辛伐他汀预处理减轻缺血再灌注心肌损伤的实验研究

目的 研究辛伐他汀预处理对大鼠缺血再灌注心肌损伤的保护作用并探讨相关机制.方法 通过冠状动脉结扎法建立大鼠心肌缺血再灌注模型.实验动物分为假手术组、对照组和辛伐他汀组.辛伐他汀组按照5 mg/(kg·d)的剂量术前7 d起灌胃.观察各组室性心律失常发生率及心肌细胞超微结构变化,测定梗死心肌面积,检测血清心肌酶谱、脂质水平及心肌肿瘤坏死因子(TNF)-α、白细胞介素(IL)-6和单核细胞趋化因子(MCP)-1的含量.结果 与对照组相比,辛伐他汀预处理可以:(1)显著降低心律失常评分;(2)显著下调血清磷酸肌酸激酶同工酶(CK-MB)、乳酸脱氢酶(LDH)水平;(3)减少再灌注后心肌梗死区面积/缺血危险区面积比;(4)保护再灌注心肌细胞超微结构.各组血清总胆固醇、三酰甘油、低密度脂蛋白、高密度脂蛋白未见差异,辛伐他汀组心肌组织TNF-α、IL-6和MCP-1含量与对照组比较差异有统计学意义(P<0.01).结论 辛伐他汀预处理能减轻大鼠心肌缺血再灌注损伤,这种作用不依赖于其降脂作用,可能与其降低再灌注心肌炎性细胞因子表达相关.

Experimental study on the effects of pretreatment with simvastatin on ischemia reperfusion induced myocardial injury in rats

Objective To investigate the effects of pretreatment with simvastatin on iscbemia reperfusion induced myocardial injury, and to further explore related mechanism with respect to inflammation modulation. Methods The rat myocardial ischemia reperfusion model was established by the method of coronary artery ligation. The animals were divided into 3 groups: the sham group, the control group and the simvastatin group. In the simvastatin group, the animals were pretreated with simvastatin (5 mg/kg) one week before by intragastric administration. Ventricular arrhythmia was monitored and scored, infarct size and area at risk of myocardium were determined, and uhrastructural changes were observed. The serum levels of myocardial enzymes and lipids were measured. The content of myocardial inflammatory cytokines tumor necrosis factor (TNF) -α、interleukin(IL) -6, and monocyte chemoattractant protein(MCP) - 1]were also evaluated. Results When compared with those of the control group, the amount and duration of ventricular arrhythmia in simvastatin group were less and score of ventricular arrhythmia was significantly lower. When pretreated with simvastatin, the serum levels of CK-MB and LDH in simvastatin group were significantly lower than those of the control group. The infarct size/area at risk ratio of the simvastatin treated group was significantly less than those of the control group. The uhrastructures of myocardial cells were better maintained in simvastatin group. No significant differences were observed in the serum concentrations of total cholesterol, triglycerides, low density lipoprotein and high density lipoprotein when comparisons were made each other among the three groups. However, the levels of TNF-α,IL-6 and MCP-1 in heart tissue of the treated animals were significantly lower than those of the control group. Conclusions Pretreatment with simvastatin ameliorates ischemia reperfusion induced myocardial injury, which is partly related with the down-regulation of inflammatory cytokines expression in heart tissue but independent of its role of lipids modulation.