Nutrient provision increases signalling and protein synthesis in human skeletal muscle after repeated sprints
Nutrient provision increases signalling and protein synthesis in human skeletal muscle after repeated sprints
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DOI：
10.1007/s00421-010-1768-0
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发表时间：
2011-07-01
影响因子：
3
通讯作者：
Hawley, John A.
中科院分区：
文献类型：
--
作者：
Coffey, Vernon G.;Moore, Daniel R.;Hawley, John A.
营养可用性对重复冲刺运动后急性分子反应的影响尚不清楚。本研究的目的是确定在提供营养的重复冲刺运动后骨骼肌细胞和蛋白质合成反应。八名健康年轻男性受试者进行了两次冲刺骑行训练（10 x 6 秒，0.75 N·m 扭矩 kg(-1)，54 秒恢复），并摄入运动前营养物质（24 克乳清、4.8 克亮氨酸、50 克麦芽糖糊精）或摄入无热量安慰剂。肌肉活检取自静止时的股外侧肌，以及运动后恢复后15分钟和240分钟，通过持续输注l-[环-C-13(6)]苯丙氨酸来确定肌肉细胞信号传导反应和蛋白质合成。营养剂试验和安慰剂试验之间的峰值和平均功率输出相似。与安慰剂相比，营养摄入后运动后肌原纤维蛋白合成率更高（相似于 48%，P < 0.05），但治疗之间线粒体蛋白合成率相似。冲刺后摄入营养物质的肌原纤维蛋白合成增加与运动后 15 分钟 Akt-mTOR-S6K-rpS6 磷酸化的协调增加相关（类似于 200-600%，P < 0.05），而在禁食状态下进行运动时对这些信号分子没有影响。我们首次报道了重复冲刺运动后营养供应对合成代谢信号和肌肉肌原纤维蛋白合成的有益影响。在高强度冲刺运动附近摄入蛋白质/碳水化合物提供了一个增加细胞信号传导和蛋白质合成的环境。
The effect of nutrient availability on the acute molecular responses following repeated sprint exercise is unknown. The aim of this study was to determine skeletal muscle cellular and protein synthetic responses following repeated sprint exercise with nutrient provision. Eight healthy young male subjects undertook two sprint cycling sessions (10 x 6 s, 0.75 N m torque kg(-1), 54 s recovery) with either pre-exercise nutrient (24 g whey, 4.8 g leucine, 50 g maltodextrin) or non-caloric placebo ingestion. Muscle biopsies were taken from vastus lateralis at rest, and after 15 and 240 min post-exercise recovery to determine muscle cell signalling responses and protein synthesis by primed constant infusion of l-[ring-C-13(6)] phenylalanine. Peak and mean power outputs were similar between nutrient and placebo trials. Post-exercise myofibrillar protein synthetic rate was greater with nutrient ingestion compared with placebo (similar to 48%, P < 0.05) but the rate of mitochondrial protein synthesis was similar between treatments. The increased myofibrillar protein synthesis following sprints with nutrient ingestion was associated with coordinated increases in Akt-mTOR-S6K-rpS6 phosphorylation 15 min post-exercise (similar to 200-600%, P < 0.05), while there was no effect on these signalling molecules when exercise was undertaken in the fasted state. For the first time we report a beneficial effect of nutrient provision on anabolic signalling and muscle myofibrillar protein synthesis following repeated sprint exercise. Ingestion of protein/carbohydrate in close proximity to high-intensity sprint exercise provides an environment that increases cell signalling and protein synthesis.