RESUMO
OBJECTIVE: Pituitary adenylate cyclase-activating polypeptide (PACAP), a novel hypothalamic neuropeptide, has been suggested to play a role in ovarian folliculogenesis. The present study evaluated the effect of PACAP on the growth of preantral follicles. METHODS: Preantral follicles were mechanically isolated from ovaries of 21-day-old rats and cultured in groups for 3 days in serum-free medium in the absence or presence of PACAP-38 (10-6 M). RESULTS: Treatment with PACAP-38 resulted in an increase in follicle diameter by 75% whereas treatment with follicle stimulating hormone (FSH) increased follicle diameter by 65%. PACAP-38 treatment enhanced the granulosa cell proliferation as measured by thymidine incorporation analysis. Furthermore, the production of progesterone by cultured granulosa cells and GFSHR-17 cell line was stimulated by PACAP-38. Interestingly, PACAP enhanced FSH action on stimulation of SF-1 and aromatase gene expression. CONCLUSION: The present results demonstrate that PACAP stimulated preantral follicle growth by potentiating proliferation and by stimulating steroidogenesis.