Nakatani A, Han D H, Hansen P A, Nolte L A, Host H H, Hickner R C, Holloszy J O
Department of Internal Medicine, Washington University, School of Medicine, St Louis, Missouri 63110, USA.
J Appl Physiol (1985). 1997 Feb;82(2):711-5. doi: 10.1152/jappl.1997.82.2.711.
The purpose of this study was to test the hypothesis that the rate and extent of glycogen supercompensation in skeletal muscle are increased by endurance exercise training. Rats were trained by using a 5-wk-long swimming program in which the duration of swimming was gradually increased to 6 h/day over 3 wk and then maintained at 6 h/day for an additional 2 wk. Glycogen repletion was measured in trained and untrained rats after a glycogen-depleting bout of exercise. The rats were given a rodent chow diet plus 5% sucrose in their drinking water and libitum during the recovery period. There were remarkable differences in both the rates of glycogen accumulation and the glycogen concentrations attained in the two groups. The concentration of glycogen in epitrochlearis muscle averaged 13.1 +/- 0.9 mg/g wet wt in the untrained group and 31.7 +/- 2.7 mg/g in the trained group (P < 0.001) 24 h after the exercise. This difference could not be explained by a training effect on glycogen synthase. The training induced approximately 50% increases in muscle GLUT-4 glucose transporter protein and in hexokinase activity in epitrochlearis muscles. We conclude that endurance exercise training results in increases in both the rate and magnitude of muscle glycogen supercompensation in rats.
本研究的目的是验证耐力运动训练可提高骨骼肌糖原超量补偿的速率和程度这一假设。通过一项为期5周的游泳训练计划对大鼠进行训练，在3周内将游泳时长逐渐增加至6小时/天，然后在接下来的2周内维持在6小时/天。在进行糖原耗竭运动后，测量训练组和未训练组大鼠的糖原再合成情况。在恢复期，给大鼠提供啮齿动物饲料，并在饮水中添加5%的蔗糖，任其自由饮用。两组大鼠在糖原积累速率和达到的糖原浓度方面均存在显著差异。运动后24小时，未训练组肱三头肌糖原浓度平均为13.1±0.9毫克/克湿重，训练组为31.7±2.7毫克/克（P<0.001）。这种差异无法用训练对糖原合酶的影响来解释。训练使肱三头肌中肌肉葡萄糖转运蛋白4（GLUT-4）和己糖激酶活性增加了约50%。我们得出结论，耐力运动训练可使大鼠肌肉糖原超量补偿的速率和幅度均增加。
