Kusunoki M, Storlien L H, MacDessi J, Oakes N D, Kennedy C, Chisholm D J, Kraegen E W
Garvan Institute of Medical Research, St. Vincent's Hospital, Sydney, New South Wales, Australia.
Am J Physiol. 1993 Feb;264(2 Pt 1):E167-72. doi: 10.1152/ajpendo.1993.264.2.E167.
It is not generally known whether impaired stimulation of muscle glucose metabolism in insulin-resistant states is specific to insulin stimulation. Our aim was to examine whether glucose uptake responded normally to exercise and postexercise recovery in insulin-resistant high-fat-fed (HFF) rats. Three-week HFF or Chow-fed [control (Con)] adult rats were studied 5 days after cannulation. Before, during, or immediately after (recovery) 50 min of treadmill exercise, bolus 2-deoxy-[3H]glucose and [14C]glucose were administered to estimate muscle glucose uptake (R'g) and glycogen incorporation rates. Mean exercise and recovery plasma glucose levels were similar in HFF and Con rats. In hindlimb muscles sampled, exercise and recovery R'g were similar in HFF and Con (e.g., red quadriceps exercise 104 +/- 13 vs. 113 +/- 8, recovery 45.3 +/- 3.9 vs. 47.7 +/- 4.5 mumol.100 g-1.min-1, respectively). Moreover, muscle glucose transporter (GLUT-4) content was not reduced in HFF rats. Glycogen resynthesis accounted almost entirely for R'g during recovery and was equivalent between groups. We conclude that impaired muscle glucose uptake and glycogen synthesis in HFF rats are characteristic of insulin but not of exercise or postexercise stimulation.
胰岛素抵抗状态下肌肉葡萄糖代谢刺激受损是否特异性地针对胰岛素刺激，目前尚无普遍认知。我们的目的是研究胰岛素抵抗的高脂喂养（HFF）大鼠的葡萄糖摄取对运动及运动后恢复的反应是否正常。对插管5天后的3周龄HFF或普通饲料喂养[对照（Con）]成年大鼠进行研究。在50分钟跑步机运动前、运动期间或运动后立即（恢复阶段），给予大剂量2-脱氧-[3H]葡萄糖和[14C]葡萄糖，以估算肌肉葡萄糖摄取（R'g）和糖原掺入率。HFF大鼠和Con大鼠运动及恢复阶段的平均血糖水平相似。在采集的后肢肌肉中，HFF大鼠和Con大鼠运动及恢复阶段的R'g相似（例如，红色股四头肌运动时分别为104±13与113±8，恢复阶段分别为45.3±3.9与47.7±4.5 μmol·100 g-1·min-1）。此外，HFF大鼠肌肉葡萄糖转运蛋白（GLUT-4）含量未降低。恢复阶段糖原再合成几乎完全占R'g，且两组间相当。我们得出结论，HFF大鼠肌肉葡萄糖摄取和糖原合成受损是胰岛素的特征，而非运动或运动后刺激的特征。
