Previous studies from our laboratory have shown that FSH increases follicular transforming growth factor a secretion and that this theca-derived growth factor induces follicular growth in vitro. In this context, recent studies using a coculture of bovine ovarian granulosa and theca cells have shown that the theca cells are essential in protecting granulosa cells from undergoing apoptosis, a process that is follicular stage-specific. These results suggest that theca cells may secrete one or more survival factors necessary for maintenance of granulosa cell viability, although the identity of this factor is yet to be defined. It is also possible that the regulation of follicular growth by FSH is mediated by the action of TNFa. buy Endep online
Previous studies have shown that gonadotropins increase ovarian TNFa content during follicular development and that this cytokine is antiapoptotic and capable of inducing XIAP expression in rat granulosa cells. The intraovarian regulation of follicular development and atresia by gonadotropin remains to be fully explored.
In conclusion, a follicle culture system coupled to an adenoviral gene-delivery procedure has been established, to our knowledge for the first time. Using this approach, we have demonstrated that XIAP plays an important role in the determination of granulosa cell fate following FSH challenge and that changes in XIAP expression induced by gonadotropin are critical for the maintenance of normal follicular growth and development.