Effects of recombinant nattokinase on coagulation and fibrinolytic function of Beagle dogs

Objective:To assess the effects of recombinant nattokinase (r-NK) on coagulation and fibrinolytic function of Beagle dogs.Methods:Beagle dogs were administered with multiple and large doses of r-NK.Platelet parameters were analyzed by a blood analyzer.The fibrinogen (Fib),acti- vated partial thrombin time (APTT),prothrombin time (PT) and thrombin time (TT) were determined using a coagulation detector.Plasminogen (PLG) and tissue-type plasminogen activator (t-PA) were tested by ELISA.Results:The r-NK-treated dogs experienced severe coagulation impediment,multiple and diffused bleeding,and even death.In two weeks post the administration,the dogs showed significant reduction of platelets number,PT prolongation and escalation of both Fib concentration and the activity of PLG.Conclusion:The multi and large dosing of r-NK imbalanced the coagulation and fibrinolysis sys- tem,leading to weaker coagulation and abnormally higher fibrinolytic function.