过氧化氢对游离线粒体Cyt-c释放的影响  

Effect of Hydrogen Peroxide on Free Mitochondrial Cytochrome-c Release

作　　者：李小倩[1] 冯润荷[2] 李静[1] 唐向东[1] 

机构地区：[1]南开大学医学院 ,300071 [2] 天津医学高等专科学校

出　　处：《天津医药》2014年第3期220-223,共4页Tianjin Medical Journal

基　　金：国家自然科学基金资助项目(项目编号:81072629);天津市自然科学基金资助项目(项目编号:10JCYBJC14800);天津市高等学校科技发展基金项目(项目编号:20100115)

摘　　要：目的在线粒体水平探讨过氧化氢(H2O2)预处理对游离线粒体细胞色素c(Cyt-c)释放的影响,揭示缺血预适应(IPC)对缺血再灌注(IR)损伤的作用机制。方法分离大鼠肝脏线粒体,制成游离线粒体。将游离线粒体分为5组,(1)为对照(C)组、(2)^(5)组分别加入12.5、25、50和100μmol/L的Ca2+,刺激游离线粒体10 min,检测游离线粒体Cyt-c,胱氨酸酶激活剂(Smac)的释放量。建立游离线粒体IPC再灌注模型,将游离线粒体分为7组,C组、IR组、加H2O2组共7组,对加H2O2组分别加入2μL H2O2,终浓度分别为1、2、5、20和100μmol/L;在H2O2处理后,再用100μmol/L Ca2+对IR组、加H2O2组模拟再灌注,检测Cyt-c的释放量,再对IR组和H2O2终浓度为1和2μmol/L组检测心磷脂活性的变化。结果与C组比较,Ca2+浓度25、50和100μmol/L组Cyt-c、Smac的释放量显著增高(P<0.05)。与IR组比较,H2O2浓度1、2μmol/L组Cyt-c的释放量明显减少(P<0.05)。Cyt-c释放减少时可改变心磷脂的活性。结论低浓度H2O2预处理通过使Cyt-c与心磷脂结合得更加紧密,而使线粒体在高Ca2+(100μmol/L)刺激后Cyt-c释放量减少,阻滞了凋亡途径的发生,是IPC对缺血再灌注损伤发挥效应的关键因素。Objective To investigate the effect of hydrogen peroxide （H2O2） pretreatment on free mitochondrial cyto-chrome c （Cyt-c） release in mitochondrial levels, and reveal the mechanism of the ischemic preconditioning （IPC） on the ischemia reperfusion （IR） injury thereof. Methods The rat liver mitochondria was isolated and made free mitochondria. Free mitochondria were divided into 5 groups：control group （C） and different concentrations of Ca2＋groups （12.5, 25, 50 and 100 μmol/L）. The levels of Cyt-c and second mitochondria-defived activator of caspase （Smac） were detected after 10 min stimulation of free mitochondria. The free mitochondrial IPC reperfusion model was made and divided into seven groups：C group, IR group and different concentrations of H2O2 groups （2 μL H2O2 in 200 μL system respectively, final concentration of 1, 2, 5, 20 and 100 μmol/L respectively）. 100 μmol/L Ca2＋was used again on the simulation of IR group. The level of Cyt-c release was detected. The changes in the activity of cardiolipin were detected in IR group and H2O2 （1 and 2 μmol/L of final concentration） groups.Results Compared with C group, there were significantly higher levels of Cyt-c and Smac emission in 25, 50, and 100 μmol/L Ca2＋groups （P＆lt;0.05）. Compared with IR group, there was significantly decreased level of Cyt-c emission in H2O2 （1 and 2 μmol/L） groups （P ＆lt; 0.05）. The activity of cardiolipin was changed when reducing release of Cyt-c. Conclusion Cyt-c was bonded with cardiolipin more closely when the low concentration of H2O2 pretreatment in mitochondria. There was a lower level of Cyt-c emission in mitochondria after stimulation with high concentration of Ca 2＋（100 μmol/L Ca2＋）. The blocking apoptotic pathway plays a key fact in the effect of IPC on IR injury.

关 键 词：过氧化氢 再灌注损伤 钙超载 线粒体通透性转换孔 

分 类 号：R363[医药卫生—病理学] R966[医药卫生—基础医学]