Short-term hemodynamic effects of vasopressin V1-receptor inhibition in chronic right-sided congestive heart failure.

Arginine vasopressin is elevated in congestive heart failure. To determine the effect of arginine vasopressin upon systemic hemodynamics and regional blood flows, we administered the specific inhibitor of the vascular action of vasopressin [1-(beta-mercapto-beta,beta-cyclopentamethylenepropionic acid),2-(O-methyl)-tyrosine]-arginine vasopressin [d(CH2)5Tyr(Me)AVP] to 15 dogs with chronic right-heart failure produced by tricuspid avulsion and progressive pulmonary artery constriction. The animals exhibited increased plasma arginine vasopressin and norepinephrine levels. Vasopressin inhibition increased cardiac output and left ventricular dP/dt and dP/dt/P, and it decreased total peripheral vascular resistance, whereas mean aortic pressure did not change significantly. Simultaneously, blood flow increased to skeletal muscle, kidneys, skin, and right and left ventricular myocardium. Plasma catecholamines also increased. Pretreatment with propranolol and prazosin abolished the increases in cardiac output and left ventricular function produced by vasopressin inhibition. Pretreatment also led to a decrease in mean aortic pressure after vasopressor inhibition. In contrast, administration of d(CH)2)5Tyr(Me)AVP to 11 sham-operated animals or administration of normal saline to nine sham-operated and eight heart-failure dogs was without effect either in the absence or in the presence of adrenergic receptor blockade. Thus, arginine vasopressin participates in the control of the circulation in right-sided congestive heart failure, with both a direct constrictor action on blood vessels and an indirect action by inhibition of the sympathetic nervous system.