circulating luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone and immunoreactive (ir-) inhibin and the degree of musth were evaluated for 4 years. LH increased 4 weeks before musth began. The highest concentrations of testosterone and ir-inhibin were observed from April to October. There were positive correlations among testosterone, ir-inhibin and musth behavior. These findings suggested that the surge-like LH in the pre-musth period might stimulate secretion of testosterone and ir-inhibin and thus initiate the musth behavior. This study also suggested that the high LH level before musth might be a useful biomarker for the beginning of the musth season.

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  • Secretion of Inhibin during the Estrous Cycle in the Female Asian Elephant (Elephas maximus) 査読

    Saroch Kaewmanee, Gen Watanabe, Miori Kishimoto, Wan Zhu Jin, Yuki Yamamoto, Tatsuya Yamamoto, Kentaro Nagaoka, Etsuo Narushima, Teruyuki Komiya, Kazuyoshi Taya

    JOURNAL OF VETERINARY MEDICAL SCIENCE   73 ( 1 )   77 - 82   2011年1月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:JAPAN SOC VET SCI  

    To define the source of circulating inhibin in female Asian elephants, the immunolocalizations of the inhibin alpha, beta(A), and beta(B) subunits, 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), aromatase cytochrome P450 (P450arom) and cytochrome 17 alpha-hydroxylase P450 (P450 c17) were investigated. Concentrations of immunoreactive (ir-) inhibin, progesterone and follicle-stimulating hormone (FSH) during die estrous cycle were measured by radioimmunoassay. Inhibin immunoreactivity in follicular fluid and homogenate of corpora lutea was also measured. Immunolocalizations of inhibin subunits, 3 beta-HSD, P450arom and P450c17 were detected in the granulosa cells of antral follicles and luteal cells. The follicular fluid contained high levels of ir-inhibin and bioactive inhibin. The homogenate of corpora lutea also contained ir-inhibin. Serum ir-inhibin remained at low levels during the early non-luteal phase, began to increase from the late non-luteal phase and continued to increase during the early luteal phase. Serum ir-inhibin showed maximal levels in the middle of the luteal phase and gradually decreased to baseline three weeks prior to progesterone decline. The serum ir-inhibin levels were positively correlated with progesterone throughout the estrous cycle. On the other hand, ir-inhibin was negatively correlated with FSH during the late non-luteal and early luteal phases. These findings strongly suggest that the corpus luteum is one of the sources of inhibin as well as granulosa cells in the Asian elephant.

    DOI: 10.1292/jvms.10-0267

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  • Updated Reproductive Hormonal Profiles in Female Elephants 査読

    Saroch Kaewmanee, Gen Watanabe, Yuki Yamamoto, Tatsuya Yamamoto, Miori Kishimoto, Kentaro Nagaoka, Chowalit Nakthong, Marnoch Yindee, Nicharee Income, Imke Lueders, Chatchote Thitaram, Parntep Ratanakorn, Kazuyoshi Taya

    THAI JOURNAL OF VETERINARY MEDICINE   41   91 - 94   2011年

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:CHULALONGKORN UNIV  

    Through advances in endocrine monitoring and ultrasonographic examination, we have understood some of the complex mechanisms controlling reproductive function in elephants. Several reproductive characteristics appear to be unique such as luteal steroidogenic function, follicular development patterns, pituitary gonadotrophin secretion, and long estrous cycle and gestation lengths. This review describes current knowledge of female elephant endocrinology and how it is being used for maximal reproductive efficiency and enhancement of proper management.

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  • Prolactin Secretion and Ovarian Function in Cycling and Non-Cycling African Female Elephants (Loxodonta africana) 査読

    Yuki Yamamoto, Tatsuya Yamamoto, Gen Watanabe, Natsuki Yuto, Megumi Keio, Etsuo Narushima, Masayuki Katayanagi, Risa Nakao, Syu Morikubo, Yuko Sakurai, Mikako Kaneko, Saroch Kaewmanee, Kazuyoshi Taya

    JOURNAL OF VETERINARY MEDICAL SCIENCE   72 ( 7 )   845 - 852   2010年7月

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    記述言語:英語   掲載種別:研究論文(学術雑誌)   出版者・発行元:JAPAN SOC VET SCI  

    Reproduction of captive elephants in zoos has shown a low fecundity and requires improvement. One of the reasons for low fecundity is ovarian dysfunction in many female elephants. To investigate whether prolactin has a correlation with ovarian function in female elephants, the serum concentrations of prolactin, progesterone and estradiol-17 beta in four African female elephants (one cycling female and three non-cycling female elephants) were measured. Cyclic patterns of prolactin and estradiol-17 beta were observed in the cycling female elephant, which tended to be high during the follicular phase and low during the luteal phase. On the other hand, a cyclic pattern of prolactin was not observed in the non-cycling female elephants. One of the three non-cycling females (Mako) had developed breasts and showed significantly higher average levels of prolactin than the other female elephants. These results suggested that high concentrations of circulating estradiol-17 beta during the follicular phase stimulated prolactin secretion. They also suggested that hyperprolactinemia in Mako was one of the causes of the developed mammary glands and ovarian dysfunction.

