缺氧大鼠心肌线粒体呼吸功能、ATP含量的变化

Changes of mycardial mitochondrial respiratory function and ATP content in hypoxic rats

目的：探讨缺氧大鼠心肌线粒体呼吸功能和心肌能量代谢的变化。方法：通过Ｃｌａｒｋ氧电极法和生化方法测定线粒体功能和ＦｏＦ１－ＡＴＰ酶活力，运用高效液相色谱技术（ＨＰＬＣ）测定心肌组织ＡＴＰ含量。结果：急性缺氧大鼠心肌线粒体呼吸功能，ＦｏＦ１－ＡＴＰ酶活力以及１－苯胺基，８－萘磺酸镁（ＡＮＳ）相对荧光强度明显降低（Ｐ＜０．０１），表明：ＦｏＦ１－ＡＴＰ酶构象发生改变。心肌组织ＡＴＰ含量明显减少（Ｐ＜０．０１）。慢性缺氧上述指标不同程度有所恢复，但仍明显低于平原水平。经相关分析表明：ＡＴＰ含量与线粒体呼吸控制率（ＲＣＲ），ＦｏＦ１－ＡＴＰ酶活力及ＰａＯ２呈明显正相关（Ｐ＜０．０１）。结论：急性缺氧动物心肌能量代谢障碍可能与心肌线粒体呼吸功能降低，ＦｏＦ１－ＡＴＰ酶活力降低有关系。慢性缺氧后能量代谢的改善，可能是缺氧适应的机理之一。

Objective: To determine the changes of myocardial energy metabolism in hypoxic rats. Method: 30 adult Wistar rats were equally devided into three groups: 1)normal control group; 2)actuhypoxic group; 3)chronichypoxic group. The changes of respiratory function, activity of FoF1ATPase and ANS fluroescense intensity in myocardial mitochondria were observed with clark oxygen electrode and tiochemical method and the content of ATP in myocardial tissue measured with high performance liquid chromatography (HPLC). Results: 1)The respiratory function, FoF1ATPase activity and ANS flurosecense intensity were significantly decreased in acutehypoxic. Though the above parameters were increased in chronichypoxic group as compared with thore in the acutehypoxic group, they remained lower than those in the control. 2)ATP content was positively correlated to PCR, FoF1ATPase activity and PaO2. Conclusion: The failure of myocardial energy metabolism in acutehypoxic rats may be due to the decrease of mitochondrial respiratory. function and ATP production. The improvement of energy metabolism in chronichypoxic rats in one of the mechanisms for hypoxic adjustment.