急、慢性缺氧对大鼠脑线粒体能量代谢的影响

目的:探讨缺氧大鼠脑线粒体能量代谢的特点。方法:雄性Wistar大鼠随机分为急性缺氧组(AH)、慢性缺氧组(CH)和对照组。急、慢性缺氧组动物分别连续暴露于模拟4000m高原3d(AH)和40d(CH)。分离脑线粒体,分别测定线粒体呼吸功能、线粒体内腺苷酸池含量、ATP生成能力和F₀F₁-ATP酶活性。结果:急性缺氧大鼠IV态呼吸(ST₄)显著升高,伴呼吸控制率(RCR)降低,同时线粒体内ATP含量、ATP生成率和F₀F₁-ATP酶活性均显著降低;慢性缺氧大鼠ST₄、RCR、线粒体ATP含量和F₀F₁-ATP酶活性部分恢复。结论:急性缺氧脑线粒体代谢是以功能受损为特点,而慢性缺氧时则表现为功能的部分代偿。

Characteristics of energy metabolism in brain mitochondria of rats exposed to hypoxia

AIM:To explore the characteristics of energy metabolism in brain mitochondria of rats exposed to acute and chronic hypoxia. METHODS: Animal grouping: Wistar rats were randomized into acute hypoxic group (AH), chronic hypoxic group (CH) and the control. Respiratory function, F 0F 1-ATPase activity, mitochondrial ATP, ADP and AMP contents and ATP production rate were measured respectively. RESULTS: In AH, brain mitochondrial respiratory state IV (ST 4) was increased, while respiratory control rate (RCR), mitochondrial ATP content, ATP production rate and F 0F 1-ATPase activity were decreased respectively. In CH, ST 4, RCR, mitochondrial ATP content and F 0F 1-ATPase activity were reversed partially. CONCLUSION: Acute hypoxia may impair brain mitochondria energy metabolism by way of depressing mitochondrial oxidative phosphorylation and ATP production and these parameters gain partial reablement during chronic hypoxia.