    DOI: 10.1292/jvms.09-0480

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  • Special characteristic of a luteinizing hormone surge in captive male African elephant (Loxodonta africana)

    Saroch Kaewmanee, Gen Watanabe, Megumi Keio, Natsuki Yuto, Tatsuya Yamamoto, Yuki Yamamoto, Etsuo Narushima, Masayuki Katayanagi, Risa Nakao, Yuko Sakurai, Shu Morikubo, Mikako Kaneko, Kazuyoshi Taya

    ENDOCRINE JOURNAL   57   S611 - S611   2010年3月

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    記述言語:英語   出版者・発行元:JAPAN ENDOCRINE SOC  

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  • Corpora Lutea as a Major Source of Inhibin Secretion During Luteal Phase in the Female Asian Elephant (Elephas maximus)

    Saroch Kaewmanee, Gen Watanabe, Wan Zhu Jin, Megumi Keio, Natsuki Yuto, Yuki Yamamoto, Tatsuya Yamamoto, Etsuo Narushima, Teruyuki Komiya, Kazuyoshi Taya

    BIOLOGY OF REPRODUCTION   96 - 96   2009年

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    記述言語:英語   出版者・発行元:SOC STUDY REPRODUCTION  

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▼全件表示

書籍等出版物

  • 実践 卵管学

    ( 担当: 分担執筆 ,  範囲: P52-62)

    中外医学社  2021年1月 

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    記述言語:日本語 著書種別:学術書

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MISC

  • 暑熱環境下におけるウシ子宮内膜間質細胞は小胞体ストレス応答経路を介してIL-6発現を増加させる

    酒井 駿介, 山本 ゆき, 木村 康二

    The Journal of Reproduction and Development   66 ( Suppl. )   j41 - j41   2020年9月

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    記述言語:日本語   出版者・発行元:(公社)日本繁殖生物学会  

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  • ウシ卵管上皮細胞の3次元培養における細胞凝集体およびシスト形成能の評価

    杉野 耀亮, 伊藤 さやか, 佐藤 太紀, 酒井 駿介, 梅原 依吹, 窪田 早耶香, 宗友 真帆, 山本 ゆき, 木村 康二

    The Journal of Reproduction and Development   66 ( Suppl. )   j76 - j76   2020年9月

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    記述言語:日本語   出版者・発行元:(公社)日本繁殖生物学会  

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  • ウシの子宮内膜における精子走化性因子発現の検討

    宗友 真帆, 酒井 駿介, 山本 ゆき, 木村 康二

    The Journal of Reproduction and Development   66 ( Suppl. )   j78 - j78   2020年9月

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    記述言語:日本語   出版者・発行元:(公社)日本繁殖生物学会  

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  • 当帰芍薬散がウシ卵管収縮弛緩運動に与える影響

    窪田 早耶香, 山本 ゆき, 木村 康二

    The Journal of Reproduction and Development   66 ( Suppl. )   j75 - j75   2020年9月

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    記述言語:日本語   出版者・発行元:(公社)日本繁殖生物学会  

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  • 培養ウシ卵管平滑筋細胞のCa2+変動解析

    山本 ゆき, 石本 健太, 木村 康二

    The Journal of Reproduction and Development   66 ( Suppl. )   j76 - j76   2020年9月

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    記述言語:日本語   出版者・発行元:(公社)日本繁殖生物学会  

    J-GLOBAL

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  • ウシの発情周期中における卵管自発収縮の制御機構

    山本ゆき, 山本ゆき, 小川泰司, 黒川真帆, 窪田早耶香, 木村康二, 木村康二

    日本分子生物学会年会プログラム・要旨集(Web)   43rd   2020年

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  • 暑熱ストレスは小胞体ストレスを介して子宮内膜間質細胞のIL6発現を増加させる

