Moderate Intravascular Hemolysis and Experimental Venous Thrombosis in Rats

Abstract

Summary and ConclusionsModerate intravascular hemolysis was produced in rats by intraperitoneal injections of hemolysate prepared from rats.1. An accelerated clotting time of recalcified plasma and an increased platelet adhesiveness were observed during the first ten hours after the injection.2. An increase of the fibrinogen and proaccelerin level of plasma were observed 24—48 hours after the injection.3. No increased antifibrinolytic activity was found.4. No significant increase in the incidence of thrombosis was observed during the first 24 hours after the injection whereas a high incidence of thrombosis indicating a hyperthrombotic state was observed 24—48 hours after the injection, at a time when the hemoglobinemia had disappeared. In a group of animals given a second injection of hemolysate 24 hours after the first injection a hyperthrombotic state was still present 25—48 hours after the first injection with an incidence of thrombosis equal to that noted 24—48 hours after a single injecion only.5. The present study may indicate that the hyperthrombotic state present during moderate intravascular hemolysis is associated with an increased formation of fibrinogen, factor V (proaccelerin) and probably factor VIII (AHG).