Vascular Ionic Effects of Angiotensin II in the Rat 1

Abstract

Summary

The net transfers of sodium and potassium ions induced in the rat tail vascular bed by infusion of three vasopressor agents have been measured by means of ion-selective capillary glass electrodes. Increases in perfusion pressure induced by epinephrine or vasopressin were accompanied by a consistent loss of sodium and a gain in potassium by the perfusing medium. Pressor doses of angiotensin did not have any significant effect on sodium and potassium movements. At lower, subpressor doses, angiotensin shifted the ions in the opposite direction, resulting in a gain in sodium, and a loss of potassium by the perfusing fluid. Angiotensin thus appears to have at least two effects on vascular tissues, one inducing ionic transfers, the other triggering vasoconstriction.