Development of an in vitro model to study clot lysis activity of thrombolytic drugs

Whole blood from healthy individuals (n = 20) was allowed to form clots in a pre-weighed sterile microcentrifuge tubes; serum was removed and clot was weighed. After lysis by streptokinase fluid was removed and remnants of clot were again weighed along with the tube. Percentage of Clot lysis was calculated on the basis of the weight difference of microcentrifuge tubes obtained before and after clot lysis.There was a significant percentage of clot lysis observed when streptokinase was used. On the other hand with water (negative control), minimal (2.5%) clot lysis was observed. There was a significant difference between clot lysis done by streptokinase and water.Our study could be a rapid and effective methodology to study clot-lytic effect of newly developed drugs as well as known drugs.Cerebral venous sinus thrombosis (CVST) is a common disorder that is often accompanied by significant morbidity and mortality [1,2]. In anticoagulation therapy the intravenous heparin [2,3] is the first line of treatment for CVST, because of its efficacy, safety and feasibility. However, thrombolytic therapy, with its ability to produce rapid clot lysis, has long been considered an attractive alternative [4]. Thrombolytic drugs like tissue plasminogen activator (t-PA), urokinase, streptokinase etc. play a crucial role in the management of patients with CVST. In India though streptokinase and urokinase are widely used due to its lower cost, as compared to other thrombolytic drugs, these are dangerous [5-9] because they might cause serious bleeding complications along with reocclusion and reinfarction.Various methods were developed to measure the clot lysis activity of thrombolytic drugs. The best way to study thrombolytic drugs is through in vitro clot lysis model [10-19]. Earlier Basta et al [10] worked on artificial clots and used ultrasound methods to measure the thrombolytic activity of streptokinase. Several other models have been reported which either uses complicated mathematic