低氧对大鼠胃肠组织线粒体呼吸链复合物的抑制效应

摘要

To study the effect of hypoxia on the activity of mitochondrial respiratory chain complex and free radical metabolism in rat gastrointestinal tissue.Male Wister rats are exposed to hypoxia at the simulate altitude of 5 000 m at 4 h,24 h,72 h respectively.Take the stomach and small intestine tissue as research objects,the mitochondrial respiratory chain enzyme complexes Ⅰ~Ⅳ activity, the mitochondrial superoxide dismutase(SOD)activity and malondialdehyde(MDA)content are tested by spectrophotometry.The results show that hypoxia exposure of the simulate altitude at 4 h and 24 h significantly decrease the enzyme activity of mitochondrial respiratory chain of four kinds of complexes in gastrointestinal(P <0.01) and the active level of these is recovered close to those of control group at the 72 h (P > 0.05 ).The mitochondrial SOD activity at hypoxia treatment groups is significantly lower than the control group(P <0.01)after hypoxia exposure and the content of MDA is higher than that of control group(P <0.01 )at gastrointestinal tissue. Therefore, the acute altitude hypoxia can inhibit the enzyme activity of rat gastrointestinal mitochondrial respiratory chain components and the effect may be relate to the directaction of hypoxia and oxidative stress damage thereby.%为研究低氧环境对大鼠胃肠线粒体呼吸链复合物活性和自由基代谢的影响,将雄性 Wister 大鼠分别暴露于模拟5000 m 海拔进行4,24,72 h 的低氧处理.取小肠和胃组织,采用分光光度法测定线粒体呼吸链酶复合物 CⅠ~CⅣ活性,检测线粒体超氧化物歧化酶(SOD)活性及丙二醛(MDA)的含量.结果表明,模拟高原低氧暴露4,24 h 可引起胃肠组织中线粒体呼吸链四种复合酶的活性明显降低(P <0.01),而在72 h 后恢复为接近对照组水平(P >0.05).低氧处理后胃肠组织的线粒体 SOD 活性明显低于对照组(P <0.01),MDA 含量高于对照组(P <0.01).因此,高原低氧可抑制大鼠胃肠线粒体呼吸链组分的酶活性,该效应可能与低氧的直接作用和由此引起的氧化应激损伤有关.