GDP对大鼠脑线粒体呼吸氧耗的抑制作用及其对膜电位的影响  

Inhibition of GDP on mitochondrial respiratory oxygen consumption and its effect on the mitochondrial membrane potential of rat brain

作　　者：夏琛[1] 柳君泽[1] 徐瑜[1] 

机构地区：[1]第三军医大学高原军事医学系病理生理学与高原生理学教研室

出　　处：《第三军医大学学报》2007年第5期390-392,共3页Journal of Third Military Medical University

基　　金：全军医学科学技术研究"十一五"计划课题(06MA193)~~

摘　　要：目的通过观察二磷酸鸟苷（guanosine diphosphate，GDP）对大鼠脑线粒体呼吸氧耗作用的量-效关系及对膜电位的影响，探讨脱偶联蛋白（uncoupling proteins，UCPs）活性改变与线粒体呼吸氧耗和膜电位的关系。方法应用差速离心法提取大鼠脑线粒体，分别在不同浓度GDP干预下采用Clark氧电极法测定线粒体呼吸氧耗并计算Ⅲ态呼吸（state 3 respiration，ST3）、Ⅳ态呼吸（state 4 respiration，ST4）、呼吸控制率（respiratory control rate，RCR）、氧化磷酸化效率（oxidative phosphorylation，OPR）和采用Rhodamine123法测定线粒体膜电位（MMP）。结果大鼠脑线粒体ST3、ST4、RCR、OPR随GDP的浓度改变而改变；当GDP的浓度为0-1．4mmol／L时，呈剂量依赖关系；当GDP达到1mmoL／L时抑制作用最明显，抑制率达51．3％；大于或小于1mmol／L时其抑制率均降低；在GDP对呼吸氧耗抑制率最高时MMP最高。结论UCPs的抑制剂（GDP）可直接抑制分离的大鼠脑线粒体呼吸氧耗和MMP，并呈一定的量-效关系，提示UCPs活性改变可影响线粒体呼吸氧耗和MMP。Objective To investigate effect of guanosine diphosphate （GDP） on the mitochondrial respiratory oxygen consumption and the mitochondrial membrane potential （MMP） of rat brain and explore the relationship of the change of uncoupling proteins （ UCPs ） activity with the oxygen consumption and MMP. Methods The mitochondria of rat brain were isolated by centrifugation. Mitochondria oxidative respiratory consumption was measured by Clark electrode after the treatment of GDP at different concentrations so as to calculate mitochondrial state 3 respiration （ ST3 ）, mitochondrial state 4 respiration （ ST4 ）, respiratory control rate （RCR）, and the rate of oxidative phosphorylation （OPR）. MMP was detected by Rhodamine 123 method at the different concentrations of GDP. Results With the increase of GDP concentration form 0 to 1.0 mmol/L,the values of ST3, ST4 and OPR were reduced while RCR was elevated. But when the concentration increased to 1.4 mmol/L, the former 3 indexes begun to increase while the later declined. When the GDP concentration reached to 1 mmol/L, the inhibitory rate was only 35.1%, 51.3%, 14.2% to ST3, ST4 and OPR respectively, while RCR was increased to 133.2%. No matter the concentration was over 1 mmol/L or under 1 mmol/L, the ability of inhibition was attenuated. MMP reached to the highest point when GDP exerted the highest inhibitory rate on mitochondrial respiratory oxygen consumption. Conclusion GDP, an inhibitor of UCPs, can regulate the respiratory oxygen consumption and MMP of the isolated rat brain mitochondrial directly in a dose-effect fashion. The change of UCPs activity can affect the respiratory oxygen consumption and MMP.

关 键 词：二磷酸鸟苷 线粒体呼吸氧耗 膜电位 

分 类 号：R322.81[医药卫生—人体解剖和组织胚胎学] R329.25[医药卫生—基础医学]