Lack of venodilative activity of alpha human atrial natriuretic polypeptide in patients with congestive heart failure.

We studied the effect of alpha human atrial natriuretic polypeptide (hANP) on venous vessels by occlusion plethysmography in 7 patients with congestive heart failure. In another 8 patients the effect of nitroglycerin was studied to validate the methodology. Forearm venous pressure (VP) and volume change (delta V) were measured simultaneously. The relationship between venous pressure and volume change was described by the equation VP = C x e(K x delta V) (r = 0.98 +/- 0.01) and the venous stiffness constant (K) was calculated. Alpha human atrial natriuretic polypeptide (0.1 microM/kg/min) was infused intravenously at a dose sufficient to cause arteriodilation. The pressure-volume curve of the peripheral veins was shifted rightward on the volume axis and the stiffness constant (K) was decreased (-28.1%, p less than 0.03) significantly by nitroglycerin. Alpha human atrial natriuretic polypeptide significantly decreased systemic vascular resistance but did not shift the pressure-volume curve of the vein nor did it decrease the stiffness constant (K). We conclude that hANP has far less venodilating effect than arteriodilating effect in congestive heart failure patients.