间歇低氧对线粒体钙转运及能量代谢的影响

The effects of intermittent hypoxic on mitochondria calcium transports and energy metabolism

目的:研究间歇低氧对线粒体钙转运及能量代谢的影响,探讨低氧适应的机制。方法:SD雄性大鼠分为常氧组、急性低氧组和间歇低氧组,每组10只。采用荧光分光光度法和生物发光技术分别测定心肌、肝脏和骨骼肌线粒游离体Ca2+浓度和心肌线粒体ATP含量,并用分光光度法测定线粒体ATP酶活性。结果:急性低氧应激后线粒体游离Ca2+浓度犤心肌、肝脏、骨骼肌分别为(323±44,334±46,284±45)μmol/g蛋白〗、ATP含量犤(185±55)μg/g犦和ATP酶活性犤(0.001±0.0003)～(0.0014±0.0002)mol/(kg·s)犦下降(P<0.05),血乳酸犤(5.2±1.4)mmol/L犦明显上升(P<0.05～0.01);经过间歇低氧适应后以上指标呈上升趋势,血乳酸上升程度减低。结论:间歇性低氧适应能提高线粒体钙离子转运功能,并使能量代谢得到改善。

AIM:To explore the mechanisms of hypoxic acclimatization ,and the effects of i ntermittent hypoxic on the function of mitochondria calcium transports and energ y metabolism. METHODS:Male Sprague-Dawley(SD) rats were randomly divided into three groups: normoxia group(n=10),acute hypoxia group(n=10) and intermittent hypoxic group(n =10). Fluorospectrophotometry and bioluminescence were used to assay the Ca2+co ncentration of intermittent in the heart, liver and skeletal muscle tissue, ATP content and ATPase activity of mitochondria in the heart tissue were assessed by spectrophotography. RESULTS:Free Ca2+concentration of mitochondria in the heart[(323±44) μmol/g protein], liver[(334±46)μmol/g protein] and skeletal muscle tissue[(184±45) μmol/g protein], ATP content[(185±55)μg/g] and ATPase activity [(0.001±0.00 03)-(0.0014±0.0002)mol/(kg·s)] decreased after hypoxic stress(P< 0.05), wh ile blood lactic acid[(5.2±1.4)mmol/L]in creased significantly (P< 0.05-0.01 ). The items above appeared to increase after intermittent hypoxic acclimatizat ion, while the increasing degree of blood lactic acid lowered.