Effect of urokinase on fibrinolysis and fibrinogenolysis.

The thrombolytic (fibrinolytic) effect of the urinary plasminogen activator, urokinase (UK), was compared with its fibrinogenolytic effect, using an artificial circulating system, and in in vivo pulmonary embolus and femoral vein thrombosis models. The thrombus lysing efficiency (fibrinolysis/fibrinogenolysis) was, in all cases, below 1.00, indicating that fibrinogenolysis is a primary function of UK while fibrinolysis is a secondary one.