阿托伐他汀对大鼠缺血再灌注脑组织中NADPH氧化酶源性超氧阴离子的抑制作用

目的：脑组织在缺血再灌注的早期，超氧阴离子的大量生成加重了脑组织损伤，本实验研究阿托伐他汀对缺血再灌注脑组织保护作用的可能机制。方法:成年雄性Sprague-Dawley大鼠经线栓法阻断大脑中动脉建立脑缺血再灌注模型，再灌注前经腹腔给予阿托伐他汀（立普妥）治疗。脑梗死灶体积用四唑氮蓝染色后测量；NADPH氧化酶酶活性和超氧阴离子水平使用光泽精增强化学发光法定量测定；NADPH氧化酶膜亚基gp91phox、膜易位亚基p47phox和小GTP酶Rac-1蛋白的表达用蛋白质印迹分析。结果:缺血半暗区的NADPH氧化酶活性和超氧阴离子水平增高，于再灌注2 h达到高峰，但缺血中心区的NADPH氧化酶活性和超氧阴离子水平无明显增高。阿托伐他汀预治疗能抑制再灌注2 h后缺血半暗区的NADPH氧化酶活性和超氧阴离子增高，减少膜亚基gp91phox蛋白的表达和预防细胞质亚基p47phox蛋白易位至细胞膜。结论:阿托伐他汀对缺血再灌注脑组织NADPH氧化酶源性超氧阴离子的抑制作用，是其脑保护作用机制之一。

Inhibitive action of atorvastatin on NADPH oxidase-derived superoxide anion in ischemic brain tissue after reperfusion in rats

AIM: Reactive oxygen species, specifically superoxide anion formed during the early phase of reperfusion, augment neuronal injury. The present study tested the hypothesis that atorvastatin protects against cerebral infarction via inhibition of NADPH oxidase-derived superoxide anion in transient focal ischemia. METHODS: Transient focal ischemia was created in halothane-anesthetized adult male Sprague-Dawley rats by middle cerebral artery occlusion (MCAO). Atorvastatin (Liptor) was administrated subcutaneously 3 times before MCAO. Infarct volume was measured by triphenyltetrazolium chloride staining. NADPH oxidase enzymatic activity and superoxide anion levels were quantified in both ischemic core and penumbral regions by lucigenin (5 μmol/L)-enhanced chemiluminescence. The expression of NADPH oxidase membrane subunit gp91phox, membrane-translocated subunit p47phox and small GTPase Rac-1 were determined by Western blotting analyses. RESULTS: NADPH oxidase activity and superoxide anion levels increased following reperfusion and peaked within 2 h of reperfusion in the penumbra, but not in the ischemic core in MCAO rats. Atorvastatin pretreatment prevented this increases, blunted the expression of membrane subunit gp91phox and prevented the translocation of cytoplasmic subunit p47phox to the membrane in the penumbra 2 h after reperfusion. CONCLUSION: These results indicate that atorvastatin protects against cerebral infarction via inhibition of NADPH oxidase-derived superoxide anion in ischemic brain tissue after reperfusion partly.