黄芩苷对大鼠脑缺血再灌注损伤后海马神经元HSP70表达的影响

Effect of baicalin on HSP70 expression of hippocampal neurons in focal brain ischemia-reperfusion injury rats

目的研究黄芩苷对大鼠局灶性脑缺血再灌注损伤后海马神经元热休克蛋白质(HSP)70表达的影响。方法W istar大鼠随机分为假手术组、脑缺血再灌注模型组、黄芩苷组(50,100和200 mg.kg-1)以及尼莫地平0.4mg.kg-1组。利用大鼠大脑中动脉内栓线阻断法制备局灶性脑缺血再灌注损伤模型,通过HE染色、流式细胞术、免疫组织化学以及RT-PCR等方法,观察黄芩苷对缺血再灌注损伤大鼠脑组织病理形态学改变、神经细胞凋亡率以及HSP70表达的影响。结果黄芩苷可明显改善缺血再灌注损伤所致的大鼠脑组织病理形态学改变,降低神经细胞凋亡率,促进HSP70基因的转录与翻译。结论黄芩苷对大鼠局灶性脑缺血再灌注损伤具有保护作用,其作用机制可能与黄芩苷促进HSP70表达、抑制神经细胞凋亡有关。

Aim To investigate the effect of baicalin on the hippocampal neuronal apoptosis and the expression of HSP70 in rats with focal brain ischemia-reperfusion injury. Methods One hundred and twenty male Wistar rats were randomly divided into six groups：sham operated group, ischemia-reperfusion group, nimodipine group and three baicalin groups,to which baicalin was administered at doses of 50, 100 and 200 mg · kg^-1, separately. The models of focal brain ischemia-reperfusion injury induced by middle cerebral artery occlusion （MCAO） were used in this study. HE stain was used to observe the pathological changes. Flow cytometry （FCM） was used for determination of neuronal apoptosis. HSP70 protein expression of the neurons was detected with immunohistochemistry. Reverse transcription polymerase chain reaction （RT-PCR） was used to detect the expression of the mRNA level of HSP70. Results Baicalin can significantly relieve the pathological changes and inhibit apoptosis in hippocampus CA1 area, and at the same time increase the expression of HSP70 and HSP70 mRNA. Conclusion Baicalin can relieve brain damage induced by focal brain ischemia-reperfusion in rats, which may be related to inhibiting the process of the neuronal apoptosis. The mechanism of antiapoptosis effect of baicalin may be related to the promotion of transcription of HSP70 mRNA and increasing the expression of the protein.