氧化应激对培养心肌细胞线粒体酶活性的影响

Effect of oxidative stress on mitochondrial enzyme activity in cultured cardiac myocytes

目的 :观察氧化应激对心肌细胞线粒体酶活性的影响和褪黑素的保护作用。方法 :胰酶消化法分离培养原代心肌细胞 ,随机分为 :H2 O2 处理组 (10 0μmol/ L )和褪黑素 (MT)预处理组 (10 0μm ol/ L MT+10 0μm ol/ L H2 O2 )。用 H2 O2 模拟心肌细胞的氧化应激 ,用四唑盐比色试验 (MTT法 )检测 H2 O2 处理后不同时间点的线粒体酶活性 ;用台盼蓝排斥试验检测处理前和处理后 40 min细胞的存活率。结果 :H2 O2 处理组光密度 (OD490 )逐渐降低 ,组内不同时间点差异显著 (P<0 .0 1) ;而 MT预处理组组内无差异 (P>0 .0 5 ) ;40 m in内两组细胞存活率均无变化。结论 :低浓度的 H2 O2 随着时间的延长可以使线粒体酶活性逐渐降低 ,而褪黑素能保护氧化应激中的心肌细胞。

AIM: To investigate the effects of H_2O_2 and melatonin (MT) on mitochondrial enzyme activity in cultured cardiac myocytes. METHODS: Ventricular myocytes were isolated from neonatal mice and cultured for 3~4 d. Cells were divided into 2 groups randomly: H_2O_2(100 μmol/L) group and MT preconditioning group(100 μmol/L MT+100 μmol/L H_2O_2). After cells were treated, the MTT assay was used to measure the activity of mitochondrial enzyme in cardiomyocytes. The trypan blue exclusion was used to detected the cell viability. RESULTS: The OD_ 490 values were gradually decreased in H_2O_2 group(P<0.01), while there was no change in MT preconditioning group. The cell death was not increased in 40 minutes both in H_2O_2 group and in MT preconditioning group. CONCLUSION: The low concentration of H_2O_2 can inhibit the activity of mitochondrial enzyme and melatonon can protect cardiomyocytes from the injury of H_2O_2-induced oxidative stress.