The FSH is an important survival factor for preantral and antral follicular development in vivo. Whereas administration of gonadotropin induces ovarian follicular development in immature animals, gonadotropin withdrawal by anti-eCG antibody treatment resulted not only in cessation of follicular growth but also in atresia. In the present study, we have successfully established a rat follicle culture system and have demonstrated that FSH stimulates rat ovarian follicular growth and induces antral formation in a 6-day culture period. Our findings are consistent with the results of recent studies involving cultures of bovine, baboon, mouse, rat, and hamster ovarian follicles. This culture system may prove to be useful for assessment of the endocrine control of follicular development and atresia. Levitra professional Canadian pharmacy
The fate of a developing follicle (continual growth and development vs. atresia) is determined by the fate of its cells (proliferation and differentiation vs. apoptosis), which in turn is regulated by their relative expression of ‘‘death’’ and ‘‘survival’’ genes. Thus, follicular development may be a consequence of suppression of cell death genes or overexpression of cell survival genes. Follicular atresia is associated with decreased granulosa cell IAP contents, and gonadotropin administration results in the up-regulation of follicular IAPs. Although it is well established that granulosa cell survival and apoptosis are the cellular basis of follicular development and atresia, respectively, whether the changes in the expression of these intracellular antia-poptotic proteins are coincidental or causally related to these gonadotropin-regulated processes is not known.