The effects of danaparoid, dalteparin and heparin on tissue factor-inducedexperimental disseminated intravascular coagulation and bleeding time in the rat

Danaparoid and heparin, on the basis of anti-activated factor X (anti-FXa) activity, were equipotent in accelerating the rate of interaction of FXa an d antithrombin III. In rat tissue factor-induced disseminated intravascular coagulation (DIC) models, an intravenous administration of danaparoid inhi bited the decrease in plasma fibrinogen and platelet counts and the increas e in serum fibrinogen degradation products. Expressed on the basis of anti- FXa activity, these effects were comparable with those of dalteparin and he parin. In rat mesenteric small artery and vein, less bleeding was observed after intravenous administration of danaparoid than after dalteparin or hep arin. Danaparoid did not affect adenosine diphosphate- or collagen-induced platelet aggregation, and showed weaker inhibitory effects on aggregation i nduced by thrombin, or collagen + thrombin, than did dalteparin or heparin. These findings suggest that danaparoid may be useful for the prevention of DIC and has less tendency to cause bleeding than dalteparin or heparin, pr obably as a result of its weaker ability to inhibit platelet aggregation. ( C) 2001 Lippincott Williams & Wilkins.