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

STUDY ON THE CHANGES OF THE LEPTIN RECEPTOR EXPRESSION AND NEURONAL DAMAGE FOLLOWING FOCAL ISCHEMIA/REPERFUSION IN RATS

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 h7、2 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。

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 immunoelectron 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-operated 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.