Analysis of the action of tyramine on blood pressure in the rat

In urethane anaesthetized rats, tyramine, 1 mg/kg, i.v. produced a considerable rise in blood pressure. In rats pretreated with reserpine, 10 mg/kg, injected i.p. 16–24 hr before, the pressor response was still quite large.The residual response after reserpinization was almost abolished by adrenalectomy or by pithing. The findings suggest that the pressor action of tyramine in the rat is due in part to a central or centrally mediated stimulation of the nerve supply to the adrenal medulla.