Human Performance Laboratory, Department of Kinesiology, University of Connecticut, 2095 Hillside Road, Unit 1110, Storrs, CT 06269, USA.
Eur J Appl Physiol. 2013 Mar;113(3):793-802. doi: 10.1007/s00421-012-2492-8. Epub 2012 Sep 14.
Our aim was to examine the effect of betaine supplementation on selected circulating hormonal measures and Akt muscle signaling proteins after an acute exercise session. Twelve trained men (age 19.7 ± 1.23 years) underwent 2 weeks of supplementation with either betaine (B) (1.25 g BID) or placebo (P). Following a 2-week washout period, subjects underwent supplementation with the other treatment (B or P). Before and after each 2-week period, subjects performed an acute exercise session (AES). Circulating GH, IGF-1, cortisol, and insulin were measured. Vastus lateralis samples were analyzed for signaling proteins (Akt, p70 S6k, AMPK). B (vs. P) supplementation approached a significant increase in GH (mean ± SD (Area under the curve, AUC), B: 40.72 ± 6.14, P: 38.28 ± 5.54, p = 0.060) and significantly increased IGF-1 (mean ± SD (AUC), B: 106.19 ± 13.45, P: 95.10 ± 14.23, p = 0.010), but significantly decreased cortisol (mean ± SD (AUC), B: 1,079.18 ± 110.02, P: 1,228.53 ± 130.32, p = 0.007). There was no difference in insulin (AUC). B increased resting Total muscle Akt (p = 0.003). B potentiated phosphorylation (relative to P) of Akt (Ser(473)) and p70 S6 k (Thr(389)) (p = 0.016 and p = 0.005, respectively). Phosphorylation of AMPK (Thr(172)) decreased during both treatments (both p = 0.001). Betaine (vs. placebo) supplementation enhanced both the anabolic endocrine profile and the corresponding anabolic signaling environment, suggesting increased protein synthesis.
我们的目的是研究甜菜碱补充对急性运动后某些循环激素指标和 Akt 肌肉信号蛋白的影响。12 名训练有素的男性（年龄 19.7 ± 1.23 岁）接受了 2 周的甜菜碱（B）（1.25 g BID）或安慰剂（P）补充。在 2 周洗脱期后，受试者接受了另一种治疗（B 或 P）的补充。在每个 2 周周期前后，受试者进行了急性运动（AES）。测量循环 GH、IGF-1、皮质醇和胰岛素。检测股外侧肌样本的信号蛋白（Akt、p70 S6k、AMPK）。B（与 P 相比）补充接近显著增加 GH（平均值 ± SD（曲线下面积，AUC），B：40.72 ± 6.14，P：38.28 ± 5.54，p = 0.060）和显著增加 IGF-1（平均值 ± SD（AUC），B：106.19 ± 13.45，P：95.10 ± 14.23，p = 0.010），但显著降低皮质醇（平均值 ± SD（AUC），B：1079.18 ± 110.02，P：1228.53 ± 130.32，p = 0.007）。胰岛素（AUC）没有差异。B 增加了静息总肌肉 Akt（p = 0.003）。B 增强了 Akt（Ser(473))和 p70 S6 k（Thr(389)）的磷酸化（与 P 相比）（p = 0.016 和 p = 0.005）。在两种治疗中，AMPK（Thr(172))的磷酸化均降低（均 p = 0.001）。与安慰剂相比，甜菜碱补充增强了合成代谢内分泌谱和相应的合成代谢信号环境，表明蛋白质合成增加。
