还原型谷胱甘肽对缺氧／复氧心肌细胞的保护作用

Protective effects of reduced glutathione on the cardiomyocytes injured by anoxia/reoxygenation

目的探讨还原型谷胱甘肽（GSH）对缺氧／复氧（A／R）心肌细胞的保护作用及机制。方法建立大鼠心肌细胞A／R损伤模型，随机分为5组：A组为正常对照组；B组为A／R组，缺氧2h。复氧1h；C、D、E组为处理组，加入GSH分别使其终浓度为40、80、160mg／L后A／R。用黄嘌呤氧化酶法测定超氧化物歧化酶活性，硫代巴比妥酸显色法测定丙二醛含量，荧光法测定细胞内钙离子浓度变化，采用RT-PCR检测白介素-1βmRNA和肿瘤坏死因子-αmRNA表达变化。结果与A组相比，B组心肌细胞内钙离子浓度明显升高，差异有非常显著性（P〈0．01）；心肌细胞培养液中超氧化物歧化酶活性下降、丙二醛含量升高，差异有非常显著性（P〈0．01）；白介素-1βmRNA和肿瘤坏死因子-αmRNA表达迅速增强，差异有非常显著性（P〈0．01）。与B组比，D、E组上述变化明显减轻，差异有非常显著性（P〈0．01）。结论GSH对A／R心肌细胞有保护作用，其作用在一定范围内呈剂量依赖关系。

Objective To investigate the protective effects of reduced glutathione （GSH） on anoxia/ reoxygenation（A/R） injury of cultured neonatal rat＇s cardiomyocytes and its possible mechanism. Methods The A/R model of myocardial cells of neonatal rats was established. The cells were randomly divided into five groups：control group（A） ：without any treatment ;A/R group （B） ：2-hour anoxia followed by 1-hour reoxygenation;GSH conditioned group （C, D, E） ：adding GSH into culture medium till the final concentration was 40, 80,160 mg/L respectively then A/R. The activity of culture medium superoxide dismutase（SOD） was determined by the method of xanthine oxidase and the contents of culture medium malondialdehyde（MDA） were measured by the method of thiobarbituric acid. The levels of IL-1β mRNA and TNF-α mRNA were detected by RT-PCR and the intracellular Ca^2＋ concentration of cultured cadiomyocytes were also evaluated. Results Compared with group A, the group B showed great increases in the intracellular Ca^2＋ concentration, the content of MDA, and the expression levels of IL-1β mRNA as well as TNF-α mRNA （ P 〈 0.01 ）, while the activity of SOD was decreased（ P 〈 0.01 ）. Compared with group B, the changes of above indexes were significantly lighter in group D and E（ P 〈 0.01 ）. Conclusion GSH can exert a protective effect on A/R injury of neonatal rat cardiomyocytes in a dose-dependent manner.