小剂量过氧化氢对大鼠心肌细胞钙瞬变及凋亡的作用

目的:探讨小剂量过氧化氢导致的氧化应激对大鼠心肌细胞钙瞬变及细胞凋亡的作用。方法:解剖取出成年大鼠心脏,应用langendorff方法分离心肌细胞,加入fluo-3荧光指示剂后,应用不同浓度的过氧化氢作用于心肌细胞,在共聚焦显微镜下测定心肌细胞内钙瞬变。分离并培养新生大鼠心肌细胞,观察过氧化氢处理心肌细胞后其形态的变化,从而评价小剂量过氧化氢对心肌细胞的凋亡作用。结果:应用0.125 mmol/L、0.25 mmol/L及0.375 mmol/L的过氧化氢作用于心肌细胞后,心肌细胞内钙瞬变幅度明显升高,并呈时间剂量依赖性。在培养的大鼠原代心肌细胞中加入0.25 mmol/L的过氧化氢后,心肌细胞发生凋亡的形态变化。结论:小剂量过氧化氢可开放心肌细胞L-钙通道,明显增加心肌细胞内钙瞬变,并导致心肌细胞凋亡。

Effect of Low-Dose Hydrogen Peroxide on Intracellular CalciumTransientand Apoptosis in Rat Cardiomyocyte

Objective:The effect of low-dose hydrogen peroxide on intracellular calcium transient and apoptosis in ratcardiomyocyte are investigated in the experiment.Methods:We have anatomized and removed the heart of adult rat, and isolated thecardiomyocyte with langendorff method. The cells were stained with fluo-3 fluorescent indicator and determined for the changes of theintracellular calcium transient at exposing to low-dose hydrogen peroxide with confocal microscope. Moreover, we isolated andcultivated primary rat myocardial cells, and observed the morphological changes of cardiomyocyte apoptosis using different concentrationsof low-dose hydrogen peroxide.Results:After adding 0.125, 0.25 and 0.375 mmol/L of hydrogen peroxide in isolated cardiomyocyte, theintracellular calcium transient amplitude increased significantly in a dose-and time-dependent manner. The cardiomyocyte apoptoticmorphology can be observed in the cultivated rat cardiomyocyte.Conclusion:Low dose of hydrogen peroxide increased the intracellularcalciumtransient amplitude significantly, and led to cardiomyocyte apoptosis.