Local effects of various anions and H+ on dog limb and coronary vascular resistances

Abstract

The effect of intra-arterial infusion of an isosmotic solution of various sodium salts and acids on pressure gradients in the forelimb and heart was studied during constant rate blood perfusion. Forelimb resistance was reduced by Na pyruvate, Na acetate, Na nitrite, and Na citrate, by hydrochloric, nitric, lactic, pyruvic, acetic, and citric acids, and unchanged by NaCl, NaHCO₃, NaNO₃, and Na lactate. The molecular activity of Na acetate or Na nitrite exceeded that of Na pyruvate. All changes resulted mainly from fall of small vessel resistance. Na acetate also increased venous resistance, probably by a remote mechanism, and limb weight; the latter was more pronounced in the absence of artificial blood perfusion. Coronary resistance was decreased by Na acetate, Na nitrite, and Na citrate, increased slightly by NaHCO₃, and unchanged by NaCl and Na lactate. Hence, the local effect of slight excess blood pyruvate, acetate, nitrite, citrate, or hydrogen is active arteriolar dilation, the activity of acetate or nitrite exceeds that of pyruvate, and acetate greatly increases tissue water storage.