Experimental Study Of Thrombolysis In Internal Carotid Artery By Plasminogen Activator Of Gloydius Brevicaudus Venom(GBV-PA)

Objective:To observe the relationship between thrombolytic effect and doses of plasminogen activator of Gloydius brevicaudus venom (GBV-PA);To evaluate the intraarterial thrombolytic effect of GBV-PA compared with reteplase(r-PA) and urokinase(UK);To research different thrombolytic effects resulted from different approaches.Methods:The model of acute left cerebral embolism was established with interventional technique in 42 adult beagle dogs,which were randomly divided into 7 groups, including control group,reteplase group,urokinase group, GBV-PA intra- arterial high-dose group(75μg/kg),middle-dose group(37.5μg/kg), low-dose group(18.75μg/kg) and intravenous group(75μg/kg). Each group was dealt with by correspongding thrombolytics respectively. Angiography of left internal carotid artery were performed after thrombolysis 60, 120, 180,240 minutes to observe the recanalization of embolized arteries.Blood samples were collected to determine thrombin time (TT), prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB)and D-Dimer (DD).These canines were observed with activities in 24 hours. Results:(1)The recanalization rate at 2 hours after thrombolysis was 86.7% in GBV-PA high-dose group,52.4% in GBV-PA middle-dose group, 33.3% in GBV-PA low-dose group and 0.00% in control group. There was significant statistical difference in each GBV-PA groups compared with the control group. There was significant statistical difference between every two-groups.(2)The recanalization rate at 2 hours after thrombolysis was 86.7% in GBV-PA high-dose group, 88.9% in reteplase group, 57.9% in urokinase group and 0.00% in control group. There was significant difference in each thrombolytics groups compared with the control group. The vascular recanalization rate in GBV-PA high-dose group and reteplase group was higher than that in urokinase group.There was no significant statistical difference in vascular recanalization rate between GBV-PA high-dose group and reteplase group. (3)The recanalization rate at 2 hours after thrombolysis was 86.7% in GBV-PA intraarterial group, 33.3% in GBV-PA intravenous group and 0.00% in control group. There was significant statistical difference in GBV-PA groups compared with the control group. The vascular recanalization rate in intraarterial group was higher than that in intravenous group.There was significant statistical difference between two groups.(4)Hemorrhage as side effects was serious when urokinase and reteplase were functioning.The side effects of low-dose GBV-PA was not serious.As dose increased,bleeding became grave.Conclusions:The thrombolytic effect of GBV-PA was dose-dependent;The high-dose GBV-PA was stronger than urokinase in thrombolytic power.But there was no significant difference in vascular recanalization rate between GBV-PA and reteplase; Thrombolysis by intraarterial approach is more effective than that by intravenous approach.