Karelis Antony D, Péronnet François, Gardiner Phillip F
Département de Kinésiologie, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montréal, Québec H3C 3J7.
Can J Appl Physiol. 2005 Feb;30(1):105-12. doi: 10.1139/h05-108.
The purpose of this study was to determine whether glucose infusion during prolonged indirect muscle stimulation (50 Hz for 200 ms every 2.7 s at 5 V) would have an effect on resting membrane potential (RMP). The RMP measured at Min 1 in the recovery period following stimulation of the rat plantaris muscle for 60 min in situ was significantly decreased in control rats, but was back to baseline values within 2 min. When glucose was infused ([glucose] approximately 10 mM), no change was observed in RMP, and muscle fatigue and the reduction in M-wave peak-to-peak amplitude were both attenuated. However, muscle force and the electrical properties of the membrane were deteriorated both in rats infused with glucose and in control rats at Min 2 during the recovery period, at a time when RMP was not modified. These observations suggest that the effect of increased circulating glucose on fatigue-associated reductions in muscle fiber RMP seems to be modest and short-lived. Therefore, the attenuating effect of elevated glucose on muscle fatigue responses could be through mechanisms other than those associated with maintenance of RMP during fatigue.
本研究的目的是确定在长时间间接肌肉刺激（5V，每2.7秒以50Hz刺激200毫秒）期间输注葡萄糖是否会对静息膜电位（RMP）产生影响。在原位刺激大鼠比目鱼肌60分钟后的恢复期第1分钟测量的RMP，在对照大鼠中显著降低，但在2分钟内恢复到基线值。当输注葡萄糖（[葡萄糖]约为10 mM）时，RMP未观察到变化，并且肌肉疲劳和M波峰峰值幅度的降低均得到缓解。然而，在恢复期第2分钟时，输注葡萄糖的大鼠和对照大鼠的肌肉力量和膜的电特性均恶化，此时RMP未改变。这些观察结果表明，循环葡萄糖增加对疲劳相关的肌肉纤维RMP降低的影响似乎是适度且短暂的。因此，葡萄糖升高对肌肉疲劳反应的缓解作用可能是通过与疲劳期间维持RMP无关的机制实现的。
