Our present findings indicate that although FSH is capable of increasing follicular cell number (as indicated by increased Alamar Blue reduction and DNA content) and growth in a follicle culture system, it fails to stimulate proliferation when added to granulosa cell primary cultures. The reason for this apparent discrepancy is not clear, but the granulosa cells used in the present studies may have been exposed to LH (in the eCG preparation) in vivo before isolation and culture, resulting in premature luteinization of the cells and, consequently, exit from the cell cycle. cialis super active canada
Alternatively, in addition to being a cell survival factor for granulosa cells via its direct action on XIAP expression, FSH may also stimulate follicular secretion of one or more mitogens, which in turn increases granulosa cell proliferation and ovarian follicular growth. In this context, FSH-induced follicular DNA synthesis in the hamster is mediated by follicular secretion and action of epidermal growth factor. In addition to gonadotropins, various ovarian factors are believed to play an important role in rescuing follicles from apoptotic demise during follicular development.