[Effect of tri-iodine-containing x-ray contrast substances on the blood coagulation system in an experiment]

Experiments on white rats were made to examine the time course of hemocoagulation changes induced by intravenous injection of the triiodine-containing radiographic contrast agents, bilignost, verografin, triombrast, iodamide-380. The substances were found to exert a biphasic action: an initial decrease in the total coagulation is replaced by a tendency toward hypercoagulemia. In experiments in vitro, the radiographic contrast agents increased the time of plasma recalcification, the prothrombin time and retarded the thrombin-fibrinogen and thrombin-plasma reactions. Bilignost produced the most marked hypocoagulemia. It is suggested that the direct effects of the drugs on blood coagulation involve a decrease in the total blood coagulation activity.