高住低训模型大鼠心肌线粒体呼吸链酶复合物的活性: 线粒体习服过程所需时间分析

Activities of myocardial mitochondria enzyme complexes of respiratory chain in rats after living high-training low:Time for the acclimatization of mitochondria

背景：以往的研究发现，高原训练的有效时间为4～6周，而高住低训的有效训练时间、尤其是线粒体的习服所需要的时间还未见系统报道。目的：构建模拟“高住低训”训练法大鼠模型，观察低氧和高原训练刺激作用下，高住低训习服过程中模型大鼠心肌线粒体呼吸链酶复合物活性的动态变化，分析线粒体呼吸链酶复合物的高住低训习服过程所需时间。设计：分组对照动物实验。单位：辽宁师范大学体育学院运动生理实验室。材料：实验选用健康成年SD大鼠40只，雌雄不拘，由大连医科大学实验动物中心提供。实验动物的处置符合动物伦理学。实验用模型常压低氧环境所用低氧分压系统由美国Hypoxico公司制造，氧气监测仪为美国产TOXIBLAEPGM-36型。方法：随机将大鼠分为5组：常氧对照组，高住低训1，2，3，4周组，每组8只。高住低训组大鼠每天在低氧分压系统模拟的海拔2500m的高原环境生活，同时模拟海拔1300m环境下游泳运动1h，每周训练6d。主要观察指标：采用可见分光光度法测定每组大鼠心肌线粒体呼吸链复合酶体Ⅰ-Ⅳ活性，用Bradford法进行线粒体蛋白定量检测。结果：①心肌线粒体呼吸链复合酶活性：高住低训1周大鼠心肌线粒体呼吸链酶复合物Ⅰ～Ⅳ活性较对照组显著降低，差异有显著性意义（P〈0．05～0．01）；高住低训2周时酶复合Ⅲ活性与对照组比较，差异无显著性意义（P〉0．05），而其他酶复合物在高住低训3周时与对照组比较，差异无显著性意义（P〉0．05）。②线粒体蛋白含量：高住低训1，2周时与对照组比较，差异无显著性意义（P〉0．05），高住低训3，4周时高于对照组，差异有显著性意义（P〈0．05）。结论：模型大鼠心肌线粒体呼吸链酶复合物Ⅰ～Ⅳ活性的高住低训习服过程需要3周。

BACKGROUND： Previous studies have suggested living high-training low （HiLo） is effective in 4-6 weeks. We know little about the acclimatization time of mitochondria and activities of enzyme complexes during the process of HiLo. OBJECTIVE： Using rat models under simulated HiLo condition, to observe the dynamic changes in mitochondrial respiration and activities of enzyme complexes during the process of HiLo under hypoxia, so as to investigate the acclimatization time of mitochondria and enzyme complexes of respiratory chain needed during HiLo. DESIGN： Grouping and controlled animal trial. SETTING： Exercise Physiology Laboratory of Physical Education Institute of Liaoning Normal University. MATERIALS： Forty healthy adult SD rats, either male or female, were provided by the Animal Experimental Center of Dalian Medical University. The animalprocedure was accorded with the animal ethics. The hypoxia partial pressure machine （HTS） was from Hypoxico Company of America, and Oxygen partial pressure monitor was TOXIBLAEPGM-36 from America. METHODS： After 1 week of adaptive feeding, the rats were randomly divided into normoxic control group, HiLo 1, 2, 3, and 4 weeks groups with 8 rats in each group. HiLo groups lived at 2 500 m （O2 content was around 15.4%） and swam at 1 300 m （O2 content was around 19.4%）, 1 hour once for 4 weeks. MAIN OUTCOME MEASURES： The activities of enzyme complexes Ⅰ - Ⅳ in the respiratory chain of mitochondria were measured using UV-spectrophotometer, and the method of Bradford was used to quantify protein of mitochondria. RESULTS： The activities of enzyme complexes Ⅰ -Ⅳ of respiratory chain reduced significantly compared with control group in the first week （P 〈 0.05-0.01）; the activities of enzyme complexes Ⅲ recovered completely in the second week, which was not significantly different from the control group （P 〉 0.05）. The activities of enzyme complexes Ⅰ -Ⅳ recovered completely in third week compared with the control group （P 〉 0.05）. There was no significant difference in protein quantity of mitochondria between HiLo 1 and 2 weeks groups and control group （P 〉 0.05）, but significant differences were found between HiLo 3 and 4 weeks groups and control group （P 〈 0.05） CONCLUSION： The acclimatization of the activities of enzyme complexes Ⅰ -Ⅳ in the respiratory chain will complete in three weeks in rats during the process of HiLo.