Effect of pro-atrial natriuretic peptides 1-30, 31-67 and 99-126 on angiotensin II-stimulated aldosterone production in calf adrenal cells.

Pro-atrial natriuretic peptide (Pro-ANP) is a 126 amino acid peptide from which atrial natriuretic peptide (ANP) (99-126 amino acid) is derived. ANP has potent diuretic, natriuretic and vasodilatory peptides. ANP is also a potent direct and indirect inhibitor of aldosterone secretion. The N-terminus of the ANP prohormone containing the peptides 1-30 and 31-67 have been demonstrated to have diuretic, natriuretic and vasodilatory properties. Dispersed calf zona glomerulosa cells were incubated with angiotensin II (A-II) and increasing concentrations of the ANP, ProANP 1-30 and 31-67 to determine if their reported natriuretic activity was mediated through suppression of aldosterone secretion. ANP as reported by many investigators produced a dose-dependent and potent inhibition of A-II-mediated aldosterone secretion. The Pro-ANP 1-30 and 31-67 did not affect A-II-stimulated aldosterone secretion at any of the doses tested. This study shows that the reported natriuretic effect of the fragments is not mediated by inhibition of aldosterone secretion.