Effect of theα-adrenoblocker pyrroxan on the systemic hemodynamics in puppies and dogs with vasorenal hypertension

Abstract

Vasorenal hypertension was induced in puppies aged 2–3 months and in adult dogs by constricting both renal arteries. Pyrroxan (1.5 mg/kg) was injected intravenously 3 and 14 days later. Both in the adult dogs and in the puppies the elevated arterial blood pressure was lowered by pyrroxan, and in the latter it fell below normal. The hypotensive effect of the drug in the adult animals was connected with a decrease in the general peripheral vascular resistance, whereas in the puppies in addition the cardiac output was reduced. In all animals injection of pyrroxan was followed by tachycardia, shortening of the phase of isometric contraction, and activation of contractility of the myocardium.