A new, ideal technique to monitor thrombolytic therapy.

In an earlier article we have reported a technique which allows the measurement of haemostasis from whole blood by the "tube bleeding" principle. The technique is now progressed by using non-anticoagulated blood and therefore clotting-time is also measured. We report here that the technique allows a simple thrombolytic assay to perform from the same blood sample used for haemostasis measurement by detecting the length of time until the haemostatic plugs crack or are expelled. Evidence is presented that this "spontaneous" expulsion is mainly due to thrombolysis. Generation of thrombin during haemostasis is indicated by the inhibitory effect of hirudin. 125I-fibrinogen accumulates (28-fold) in the haemostatic plugs. Plasminogen activators (streptokinase and urokinase) reduce while inactivation of plasminogen by specific antibody greatly prolongs the expulsion-time. The effect of cytochalasin B shows that the retraction of the haemostatic plug is not a decisive factor of the expulsion. As the technique allows the simultaneous measurement of haemostasis, thrombolysis and clotting, it seems ideal for monitoring thrombolytic therapy.