ABSTRACT
OBJECTIVE: To evaluate the anti-thrombus activitity of EPR-hirudin (EH), a derivative of hirudin obtained by adding three amino acids at the nitrogen terminus. METHODS: The anti-thrombus activitity of EH was investigated by chromophore substrate method in vitro as well as by rat models of carotid arterial thrombosis and inferior vena cava thrombosis in vivo. RESULTS: The result of anti-thrombin experiment in vitro showed that EH did not produced anti-thrombin activity unless it was cleaved by blood coagulation factors. Then the anti-thrombus feature of EH was confirmed in vivo separately in the rat models of carotid arterial thrombosis and inferior vena cava thrombosis. The formation of arterial clot was inhibited and the weight of venous clot was decreased after administration of EH in a dose-independent manner. However, the blooding time, activated partial thromboplastin time (APTT) and thrombin time (TT) did not significantly increase in EH groups compared with HV and low molecular heparin. CONCLUSION: EPR-hirudin can inhibit the formation of arterial and venous clot and has low risk of blooding.