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目的探讨银杏内酯B对脑缺血再灌注损伤的保护作用及分子机制。方法大鼠随机分为假手术组、模型组、阳性药组(金纳多12 mg·kg-1)、银杏内酯B 1,2和4 mg·kg-1剂量组,采用线栓法建立大鼠大脑中动脉缺血再灌注模型,TTC染色测定梗死范围,HE染色检测脑组织病理变化,试剂盒检测大鼠脑组织匀浆中超氧化物歧化酶(SOD)活性、一氧化氮(NO)及丙二醛(MDA)含量的变化,透射电镜观察银杏内酯B对神经元超微结构改变,免疫组化法及Western blotting法检测胱天蛋白酶3,Bax和Bcl-2蛋白表达的影响,RT-CR检测胱天蛋白酶3、Bax和Bcl-2mRNA表达。结果与模型组比较,银杏内酯B可缩小梗死范围,减轻脑组织病理改变,明显提高脑组织SOD活性,降低脑组织中NO及MDA含量,免疫组化及Western blotting和RT-PCR结果显示脑缺血再灌注后胱天蛋白酶3、Bax蛋白及mRNA表达上调,Bcl-2表达降低;而银杏内酯B可下调胱天蛋白酶3、Bax的蛋白及mRNA表达,上调Bcl-2表达。结论银杏内酯B可减轻脑缺血再灌注神经细胞损伤,其机制可能与减少自由基产生,减轻NO神经毒性,抑制线粒体通路的诱导的神经细胞凋亡有关。
Objective To investigate the protective effect of ginkgolide B on cerebral ischemia-reperfusion injury and its molecular mechanism. Methods Rats were randomly divided into sham operation group, model group, positive group (12 g · kg-1), ginkgolide B 1,2 and 4 mg · kg-1 The model of middle cerebral artery occlusion (MCAO) in rats was established. The extent of infarction was determined by TTC staining. The pathological changes of brain tissue were detected by HE staining. The activity of superoxide dismutase (SOD), nitric oxide (NO) And malondialdehyde (MDA). The ultrastructural changes of neurons induced by Ginkgolide B were observed by transmission electron microscopy. The expressions of caspase 3, Bax and Bcl-2 were detected by immunohistochemistry and Western blotting. RT-CR detection caspase 3, Bax and Bcl-2mRNA expression. Results Compared with the model group, ginkgolide B could reduce the infarct size, alleviate the pathological changes of brain tissue, increase the activity of SOD and decrease the contents of NO and MDA in brain tissue. The results of immunohistochemistry, Western blotting and RT-PCR showed that brain The expression of caspase-3 and Bax protein and mRNA was up-regulated and the expression of Bcl-2 was decreased after ischemia / reperfusion. Ginkgolide B could down-regulate the protein and mRNA expression of caspase-3 and Bax and up-regulate the expression of Bcl-2. Conclusion Ginkgolide B can relieve the neuronal injury induced by cerebral ischemia and reperfusion. Its mechanism may be related to the reduction of free radical generation, NO-induced neurotoxicity, and the inhibition of mitochondria-induced neuronal apoptosis.