Wang Bei, Ding Zhenping, Wang Wanyi, Hwang Jungyun, Liao Yi-Hung, Ivy John L
Department of Kinesiology and Health Education, Exercise Physiology and Metabolism Laboratory, University of Texas at Austin, Austin, TX, USA,
Eur J Appl Physiol. 2015 Jun;115(6):1283-94. doi: 10.1007/s00421-015-3098-8. Epub 2015 Jan 20.
We previously reported that an amino acid mixture (AA) was able to lower the glucose response to an oral glucose challenge in both rats and humans. Increased glucose uptake and glycogen storage in muscle might be associated with the faster blood glucose clearance. We therefore tested the effect of two different doses of AA provided with a carbohydrate supplement on blood glucose homeostasis and muscle glycogen replenishment in human subjects after strenuous aerobic exercise.
Ten subjects received a carbohydrate (1.2 g/kg body weight, CHO), CHO/HAA (CHO + 13 g AA), or CHO/LAA (CHO + 6.5 g AA) supplement immediately and 2 h after an intense cycling bout. Muscle biopsies were performed immediately and 4 h after exercise.
The glucose responses for CHO/HAA and CHO/LAA during recovery were significantly lower than CHO, as was the glucose area under the curve (CHO/HAA 1259.9 ± 27.7, CHO/LAA 1251.5 ± 47.7, CHO 1376.8 ± 52.9 mmol/L 4 h, p < 0.05). Glycogen storage rate was significantly lower in CHO/HAA compared with CHO, while it did not differ significantly between CHO/LAA or CHO (CHO/HAA 15.4 ± 2.0, CHO/LAA 18.1 ± 2.0, CHO 21.5 ± 1.4 µmol/g wet muscle 4 h). CHO/HAA caused a significantly higher insulin response and a greater effect on mTOR and Akt/PKB phosphorylation compared with CHO. Phosphorylation of AS160 and glycogen synthase did not differ across treatments. Likewise, there were no differences in blood lactate across treatments.
The AA lowered the glucose response to a carbohydrate supplement after strenuous exercise. However, it was not effective in facilitating subsequent muscle glycogen storage.
我们之前报道过，一种氨基酸混合物（AA）能够降低大鼠和人类口服葡萄糖激发试验后的血糖反应。肌肉中葡萄糖摄取和糖原储存的增加可能与更快的血糖清除有关。因此，我们测试了在剧烈有氧运动后，两种不同剂量的AA与碳水化合物补充剂一起使用对人体受试者血糖稳态和肌肉糖原补充的影响。
十名受试者在剧烈骑行运动后立即和2小时后接受碳水化合物（1.2克/千克体重，CHO）、CHO/HAA（CHO + 13克AA）或CHO/LAA（CHO + 6.5克AA）补充剂。运动后立即和4小时进行肌肉活检。
恢复期间CHO/HAA和CHO/LAA的葡萄糖反应显著低于CHO，曲线下葡萄糖面积也是如此（CHO/HAA 1259.9±27.7，CHO/LAA 1251.5±47.7，CHO 1376.8±52.9毫摩尔/升4小时，p<0.05）。与CHO相比，CHO/HAA中的糖原储存率显著降低，而CHO/LAA和CHO之间没有显著差异（CHO/HAA 15.4±2.0，CHO/LAA 18.1±2.0，CHO 21.5±1.4微摩尔/克湿肌肉4小时）。与CHO相比，CHO/HAA引起显著更高的胰岛素反应以及对mTOR和Akt/PKB磷酸化的更大影响。AS160和糖原合酶的磷酸化在各治疗组之间没有差异。同样，各治疗组之间的血乳酸也没有差异。
AA降低了剧烈运动后碳水化合物补充剂的葡萄糖反应。然而，它在促进随后的肌肉糖原储存方面无效。
