参芎注射液对脑缺血再灌注大鼠的神经元保护作用

The Neuron Protective Effects of Shenxiong Injection on Focal Cerebral Ischemia-Reperfusion Injury in Rats

目的:观察参芎注射液对大鼠局灶性脑缺血再灌注后神经细胞凋亡及内质网应激相关因子葡萄糖调节蛋白/免疫球蛋白结合蛋白(GRP78/Bip)表达的影响。方法:100只雄性SD大鼠随机分为正常组、假手术组、脑缺血再灌注组、参芎治疗组;后两组根据再灌注时间不同各分为6、12、24、72 h四个亚组;采用大鼠大脑中动脉线栓法制备局灶性脑缺血再灌注模型。TUNEL法观察细胞凋亡情况;免疫组化和RT-PCR法检测各实验组中缺血周围区GRP78/Bip的表达。结果:TUNEL法表明参芎治疗组大鼠大脑神经细胞凋亡程度较缺血再灌注组明显减轻。免疫组化和RT-PCR检测均发现各时间点缺血再灌注组大鼠GRP78/Bip表达高于假手术组及正常组;脑缺血再灌注组及参芎治疗组GRP78/Bip的表达于缺血后12 h最高,72 h恢复至正常水平,且均呈现先升高后降低的趋势;各时间点缺血再灌注组GRP78/Bip表达均高于参芎治疗组。结论:再灌注损伤后12 h内出现GRP78/Bip表达升高,参芎注射液可以下调其表达,从而可能通过减轻内质网应激而减轻缺血再灌注损伤起到神经元保护的作用。

Objective： To observe the influence of Shenxiong Injection on neuronal apoptosis and expression of the Glucose regulated protein 78/immunoglobulin binding protein （GRP78/Bip）, which is associated with the endoplasmic reticulum stress （ERS） after focal cerebral ischemia-reperfusion in rats. Methods： One hundred male SD rats were divided randomly into normal group, sham-operated group, cerebral ischemia-reperfusion model group, Shenxiong injection-treated group. The last two groups were divided into four subunits according to the different reperfusion time： 6, 12, 24 and 72 hours. Middle cerebral artery occlusion was used to make the focal cerebral ischemia-reperfusion model. Neuronal apoptosis was detected by TUNEL staining. The expression of the protein and mRNA of GRP78/Bip at the edge of ischemic area were respectively evaluated by the methods of immunohistochemistry and RT-PCR. Results： Compared with the cerebral ischemia-reperfusion model group, the number of apoptotic cells significantly decreased in the Shenxiong in-jection-treated group. Immunohistochemistry staining and RT-PCR illustrated that the expressions of the protein and mRNAs of GRP78/Bip in ischemia-reperfusion group were higher than those in the sham-operated group and normal group at each time point. The expressions of GRP78/Bip in ischemia-reperfusion group and Shenxiong-treated group were the highest at 12 h, and at 72 h subsided to the base line, and the expression at 24 h was lower than that at 12 h but higher than that at 72 h. Compared with the ischemia-reperfusion group, the expression of GRP78/Bip was lower in Shenxiong-treated group at same time point. Conclusion： The expression of GRP78/Bip is upreguated whitin 12 h of cerebral ischemic injury in rats and Shenxiong can decrease its expression. Shenxiong might relieve the ischemia-reperfusion injury to neurons by the way of attenuating the severity of ERS.