Distinct effects of leucine or a mixture of the branched-chain amino acids (leucine, isoleucine, and valine) supplementation on resistance to fatigue, and muscle and liver-glycogen degradation, in trained rats
Distinct effects of leucine or a mixture of the branched-chain amino acids (leucine, isoleucine, and valine) supplementation on resistance to fatigue, and muscle and liver-glycogen degradation, in trained rats
复制标题
DOI：
10.1016/j.nut.2013.05.003
复制
发表时间：
2013-11-01
期刊：
影响因子：
4.4
通讯作者：
Lancha, Antonio Herbert, Jr.
中科院分区：
文献类型：
--
作者：
Campos-Ferraz, Patricia L.;Bozza, Thomas;Lancha, Antonio Herbert, Jr.
目的：本研究的目的是评估支链氨基酸（BCAAs）补充剂的混合物与口服亮氨酸相比对接受运动诱导的糖原消耗方案的训练大鼠的肌肉生化参数的影响。游泳训练6周后，将250 g成年雄性Wistar大鼠随机分为三个实验组（每组n = 8）：BCAAs（BCAAs）、亮氨酸（LEU）和安慰剂（PLA）的混合物。所有组均接受为期6周的游泳训练，并在训练的最后一周补充BCAA、亮氨酸或安慰剂的混合物。在该方案的第7周，对大鼠进行间歇性、渐进性游泳试验，直至力竭并处死。描绘肌肉腓肠肌和肝脏，以确定总糖原，三羧酸循环（TCA）的中间体，和酶活性。结果：BCAAs混合组肌肉和肝糖原降解率均显著高于PLA组（P < 0.05），LEU组肝糖原降解率显著低于BCAAs混合组（P < 0.05）。BCAAs和LEU混合组的肌糖原和肝糖原含量均显著低于PLA组（P < 0.01）。试验结果表明，与BCAAs混合组相比，LEU组的力竭耐力显著提高（P < 0.001），而与PLA组相比，LEU组的力竭耐力无显著性差异（P > 0.05）。与PLA组相比，BCAAs混合组的肌肉柠檬酸含量显著升高（P < 0.001）。BCAAs组肌肉中苹果酸含量显著高于PLA组（P < 0.001）和LEU组（P < 0.001）。结论：与BCAAs混合物组相比，补充亮氨酸组的BCAT活性显著降低（P < 0.001），尽管TCA循环左侧的TCA中间浓度增加，但仍能节省肌糖原储备。(C)2013 Elsevier Inc. All rights reserved.
Objective: The aim of this study was to evaluate the effects of the mixture of branched-chain amino acids (BCAAs) supplementation compared with leucine administered orally on muscle biochemical parameters of trained rats submitted to an exercise-induced protocol of glycogen depletion.Methods: After 6 wk of swimming exercise, 8 wk-old (250 g, adult) male Wistar rats were randomly divided into three experimental groups (n = 8 per group): the mixture of BCAAs (BCAAs), leucine (LEU), and placebo (PLA). All groups were submitted to swimming exercise for 6 wk and supplemented with either the mixture of BCAAs, leucine, or placebo during the last week of training. At week 7 of the protocol, the rats were submitted to an intermittent, progressive swimming test until exhaustion and sacrificed. Muscle gastrocnemius and liver were depicted to determine total glycogen, tricarboxylic acid cycle (TCA) intermediates, and enzymatic activities. Statistical evaluation was performed by one-way analysis of variance with Tukey post hoc test.Results: Both muscle and liver glycogen degradation ratio were significantly higher in the mixture of BCAAs group compared to the PLA group (P < 0.05) and the LEU group presented decreased liver glycogen degradation ratio compared with the mixture of BCAAs group (P < 0.05). Both muscle and liver glycogen content were significantly spared in the mixture of BCAAs and LEU groups compared to the PLA group (P < 0.01). A performance test demonstrated that LEU supplementation enhanced resistance to exhaustion compared to the mixture of BCAAs (P < 0.001), however, no difference was found when LEU supplementation was compared to PLA (P > 0.05) Muscle citrate content was significantly higher in the mixture of BCAAs group compared with the PLA group (P < 0.001). Muscle malate content was significantly elevated in the mixture of BCAAs group compared with both the PLA (P < 0.001) and LEU groups (P < 0.001). BCAT activity was significantly reduced in the mixture of BCAAs supplementation group compared with the LEU group (P < 0.001).Conclusion: Leucine supplementation improved performance compared with the mixture of BCAAs supplementation, sparing muscle glycogen stores despite the augmentation of some TCA intermediate concentrations on the left side of the TCA cycle. (C) 2013 Elsevier Inc. All rights reserved.