The Coagulation and Fibrinolysis Systems of Japanese and Rhesus Monkeys

Abstract

It has been studied about the induction of experimental disease of thrombosis or disseminated intravascular coagulation (DIC) using small animals. The blood coagulation or fibrinolysis system in small animals are different from that of human.In present study, we investigated the coagulation and fibrinolysis systems of Japanese and Rhesus monkeys as compared with human.These monkey's coagulation system was very similar to that of human from the results of prothrombin time test, partial thromboplastin time test, thrombin time test and the level of fibrinogen, whereas the fibrinolysis system of these monkeys were different from that of human. That is, the plasma lysis time and euglobulin lysis time were extremely prolonged in comparison with that of human.The level of plasmin inhibitor (including antiactivator), however, was same as the human. And the concentration of plasminogen in plasma from monkeys was higher significantly (p<0.01) than that from human. Although the plasminogen activator in plasma and FDP in serum from the monkeys in normal state were nondetectable, in the monkeys given the stress when blood was collected some activator and FDP were detected.So, it seems that the monkey's fibrinolysis system has potential fibrinolytic activity and is difficult to be activated.In addition, the Japanese monkey's plasminogen was activated by small dose of streptokinase (SK) to the same fibrinolytic activity as human's. Whereas the plasminogen-SK complex of monkey had little activity of activator to bovine plasminogen.In spite of a little differences in the coagulation or fibrinolysis system between monkey and human, it is great useful to try to experiment using monkey about the thrombosis, DIC or atherosclerosis in place of the small animals.