Terada S, Kawanaka K, Goto M, Shimokawa T, Tabata I
Division of Health Promotion and Exercise, Incorporated Administrative Agency, National Institute of Health and Nutrition, Toyama, Shinjuku City, Tokyo, Japan.
Acta Physiol Scand. 2005 May;184(1):59-65. doi: 10.1111/j.1365-201X.2005.01423.x.
The aim of the present investigation was to elucidate the effects of exercise intensity on exercise-induced expression of peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1alpha) protein in rat skeletal muscle.
We measured PGC-1alpha content in the skeletal muscles of male Sprague-Dawley rats (age: 5-6 weeks old; body weight: 150-170 g) after a single session of high-intensity intermittent exercise (HIE) or low-intensity prolonged swimming exercise (LIE). During HIE, the rats swam for fourteen 20-s periods carrying a weight (14% of body weight), and the periods of swimming were separated by a 10-s pause. LIE rats swam with no load for 6 h in two 3-h sessions, separated by 45 min of rest.
After HIE, the PGC-1alpha protein content in rat epitrochlearis muscle had increased by 126, 140 and 126% at 2, 6 and 18 h, respectively, compared with that of the age-matched sedentary control rats' muscle. Immediately, 6 and 18-h after LIE, the PGC-1alpha protein content in the muscle was significantly elevated by 84, 95 and 67% respectively. The PGC-1alpha protein content observed 6 h after HIE tended to be higher than that observed after LIE. However, there was no statistically significant difference between the two values (P = 0.12).
The present investigation suggests that irrespective of the intensity of the exercise, PGC-1alpha protein content in rat skeletal muscle increases to a comparable level when stimuli induced by different protocols are saturated. Further, HIE is a potent stimulus for enhancing the expression of PGC-1alpha protein, which may induce mitochondrial biogenesis in exercise-activated skeletal muscle.
本研究旨在阐明运动强度对大鼠骨骼肌中运动诱导的过氧化物酶体增殖物激活受体γ共激活因子-1α（PGC-1α）蛋白表达的影响。
我们测量了雄性Sprague-Dawley大鼠（年龄：5-6周龄；体重：150-170 g）在单次高强度间歇运动（HIE）或低强度长时间游泳运动（LIE）后骨骼肌中PGC-1α的含量。在HIE期间，大鼠负重（体重的14%）游泳14个20秒时段，游泳时段之间间隔10秒休息。LIE组大鼠无负荷游泳6小时，分两个3小时时段，中间休息45分钟。
HIE后，与年龄匹配的久坐对照大鼠肌肉相比，大鼠肱三头肌中PGC-1α蛋白含量在2、6和18小时分别增加了126%、140%和126%。LIE后即刻、6小时和18小时，肌肉中PGC-1α蛋白含量分别显著升高84%、95%和67%。HIE后6小时观察到的PGC-1α蛋白含量倾向于高于LIE后观察到的含量。然而，这两个值之间没有统计学显著差异（P = 0.12）。
本研究表明，无论运动强度如何，当不同方案诱导的刺激达到饱和时，大鼠骨骼肌中PGC-1α蛋白含量会增加到相当的水平。此外，HIE是增强PGC-1α蛋白表达的有效刺激因素，这可能在运动激活的骨骼肌中诱导线粒体生物发生。
