The Study Of MMP-9Expression In Rats With Different Time Window Thrombolytic Therapy

Objective:Observed cerebral infarction and diabetic with cerebral infarction rats after rt-PA thrombolytic therapy efficacy in different time windows, and to explore the internal mechanism of the malignant complications of hemorrhagic transformation after thrombolytic therapy.Methods:Use high-fat diet plus intraperitoneal injection of streptozotocin, establish type2diabetic rat model, Select mode mouse further to establish rat model of cerebral infarction by autologous blood clot. Healthy adult male wistar rats120weighing about200-250g, were randomly divided into simple cerebral infarction group (40), diabetes cerebral infarction group (40), sham operation group (40), each group re-equalization were randomly divided into group2h (20) and4h (20), The CI group and DM+CI group were given rt-PA thrombolysis in2h、4h time points, sham operation group were given saline time points2h、4h, all rats were observed after thrombolysis24h, in each group randomly selected six conducted brain tissue water content calculation, randomly selected six conducted evans blue (EB) determination of the blood-brain barrier permeability, randomly selected six conducted immunohistochemical method for the determination of MMP-9expression. Longa-bederson score>0and <5points were enrolled. Each set of data using statistical software SPSS13.0for data analysis, quantitative data group differences in mean±standard deviation, a number of sample data homogeneity of variance using analysis of variance, heterogeneity of variance using the Kruskal-Wallis test, multiple samples were compared using LSD test.Results:1、Wet and dry weight measurement of brain water content shows, CI group and DM+CI group compared with the sham group, brain water content was significantly increased, it showed significantly difference (P<0.01); DM+CI4h group compared with the pure CI4h group, brain water content increased significantly, it showed significantly difference (P<0.01).2、Evans blue method for the determination of the blood-brain barrier permeability shows, CI group and DM+CI group compared with the sham group, the blood-brain barrier permeability increase, EB content was significantly increased by through the blood-brain barrier, it showed significantly difference (P<0.01); DM+CI4h group compared with the pure CI4h group, the EB content was significantly increased, it showed significantly difference (P <0.01).3、Immunohistochemistry shows, CI group and DM+CI group compared with the sham group, the expression of MMP-9are increased, it showed significantly difference (P<0.01); DM+CI4h group compared with the CI4h group MMP-9expression was significantly increased, it showed significantly difference (P<0.01).Conclusion:1、Diabetic rats compared with normal rats with cerebral infarction in brain tissue edema is more obvious, Severe symptoms of neurological deficit.2、After cerebral infarction, the rats blood-brain barrier damaged, and its severity increases with increasing ischemic time, on DM+CI rats, rt-PA thrombolytic therapy within3h were Effective, but thrombolytic therapy outside3h, cerebral edema Obvious and BBB severely damaged, the mechanism may be achieved by up-regulating the expression of MMP-9.