Modulation of Renin Secretion by A trial Natriuretic Factor Prohormone Fragment 31–67

Abstract

Listen

Translate article

Background: Earlier studies have indicated that the atrial natriuretic factor prohormone fragment 31-67 (Pro ANF31–67) has important effects for the promotion of sodium excretion and vasodilation in several animal species. However, the mechanisms for the natriuretic actions of Pro ANF31–67 are not completely defined. In the present study, the effects of synthetic Pro ANF31–67 on renin secretion were examined in sodium-depleted, anesthetized dogs with a single intact kidney (n = 5). Methods: After 3 20-minute control renal clearance periods, synthetic dog Pro ANF31–67 was given intrarenally at a sustained dose of 0.03 μg/kg/min for 3 20-minute experimental intervals, and after discontinuation of the peptide infusion, 3 final 20-minute recovery periods were determined. Results: Sustained intrarenal infusions of the Pro ANF31–67 produced striking decrements (p<0.05) in renin secretion, from a control value of 1418 ± 243 to 401 ± 223 ng of angiotensin l/min. This 66% fall in renin secretion was associated with significant (P < 0.05) increases in creatinine clearance (40%), renal blood flow (8%), urine flow (50%), and sodium excretion (17%). Conclusions: It is suggested that this inhibition of renin secretion was mediated, at least in part, in response to a ProANF31–67-induced increment in the sodium load delivered to the macula densa. An interaction of the peptide with the renal vascular receptor for suppression of renin release is also possible. ProANF31–67 may represent an important hormonal mechanism involved in the regulation of body-fluid balance.