Effect of Angiotensin II on the Intact Forearm Veins of Man

Abstract

Angiotensin II was injected into an isolated venous segment in eighteen human subjects and administered intravenously into a systemic vein in five other subjects. Injections of angiotensin II into an intact isolated venous segment produced no constriction of the segment. Intravenous systemic infusion of angiotensin II produced a slight constriction of the isolated venous segment in three subjects (mean 44 mm H 2 O) and no constriction of the segment in two subjects. The constriction in the venous segment associated with the systemic intravenous administration of the drug could be interrupted by blocking the nerves supplying the venous segment. Thus, angiotensin II has no direct effect upon the forearm veins of man. The rise in segmental venous pressure following the intravenous infusion of angiotensin II appears to originate from reflexes located outside the venous system which influence tone of the superficial veins of the forearm of man.