Studies on vasoactivity of catecholamines in man

Abstract The effects of administration of noradrenaline and serotonin on systemic arterial pressure, cardiac output, renal plasma flow and blood flow to the lower extremities in man were compared. Modification of vascular responses to these two substances by drug-induced hypotension were studied. The results failed to support the hypothesis that noradrenaline may play a major role in the mechanism of hypertension in human beings. On the other hand, blood flow responses after administration of catecholamine inhibitors as well as after use of a monoamine oxidase inhibitor strongly support the view that noradrenaline is one of the most potent physiologic peripheral vasoconstrictors in man.