预缺氧对急性缺氧大鼠心肌线粒体功能及ATP含量的影响

Effects of hypoxic preconditioning on myocardial mitochondrial respiratory function and ATP content in acute hypoxic rats

目的：观察预缺氧对急性缺氧大鼠心肌线粒体功能及ＡＴＰ含量的影响。方法：实验大鼠分三组。１常氧对照组；２急性缺氧组；３预缺氧组。测定了心肌ＡＴＰ含量及线粒体呼吸功能，以荧光偏振法测定线粒体膜流动性。结果：经预缺氧处理的大鼠遭受急性缺氧后ＡＴＰ含量从（３１８±２４２）ｍｇ１·ｇ－１增加到（６０５５±３．５２）ｍｇ－１·ｇ－１（Ｐ＜００１）；线粒体呼吸控制率（ＲＣＲ）从１８４±０５８上升到４５５±０３２（Ｐ＜００１）；线粒体膜流动性（ＭＭＦ）明显增加（Ｐ＜００５），Ｆ０Ｆ１－ＡＴＰ酶及Ｎａ＋－Ｋ＋－ＡＴＰ酶活性分别提高６６％和２５％。结论：预缺氧可有效改善缺氧大鼠心肌能量代谢，其作用环节可能和提高线粒体膜流动性，改善线粒体呼吸功能有关。

AIM:To observe the effects of the hypoxic preconditioning on myocardial mitochondrial respiratory function and ATP content in acute hypoxic rats. METHODS:Rats were divided into 3 groups:normoxic group (control), acute hypoxic group, preconditioing hypoxic group. The myocardial ATP content and mitochondrial respiratory function were measured. Mitochondrial membrane fluidity was assayed with fluorescence polariative method. RESULTS:After administrating hypoxic preconditioning, ATP content in myocardial tissue was enhanced from(31.89±2.42) mg -1 ·g -1 to (60.55±3.52) mg -1 ·g -1 ( P <0.01); mitochondrial respiratory control rate (RCR) was increased from 1.84±0.58 to 4.55±0.32( P <0.01);mitochondrial membrane fluidity was enhanced ( P <0.05); F 0F 1-ATP ase activity and Na +-K +-ATPase activity were increased 66% and 25% respectively. CONCLUSION:Hypoxic preconditioning efficiently improved the myocardial mitochondrial enerygy metabolism possibly through enhancing mitochondrial membrane fluidity and mitochondrial respiratory function.