Zorzano A, Balon T W, Goodman M N, Ruderman N B
Am J Physiol. 1986 Dec;251(6 Pt 1):E664-9. doi: 10.1152/ajpendo.1986.251.6.E664.
As judged by its ability to stimulate glucose uptake and alpha-aminoisobutyric acid (AIB) transport, the sensitivity and the responsiveness of perfused rat muscle to insulin are enhanced after moderately intense treadmill exercise. In fed rats, these enhanced effects of insulin are predominantly restricted to muscles that performed work as evidenced by glycogen depletion. The present study was designed to examine the relationship between glycogen depletion per se and the postexercise changes in insulin action. Toward this end, fed and 48-h starved rats were run on a treadmill for 45 min at moderate intensity, and glucose and AIB uptake were then assessed using the isolated perfused hindquarter preparation. Glycogen is depleted in red muscles such as the soleus and red fibers of the gastrocnemius in fed rats immediately after such exercise, whereas, in starved rats, muscle glycogen is unchanged. As previously shown, the stimulation by insulin of glucose utilization by the hindquarter and AIB transport into red muscles was substantially increased in fed rats after the treadmill run. This was due to increases in both insulin sensitivity and responsiveness. In starved rats, the treadmill run also enhanced the ability of insulin to stimulate these processes; however, this was solely due to an increase in insulin sensitivity. No change in insulin responsiveness was observed. The results indicate that the enhanced sensitivity of muscle to insulin after exercise is not dependent on glycogen depletion, whereas increased insulin responsiveness does not occur in its absence. They also suggest that the mechanisms by which prior exercise acts to increase insulin sensitivity and responsiveness are different.
根据其刺激葡萄糖摄取和α-氨基异丁酸（AIB）转运的能力判断，适度强度的跑步机运动后，灌注大鼠肌肉对胰岛素的敏感性和反应性增强。在喂食的大鼠中，胰岛素的这些增强作用主要局限于因糖原消耗而进行了运动的肌肉。本研究旨在检查糖原消耗本身与运动后胰岛素作用变化之间的关系。为此，将喂食的和饥饿48小时的大鼠在跑步机上以中等强度跑步45分钟，然后使用分离的灌注后肢制备物评估葡萄糖和AIB摄取。在喂食的大鼠中，此类运动后立即在比目鱼肌和腓肠肌的红色纤维等红色肌肉中糖原被耗尽，而在饥饿的大鼠中，肌肉糖原没有变化。如先前所示，跑步机跑步后，喂食的大鼠中胰岛素对后肢葡萄糖利用和AIB转运至红色肌肉的刺激作用大幅增加。这是由于胰岛素敏感性和反应性均增加。在饥饿的大鼠中，跑步机跑步也增强了胰岛素刺激这些过程的能力；然而，这完全是由于胰岛素敏感性增加。未观察到胰岛素反应性的变化。结果表明，运动后肌肉对胰岛素敏感性的增强不依赖于糖原消耗，而在没有糖原消耗的情况下不会出现胰岛素反应性增加。它们还表明，先前运动增加胰岛素敏感性和反应性的机制是不同的。
