Zorzano A, Balon T W, Garetto L P, Goodman M N, Ruderman N B
Am J Physiol. 1985 May;248(5 Pt 1):E546-52. doi: 10.1152/ajpendo.1985.248.5.E546.
After exercise the ability of insulin to stimulate glucose transport and glycogen synthesis in rat skeletal muscle is markedly enhanced (25). The present study was designed to determine whether prior exercise augments the stimulation of other processes by insulin and, if so, whether this can be attributed to an increase in insulin binding to its receptor. Toward this end rats were run on a treadmill for 45 min at moderate intensity and the uptake of alpha-aminoisobutyric acid (AIB) by muscle was then assessed using the isolated perfused hindquarter preparation. Approximately 30 min after the cessation of exercise, both the sensitivity and responsiveness of insulin-stimulated AIB uptake were significantly enhanced in the soleus and the red portion of the gastrocnemius. As previously shown for glucose transport and glycogen synthesis, only small effects were observed in the white portion of the gastrocnemius, which unlike the other muscles was not depleted of glycogen during the run. Insulin-stimulated glucose utilization was also enhanced in the incubated soleus muscle of exercised rats; however, insulin binding to the soleus was not altered. These studies indicate that the ability of insulin to stimulate processes other than glucose transport and glycogen synthesis is enhanced in skeletal muscle after exercise and that this is not due to an alteration in insulin binding. The changes in insulin-stimulated AIB uptake and glucose metabolism after exercise are the reverse of those found in denervated and immobilized muscle and in both situations insulin binding is not altered. This suggests that a common factor(s) modulates the increase in insulin effect after exercise and the insulin resistance of disuse.
运动后，胰岛素刺激大鼠骨骼肌葡萄糖转运和糖原合成的能力显著增强（25）。本研究旨在确定预先运动是否会增强胰岛素对其他过程的刺激作用，如果是，这是否可归因于胰岛素与其受体结合增加。为此，将大鼠在跑步机上以中等强度跑45分钟，然后使用离体灌注后肢标本评估肌肉对α-氨基异丁酸（AIB）的摄取。运动停止后约30分钟，比目鱼肌和腓肠肌红色部分中胰岛素刺激的AIB摄取的敏感性和反应性均显著增强。如先前对葡萄糖转运和糖原合成的研究所示，在腓肠肌白色部分观察到的影响较小，与其他肌肉不同，该部分在跑步过程中糖原未被耗尽。在运动大鼠的离体比目鱼肌中，胰岛素刺激的葡萄糖利用也增强；然而，胰岛素与比目鱼肌的结合未发生改变。这些研究表明，运动后骨骼肌中胰岛素刺激除葡萄糖转运和糖原合成以外其他过程的能力增强，且这并非由于胰岛素结合的改变。运动后胰岛素刺激的AIB摄取和葡萄糖代谢的变化与去神经和固定肌肉中的变化相反，在这两种情况下胰岛素结合均未改变。这表明一个共同因素调节运动后胰岛素作用的增强和废用性胰岛素抵抗。
