Shi F, Ozawa M, Komura H, Yang P, Trewin A L, Hutz R J, Watanabe G, Taya K
Laboratory of Veterinary Physiology, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan.
Biol Reprod. 1999 Jan;60(1):78-84. doi: 10.1095/biolreprod60.1.78.
To characterize inhibin secretion during the estrous cycle in guinea pigs, the concentrations of plasma inhibin, estradiol, progesterone, and FSH were determined. A significant positive correlation was observed between inhibin and estradiol throughout the estrous cycle. Plasma inhibin and estradiol started to increase a few days before ovulation (Day 0 = day of estimated ovulation), and decreased after ovulation. These two hormones remained low during the luteal phase. The immunoreactivity of inhibin alpha, betaA, and betaB subunits was colocalized in the granulosa cells of one or two healthy large follicles in the ovary before ovulation. There was no positive reaction of inhibin alpha and beta subunits in the corpora lutea or other follicles. Ovariectomy resulted in an abrupt decrease in plasma inhibin and a significant increase in plasma FSH. Injection of anti-inhibin serum into adult female guinea pigs induced an elevation in plasma FSH in a dose-dependent manner. This report presents the first description of sequential changes in plasma inhibin and estradiol during the estrous cycle of guinea pigs. Results suggest that inhibin is secreted mainly by granulosa cells of a few healthy large follicles in the ovary and that it plays an important role in the regulation of FSH secretion during the estrous cycle in guinea pigs.
为了表征豚鼠发情周期中抑制素的分泌情况，测定了血浆中抑制素、雌二醇、孕酮和促卵泡激素（FSH）的浓度。在整个发情周期中，抑制素与雌二醇之间存在显著的正相关。血浆抑制素和雌二醇在排卵前几天开始升高（第0天=预计排卵日），排卵后下降。这两种激素在黄体期保持在低水平。排卵前，抑制素α、βA和βB亚基的免疫反应性共定位于卵巢中一两个健康大卵泡的颗粒细胞中。黄体或其他卵泡中抑制素α和β亚基无阳性反应。卵巢切除导致血浆抑制素突然下降，血浆FSH显著升高。向成年雌性豚鼠注射抗抑制素血清会以剂量依赖的方式诱导血浆FSH升高。本报告首次描述了豚鼠发情周期中血浆抑制素和雌二醇的顺序变化。结果表明，抑制素主要由卵巢中少数健康大卵泡的颗粒细胞分泌，并且在豚鼠发情周期中FSH分泌的调节中起重要作用。
