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目的:研究高尿酸对缺血/缺氧条件下心肌细胞的影响及钙蛋白酶(Calpains)在其中的作用.方法:将小鼠心肌细胞系分为3组:0 μmol/L尿酸+缺血/缺氧组(单纯缺血/缺氧组);600 μmol/L尿酸+缺血/缺氧组;1 200 μmol/L尿酸+缺血/缺氧组,通过流式细胞技术检测各组心肌细胞凋亡比例,并进一步将凋亡比例明显增加的实验组分为:1 200 μmol/L尿酸+缺血缺氧组;MDL28170+1 200 μmol/L尿酸+缺血缺氧组.采用DHE染色法与ELISA试剂盒测定心肌细胞中活性氧簇(ROS)水平,q-PCR法及Western blot检测心肌细胞中Calpain1、Calpain2、Calpastatin的表达情况.结果:高尿酸可明显增加缺血/缺氧状态下心肌细胞凋亡水平(P＜0.05).与单纯缺血/缺氧组相比,高尿酸显著增加了Calpain1/2的表达,明显抑制了Calpastatin的表达(P＜0.05),同时显著增加了心肌细胞中ROS的水平(P＜0.05),而在加入MDL28170干预后,心肌细胞的ROS水平及凋亡比例均有所降低(P＜0.05).结论:高尿酸通过激活Calpain所介导的氧化应激反应加重缺血/缺氧状态下心肌细胞凋亡.“,”Objective:To investigate the effects of elevated uric acid on myocardial cells in ischemic condition and to clarify the role of calpains in it.Method:The myocardial cell line (MCM) was divided into three groups:0 μmol/L uric acid group,600 μmol/L group and 1 200 μmol/L uric acid,all of groups treated with ischemia/hy poxia.Furthermore,the intervention group of much higher apoptosis rate was divided into two groups:1 200 μmol/L uric acid with ischemia/hypoxia group and 1 200 μmol/L uric acid with ischemia/hypoxia group incubated with Calpain inhibitor MDL28170 (6 mmol/L) for 24 hours.Accordingly,the apoptosis of cardiomyocytes were measured by flow cytometer,the levels of reactive oxygen species (ROS) were detected by DHE staining and ELISA kits,the expressions of Calpain1/Calpain2/Calpastatin were determined by q PCR and Western blot.Result:The apoptotic ratio of myocardial cells gradually increased with elevated concentration of uric acid (P＜0.05).Moreover,compared with control group,hyperuricemia obviously stimulated the expression of calpains in cardiomyocytes (P＜0.05) and significantly aggravated the generation of ROS (P＜0.05).In contrast,the apoptotic ratio was reduced by the application of MDL28170 (P＜0.05).Conclusion:Hyperuricemia can exacerbate the vulnerability and the apoptosis of cardiomyocytes induced by ischemia/hypoxia through the increased generation of ROS via calpains.