Study On The Model Of Middle Cerebral Artery Occlusion On Ischemic Stroke

[Objective] With the arrival of aging society in China, the incidence of ischemic stroke is increasing. But only a small proportion of patients are able to receive thrombolysis within the treatment time. Study on the treatment requires appropriate animal model. The suture model is a widely used model on stroke. However, due to many factors, such as the impact suture, rat strains, age, methods of operation, the model results,have great variability The Longa method and the Koizuma method are common methods of making suture model. Currently, suture coated with the popular silicone used is made. The suture has been greatly improved to reduce effect on the success rate of the model on a certain extent. Previous article study on the contrast of Longa and Koizuma using the traditional suture. We study the constrast of Longa and Koizuma with the popular suture law.Further more, The therapy time window on reperfusion has been studied and make the groundwork. for the treatment of stroke infuture.[Method] preparing suture model is affected by many factors,In order to improve the success rateof the model, this experiment improved the process for preparing the suture. The SD rats were divided into four groups,Goup A: ischemia-reperfusion Longa group(20); Group B: ischemia-reperfusion Koizuma group(20); Group C: Permanent Ischemia Longa group(20); D group : permanent ischemia Koizuma group(20). By comparing the success rate, mortality, TTC staining, neurological function in rats, we contrast the Longa and Koizuma method with the modified suture. At the same time with Longa method, Make the reperfusion at different time points of ischemia 15 min, 0.5h, 1h, 1.5h, 2h, 3h on 24 h TTC staining after transient ischemic reperfusion therapy time window.[Results] 1. To make the same model,the mortality of rats, model success rate, TTC staining volume was reduced with Longa group compared with the Koizuma group, the difference was statistically significant(P <0.05);. 2 With the same method, permanent cerebral ischemia group increased the mortality of rats and the model stable rate reduction, than that in ischemia-reperfusion group(P <0.05); 3 Preparation of ischemia-reperfusion model, the neural score difference was not statistically significant between Longa group and Koizuma group(P> 0.05), Preparation of permanent cerebral ischemia model, the neurological score was no significant difference between Longa group Koizuma group of(P> 0.05);. 4 After the transient cerebral ischemia, the 2h reperfusion time group increased the infarction compared with the 1.5h reperfusion group, the difference was statistically significant(P <0.05);the TTC stained area of the 2h has not the statistical significance than the 3h group(P> 0.05).[Conclusion] 1. Preparation of the same ischemia-reperfusion or permanent cerebral ischemia, Longa method has more success rate and less mortality in rats than that of Koizuma,2 With Longa or Koizuma method,the permanent. cerebral ischemia increased mortality in rats and reduced the model stable rate,compared with ischemia-reperfusion model,; 3. prepared the same model, the neurological of Longa method has no rating significant differences than that of Koizuma law; 4.the infarct area of the brain increase over time after transient ischemic, a significant increase in 1.5-2h period of cerebral infarction area, the groups on > 2h ischemia-reperfusion has no significant changes in the infarct area than that of 2h; 3. the therapy time window on the transient ischemic reperfusion is 2h.