The effects of a constituent of hemolyzed blood on pulmonary arterial pressure, systemic arterial pressure, and heart rate in dogs

Abstract

Extracorporeal blood circulating devices are recognized as a common source of trauma to circulating erythrocytes. Since hemolyzed blood is a possible source of pharmacologically active substances, the present study was undertaken to isolate a pharmacologically active fraction from hemolyzed blood. Blood collected from dogs was hemolyzed by mixing with an equal volume of sterile distilled water. Five precipitates were prepared from the hemolyzed blood-water solution by adding ammonium sulfate until the solution was 10%, 20%, 30%, 40%, and 50% saturated with the salt. These five precipitates were injected intravenously into 14 recipient dogs while the mean pulmonary arterial pressure, mean systemic arterial pressure, and mean heart rate were monitored. The 30% ammonium sulfate precipitate produced the greatest physiological alterations. This precipitate consistently reduced mean systemic arterial pressure, elevated mean heart rate, and occasionally, elicited marked elevations in mean pulmonary arterial pressure. Four gel filtration fractions were isolated from the 30% precipitate using Sephadex G-200. When injected intravenously into nine dogs, fraction 2 consistently elevated mean pulmonary arterial pressure and reduced mean systemic arterial pressure. This fraction also elicited slight alterations in mean heart rate. Fraction 3 produced a transient decrease in mean systemic arterial pressure. In some recipients, arrhythmias occurred following injection of fraction 3. The remaining two gel filtration fractions produced minimal changes. Due to its biochemical characteristics, the active principle appeared to be a protein or a compound adsorbed on a protein.