Effects of Small Oral Doses of Reserpine on Vascular Responses to Tyramine and Norepinephrine in Man.

IN ANIMALS, reserpine depletes tissues of catecholamines, -3 reduces the response of smooth muscle to tyramine,4' 5 and potentiates the action of norepinephrine.4 6, The decreased response to tyramine probably results from depletion, since the action of this sympathomimetic amine appears to be mediated through the release of norepinephrine.4-6 The cause of hypersensitivity to exogenous norepinephrine after reserpine is not known.7 8 It seemed important to determine if the two phenomena, namely, the subsensitivity to tyramine and the hypersensitivity to norepinephrine, occur in men receiving small doses of reserpine orally. Such findings would have important clinical implications.9