[Effects of alpha-human atrial natriuretic polypeptide (alpha-hANP) on congestive heart failure in dogs]

Effects of alpha-human atrial natriuretic polypeptide (alpha-hANP) on a model of congestive heart failure (CHF), we established in dogs, were investigated. The model was made by protease injection into the left ventricular free wall, saline loading, and dextran and methoxamine infusion. By this maneuver, left atrial pressure (LAP), systemic vascular resistance (SVR) and left ventricular end-diastolic pressure (LVEDP) were markedly increased, aortic blood flow (AoBF) was decreased and systemic blood pressure (SBP) was unchanged. Following intravenous application of 0.50 microgram/kg alpha-hANP, LAP was reduced from 18.9 to 14.0 mmHg (N = 7, mean); SBP, from 114.4 to 105.1 mmHg; SVR, from 21603 to 15602 dyne sec/cm5; and LVEDP, from 22.2 to 17.6 mmHg; while AoBF was increased from 0.46 to 0.54 l/min. Vmax and T were little influenced. The results indicate that alpha-hANP improved canine CHF mainly through its vasodilating action.