大鼠局灶脑缺血-再灌注动物模型半暗带的动态变化

Dynamic Penumbra in a Rat Model of Focal Cerebral Ischemia and Reperfusion

目的 根据黑色神经元辨认不同缺血和再灌注期间的缺血中心区 ,阐明缺血早期半暗带的范围 ,并对其进行动态观察 ,以期阐明半暗带的形态特征。方法 将 72只雄性 Wistar大鼠随机分为假手术组、空白对照组、持续缺血 2 4h(O2 4R0 )、缺血 4h再灌注 2 4h组 (O4R2 4) ,以下类推 ,即 O2 R0、O2 R0 .5、O2 R2、O2 R4、O2 R8、O2 R2 4、O2 R48、O2 R96组 ,每组 6只动物。实验组经线栓法制成局灶脑缺血 -再灌注模型。动物脑组织经灌注固定后进行苏木素 -伊红、甲苯胺蓝和铅铀染色 ,分别作光镜和电镜观察 ,并用图像分析仪测量缺血中心区和半暗带范围。结果 再灌注后短期内半暗带扩大 ,于再灌注 2 h达最大 (P<0 .0 5 ) ,再灌注 4～ 48h内半暗带范围相对稳定。缺血中心区和半暗带内细胞形态有多种类型 ,并随再灌注时间而变化。

Objectives To identify the ischemic core and penumbra of variant ischemia and reperfusion period by the dark neuron method,observe them dynamically, and elicit the morphological character of ischemic penumbra. Methods Total 72 male Wistar rats were randomly divided into the following groups: pseudosurgical, blankcontrol,O24R0 (sustained ischemia for 24 hours),O4R24(ischemia for 4 hours and reperfused for 24 hours, the following may be deduced by analogy),O2R0,O2R05,O2R2,O2R4,O2R8,O2R24,O2R48,O2R96.There were 6 rats in each group. Rats in experimental groups were suffered focal cerebral ischemiareperfusion through a nylon suture method. After perfusion fixed, the brains were coronal sectioned and stained with HE, TB and acetum plumbi/silver nitrate. Sections were observed with light microscope and electron microscope. The area of ischemic core and penumbra was measured and analyzed with an image analysis system. Results The penumbra expanded rapidly in a short period after reperfusion, and reach its apex when reperfued for 2 hours (P<005). The penumbra was relatively stable during 4 to 48 hours reperfusion. There were many cell types in ischemic core and penumbra, the proportion of cells changed according to reperfusion time. Conclusions Reperfusion could aggravate cerebral edema and make the ischemic penumbra to expand during the first hours.