Ohshima K, Kishi H, Itoh M, Watanabe G, Arai K, Uehara K, Groome N P, Taya K
Laboratory of Veterinary Physiology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
J Endocrinol. 1999 Sep;162(3):451-6. doi: 10.1677/joe.0.1620451.
Plasma concentrations of inhibin pro-alphaC, inhibin A and inhibin B were determined by enzyme-linked immunosorbent assay at 6 h intervals throughout the 4-day oestrous cycle of the golden hamster. Plasma concentrations of follicle-stimulating hormone (FSH) and oestradiol-17beta were also measured by radioimmunoassay during the oestrous cycle. Plasma concentrations of inhibin A increased from the early morning of day 1 (day 1=day of ovulation) and reached plateau levels at 0500 h on day 2. An abrupt increase in plasma concentrations of inhibin A was found at 1700 h on day 4, when the preovulatory FSH surge was observed. An increase in plasma concentrations of inhibin B occurred on day 1 and reached plateau levels at 1700 h on day 1. The levels remained elevated until 0500 h on day 4 and declined gradually by 2300 h on day 4. Plasma concentrations of inhibin pro-alphaC gradually increased with some fluctuation from day 1 to 1700 h on day 4 and then declined. Significant negative relationships were noted between plasma FSH and both dimeric forms of inhibin from day 1 to day 3. Significant positive relationships were found between plasma oestradiol-17beta and inhibin A or inhibin pro-alphaC throughout the oestrous cycle. In contrast, no significant relationship was found between plasma oestradiol-17beta and inhibin B. These findings suggest that both dimeric forms of inhibin play a role in the regulation of FSH secretion during follicular development. These findings also suggest that inhibin pro-alphaC could be secreted primarily by large follicles, and early atretic follicles could also be responsible for inhibin pro-alphaC secretion. On the other hand, the secretory pattern of dimeric inhibins might shift from inhibin B to inhibin A with follicular development.
在金黄仓鼠4天的发情周期中，每隔6小时通过酶联免疫吸附测定法测定抑制素原αC、抑制素A和抑制素B的血浆浓度。在发情周期中，还通过放射免疫测定法测量促卵泡激素（FSH）和雌二醇-17β的血浆浓度。抑制素A的血浆浓度从第1天清晨（第1天=排卵日）开始升高，并在第2天05:00达到平台期水平。在第4天17:00观察到排卵前FSH激增时，抑制素A的血浆浓度突然升高。抑制素B的血浆浓度在第1天升高，并在第1天17:00达到平台期水平。这些水平一直升高到第4天05:00，并在第4天23:00逐渐下降。抑制素原αC的血浆浓度从第1天到第4天17:00逐渐升高，有一些波动，然后下降。从第1天到第3天，血浆FSH与两种二聚体形式的抑制素之间均存在显著的负相关关系。在整个发情周期中，血浆雌二醇-17β与抑制素A或抑制素原αC之间均存在显著的正相关关系。相比之下，血浆雌二醇-17β与抑制素B之间未发现显著关系。这些发现表明，两种二聚体形式的抑制素在卵泡发育过程中对FSH分泌的调节中发挥作用。这些发现还表明，抑制素原αC可能主要由大卵泡分泌，早期闭锁卵泡也可能负责抑制素原αC的分泌。另一方面，随着卵泡发育，二聚体抑制素的分泌模式可能从抑制素B转变为抑制素A。
