辛伐他汀对高糖损伤乳鼠心肌细胞氧化应激的影响

Influence of simvastatin on the oxidative stress of hyperglycemia-damaged myocardial cells of suckling rat

目的探讨辛伐他汀对高糖损伤乳鼠心肌细胞内还原型烟酰胺腺嘌呤二核苷酸磷酸(NADPH)氧化酶活性氧通路的干预作用。方法培养新生1～3 d SD雄性大鼠心肌细胞,随机分为对照组、高浓度葡萄糖刺激组(GS组)、不同浓度辛伐他汀干预组[分别为GS+10^(-7) mol/L Sim组(GS+10^(-7) Msim组)、GS+10^(-6) mol/L Sim组(GS+10^(-6) MSim组)、GS+10^(-5) mol/L Sim组(GS++10^(-5) MSim组),以MTT比色法测定各组心肌细胞活力;化学比色法测定心肌细胞丙二醛含量、超氧化物歧化酶活力及活性氧水平:RT-PCR检测细胞内NADPH氧化酶p22phox mRNA、p47phox mRNA的表达水平。结果与GS组比较,GS+10^(-7) MSim组、GS+10^(-6) MSim组、GS+10^(-5) MSim组丙二醛含量、活性氧水平明显降低.p22phox mRNA、p47phox mRNA表达明显下调,超氧化物歧化酶活力明显升高(P<0.05)。结论心肌细胞内NADPH氧化酶源性的活性氧升高是介导高糖损伤心肌细胞的重要机制,辛伐他汀可能通过抑制NADPH氧化酶-活性氧通路减轻心肌细胞损伤。

Objective To observe the impact of simvastatin on the change of NADPH oxidase-reactive oxygen species（ROS） signal pathway induced by high glucose in the neonatal rat cardiomyocytes. Methods Ventricular myocytes were isolated from hearts of the neonatal SD rats by enzymatic digestion and anchorage velocity-dependent separation method for primary culture. The car- diomyocytes were randomly divided into five groups： control group, high glucose group, different concentrations of simvastatin （ 10^-7 mol/L, 10^-6 mol/L, 10^-5 mol/L） ＋ high glucose groups. The following parameters were detected respectively： cardiomyocyte viability, activities of superoxide dismutase（SOD）, the contents of malondialdehyde（MDA）,concentration of intracellular ROS and the mRNA expression of NADPH oxidase subunits p22phox and p47phox. Results Simvastatin could protect the myocardial cells from high glucose injury in a dose-dependent manner,and simvastatin（10^-5mol/L） preconditioning showed the greatest protective effect. Therefore, simvastatin preconditioning could significantly attenuate the increased MDA and ROS level and antagonize the reduced cardiomyocyte viability, SOD activity and increased relative mRNA expression rate of NADPH oxidase subunits p22phox and p47phox. Conclusion It was an important mechanism that ROS was generated by NADPH oxidase in high glucose-induced injury in the neonatal rat cardio- myocytes. Simvastatin can inhibit the activity of NADPH oxidase- reactive oxygen signal transduction pathway to alleviate the cardiomyocyte damage in high glucose-injured cardiomyocytes.