School of Medical Science, Health Innovations Research Institute, RMIT University, Melbourne, Australia.
Med Sci Sports Exerc. 2010 Oct;42(10):1843-52. doi: 10.1249/MSS.0b013e3181d964e4.
The aim of this study was to determine the early time course of exercise-induced signaling after divergent contractile activity associated with resistance and endurance exercise.
Sixteen male subjects were randomly assigned to either a cycling (CYC; n = 8, 60 min, 70% V˙O2peak) or resistance (REX; n = 8, 8 x 5 leg extension, 80% one-repetition maximum, 3-min recovery) exercise group. Serial muscle biopsies were obtained from vastus lateralis at rest before, immediately after, and after 15, 30, and 60 min of passive recovery to determine early signaling responses after exercise.
There were comparable increases from rest in Akt(Thr308/Ser473) and mTOR(Ser2448) phosphorylation during the postexercise time course that peaked 30-60 min after both CYC and REX (P < 0.05). There were also similar patterns in p70S6K(Thr389) and 4E-BP1(Thr37/46) phosphorylation, but a greater magnitude of effect was observed for REX and CYC, respectively (P < 0.05). However, AMPK(Thr172) phosphorylation was only significantly elevated after CYC (P < 0.05), and we observed divergent responses for glycogen synthase(Ser641) and AS160 phosphorylation that were enhanced after CYC but not REX (P < 0.05).
We show a similar time course for Akt-mTOR-S6K phosphorylation during the initial 60-min recovery period after divergent contractile stimuli. Conversely, enhanced phosphorylation status of proteins that promote glucose transport and glycogen synthesis only occurred after endurance exercise. Our results indicate that endurance and resistance exercise initiate translational signaling, but high-load, low-repetition contractile activity failed to promote phosphorylation of pathways regulating glucose metabolism.
本研究旨在确定与抗阻运动和耐力运动相关的收缩活动后，运动诱导信号的早期时程。
16 名男性受试者被随机分为自行车运动（CYC；n=8，60 分钟，70%最大摄氧量峰值）或抗阻运动（REX；n=8，8 x 5 次腿屈伸，80%一次重复最大强度，3 分钟恢复期）组。在被动恢复期的休息、运动后即刻和 15、30 和 60 分钟时，从股外侧肌获得连续肌肉活检，以确定运动后的早期信号反应。
在 CYC 和 REX 后，Akt（Thr308/Ser473）和 mTOR（Ser2448）磷酸化的激活在整个运动后时间过程中均呈相似的增加趋势，在 30-60 分钟时达到峰值（P < 0.05）。p70S6K（Thr389）和 4E-BP1（Thr37/46）磷酸化也呈现相似的模式，但 REX 和 CYC 的影响幅度更大（P < 0.05）。然而，只有 CYC 后 AMPK（Thr172）磷酸化显著升高（P < 0.05），我们观察到糖原合酶（Ser641）和 AS160 磷酸化的不同反应，这两种反应在 CYC 后增强，但在 REX 后没有增强（P < 0.05）。
我们在不同收缩刺激后的最初 60 分钟恢复期内显示出 Akt-mTOR-S6K 磷酸化的相似时间过程。相反，只有在耐力运动后，才会增强促进葡萄糖转运和糖原合成的蛋白的磷酸化状态。我们的结果表明，耐力运动和抗阻运动启动翻译信号，但高负荷、低重复收缩活动未能促进调节葡萄糖代谢的途径的磷酸化。
