Effect Of Bretylium Tosylate On Pulmonary Arterial And Venous Circulations Of Intact Anesthetized Dog

The effects of intravenous bretylium tosylate on the pulmonary circulation, including the small pulmonary veins, were studied in 9 intact dogs anesthetized with urethane. Bretylium produced a transient rise in femoral and pulmonary arterial pressures and in cardiac output and heart rate. The small pulmonary vein pressure did not change; and, since pulmonary blood volume did not change, there was no significant change in pulmonary venous tone. It is concluded that the initial pulmonary hypertensive effects of intravenous bretylium are primarily due to constriction of small arterial vessels.