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 properties. 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 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.