[Regulation of hormone biosynthesis in guinea pig adrenal glands by potassium ions as affected by dihydropyridines. 2. Possible mechanisms of changes in steroidogenesis induced by 1,4-dihydropyridines in dispersed adrenocorticocytes].

: Formation of aldosterone, corticosterone, cortisol and cortisone of labelled cholesterol in the dispersed adrenocorticocytes significantly intensifies at high potassium concentrations in the incubation medium. Labelling of aldosterone and corticosterone in the presence of DHP-51 remains unchanged in the medium containing 3 mmol/l of K+, but is inhibited at 8 mmol/l of potassium. Labelling of 17-hydroxylated corticosteroids, cortisol and cortisone grows at low K+ concentration and falls at the high concentration as a result of DHP-51 addition to the incubation medium. This relationship is disturbed only at high concentration of DHP-51. Incorporation of [3H]-leucine into proteins of adrenocorticocytes grows with K+ concentrations. DHP-51 causes insignificant changes in incorporation of [3H]-leucine into proteins at low potassium content, inhibiting incorporation in the medium at high K+ level. DHP-51 blocked Ca2+ transport into adrenocorticocytes, activated by raised level of potassium in the medium. The mechanism of DHP-51 action on regulation of steroidogenesis in adrenocorticocytes is discussed.