大鼠卵巢颗粒细胞IGF-Ⅰ、TGFβ、Fas-L表达与卵泡闭锁发生的研究

The Expression of IGF , TGF and FasL in Granulosa cells of Ovarian Follicle with Relation to the Onset of Atresia in Rats

为研究ＩＧＦ－Ⅰ，ＴＧＦβ和Ｆａｓ－Ｌ在维持卵泡颗粒细胞存活和介导颗粒细胞凋亡中的作用，探讨卵泡闭锁的局部分子机理，将ＳＤ大鼠卵巢石蜡切片，用ＴＵＮＥＬ法和ＰＣＮＡ免疫组化法区别闭锁和生长卵泡，用免疫组化法标记这三种因子以及它们的膜受体在卵泡内的表达。结果显示：无腔和有腔生长卵泡内大多数颗粒细胞为ＰＣＮＡ阳性；早期有腔闭锁卵泡有５个以上颗粒细胞被ＴＵＮＥＬ法标记，部分颗粒细胞为ＰＣＮＡ阳性；晚期有腔闭锁卵泡剩余颗粒细胞多数被ＴＵＮＥＬ法所标记，但为ＰＣＮＡ阴性。有腔生长卵泡颗粒细胞ＩＧＦ－Ⅰ、ＩＧＦ－ＩＲ、ＴＧＦβ、ＴＧＦβＲ、Ｆａｓ、Ｆａｓ－Ｌ均为阳性。早晚期有腔闭锁卵泡的颗粒细胞为Ｆａｓ、ＴＧＦβ和ＴＧＦβＲ阳性。结果提示：ＴＵＮＥＬ法和ＰＣＮＡ免疫组化联合运用有利于区分闭锁卵泡和生长卵泡。ＩＧＦ－Ⅰ仅对有腔生长卵泡颗粒细胞有促进增殖和维持存活的作用，其表达的下降和消失为有腔卵泡闭锁的重要诱因。ＴＧＦβ、Ｆａｓ－Ｌ和Ｆａｓ可能介导有腔卵泡颗粒细胞的凋亡，参与闭锁过程，但在有ＩＧＦ－Ⅰ存在的条件下。

This study was designed to investigate the effects of IGF ,TGF and FasL on the sustaining of granulosa cells of ovarian follicle and the modulation of apoptosis of those cells, and to understand the molecular mechanisms of ovarian follicle atresia. Paraffinembedded sections of SD rat ovary were made. Both TUNEL method and PCNA immunohistochemistry were employed to recognize atretic and healthy follicles. The expression of IGF , TGF , FasL and their receptors was displayed by immunostaining. The results showed that most of the granulosa cells within the healthy preantral and antral follicles were PCNA(+). At the early stage of atretic antral follicle, more than 5 granulosa cells were labelled by TUNEL method, and some granulosa cells were PCNA(+). At the late stage of atretic antral follicle, were labelled by TUNEL method. The immunoreactive products of IGF ,IGFIR,TGF,TGFR, Fas and FasL could be seen in the granulosa cells of healthy antral follicles. But, Granulosa cells were only TGF,TGFR and Fas immunopositive in all atretic antral follicles. In conclusion, combination of TUNEL method and PCNA immunochemistry is of benefit for distinguishing atretic follicles from healthy follicles. IGF might play an important role in stimulating proliferation of the granulosa cells and sustaining them. The lower expression or disappearance of IGF in the antral follicle might cause the onset of atresia. TGF, FasL and Fas might mediate apoptosis of the granulosa cells in antral follicles, causing follicle atresia. But, their effects of mediation could be inhibited as IGF exists in the follicles.