Metabolism of Vasoactrve Substances in the Lung

Abstract

Inactivation of vasoactive substances in pulmonary circulation were studied in vivo experiment and heart-lung preparation using rabbits. In vivo experiments, pressor substances such as angiotensin vasopression, epinephrine, and norepinephrine passed through the lung without any change on their pressor activities, but all the depressor substances, such as bradykinin, 5-hydroxytryptamine, adenosine, ATP, poly A and prostaglandin E₁ were markedly affected in their depressor activities through pulmonary circulation. In the heart-lung preparation, inactivation of bradykinin and prostaglandin E$₁, as well as the activation of angiotensin I, were observed, however other depressor substances were not inactivated.