Leucine supplementation does not affect protein turnover and impairs the beneficial effects of endurance training on glucose homeostasis in healthy mice
Leucine supplementation does not affect protein turnover and impairs the beneficial effects of endurance training on glucose homeostasis in healthy mice
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DOI：
10.1007/s00726-014-1903-z
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发表时间：
2015-04-01
期刊：
影响因子：
3.5
通讯作者：
Carneiro, Everardo M.
中科院分区：
文献类型：
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作者：
Costa Junior, Jose M.;Rosa, Morgana R.;Carneiro, Everardo M.
耐力运动训练以及亮氨酸补充可调节哺乳动物的葡萄糖稳态和蛋白质周转。在这里，我们分析亮氨酸补充是否会改变耐力运动对健康小鼠这些参数的影响。将小鼠分为久坐组（C）和运动组（T）。锻炼组进行了为期 12 周的游泳方案。在整个实验过程中，一半的 C 和 T 小鼠（指定为 CL 和 TL 组）补充了亮氨酸（1.5% 溶解在饮用水中）。众所周知，耐力运动训练可以减轻体重和腹膜后脂肪垫，增加比目鱼肌质量，增加最大摄氧量，减少肌肉蛋白水解，并改善外周胰岛素敏感性。补充亮氨酸对任何这些参数都没有影响，并且使 CL 和 TL 小鼠的葡萄糖耐量恶化。在T组的比目鱼肌中，在基础条件和胰岛素刺激条件下运动均增加了AS-160（Thr-642）（160 kDa的AKT底物）和AMPK（Thr-172）（AMP激活蛋白激酶）的磷酸化，但与T组相比，在胰岛素刺激的TL小鼠中磷酸化有所减少。 Akt 磷酸化不受运动影响，但与其他组相比，CL 组的磷酸化水平较低。补充亮氨酸会增加基础条件下的 mTOR 磷酸化，而运动会在胰岛素存在的情况下降低 mTOR 磷酸化，尽管蛋白质合成没有改变。在训练组中，FoxO3a 总蛋白含量以及特定亚型 E2 和 E3 连接酶的 mRNA 减少。总之，补充亮氨酸并没有增强耐力训练对蛋白质周转的影响，而且还降低了其对葡萄糖稳态的积极影响。
Endurance exercise training as well as leucine supplementation modulates glucose homeostasis and protein turnover in mammals. Here, we analyze whether leucine supplementation alters the effects of endurance exercise on these parameters in healthy mice. Mice were distributed into sedentary (C) and exercise (T) groups. The exercise group performed a 12-week swimming protocol. Half of the C and T mice, designated as the CL and TL groups, were supplemented with leucine (1.5 % dissolved in the drinking water) throughout the experiment. As well known, endurance exercise training reduced body weight and the retroperitoneal fat pad, increased soleus mass, increased VO2max, decreased muscle proteolysis, and ameliorated peripheral insulin sensitivity. Leucine supplementation had no effect on any of these parameters and worsened glucose tolerance in both CL and TL mice. In the soleus muscle of the T group, AS-160(Thr-642) (AKT substrate of 160 kDa) and AMPK(Thr-172) (AMP-Activated Protein Kinase) phosphorylation was increased by exercise in both basal and insulin-stimulated conditions, but it was reduced in TL mice with insulin stimulation compared with the T group. Akt phosphorylation was not affected by exercise but was lower in the CL group compared with the other groups. Leucine supplementation increased mTOR phosphorylation at basal conditions, whereas exercise reduced it in the presence of insulin, despite no alterations in protein synthesis. In trained groups, the total FoxO3a protein content and the mRNA for the specific isoforms E2 and E3 ligases were reduced. In conclusion, leucine supplementation did not potentiate the effects of endurance training on protein turnover, and it also reduced its positive effects on glucose homeostasis.