Effect of atrial natriuretic peptide on renin release in a superfusion system of kidney slices and dispersed juxtaglomerular cells.

The effect of atrial natriuretic peptide (ANP) on renin release is controversial. Several reports state that ANP inhibits renin secretion, while others have shown no effect. We investigated the effect of synthetic rat ANP with 24 amino acids (atriopeptin III) on renin release in vitro in a dynamic superfusion system of renal cortical slices as well as collagenase-dispersed juxtaglomerular cells. In the superfusion system of kidney slices, isoproterenol (5 x 10(-8) M) clearly stimulated renin release from kidney slices, while angiotensin II (AII; 10(-5) M) suppressed renin release. ANP (10(-10)-10(-6) M) did not inhibit basal renin release or blunt the stimulatory effect of isoproterenol. The suppression of renin secretion by AII was never modified in the presence of ANP. The superfusion system of juxtaglomerular cells demonstrated greater sensitivity of renin release in responses to isoproterenol and AII. In this system, ANP (10(-6) M) did not alter renin release from the cells stimulated by isoproterenol (5 x 10(-8) M) or inhibited by AII (10(-8) M). However, basal renin release was slightly stimulated in the late phase of ANP superfusion and for 20 min after the ANP perfusion was stopped. Similarly, 8 bromo-cGMP (10(-6) M) did not inhibit, but, rather, stimulated basal renin release slightly. These results suggest that ANP does not inhibit renin release by a direct effect on the juxtaglomerular cell in the rat.