Effect of platelet antiserum on the activation of intravascular coagulation by endotoxin

Abstract

The importance of platelets in the activation of endotoxin-induced intravascular coagulation was investigated in rabbits made severely thrombocytopenic by an intravenous injection of platelet antiserum. Goat antiserum removed more than 98% of the circulating platelets. If two doses of endotoxin were injected intravenously into thrombocytopenic rabbits, renal glomerular microclots still occurred, but coagulation analysis showed a definite reduction of intravascular coagulation. The occurrence of microclots after endotoxin injection into thrombocytopenic rabbits could be prevented by continuous infusion of heparin. The treatment of another group of rabbits with the threefold dose of antiserum prevented the occurrence of renal glomerular microclots after endotoxin injection. No correlation between platelet counts prior to the second dose of endotoxin and the occurrence of glomerular microclots could be demonstrated. With this study, the importance of platelets in triggering endotoxin-induced generalized intravascular coagulation becomes doubtful. The effect of platelet antiserum in preventing the occurrence of generalized intravascular coagulation may depend on its influence on other mechanisms important in activating intravascular coagulation by endotoxin.