Intramuscular glycogen and intramyocellular lipid utilization during prolonged exercise and recovery in man:: A 13C and 1H nuclear magnetic resonance spectroscopy study
Intramuscular glycogen and intramyocellular lipid utilization during prolonged exercise and recovery in man:: A 13C and 1H nuclear magnetic resonance spectroscopy study
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DOI：
10.1210/jc.85.2.748
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发表时间：
2000-02-01
影响因子：
5.8
通讯作者：
Shulman, GI
中科院分区：
文献类型：
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作者：
Krssak, M;Petersen, KF;Shulman, GI
在长时间的运动中，肌糖原的消耗被认为是一个限制运动表现的因素，而细胞内脂质（IMCL）池的作用尚不完全清楚。我们检查了1)长时间运动时的细胞内糖原和脂质利用，2)恢复期间肌糖原和脂质的再合成，以及3)恢复期间非运动和运动肌肉之间糖原含量的变化。受试者在跑步机上以次最大强度跑步直到筋疲力尽。在大腿、小腿和非运动前臂肌肉中评估糖原浓度，并使用磁共振波谱技术测量比目鱼肌中IMCL含量。在消耗时，小腿肌肉的糖原消耗是大腿肌肉的2倍，但两条腿的肌肉中仍有大量的糖原。在恢复的最初5小时内，非运动前臂肌肉中的糖原浓度下降到基线值的73%。在锻炼过程中，IMCL含量下降到67%，随后在恢复过程中增加到基线值的83%。总之，我们发现在长时间跑步中，1)小腿肌群的肌糖原利用率明显高于大腿肌群，2)比目鱼肌的IMCL利用率显著提高，3)非运动肌肉的糖原含量降低，运动后恢复肌肉的糖原含量增加。这些数据与跑步运动后，糖原通过葡萄糖->乳酸和葡萄糖->丙氨酸循环从静止肌肉（前臂）转移到恢复肌肉（大腿和小腿）的假设是一致的。
Depletion of muscle glycogen is considered a limiting performance factor during prolonged exercise, whereas the role of the intramyocellular lipid (IMCL) pool is not yet fully understood. We examined 1) intramyocellular glycogen and Lipid utilization during prolonged exercise, 2) resynthesis of muscle glycogen and lipids during recovery, and 3) changes in glycogen content between nonexercising and exercising muscles during recovery. Subjects ran on a treadmill at submaximal intensity until exhaustion. Glycogen concentrations were assessed in thigh, calf, and nonexercising forearm muscle, and IMCL content was measured in soleus muscle using magnetic resonance spectroscopy techniques. At the time of exhaustion, glycogen depletion was 2-fold greater in calf than in thigh muscles, but a significant amount of glycogen was left in both leg muscles. The glycogen concentration in nonexercising forearm muscle decreased during the initial 5 h of recovery to 73% of the baseline value. During the exercise, the IMCL content decreased to 67% and subsequently during recovery increased to 83% of the baseline value. In summary, we found during prolonged running 1) significantly greater muscle glycogen utilization in the calf muscle group than in the thigh muscle group, 2) significant utilization of IMCL in the soleus muscle, and 3) a decrease in glycogen content in nonexercising muscle and an increase in glycogen content in recovering muscles during the postexercise phase. These latter data are consistent with the hypothesis that there is transfer of glycogen by the glucose-->lactate and the glucose-->alanine cycle from the resting muscle (forearm) to recovering muscles (thigh and calf) after running exercise.