低氧对小鼠骨骼肌离体线粒体膜通透性转换孔功能的影响

Disfunction in mice'MPTP of isolated skeletal muscle induced by hypoxia

目的:探讨低氧对小鼠骨骼肌离体线粒体膜通透性转换孔(MPTP)功能的影响。方法:雄性SPF级C57BL/6小鼠32只,随机分成低氧组和常氧组,每组16只。两组均用差速离心法分离线粒体。低氧组放入低氧环境中,常氧组置于空气中,30 min后用荧光分光光度计检测骨骼肌离体线粒体膜电位,酶标仪检测MPTP开放程度,ELISA法检测细胞色素C(CytC)含量,分光光度计法检测超氧化物歧化酶(SOD)活性和谷胱甘肽(GSH)、丙二醛(MDA)含量。结果:低氧组骨骼肌离体线粒体膜电位降低,差异有统计学意义(P<0.05);MPTP开放增加,CytC含量增加,SOD活性降低,GSH含量降低,MDA含量增加,差异均有统计学意义(P<0.01)。结论:低氧可导致小鼠骨骼肌离体线粒体MPTP功能异常,促进MPTP开放、释放CytC,这可能与低氧导致的氧化应激有关。

Objective： To explore the influence of hypoxia on the function in mice＇ isolated skeletal muscle MMTP.Methods： Thirty-two male C57BL/6 mice were randomly divided into two groups（n=16）：the hypoxic experiment group and normal control group.The mitochon-dria was separated by differential centrifugation.The experiment group was exposed to hypoxic environment for thirty minutes while normal control group to normal environment for thirty minutes.The membrane potential of the mitochondria was measured by fluorescence spectrophotometer.The opening of MPTP was tested by microplate reader and the concentration of CytC by ELISA.The activity of the SOD and the concentration of GSH as well as MDA were measured by ultraviolet spectrophotometer.Results： Compared with the normal control group,the density of the membrane potential of the mitochondria was decreased（P 0.05）,the opening of MPTP increased（P 0.01）,the concentration of CytC and GSH in the mitochondria increased obviously while the concentration of GSH decreased（P 0.01）,and the activity of SOD de-creased significantly respectively（P 0.01）.Conclusion： Hypoxia may lead to MPTP dysfunc-tion of mice＇ isolated skeletal muscle and induce the opening of MPTP and increase the release of CytC,which may be related to oxidative stress reaction.