Cardiovascular effects of imipramine in intact dogs and isolated dog atria.

Publisher Website
Google Scholar
Abstract
The effects of imipramine [a tricyclic antidepressant] were investigated on the blood pressure and heart rate in the intact dog and on the atrial rate and contractile force in the isolated atrial muscle perfused with arterial blood of the donor dog. A continuous infusion of small doses of imipramine (30 .mu.g/kg per min, i.v., 30 min) produced an increase in the blood pressure and heart rate of the donor dog and the positive chronotropic and inotropic effects in isolated atria. These responses were blocked by treatment with propranolol. When a large dose of imipramine (1 mg/kg per min, i.v., 15 min) was administered to the donor dog, the blood pressure fell and the heart rate initially increased and then decreased (i.e., 15 min later it decreased .apprx. 20% under the control level), and in isolated atria, the developed tension initially increased and 15 min later decreased but the atrial rate maintained over the control level. Examined doses of imipramine caused a potentiation of norepinephrine-induced action, and a large dose of imipramine significantly diminished norepinephrine-induced reflex bradycardia and/or frequently inverted to tachycardia. Acetylcholine-induced reflex tachycardia was suppressed by imipramine treatment. Imipramine may cause a hypotension mainly due to peripheral vasodilation and may induce a suppression of baroceptive reflex mechanism.

This publication has 1 reference indexed in Scilit: