Activin A stimulates meiotic maturation of human oocytes and modulates granulosa cell steroidogenesis in vitro

Objective To test the hypothesis that activin A promotes in vitro human oocyte meiotic maturation while inhibiting steroid secretion by nonluteinized antral granulosa cells. Design: Prospective randomized controlled study. Setting: A university medical center. Patient(s): Nine women ranging in age from 31-44 years who were undergoing oophorectomy for nonovarian pathology. Intervention(s): Analysis of meiotic maturation of oocytes and steroid secretion by granulosa cells cultured in the presence or absence of activin A. Main Outcome Measure(s): Germinal vesicle breakdown (GVBD) and attainment of metaphase a (MII) in oocytes, and progesterone and E-2 secretion by granulosa cells. Result(s): Activin A significantly enhanced GVBD (91% vs. 65%) for control and maturation to Mn: (56% vs. 35% for control) of immature oocytes, Activin A significantly suppressed basal, and inhibin A-and FSH-stimulated progesterone and E-2 secretion by nonluteinized granulosa cells. Conclusion(s): Activin A is a promoter of oocyte maturation in vitro and a modulator of granulosa cell steroidogenesis in culture. (Fertil Steril(R) 1998;70:1126-30. (C) 1998 by American Society for Reproductive Medicine.).