Mechanism of ANP and BNP Action on the Suppression of Aldosterone Secretion by Cultured Bovine Adrenal Glomerulosa Cells

Atrial natriuretic peptide (ANP) (10-8mol/l), brain natriuretic peptide (BNP) (10-8mol/l), the protein kinase C (PKC) inhibitors H-7 (10-5mol/l) and staurosporin (10-8mol/l) suppressed aldosterone secretion in cultured bovine adrenal glomerulosa cells by 40 to 50 % compared with untreated control cells. When cells incubated with 10-8mol/l angiotensin II (All) were also treated with ANP, BNP, or PKC inhibitors, aldosterone secretion was 50 to 60 % of that seen in untreated cells. ANP, BNP and PKC inhibitors suppressing the expression of PKC, suggested that PKC plays a role in aldosterone secretion. Our results suggest that ANP and BNP may have an unknown second messenger pathway in which the suppression of PKC is essential for the ex-