Gaster M, Franch J, Beck-Nielsen H, Schrøder H D
Dept. of Pathology, Odense University Hospital, 5000 Odense, Denmark.
Pflugers Arch. 2001 Nov;443(2):196-201. doi: 10.1007/s004240100698.
The influence of training on GLUT4 expression in slow- and fast-twitch skeletal muscle fibres was studied in male endurance-trained athletes and control subjects. The trained state was ensured by elevated maximal oxygen uptake (29%), as well as citrate synthase (60%) and 3-hydroxy-acyl-CoA dehydrogenase (38%) activities in muscle biopsy samples of the vastus lateralis. GLUT4 densities in slow- and fast-twitch fibres were measured by the use of a newly developed, sensitive method combining immunohistochemistry with morphometry, and no effect of training was found. GLUT4 density was higher in slow-twitch fibres compared to fast-twitch fibres (P<0.05) when biopsy samples from untrained subjects were examined. In athletes GLUT4 density was identical in slow- and fast-twitch fibres. Slow-twitch fibre diameters were 10% larger in the athletes (P<0.01), and slow-twitch fibre fractions were 140% of the fraction in the control group. Thus, GLUT4 originating from slow-twitch fibres was increased by 30% (P<0.02) in athletes. We conclude that long-lasting endurance training increases slow-twitch fibre GLUT4 expression by means of an elevated slow-twitch fibre mass in human skeletal muscle.
在男性耐力训练运动员和对照组受试者中，研究了训练对慢肌纤维和快肌纤维中葡萄糖转运蛋白4（GLUT4）表达的影响。通过提高最大摄氧量（29%）以及股外侧肌肌肉活检样本中的柠檬酸合酶（60%）和3-羟基酰基辅酶A脱氢酶（38%）活性来确保训练状态。使用一种新开发的、将免疫组织化学与形态测量学相结合的灵敏方法测量慢肌纤维和快肌纤维中的GLUT4密度，未发现训练有影响。检查未训练受试者的活检样本时，慢肌纤维中的GLUT4密度高于快肌纤维（P<0.05）。在运动员中，慢肌纤维和快肌纤维中的GLUT4密度相同。运动员的慢肌纤维直径大10%（P<0.01），慢肌纤维比例是对照组的140%。因此，运动员中源自慢肌纤维的GLUT4增加了30%（P<0.02）。我们得出结论，长期耐力训练通过增加人类骨骼肌中慢肌纤维的质量来提高慢肌纤维GLUT4的表达。
