Regulatory role of guanosine 3',5'-monophosphate in adrenocorticotropin hormone-induced steroidogenesis.

The relation between steroidogenesis induced by adrenocorticotropic hormone and the concentrations of adenosine 3',5'-monophosphate (cyclic AMP) and guanosine 3',5'-monophosphate (cyclic GMP) was studied at different time intervals in isolated adrenal cells. Submaximal and supramaximal steroidogenic concentrations of the hormone did not cause detectable changes in cyclic AMP during the first 30 minutes, whereas there was an increase in the concentration of cyclic GMP that was accompanied by phosphorylation and steroidogenesis. It is therefore suggested that cyclic GMP, rather than cyclic AMP, is the physiological mediator of adrenocorticotropic hormone-induced adrenal steroidogenesis.