Subcutaneous administration of brain natriuretic peptide in experimental heart failure

OBJECTIVES The objective of this investigation was to define for the first time the cardiorenal and humoral actions of repeated short-term administrat ion of subcutaneous (SQ) brain natriuretic peptide (BNP) administration dur ing the evolution of experimental heart failure. BACKGROUND The rationale of this study was based on BNP as a vasodilating, natriuretic, renin-inhibiting and lusitropic peptide of cardiac origin. METHODS First, we defined the cardiorenal and humoral responses to acute lo w and high dose (5 mug/kg or 25 mug/kg) of SQ BNP in experimental heart fai lure to establish the acute efficacy of an SQ delivery. Second, we characte rized the response to 10 days of repeated short-term administration of BNP during the evolution of experimental heart failure produced by rapid ventri cular pacing. RESULTS Plasma BNP and 3',5'-cyclic guanosine monophosphate rapidly increas ed and peaked at 30 min after acute SQ BNP administration with increases in urinary sodium excretion, urine flow and renal blood flow in association w ith reductions in cardiac filling pressures. After 10 days of repeated shor t term administration of SQ BNP, cardiac output was increased and systemic vascular resistance and pulmonary capillary wedge pressure were decreased, as compared with untreated dogs with heart failure. CONCLUSION This study demonstrated for the first time that repeated short-t erm administration of SQ BNP administration for 10 days during the evolutio n of left ventricular dysfunction in a canine model results in an improveme nt in cardiovascular hemodynamics. This investigation supports a potential novel strategy for the chronic administration of BNP in the therapeutics of heart failure. (C) 2000 by the American College of Cardiology.