【摘要】 目的:探讨小剂量多巴胺(DA)对氧化应激诱导大鼠心肌细胞凋亡的作用及可能机制。方法:采用培养的新生大鼠心肌细胞,随机分为正常对照组(control),过氧化氢处理组(H2O2),小剂量多巴胺干预组(DA+H2O2),多巴胺受体Ⅰ型阻断剂干预组(DR1+DA+H2O2),多巴胺受体II型阻断剂干预组(DR2+DA+H2O2);应用流式细胞仪、MTT检测心肌细胞的凋亡率,透射电子显微镜检测细胞超微结构的变化,比色法检测细胞培养液中乳酸脱氢酶(LDH)、超氧化物歧化酶(SOD)活性,Western blot检测Cytochrone c、Caspase 3、Caspase 9的蛋白表达情况。结果:与单纯H2O2组相比,小剂量多巴胺(10μmol/L)可降低LDH活性,升高SOD活性,抑制心肌细胞凋亡和凋亡相关蛋白的表达;DR1阻断剂SCH-23390干预后,能够部分逆转这种作用,而DR2阻断剂Haloperido干预后没有明显的变化。结论:小剂量多巴胺可能通过DR1抑制氧化应激诱导的心肌细胞凋亡。更多还原

【Abstract】 Objective: To study the effects of low concentration dopamine( DA) on hydrogen peroxide-induced apoptosis in cultured rat cardiomyocytes as well as the possible molecular mechanisms. Methods: Cultured neonatal rat cardiomyocytes were randomly divided into the following groups: control group( control),hydrogen peroxide group( H2O2),pretreated with low concentration dopamine( DA + H2O2),dopamine receptor 1( DR1) antagonist group( DR1 + DA + H2O2),dopamine receptor 2( DR2) antagonist group( DR2 + DA + H2O2). The cell apoptosis was then assessed by MTT and flow cytometry. The cellular ultrastructure changes were observed by transmission electron microscope. The activity of lactate dehydrogenase( LDH) and superoxide dismutase( SOD) in cell medium was analyzed by colorimetry. The protein expressions of Cytochrone c,Caspase 3 and Caspase 9 were obtained by Western blot.Results: Compared with hydrogen peroxide group,low concentration dopamine( 10 μmol / L) decreased the apoptosis rate and the expression of protein of apoptosis related protein,enhanced SOD activity,decreased LDH activity. DR1 antagonist SCH-23390 treatment inhibited dopamine induced cardiac protective effect. DR2 antagonist haloperido treatment had no changes compared with dopamine group. Conclusion: Above findings indicate that low concentration dopamine inhibits apoptosis induced by hydrogen peroxide in neonatal rat cardiomyocytes,which is partly associated with the activation of DR1.更多还原