Action of a Sympathomimetic Drug and of Theophylline Ethylene Diamine on the Pulmonary Circulation

Abstract

The action of two drugs, β-(2,5-diethoxyphenyl)-β-hydroxy-isopropylamine (BW 45/50) and theophylline ethylene diamine, on the pulmonary circulation of dogs and cats was tested. These experiments were made on intact animals, or animals with open chests, or on isolated perfused lungs. BW 45/50 reduced pulmonary arterial pressure in cats and dogs probably because of a fall in cardiac output; pulmonary vascular resistance was usually increased. Theophylline ethylene diamine caused a decrease in pulmonary vascular resistance; its value in pulmonary embolism is suggested.