[Role of cAMP in the regulation of adrenal mineralocorticoid function by potassium ions].

The role of cAMP in K+-dependent regulation of aldosterone output was studied. Guinea pig adrenal slices were incubated with various concentrations of K+ for 20 min. Aldosterone and cAMP output, protein synthesis and phosphorylation were increased with a rise in K+ concentration. The increase in the phosphorylation of the protein with apparent molecular weight of about 38 kD resulted from the increase in K+ concentration in the incubation medium. Proteins from adrenal slices preincubated with 3.0 and 11.0 mM K+ were separated by SDS polyacrylamide gel electrophoresis. No qualitative differences were revealed in autoradiograms of [14C]-prelabeled proteins; however, quantitative differences were present. These results suggest that the cAMP messenger system may be involved in the K+-dependent control of aldosterone biosynthesis.