Cardiovascular effects of radioprotective compound beta-aminoethylisothiuronium Br-HBr (AET)

¹ Clinical Physiology Laboratories, Institute of Clinical Investigation, University of Tennessee College of Medicine, Memphis, Tennessee

The radioprotective compound beta-aminoethylisothiuronium Br-HBr (AET) produces marked cardiovascular changes in various mammals. This problem was investigated in the dog by the slow intravenous infusion and the rapid intravenous injection of AET. Blood pressure, electrocardiogram, and cardiac output were measured, and peripheral resistance, plasma and blood volumes, stroke volume, and modal circulation time were subsequently determined. A dominant response noted in this study was a marked hypertension induced by the slow infusion and rapid injection of AET. This alteration was due to an increased peripheral resistance. In addition, a rapidly developing hypotension following a hypertensive peak was observed in animals which were rapidly injected with AET. It was also noted that the myocardium was refractory to vagal stimulation after AET administration. The action of this compound appears to be a direct one on the peripheral vasculature and the myocardium.