过氧化氢对乳鼠心肌细胞内游离钙浓度的影响及卡维地洛的拮抗作用

Effects of hydrogen peroxide on intracellular free calcium concentration in cultured neonatal rat cardiac myocytes and its antagonism by carvedilol

目的 研究过氧化氢 (H2 O2 )对心肌细胞[Ca2 + ]i的影响 ,以及卡维地洛对H2 O2 诱导钙超载的拮抗作用。方法 采用SD大鼠乳鼠进行心肌细胞培养。实验分为 4组 :正常对照组 ;H2 O2 组 :加入终浓度为 10 0 μmol/L的H2 O2 ;卡维地洛组 :加入终浓度为 1μmol/L的卡维地洛 ;H2 O2 +卡维地洛组 :同时加入卡维地洛 1μmol/L与H2 O2 10 0 μmol/L。以Fluo 3/AM荧光指示剂负载 ,应用激光共聚焦显微镜技术 ,分别于加入H2 O2 后即刻和 15min时检测 [Ca2 + ]i的变化。结果 对照组和卡维地洛组心肌细胞内荧光强度和荧光光密度值较低。一加入H2 O2 ,细胞内荧光光密度值便开始增加 ,15min后细胞内荧光强度和荧光光密度值较对照组显著增高 (P <0 0 5 )。而H2 O2 +卡维地洛组细胞内荧光光密度值显著低于H2 O2 组 (P <0 0 5 )。结论 H2 O2 可引起心肌细胞内钙超载 ,卡维地洛能显著减轻H2 O2 诱导的心肌细胞内Ca2 +

Objective To examine effects of hydrogen peroxide on intracellular free calcium concentration(i) in cardiac myocytes and its antagonism by carvedilol. Methods A cell culture of neonatal rat cardiac myocytes was used for experimentation. They were divided into four groups, i.e. control group, hydrogen peroxide (H 2O 2) group, carvedilol group,and H 2O 2 + carvedilol group. Confocal microscope was used with Fluo-3/AM as calcium indicator to detect changes in i immediately and 15 minutes after H 2O 2 intervention, respectively. Results The intracellular fluoresence intensity of a single cardiae myocyts in the control group and carvedilol group was low. The intracellular fluoresence intensity of a single cardiac myocyte in H 2O 2 group was significantly higher than in the control group 15 minutes after intervention (P<0.05). When carvedilol was added simultaneously with H 2O 2, the values were much lower compared with H 2O 2 group (P<0.05). Conclusion Hydrogen peroxide induces intracellular calcium overload in cardiac myocytes, and carvedilol can decrease i overload in the cells induced by hydrogen peroxide.