目的:观察丹参酮ⅡA对过氧化氢诱导的心肌细胞凋亡的保护作用及其机制。方法:采用差数贴壁法体外分离培养新生乳鼠心肌细胞,以200μmol/L过氧化氢作用2h模拟心肌细胞氧化应激模型,分别以丹参酮ⅡA高、中、低剂量在造模前干预24h。采用流式细胞仪检测细胞凋亡率、细胞内游离钙及心肌细胞线粒体膜电位的变化,检测心肌细胞膜Na^+ -K^+ -ATP酶、Ca2^2+ Mg^2+ -ATP酶活性。结果:模型组心肌细胞经200μmol/L过氧化氢作用2h后,凋亡率显著增高。与模型组比较,丹参酮ⅡA可呈浓度依赖性显著降低细胞凋亡率。过氧化氢可导致心肌细胞内游离钙显著增加,线粒体膜电位、Na^+ -K^+ -ATP酶、Ca^2+-Mg^2+ -ATP酶活性显著降低。丹参酮ⅡA可呈浓度依赖性显著降低细胞内游离钙浓度,增加线粒体膜电位、Na^+ -K^+ -ATP酶、Ca^+ -Mg^2+ ATP酶活性。结论:丹参酮ⅡA可以抑制过氧化氢诱导的心肌细胞凋亡,这可能与其增强细胞Na^+ -K^+ -ATP酶、Ca^+- Mg^2+ -ATP酶活性,降低细胞内钙超载有关。
Objective :To study protective effect and mechanism of Tanshinone ⅡA on damage induced by hydrogen peroxide in myocardial cell. Methods :Primary cultured neonate rat myocardial cell was cultured in medium with 200μmol/L hydrogen peroxide, and the medium was supplemented with different concentrations of Tanshinone ⅡA in advance. Apeptosis rate, [ Ca^2+] i and mitochondrial membrane potential was determined by flow cytometric analysis. Besides, Na^+ - K^+ - ATPase and Ca^2+ - Mg^2+ - ATPase was also evaluated in each group. Results : In model group, apoptosis rate rose significantly compared with normal group. Comparing with model group,Tanshinone ⅡA decreased apoptosis rate in a dose dependent manner. Comparing with norreal group, [ Ca^2+ ] i was increased remarkably, while mitochondrial membrane potential, Na^+ -K^+ -ATPase and Ca^2+ -Mg^2+ - ATPase dropped remarkably in model group. Comparing with model group,Tanshinone Ⅱ A decreased [ Ca^2+ ] i significantly, and increased mitochondrial membrane potential,Na^+ -K^+ -ATPase and Ca^2+ -Mg^2+ -ATPase significantly in a dose dependent manner. Conclusion:Tanshinone Ⅱ A could attenuate apoptosis induced by hydrogen peroxide,the mechanism may be that Tanshi- none Ⅱ A could enhance Na^+ - K^+ - ATPase and Ca^+2 - Mg^2 + - ATPase activity, and thus reduce intracellular free calcium.