Regulation of aldosterone secretion by Ca v 1.3

Aldosterone-producing adenomas (APAs) vary in phenotype and genotype. Zona glomerulosa (ZG)-like APAs frequently have mutations of an L-type calcium channel (LTCC) Ca V 1.3. Using a novel antagonist of Ca V 1.3, compound 8 , we investigated the role of Ca V 1.3 on steroidogenesis in the human adrenocortical cell line, H295R and in primary human adrenal cells. This investigational drug was compared with the common antihypertensive drug nifedipine, which has 4.5-fold selectivity for the vascular LTCC, Ca V 1.2, over Ca V 1.3. In H295R cells transfected with wild-type or mutant Ca V 1.3 channels, the latter produced more aldosterone than wild-type, which was ameliorated by 100 μM of compound 8 . In primary adrenal and non-transfected H295R cells, compound 8 decreased aldosterone production similar to high concentration of nifedipine (100 μM). Selective Ca V 1.3 blockade may offer a novel way of treating primary hyperaldosteronism, which avoids the vascular side effects of Ca V 1.2-blockade and provides targeted treatment for ZG-like APAs with mutations of Ca V 1.3.