Signal Transduction of Follicle-Stimulating Hormone in the Production of ZPC-homologue in Cultured Quail Granulosa Cells.

In a previous study, we found that follicle-stimulating hormone (FSH) promotes the production of ZPC-homologue in quail granulosa cells during culture. In order to evaluate the role of protein kinases in ZPC-homologue production, granulosa cells were cultured with FSH, dibutyryl cAMP or phorbol ester in the presence or absence of phosphodiesterase inhibitor, and the amount of ZPC-homologue production was then measured by radioactivity incorporation in proteins immunoprecipitated by anti ZPC-homologue antibody after incubation of the cells with [3H] leucine for 6hr. When the granulosa cells were incubated with FSH, ZPC-homologue production was increased in a dose-dependent manner. This effect was mimicked by dibutyryl cAMP, whereas phorbol ester had no such effect. Furthermore, phosphodiesterase inhibitor significantly potentiated FSH-stimulated ZPC-homologue production. These results demonstrate that quail granulosa cells in culture produce a ZPC-homologue when stimulated with FSH and that this process might be, at least in part, mediated by the intracellular signal transduction system involving adenylate cyclase and cyclic AMP.