大鼠局灶性脑皮质缺血/再灌注对脑神经元损伤作用及瘦素受体表达的改变

目的:研究脑缺血/再灌注(I/R)损伤后瘦素受体(OB-R)表达的变化情况.方法:雄性成年Wistar大鼠20只,随机分成4组:假手术24 h、72 h对照组及I/R 24 h、72 h实验组.线栓法制备大鼠局灶性脑皮质I/R损伤模型,在脑I/R后相应时间点分别处死大鼠,采用免疫组织化学、免疫电镜方法观察大脑皮质OB-R的表达,在光镜及电镜下观察神经元损伤改变.结果:左顶叶皮质锥体细胞、血管内皮、脉络丛发现有OB-R阳性表达;与假手术对照组相比,I/R 24 h(I/R早期)锥体细胞OB-R免疫反应阳性细胞表达减少(P＜0.05),I/R 72 h(I/R晚期)锥体细胞OB-R免疫反应阳性细胞减少更明显(P＜0.001);光镜及电镜对缺血中心区神经元的观察均显示I/R晚期的神经元损伤明显重于早期.结论:脑I/R损伤后早期神经元损害和迟发性神经元损害均伴随有OB-R的表达减少,且迟发性神经元损害表达减少更明显,因此在脑梗塞的防治中有必要对瘦素及其OB-R的作用进一步研究.

Study on the changes of the leptin receptor expression and neuronal damage following focal ischemia/reperfusion in rats

Aim: To study the expression of leptin receptor(OB-R) and neuronal damage following focal ischemia/reperfusion in rats.Me(thods:) 20 adult male Wistar rats were divided into four groups randomly: sham-operated 24 h,72 h control group and ischemic/reperfusion 24 h,72 h experiment group.Focal ischemia/reperfusion model was made with MCAO.Immunohistochemistry and immuno-electron microscope were used to observe the expression of OB-R of the cortex and neuronal damage.Results: The positive cells of OB-R were found in pyramidal cells of the parietal cortex,choroid plexus and blood vessel endothelium.Compared with sham-opera-ted group,significant reduction of OB-R positive cells in the pyramidal cells was observed in the ischemia/reperfusion rats 24 hours after cerebral ischemia(P<0.05).The positive cells of OB-R of sham-operated 72h group reduced further(P<0.01).Histochemistry and electron microscope showed neuronal damage in the core area of cerebral ischemia in the late period was more obvious than in the early period.Conclusion: The early and delayed ischemia/reperfusion neuronal damage were accompanied with reduction of OB-R expression.Thus,it is worth to study the effect of OB-R in cerebral ischemia.