A comparison of the direct peripheral actions upon systemic venous pressure of k-strophanthosid, digoxin and ouabain.

Abstract

1. Digoxin and k‐strophanthosid and, to a lesser extent, ouabain have a direct peripheral action on systemic venous pressure, independent of cardiac effects. These glycosides in therapeutic doses caused a rise of mean inferior and superior vena caval pressure in sheep whose pulmonary and systemic circulations were perfused at constant rates, with functional exclusion of the animal's own heart, and with central venous pressure fixed at atmospheric pressure. The only explanation is that these drugs constrict the systemic veins. This might be due to action on the vein wall itself or on venomotor nerves.2. Digitalis caused a rise of hepatic venous pressure in perfused sheep, as reported by others in dogs.3. In sheep with intact circulations, therapeutic doses of digoxin, k‐strophanthosid and ouabain usually caused no alteration of systemic venous pressure, but occasionally a slight fall.4. The direct effect on venous pressure is probably not the principal action of these drugs, but should be considered in interpreting the many effects of digitalis on the intact animal.