A study of its effects on the cardiovascular system of the dog revealed that a single intravenous dose of 30 mg./kg. lowered the arterial pressure of neurogenic and renal hypertensive dogs. However, in normotensive animals 30 mg./kg. of the compound given intravenously eliminated the severe hypertension elicited by high doses of amphetamine and ephedrine and also markedly antagonized carotid occlusion reflex pressor re-
