REGULATION OF FOLLICULAR MATURATION BY HUMAN OVARIAN FOLLICULAR-FLUIDPEPTIDE

Follicular development, ovulation and luteal function are-controlled b y gonadotrophins. However, recent evidence indicates that local factor s are also responsible for the regulation of folliculogenesis. In addi tion to their endocrine action on pituitary gonadotrophins, inhibin, a ctivin and follistatin also have a paracrine role in follicular matura tion. An ovarian follicular fluid peptide (OFFP) has been identified f rom sheep and humans. Purification of OFFP has been achieved by ultraf iltration and gel chromatography with further purification by fast per formance liquid chromatography and reversed phase-high pressure liquid chromatography. OFFP is a small (< 5 kDa) peptide that competes with FSH in binding to granulosa cells in vitro and inhibits progesterone s ecretion from granulosa cells in culture. Immunohistochemical localiza tion revealed the presence of OFFP mainly in granulosa cells of ovaria n follicles. Furthermore, the peptide caused apoptosis in granulosa ce lls and induced follicular atresia. OFFP may act indirectly on oocytes via its effect on granulosa cells. The peptide from ovarian follicula r fluid appears to have an important autocrine or paracrine role in th e regulation of folliculogenesis.