EFFECT OF GLUCOSE-INFUSION ON MUSCLE MALONYL-COA DURING EXERCISE
EFFECT OF GLUCOSE-INFUSION ON MUSCLE MALONYL-COA DURING EXERCISE
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DOI：
10.1152/jappl.1991.70.4.1495
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发表时间：
1991-04-01
影响因子：
3.3
通讯作者：
WINDER, WW
中科院分区：
文献类型：
--
作者：
ELAYAN, IM;WINDER, WW
该实验室先前的研究表明，肌肉丙二酸辅酶a，肉碱棕榈酰基转移酶I （CPT I）的抑制剂，在运动中减少。肝脏丙二酰辅酶a含量降低，当葡萄糖可用性降低，如在禁食期间或当胰高血糖素与胰岛素的比率增加，如在长时间的运动或胰岛素缺乏的反应。为了研究运动过程中葡萄糖输注对肌肉丙二酰辅酶a的影响，雄性大鼠在休息或跑步后（21 m/min， 15%等级）麻醉30或60分钟（通过静脉导管麻醉戊巴比妥）。运动时以葡萄糖（0.625 g/ml）或生理盐水（1.5 ml/h）灌胃。腓肠肌和肝脏样品在液氮温度下冷冻。运动60 min时，葡萄糖输注肌肉丙二酰辅酶a从1.24 +/- 0.06 nmol/g降至0.69 +/- 0.05 nmol/g，生理盐水输注肌肉丙二酰辅酶a降至0.43 +/- 0.04 nmol/g。在肝脏中，葡萄糖输注阻止丙二酰辅酶a的下降。这表明葡萄糖输注可以减缓肌肉丙二酰辅酶a的进行性下降，并防止长时间运动中肝脏丙二酰辅酶a的下降。
Previous work in this laboratory has shown that muscle malony-CoA, the inhibitor of carnitine palmitoyltransferase I (CPT I), decreased during exercise. Hepatic malonyl-CoA content decreases when glucose availability decreases such as during fasting or when the glucagon-to-insulin ratio increases such as during prolonged exercise or in response to insulin deficiency. To investigate the effect of glucose infusion on muscle malonyl-CoA during exercise, male rats were anesthetized (pentobarbital via venous catheters) at rest or after running (21 m/min, 15% grade) for 30 or 60 min. During exercise rats were infused with either glucose (0.625 g/ml) or saline at a rate of 1.5 ml/h. Gastrocnemius muscles and liver samples were frozen at liquid nitrogen temperature. Muscle malonyl-CoA decreased from 1.24 +/- 0.06 to 0.69 +/- 0.05 nmol/g with glucose infusion and to 0.43 +/- 0.04 nmol/g with saline infusion during 60 min of exercise. In the liver, glucose infusion prevented the drop in malonyl-CoA. This indicates that glucose infusion attenuates the progressive decline in muscle malonyl-CoA and prevents the decline in liver malonyl-CoA during prolonged exercise.