Lanthanum Trichloride induced blood coagulation defect and liver injury

The rare earth metals have anticoagulant and hepatotoxic effects, among others. In view of the connection between liver and blood coagulation, the character of the coagulation defect developing in rabbits treated with lanthanum trichloride (La) was studied and in connection with it, the role of the liver injury described earlier. The results showed the effect to depend primarily on the dose of the drug administered; acute and prolonged treatments produce coagulation defects different in type. The effect of a single large dose is characterized by a severe disturbance of thrombin formation: Prothrombin activity is decreased, PTT is prolonged, native blood does not coagulate but may be coagulated with thrombin, and its fibrinogen content is high. The effect cannot be regarded as a result of the liver injury. On giving La in repeated smaller doses, a disturbance of intrinsic thromboplastin (or thrombin) formation develops, as indicated by a decrease in prothrombin consumption. This might be due to an alteration of some serum factor or of the thrombocyte lipid factor (factor 3) and is probably connected with the liver injury.