    酒井駿介, 山本ゆき, 木村康二

    日本分子生物学会年会プログラム・要旨集(Web)   43rd   2020年

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  • ウマ子宮内膜におけるPGF2α自己増幅機構

    香西 圭輔, 徳山 翔太, Szostek Anna Z, 登石 裕子, 角田 修男, 田谷 一善, 阪谷 美樹, 高橋 昌志, 南保 泰雄, Skarzynski Dariusz J, 山本 ゆき, 木村 康二, 奥田 潔

    馬の科学 = Equine science   56 ( 4 )   282 - 293   2019年

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    記述言語:日本語   出版者・発行元:日本中央競馬会競走馬総合研究所  

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  • 卵管自発収縮に関わるイオンチャネルと培養平滑筋細胞内カルシウム変動

    山本ゆき, 山本ゆき, 黒川真帆, 小川泰司, 木村康二, 木村康二

    日本分子生物学会年会プログラム・要旨集(Web)   42nd   2019年

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  • 暑熱環境下におけるウシ子宮内膜細胞のマクロファージ走化性物質産生の変化

    酒井駿介, 山本ゆき, 木村康二

    日本分子生物学会年会プログラム・要旨集(Web)   42nd   2019年

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  • ウシ卵管上皮構成細胞のタンパク質発現解析による分化経路の推測

    伊藤さやか, 山本ゆき, 木村康二

    Journal of Reproduction and Development   64 ( Suppl Japanese Issue )   2018年

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  • ウシ卵管上皮にみられる段階的な繊毛形成過程

    伊藤さやか, 山本ゆき, 木村康二

    日本分子生物学会年会プログラム・要旨集(Web)   41st   2018年

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  • ウシ卵管自発収縮に関与するイオンチャネルと平滑筋細胞内カルシウム変動の解析

    山本ゆき, 山本ゆき, 黒川真帆, 小川泰司, 木村康二, 木村康二

    Journal of Reproduction and Development   64 ( Suppl Japanese Issue )   2018年

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  • 暑熱によるウシ子宮内膜のプロスタグランジン分泌増加と温度感受性チャネルの関係

    山田亜依, 高見恵都, 酒井駿介, 山本ゆき, 山本ゆき, 木村康二, 木村康二

    Journal of Reproduction and Development   64 ( Suppl Japanese Issue )   2018年

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  • ウシ卵管平滑筋運動を制御する局所 因子とその発現制御機構

    山本 ゆき

    岡山大学農学部学術報告   105   29 - 33   2016年2月

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    記述言語:日本語   出版者・発行元:岡山大学農学部  

    Oviductal motility is required for transport of oocyte and embryo resulting in successful fertilization and implantation in mammals. The oviduct consists of epithelial, stromal and smooth muscle layers. Oviductal motility is systemically and locally regulated by various factors including prostaglandin F2 alpha (PGF) and endothelins (EDNs), and relaxing factors including prostaglandin E2 (PGE2) and nitric oxide (NO). The objective of our research is to clarify the regulatory system of oviductal motility including the production mechanisms of these factors in cattle. First, the expressions of regulating factors of oviductal motility were examined throughout the estrous cycle in the bovine oviduct. Some of them showed cyclical changes, which suggested that they were controlled by some other factors. Second, the effects of ovarian steroids or oviductal local factors on the expressions of PGs, EDNs and NO synthases were investigated using cell culture method. Several factors such as estradiol‒17beta, progesterone and lysophosphatidic acid affected the expressions of regulating factors of smooth muscle motility. In addition, we found that these actions differed between the ampulla and isthmus in same types of cultured cell. Our studies suggest that regulatory factors of oviductal motility are produced during the optimal period and at proper location to transport the oocyte and early embryo in the bovine oviduct. Although the precise control of oviductal motility is essential for successful pregnancy, methods for diagnosing and treating of its functional abnormality have not been established yet not only in cows but also in other animals including human. Our studies should contribute to improving the fertility rates in mammals.

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  • ウシ黄体におけるtestosterone合成酵素の遺伝子発現

    入江結唯, 羽柴一久, 吉岡伸, 木村康二, 山本ゆき, 奥田潔

    Journal of Reproduction and Development   61 ( Suppl Japanese Issue )   2015年

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  • 牛卵管機能に及ぼす夏季暑熱ストレスの影響~性ホルモン受容体とヒートショックタンパク質の関係性~

    山本ゆき, 奥田潔

    食肉に関する助成研究調査成果報告書   33   2015年

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  • ウシ卵管における細胞模型エストロジェン受容体(GPER)を介したestradiol-17β(E2)の作用

    西江拓海, 小林芳彦, 山本ゆき, 木村康二, 奥田潔, 奥田潔

    日本畜産学会大会講演要旨   119th   2015年

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  • ウシ卵管機能制御の候補因子activin Aとその関連因子の発現

