Study for Effects of Ovarian Thecal Cells on Granulosa Cell Diferentiation during Follicular Maturation.

我们已经开发了一种共培养系统，其中颗粒细胞和卵泡膜细胞保持在胶原膜的相对表面上。利用这一系统，我们研究了卵泡膜细胞在牛卵泡发育过程中对激素产生的调控作用以及颗粒细胞的超微结构。卵泡膜细胞在卵泡发育早期减少颗粒细胞分泌雌二醇、雌二醇和睾酮，而在卵泡发育晚期增加颗粒细胞分泌雌二醇、雌二醇和睾酮。与卵泡膜细胞共培养的颗粒细胞的形态学分析显示溶酶体聚集减少，与单独培养的细胞相比，小卵泡细胞的内质网和线粒体收缩，但成熟卵泡细胞的这些细胞分化特征增强。其抑制未成熟颗粒细胞的分化而促进成熟颗粒细胞的分化，提示卵泡膜细胞在卵巢卵泡发育过程中对颗粒细胞的分化起重要控制作用。

We have developed a co-culture system in which granulosa and thecal cells were maintained on the opposite surface of a collagen membrane. Using this system, we have investigated the possible role of thecal cells in the conrol of the hormonal producing activity and the ultrastructure of granulosa cells during bovine ovarian follicular development. Thecal cells reduced estradiol, inhibin and progester one production by granulosa cells from early stage of follicular development, respectively, while augmented those by cells at late developmental stage. Morphological analysis of granulosa cells co-cultured with thecal cells shows a decreasein the clustering of lysosomes, shrinkage of endoplasmic reticulum and mitochondria of cells from small follicles but an enhancement of these cytodifferentiative features in cells from mature follicles when compared to the cells cultured alone.These results demonstrate that the thecal cells secrete factor (s) which inhibits the differentiation of the immature granulosa cells while promoting that of the matured ones and suggest that the thecal cells play an important role in the control of granulosa cell differentiation during ovarian follicular development.