Comparison of focal embolic and thrombotic cerebral ischemia model in rat

초록

Background : Most experimental results using animal stroke model do not fit into clinical situation, especially in case of neuroprotective drug trials. Besides species difference, pathophysiologic difference between animal model and clincal stroke is thought to be the reason explaining these discrepancies. As most human clinical stroke is transient focal ischemia, intraluminar suture model is currently most widely used. But it blocks and opens middle cerebral artery (MCA) in a mechanical way using nylon thread, so still have limitation of different pathophysiologic mechanism. We tried to compare recently developed animal stroke model which is pathophysiolocally most similar to human stroke, by inducing local thrombosis or embolism. Methods : In male wistar rats, modified microcatheter was inserted into the internal carotid artery and placed at proximal MCA. In thrombotic model(n=20), 100 unit of thrombin was injected with 10 ul of autologous blood directly into the proximal MCA, inducing local thrombosis. In embolic model(n=20), previously prepared microclot was injected through the microcatheter into the proximal MCA, making local embolism. Resulting infarct was confirmed after 24 hour by TTC staining. Results : The percent of infarct compared to contralateral hemisphere in thrombotic and embolic model is 24.4+15.2 and 24.6+14.3 % respecively, difference between them statistically not significant. Conclusions : Both thrombotic and embolic model are comparable each other in making infarct, and applicable to thrombolysis also.