Koopman René, Pennings Bart, Zorenc Antoine H G, van Loon Luc J C
Department of Movement Sciences, Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Maastricht University, Maastricht 6200 MD, The Netherlands.
J Nutr. 2007 Aug;137(8):1880-6. doi: 10.1093/jn/137.8.1880.
Our objective was to determine the impact of carbohydrate and/or protein ingestion before and after exercise on ribosomal protein S6 kinase (S6K1) and S6 phosphorylation status in human skeletal muscle tissue. Seven healthy, untrained men (22.5 +/- 0.9 y) were randomly assigned to 2 cross-over experiments. Before, immediately after, and 1 h after a single bout of resistance exercise, subjects consumed 0.3 g x kg(-1) carbohydrate with or without 0.3 g x kg(-1) protein hydrolysate (CHO+PRO and CHO, respectively). Muscle biopsies were taken before and immediately after exercise and after 1 and 4 h of postexercise recovery to determine 4E-BP1, S6K1 (both T(421)/S(424) and T(389)), and S6 phosphorylation status. Following resistance exercise, 4E-BP1 phosphorylation was reduced to a greater extent in the CHO treatment (-48 +/- 7%) than in the CHO+PRO treatment (-15 +/- 14%, P < 0.01). During recovery, 4E-BP1 phosphorylation increased in both experiments (P < 0.01), and tended to be higher in the CHO+PRO test (P = 0.08). S6K1 phosphorylation at T(421)/S(424) substantially increased following exercise and remained elevated during recovery with no differences between treatments. In contrast to the CHO treatment (-4 +/- 2%), S6K1 phosphorylation at T(389) was higher following exercise in the CHO+PRO treatment only (+78 +/- 2%, P < 0.01). During recovery, S6K1 phosphorylation at T(389) remained higher in CHO+PRO than in CHO (P < 0.05). S6 phosphorylation was substantially higher following exercise in the CHO+PRO (1.69 +/- 0.35) than in the CHO experiment (0.45 +/- 0.07, P < 0.01) and remained elevated during recovery (P < 0.05). We conclude that the availability of dietary protein further enhances phosphorylation of S6K1 during recovery from resistance type exercise.
我们的目的是确定运动前后摄入碳水化合物和/或蛋白质对人体骨骼肌组织中核糖体蛋白S6激酶（S6K1）和S6磷酸化状态的影响。七名健康的未经训练的男性（22.5±0.9岁）被随机分配到2个交叉实验中。在单次抗阻运动前、运动后立即以及运动后1小时，受试者分别摄入0.3g/kg碳水化合物（加或不加0.3g/kg蛋白质水解物，分别为CHO+PRO和CHO）。在运动前、运动后立即以及运动后恢复1小时和4小时时采集肌肉活检样本，以测定4E-BP1、S6K1（T(421)/S(424)和T(389)）以及S6的磷酸化状态。抗阻运动后，CHO组中4E-BP1磷酸化程度降低幅度（-48±7%）大于CHO+PRO组（-15±14%，P<0.01）。在恢复过程中，两个实验中4E-BP1磷酸化均增加（P<0.01），且在CHO+PRO组中4E-BP1磷酸化水平有更高的趋势（P=0.08）。运动后T(421)/S(424)处的S6K1磷酸化显著增加，且在恢复过程中保持升高，各处理组之间无差异。与CHO组（-4±2%）不同，仅在CHO+PRO组中运动后T(389)处的S6K1磷酸化更高（+78±2%，P<0.01）。在恢复过程中，CHO+PRO组中T(389)处的S6K1磷酸化水平仍高于CHO组（P<0.05）。运动后CHO+PRO组中S6磷酸化水平（1.69±0.35）显著高于CHO组（0.45±0.07，P<0.01），且在恢复过程中保持升高（P<0.05）。我们得出结论，膳食蛋白质的供应在抗阻运动恢复过程中进一步增强了S6K1的磷酸化。
