Kraniou Y, Cameron-Smith D, Misso M, Collier G, Hargreaves M
School of Health Sciences, Deakin University, Burwood, Victoria 3125, Australia.
J Appl Physiol (1985). 2000 Feb;88(2):794-6. doi: 10.1152/jappl.2000.88.2.794.
To investigate the effect of exercise on GLUT-4, hexokinase, and glycogenin gene expression in human skeletal muscle, 10 untrained subjects (6 women and 4 men, 21.4 +/- 1.2 yr, 66.3 +/- 5.0 kg, peak oxygen consumption = 2.30 +/- 0.19 l/min) exercised for 60 min on a cycle ergometer at a power output requiring 73 +/- 4% peak oxygen consumption. Muscle samples were obtained by needle biopsy before, immediately after, and 3 h after exercise. Gene expression was quantified, relative to 29S ribosomal protein cDNA, by RT-PCR. GLUT-4 gene expression was increased immediately after exercise (1.7 +/- 0.4 vs. 0.9 +/- 0.3 arbitrary units; P < 0.05) and remained significantly higher than baseline 3 h after the end of exercise (2. 2 +/- 0.4 vs. 0.9 +/- 0.3 arbitrary units; P < 0.05). Hexokinase II gene expression was significantly higher than the resting value 3 h after the end of exercise (2.9 +/- 0.4 vs. 1.3 +/- 0.3 arbitrary units; P < 0.05). Exercise increased glycogenin mRNA more than twofold (2.8 +/- 0.6 vs. 1.2 +/- 0.2 arbitrary units; P < 0.05) 3 h after the end of exercise. For the first time, we report that a single bout of exercise is sufficient to cause upregulation of GLUT-4 and glycogenin gene expression in human skeletal muscle. Whether these increases, together with the associated increase in hexokinase II gene expression, lead to increased expression of these key proteins in skeletal muscle and contribute to the enhanced skeletal muscle glucose uptake, glycogen synthesis, and insulin action observed following exercise remains to be determined.
为研究运动对人骨骼肌中葡萄糖转运蛋白4（GLUT-4）、己糖激酶和糖原素基因表达的影响，10名未经训练的受试者（6名女性和4名男性，年龄21.4±1.2岁，体重66.3±5.0千克，最大耗氧量=2.30±0.19升/分钟）在功率输出相当于最大耗氧量73±4%的自行车测力计上运动60分钟。在运动前、运动结束后即刻以及运动后3小时通过肌肉活检获取肌肉样本。相对于29S核糖体蛋白cDNA，通过逆转录聚合酶链反应（RT-PCR）对基因表达进行定量分析。运动结束后即刻，GLUT-4基因表达增加（1.7±0.4对0.9±0.3任意单位；P<0.05），且在运动结束3小时后仍显著高于基线水平（2.2±0.4对0.9±0.3任意单位；P<0.05）。运动结束3小时后，己糖激酶II基因表达显著高于静息值（2.9±0.4对1.3±0.3任意单位；P<0.05）。运动结束3小时后，运动使糖原素mRNA增加了两倍多（2.8±0.6对1.2±0.2任意单位；P<0.05）。我们首次报道，单次运动足以使人骨骼肌中GLUT-4和糖原素基因表达上调。这些增加以及伴随的己糖激酶II基因表达增加是否会导致骨骼肌中这些关键蛋白表达增加，并有助于运动后观察到的骨骼肌葡萄糖摄取、糖原合成及胰岛素作用增强，仍有待确定。
