PERIPHERAL AND LOCAL REGULATORS OF FOLLICULOGENESIS

The role of the gonadotrophins follicle-stimulating hormone (FSH) and luteinizing hormone and the putative local regulators, activin and fol listatin, in the control of folliculogenesis is reviewed. An account o f early work on the development and application of assays for FSH and inhibin is given, together with a summary of the data on the ovarian r esponsiveness to gonadotrophin and follicular atresia. Models for stud ying local regulation of granulosa cells in vitro are described and th e data from these experiments reviewed. It is concluded that activin h as a role in the development and maintenance of healthy oestrogenic fo llicles, preventing premature luteinization, whereas follistatin oppos es these effects of activin and promotes luteinization or atresia.