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Updated: Oct 26, 2026

A Modified Co-Culture System for Understanding Granulosa-Theca Cell Interactions in the Bovine Ovary
Published on: September 19, 2025
Activin A stimulates meiotic maturation of human oocytes and modulates granulosa cell steroidogenesis in vitro
B M Alak1, S Coskun, C I Friedman
1Department of Obstetrics and Gynecology, The Ohio State University, Columbus 43210, USA. alak.1@osu.edu
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.
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