Regulation of oocyte maturation. The role of cAMP.

We suggest that cAMP is a key molecule in regulation of oocyte maturation. In the small follicle, tonic levels of cAMP are continuously transferred to the oocytes to maintain meiotic arrest. In the preovulatory follicle, in response to LH, cAMP levels are elevated. These increased concentrations of the nucleotide affect the cumulus cells and interrupt communication in the cumulus-oocyte complex. Under these conditions the flow of cAMP to the oocyte declines, inhibition is relieved, and meiosis is resumed.