Proteolytic activation of aldosterone biosynthesis in rabbit adrenal capsular cells by alpha-chymotrypsin

The effect of chymotrypsin on aldosterone biosynthesis by dispersed rabbit adrenal capsular cells was examined. Bovine alpha-chymotrypsin at concentrations of 10(-7) to 10(-5) M stimulated aldosterone production, and human chymotrypsin had an even stronger stimulatory effect. Bovine trypsin had no effect on aldosterone production by adrenal cells. Chymotrypsin treatment did not change the sensitivity of the adrenal cells to ACTH or angiotensin II. These results suggest the existence of unique chymotrypsin-susceptible sites on rabbit adrenal capsular cells, the digestion of which results in stimulation of aldosterone biosynthesis.