    山本ゆき, 小林芳彦, 吉本弓華, 奥田潔

    Journal of Reproduction and Development   60 ( Suppl Japanese Issue )   2014年

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  • 雄アフリカゾウのマストと尿中黄体形成ホルモン(LH),プロラクチン,コルチゾールおよびテストステロン濃度の関係

    上手裕子, 山本ゆき, 吉住和規, 橋本渉, 永岡謙太郎, 渡辺元, 田谷一善

    日本野生動物医学会大会・講演要旨集   18th   2012年

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  • ゾウの生殖内分泌学:雌ゾウの卵巣機能調節機構

    田谷一善, 山本ゆき, 山本達也, 上手裕子, 永岡謙太郎, 渡辺元, LUEDERS Imke, HILDEBRANDT Thomas B.

    日本野生動物医学会大会・講演要旨集   18th   2012年

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  • The trophoblast secretes prolactin-like hormone in African elephants (Loxodonta Africana). 査読

    Yamamoto Y, Yamamoto T, Allen WR, Stansfield FJ, Watanabe G, Taya K

    International Conference on Elephant and Wildlife Health Management in Asia   119 - 125   2011年1月

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    記述言語:日本語  

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  • The secretory pattern and physiological role of prolactin in pregnant African (Loxodonta Africana) and Asian (Elephas maximus) elephants. 査読

    Yamamoto Y, Yamamoto T, Yuto N, Shiina O, Mouri Y, Sugimura K, Nagaoka K, Watanabe G, Taya K

    International Conference on Elephant and Wildlife Health Management in Asia   113 - 118   2011年1月

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    記述言語:日本語  

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  • A new hypothesis on mechanisms responsible for maturation of follicles and formation of accessory corpora lutea during the estrous cycle in the Asian elephant. 査読

    Taya K, Lueders I, Hildebrandt TB, Niemuller C, Gray C, Yamamoto Y, Yamamoto T, Kaewmanee S, Watanabe G

    Proceeding of EU Asia-Link Project Symposium “Health and Reproduction of Asian Elephants”   134 - 139   2010年1月

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    記述言語:日本語  

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  • Marked increase in luteinizing hormone secretion preceding musth in a captive bull African elephant. 査読

    Kaewmanee S, Watanabe G, Keio M, Yamamoto Y, Yamamoto T, Narushima E, Katayanagi M, Nakao R, Sakurai Y, Morikubo S, Kaneko M, Yoshihara M, Taya K

    Proceeding of EU Asia-Link Project Symposium “Health and Reproduction of Asian Elephants”   146 - 149   2010年1月

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    記述言語:日本語  

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  • 雌ゾウのプロラクチン分泌に関する研究

    山本ゆき, 山本ゆき, 成島悦雄, 片柳雅之, 浜夏樹, 関和也, 小宮輝之, 橋崎文隆, 横島雅一, 椎名修, 毛利靖, 井上金治, 望月明和, 渡辺元, 田谷一善, 渡辺元, 田谷一善

    日本野生動物医学会大会・講演要旨集   15th   2009年

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  • 雌ゾウのコルチゾール分泌パターンに関する研究

    山本ゆき, 浜夏樹, 成島悦雄, 新井浩司, 湯藤なつき, 渡辺元, 渡辺元, 田谷一善, 田谷一善

    日本野生動物医学会大会・講演要旨集   13th   2007年

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担当授業科目

  • 動物内分泌学2 (2021年度) 第2学期  - 金3,金4

  • 動物生殖機能学特論 (2021年度) 前期  - その他

  • 動物生殖生理学 (2021年度) 前期  - 月1,月2,月3,月4

  • 動物生殖生理学演習 (2021年度) 前期  - その他

  • 動物生殖生理学演習 (2021年度) 後期  - その他

  • 動物生殖生理学演習 (2021年度) 後期  - その他

  • 動物生殖生理学演習 (2021年度) 前期  - その他

  • 応用動物科学コース実験1 (2021年度) 1・2学期  - 火5,火6,火7,火8

  • 応用動物科学コース実験1-1 (2021年度) 第1学期  - 火5,火6,火7,火8

  • 応用動物科学コース実験1-2 (2021年度) 第2学期  - 火5,火6,火7,火8

  • 教養生物学(応用動植物) (2021年度) 第4学期  - 月1~2

  • 生物生産科学特別研究 (2021年度) 通年  - その他

  • 教養生物学(応用動植物) (2020年度) 第4学期  - 月1,月2

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