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 II (MII) in oocytes, and progesterone and E2 secretion by granulosa cells.

RESULT(S): Activin A significantly enhanced GVBD (91% vs. 65%) for control and maturation to MII (56% vs. 35% for control) of immature oocytes. Activin A significantly suppressed basal, and inhibin A-and FSH-stimulated progesterone and E2 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.