Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan.
Exp Anim. 2010;59(5):605-14. doi: 10.1538/expanim.59.605.
The cellular localization of the inhibin subunits (α, β(A), and β (B)), steroidogenic enzymes (3β-hydroxysteroid dehydrogenase (3βHSD) and cytochrome P450 aromatase (P450arom) were evaluated in the ovaries of cyclic (n=6) and pregnant (n=2) Shiba goats (Capra Hircus). The immunointensity of inhibin α and β(A) subunits showed an increase in the granulosa cells (GC) of developing follicles. Inhibin β(B) subunit and P450arom showed high expression in GC of antral follicles. 3βHSD immunoreactivity was uniform in preantral and antral follicles. In follicular phase and late pregnancy, there was a strong expression of inhibin α subunit in GC of antral follicles. Although in mid pregnancy, antral follicles GC showed moderate immunostaining of inhibin β subunits, the immunoreactivity of inhibin β(A) and β(B) subunits was high during the follicular and luteal stages, respectively. While, immunoreactivity of GC to P450arom was moderate during all studied stages, and 3βHSD immunoreactivity was plentiful in antral follicles during the luteal phase. The immunoreactivity to inhibin α subunit and P450arom was abundant during mid pregnancy in the luteal tissues. Immunoreaction to inhibin β subunits was faint-to-moderate in cyclic and pregnancy corpora lutea. Immunoexpression of 3βHSD was maximal in late pregnancy corpora lutea. The present results suggest that, in goats, the GC of antral follicles are the main source of dimeric inhibins and that corpora lutea may partially participate in the secretion of inhibin. Changes in ovarian hormonal levels might depend on the synthesizing capacity of hormones in the follicles and corpora lutea to regulate the goat's reproductive stages.
在周期性（n=6）和妊娠（n=2）的 Shiba 山羊（Capra Hircus）卵巢中，评估了抑制素亚基（α、β（A）和β（B））、甾体生成酶（3β-羟甾类脱氢酶（3βHSD）和细胞色素 P450 芳香酶（P450arom）的细胞定位。抑制素α和β（A）亚基的免疫强度显示发育卵泡的颗粒细胞（GC）增加。抑制素β（B）亚基和 P450arom 在窦前卵泡的 GC 中表达较高。3βHSD 免疫反应在窦前和窦卵泡中是均匀的。在卵泡期和妊娠晚期，窦卵泡 GC 中强烈表达抑制素α亚基。尽管在妊娠中期，窦卵泡 GC 中抑制素β亚基的免疫染色呈中度，但在卵泡期和黄体期，抑制素β（A）和β（B）亚基的免疫反应分别较高。而 GC 对 P450arom 的免疫反应在所有研究阶段均为中度，黄体期窦卵泡中的 3βHSD 免疫反应丰富。在妊娠中期黄体组织中，抑制素α亚基和 P450arom 的免疫反应丰富。在周期性和妊娠黄体中，抑制素β亚基的免疫反应微弱至中度。3βHSD 的免疫反应在妊娠晚期黄体中最大。本研究结果表明，在山羊中，窦前卵泡的 GC 是二聚体抑制素的主要来源，黄体可能部分参与抑制素的分泌。卵巢激素水平的变化可能取决于卵泡和黄体中激素的合成能力，以调节山羊的生殖阶段。
