脑缺血再灌注损伤模型大鼠大脑皮质BDNF mRNA表达减少

目的制备局灶性脑缺血再灌注损伤大鼠模型,并观察大脑皮质脑源性神经营养因子(BDNF)mR-NA表达的变化。方法雄性SD大鼠,采用线栓法闭塞大脑中动脉2h后进行再灌注3d,制备局灶性脑缺血再灌注损伤模型。采用神经缺失评分观察大鼠的行为学表现;TTC染色检查脑组织梗死情况;HE染色观察大鼠脑组织形态结构;RT-PCR技术检测大鼠大脑皮质BDNF mRNA的表达。结果假手术组大鼠无神经功能障碍表现;脑组织未见梗死灶;脑组织神经细胞形态规则;大脑皮质BDNF mRNA的相对表达量,与正常组相比,未见明显变化。与假手术组相比,局灶性脑缺血再灌注损伤模型大鼠出现神经功能障碍;左侧半球可见梗死灶;梗死侧脑组织形态学观察显示神经细胞大量坏死脱落、胞质呈空泡变性、疏松、胞核浓缩深染;大脑皮质BDNF mRNA表达量明显减少。结论大脑中动脉闭塞2h后进行再灌注3d可造成脑缺血再灌注损伤,可能与大脑皮质BDNF mRNA的表达减少有关。

Decrease of BDNF mRNA expression in cortex of cerebral ischemia-reperfusion injury model rats

Objective To observe brain morphology and brain-derived neurotrophic factor(BDNF) mRNA expression in cortex of cerebral ischemia-reperfusion model rats.Methods Twenty-two male SD rats were randomly divided into three groups,normal group,sham group and model group.Focal cerebral ischemia-reperfusion model was induced for 2h by middle cerebral artery occlusion(MCAO) followed by 3d reperfusion.TTC staining was used to examine brain infarction,HE staining was to examine brain morphology,and RT-PCR was used to detect BDNF mRNA expression in the cerebral cortex.Results Rats in sham-operated group showed no brain infarction,no brain morphological changes and no significant difference in cortex BDNF mRNA expression compared with rats in normal group.Compared with rats in sham group,model group rats showed infarct in the left hemisphere,necrosis of large numbers of nerve cells,osteoporosis of cytoplasm and condensed stained nuclei in the left hemisphere.In addition,BDNF mRNA expression in cortex was significantly reduced.Conclusion Middle cerebral artery occlusion(MCAO) for 2h followed by reperfusion for 3d could cause cerebral ischemia-reperfusion injury,which might be related to the decreasing expression of BDNF mRNA.