RESUMO
The effect of recombinant microplasmin (micro-plasmin) on acute cerebral infarction was evaluated in rats, and compared with recombinant tissue plasminogen activator (rt-PA). After the model of middle cerebral artery occlusion (MCAO) was established by autologous blood clots, different doses of micro-plasmin (2.5, 5, and 10 mg x kg(-1)) were administered into the thrombus intra-arterial. Twelve hours after administration of micro-plasmin, the neurological deficit score of rats was recorded and the infarct volumes were determined. Bleeding time (BT), fibrin degradation product (FDP) concentration in serum and thrombin time (TT), prothrombin time (PT) and fibrinogen (FIB) concentration in plasma were tested after administration. Intra-arterial administration of micro-plasmin could reduce significantly neurological deficit score and infarct volumes in MCAO rats. FDP concentration increased significantly as compared with model group. There were no significant differences in TT, PT and BT. FIB concentration reduced markedly as compared with model group, but had no significant difference as compared with sham group. The results suggest that micro-plasmin is effective in treatment of rat acute cerebral infarction, and has no significant influence on fibrinolytic system and blood clotting system, indicating that micro-plasmin may be useful for treatment of acute cerebral infarction, and not lead to hemorrhage. Micro-plasmin seems to be distinguished from clinical used rt-PA by its no hemorrhage effect.