Effects of brain natriuretic peptide on hemodynamics and renal function in dogs.

A new natriuretic peptide has been found in the porcine brain and termed brain natriuretic peptide (BNP). To examine the effects of BNP on the cardiovascular system and kidney as compared with alpha-hANP (ANP), BNP, and ANP (33, 167, 667 pmol/kg) were intravenously administered to anesthetized dogs. BNP dose-dependently decreased arterial pressure and left atrial pressure and dose-dependently increased heart rate, cardiac output, renal blood flow, urine volume, and sodium excretion. These effects were not significantly different from the effects of respective doses of ANP. To eliminate the possibility that these results were confounded by opposing actions of the baroreflex system, we performed additional experiments following sinoaortic denervation and vagotomy. These results also demonstrated no differences between the effects of BNP and ANP on the measured variables. Finally, we determined that the pharmacokinetics of exogenously injected BNP and ANP are indistinguishable. These findings lead to the possibility that BNP physiologically works in the body in the same manner as ANP.