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Pathophysiology of small testes in beef bulls: relationship between scrotal circumference, histopathologic features of testes and epididymides, seminal characteristics, and endocrine profiles.
1986
Rao Veeramachaneni D.N. | Ott R.S. | Heath E.H. | McEntee K. | Bolt D.J. | Hixon J.E.
Immunohistochemical study on the atretic and the growing follicles after experimental superovulation in rats 1. Number of follicles by superovulation.
1997
Kwak S.D.
Changes in plasma gonadotropins inhibin and testosterone concentrations and testicular gonadotropin receptor mRNA expression during testicular active, regressive and recrudescent phase in the captive Japanese black bear (Ursus thibetanus japonicus)
2010
Iibuchi, R., Hokkaido Univ., Sapporo (Japan) | Kamine, A. | Shimozuru, M. | Nio Kobayashi, J. | Watanabe, G. | Taya, K. | Tsubota, T.
Male Japanese black bears (Ursus thibetanus japonicus) have an explicit reproductive cycle. The objective of this study was to clarify the variation of plasma testosterone, FSH, inhibin, LH levels and testicular gonadotropin receptor mRNA expression of male bears associated with their testicular activity. Notably, this study investigated peripheral FSH concentration and localization of gonadotropin receptor mRNAs for the first time in male bears. Blood and testicular tissue samples were taken from captive, mature, male Japanese black bears during testicular active, regressive and recrudescent phases. Plasma hormone concentrations were measured by immunoassays, and gonadotropin receptor mRNA expression in the testis was investigated by in situ hybridization technique and also by real-time PCR. There were significant variations in plasma testosterone and inhibin concentrations. Changes in FSH concentration preceded these hormones with a similar tendency. Hormones started to increase during denning, and achieved the highest values at the end of the recrudescent phase for FSH and in the active phase for testosterone and inhibin. These changes in hormone concentrations were accompanied by testicular growth. In situ hybridization analysis revealed that FSH and LH receptor mRNA was possibly expressed in Sertoli cells and Leydig cells, respectively, as they are in other mammals. However, neither plasma LH concentration nor testicular gonadotropin receptor mRNA expression level varied significantly among the sampling months. These results suggest that FSH, inhibin and testosterone have roles in testicular activity in male bears. This study provides important endocrine information for comprehending seasonal reproductivity in male Japanese black bears.
Show more [+] Less [-]Timing of sequential changes in chromosome configurations during the 1st meiotic division of pig oocytes cultured in vitro
1990
Ocampo, M.B. (Hokkaido Univ., Sapporo (Japan). Faculty of Veterinary Medicine) | Ocampo, L.T.C. | Kanagawa, H.
Inductions of superovulation using several FSH regimens in Holstein-Friesian heifers
1985
Takahashi, Y. (Hokkaido Univ., Sapporo (Japan). Faculty of Veterinary Medicine) | Kanagawa, H.
Immunohistochemical study on the atratic and the growing follicles after experimental superovulation in rats 2. Atresia and growing of follicles
1997
Kwak, S.D. | Koh, P.O. | Kim, C.S. (Gyeongsang National University, Chinju (Korea Republic). College of Veterinary Medicine)
Transvaginal ultrasound-guided ovum pick-up incattle 1. Effects of estrus cycle, season and bST treatment on ovum pick-up in cattle
1997
Lee, B.C. | Yoon, K.Y. | Roh, S.H. | Lee, K.N. | Hwang, W.S. (Seoul National University, Seoul (Korea Republic). College of veterinary Medicine) | Kim, H.I. (Cheil Chem. Company, Ansan (Korea Republic))
