补糖对急性运动大鼠心肌单磷酸腺苷活化蛋白激酶激活的影响

目的 通过测量大鼠急性运动后心肌单磷酸腺苷活化蛋白激酶（AMP-activated protein kinase，AMPK）活性和糖原含量的变化，探讨补糖对运动心肌AMPK激活的影响。方法 大鼠进行急性耐力运动，并在运动前后不同时间补充不同剂量的补充葡萄糖，采用Western blot测定大鼠心肌AMPK活性的动态变化，采用蒽酮法测定心肌糖原含量。结果 运动诱发大鼠心肌AMPK活性显著增高并在急性运动后1 h保持在较高水平，然而运动补糖大鼠心肌AMPK活性却无显著增高。运动或小剂量补糖都无法引起大鼠糖原含量的显著变化，只有大剂量补糖能使糖原含量在运动后24 h显著增高。结论 （1）急性运动可使大鼠心肌AMPK活性升高，补糖能显著抑制急性运动中和运动后AMPK的激活。（2）运动后大剂量补糖能有效提高运动后24 h心肌糖原含量。

Effects of glucose supplementation on the activity of myocardial AMP-activated protein kinase in rats induced by exercise

Objective To investigate the effect of glucose supplement on AMPK activation in myocardium of exercised rats by measuring the myocardial AMPK activation and glycogen content after acute exercise training. Methods Rats were subjected to an acute endurance exercise and glucose supplement in varying doses and time points before and after exercise. The dynamic changes of myocardial AMPK activities was measured with Western blotting, changes of myocardial glycogen content were measured with Anthrone method. Results AMPK activation in myocardium of exercised rat was increased significantly throughout the exercise, and remained at a higher level 1 hour after acute exercise. However the level of AMPK activity was not significantly increased in exercised rat with glucose supplement. Glycogen content was not significantly changed after exercise. Rats subjected to lower dose glucose supplement did not show significant changes in glycogen content neither. But glycogen content was significantly increased in rats at 24 hours after exercise, subjected to higher dose of glucose supplement. Conclusions 1) Acute exercise induces a significant increase in AMPK activation in myocardium of exercised rats. Glucose supplement significantly inhibites the activation of AMPK induced by acute exercise. (2) Higher dose glucose supplement significantly increases glycogen content in the rat myocardium 24 h after exercise.