Pharmacological Action of Tyramine on the Cardiovascular System in Man.

Abstract

Tyramine produces a rise in both systolic and diastolic blood pressure after intravenous injection in man. The reproducibility of the pressor effect and the dose-effect relationships were studied in a total of 39 subjects. 0.2 mg/kg intravenously produced a systolic peak rise of 64.2 mm Hg (S. D. 17.4) and 0.4 mg/kg produced 90.2 mm Hg (S. D. 19.2) rise. Cardiac output changes were inconsistent; total peripheral resistence increased. The pressor response to 0.2 mg/kg and 0.4 mg/kg is not statistically different when repeated on the same day or the next day although variability be tween days was greater than the same day. The dose response curve obtained from 10 patients showed that the response to 0.2 and 0.4 mg/kg lay on the steep part of the curve. It is suggested that tyramine is a useful drug for testing the adequacy of catecholamine stores as its pressor response is due to release of endogenous norepinephrine.