EFFECT OF CYCLIC-AMP ON THE ISOLATED HUMAN OOCYTE CUMULUS COMPLEX

Cyclic AMP (cAMP) is one of the key regulators of the resumption of oo cyte meiosis (oocyte maturation) in several mammalian species. In this study we have examined the role for cAMP in regulation of spontaneous maturation of human oocytes. Oocytes were obtained in connection with gynaecological operations and cultured for 24 or 48 h. A significantl y larger proportion (77%) of oocytes cultured in the presence of 1 mM dibuturyl-cAMP (dbcAMP) for 24 h were arrested in meiosis compared to oocytes cultured in control medium (25%). In addition, dbcAMP stimulat ed progesterone accumulation during 48 h of incubation and inhibited m onolayer formation of the cumulus cells attached to the oocyte. The da ta presented in this study demonstrate that dbcAMP delayed the spontan eous maturation of human oocytes and stimulated progesterone productio n by the cumulus cells. These results indicate that cAMP may be import ant also for regulation of meiosis in human oocytes and confirm result s obtained in other species.