摘要
目的 :研究慢性间断低氧暴露对大鼠心肌线粒体Na+ 、K+ ATPase和Ca2 + 、Mg2 + ATPase以及呼吸链酶复合物Ⅰ、Ⅱ、Ⅲ、Ⅳ活性的影响。方法 :经慢性间断低氧暴露 (模拟海拔 30 0 0m、5 0 0 0m分别低氧 ,每天 4h ,共 2周 ,最后 80 0 0m低氧 4h)和急性低氧 (模拟海拔 80 0 0m低氧 4h)的大鼠 ,断头处死 ,迅速取出心脏 ,分离心肌线粒体 ,用水解磷酸根法测定ATP酶活性 ,用Clark氧电极法测定呼吸链酶复合物的活性。结果 :①慢性间断低氧暴露对大鼠心肌线粒体Na+ 、K+ ATPase的活性无明显影响。②急性低氧大鼠心肌线粒体Ca2 + 、Mg2 + ATPase的活性较正常大鼠显著降低 ,而慢性间断低氧暴露大鼠心肌线粒体Ca2 + 、Mg2 + ATPase的活性则明显升高 ,接近正常水平。③急性低氧大鼠心肌线粒体呼吸链酶复合物I(NADH CoQ还原酶 )、复合物Ⅱ (琥珀酸 CoQ还原酶 )、复合物IV(细胞色素氧化酶 )活性较正常大鼠显著降低 ,而经慢性间断低氧暴露后 ,三者的活性均显著提高。相同实验条件下 ,低氧对复合物Ⅲ (CoQ 细胞色素C还原酶 )活性无明显影响。结论 :慢性间断低氧暴露可以显著提高心肌线粒体Ca2 + 、Mg2 + ATPase和呼吸链酶复合物Ⅰ、Ⅱ、Ⅳ的活性 ,从而改善低氧时心肌线粒体呼吸链的功能 ,维持心肌正常能量代谢 ,最?
Aim: To study the effects of acute and chronic intermittent hypoxic exposure on the activities of Na^+,K^+-ATPase, Ca^(2+),Mg^(2+)-ATPase of myocardial mitochondria and enzyme complexes of!respiratory chain in rats. Methods: The activities of Na^+,K^+-ATPase, Ca^(2+),Mg^(2+)-ATPase of myocardial mitochondria and enzyme complexes of respiratory chain were investigated after chronic intermittent hypoxic exposure (3 000m and 5 000m, 4 h/d, 2 w respectively) and normoxic rats were exposed to hypoxia (8 000m) for 4h. Results:① Hypoxia had no effects on the activity of Na^+,K^+-ATPase in myocardial mitochondria of rats. ② Compared with normoxic control rats, the activity of Ca^(2+),Mg^(2+)-ATPase in myocardial mitochondria of acute hypoxic rats was reduced significantly. After chronic intermittent hypoxic exposure, its activity was increased significantly compared with that of acute hypoxic rats. ③ Compared with normoxic control rats, the activities of enzyme complex Ⅰ,Ⅱ and Ⅳ of respiratory chain in acute hypoxic rats were reduced significantly. After chronic intermittent hypoxic exposure, their activities were increased significantly compared with those of acute hypoxic rats. Under the same experimental conditions, hypoxia had no effects on the activity of enzyme complex Ⅲ. Conclusion: After chronic intermittent hypoxic exposure, the activities of Na^+,K^+-ATPase, Ca^(2+),Mg^(2+)-ATPase of myocardial mitochondria and enzyme complexes of respiratory chain were increased significantly. These suggested that chronic intermittent hypoxic exposure could improve the functions of respiratory chain in myocardial mitochondria and keep the normal energy metabolism.
出处
《中国应用生理学杂志》
CAS
CSCD
北大核心
2004年第3期219-222,共4页
Chinese Journal of Applied Physiology
基金
国家自然科学基金重点资助项目 ( 3 973 0 190 )
全军医药卫生科研基金资助课题 ( 0 1Z0 2 5 )
