Interactions of Steroids and Gonadotropins in the Control of Steroidogenesis in the Ovarian Follicle

The pituitary gonadotropic hormones, FSH (follicle-stimulating hormone) and LH (lutienizing hormone) play important roles in regulating both the steroidogenic and gametogenic functions of the ovary. The secretion of pituitary gonadotropins is controlled, in turn, by feedback influences, both negative and positive, exerted by ovarian steroids. There are also strong evidence suggesting that ovarian steroids may also modulate the responses of the ovary to gonadotropins through direct actions upon the ovarian cells involved. If normal development of the follicles, including oocyte maturation and the cyclic function of the ovary, is influenced by a high degree of coordination among these complex processes, then relatively minor upsets in balances between some of these opposing forces may shed light to the little understood processes of follicular atresia, refractoriness, or insensitivity to gonadotropins. This may then lead to the development of alternative forms of contraception, treatment of forms of human infertility, or development of more reliable methods of inducing multiple ovulation in domestic animals or endangered species.