Comparison of high-protein diets and leucine supplementation in the prevention of metabolic syndrome and related disorders in mice
Comparison of high-protein diets and leucine supplementation in the prevention of metabolic syndrome and related disorders in mice
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DOI：
10.1016/j.jnutbio.2011.10.005
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发表时间：
2012-11-01
影响因子：
5.6
通讯作者：
Klaus, Susanne
中科院分区：
文献类型：
--
作者：
Freudenberg, Anne;Petzke, Klaus J.;Klaus, Susanne
高蛋白饮食已被证明可以促进体重减轻，改善葡萄糖稳态，增加能量消耗和脂肪氧化。我们的目的是研究补充亮氨酸是否能够模拟高蛋白饮食对高脂肪饮食小鼠代谢综合征参数的缓解作用。雄性C57BL/6小鼠分别饲喂乳清蛋白含量充足（10%蛋白质，AP）或高（50%蛋白质，HP）的半合成高脂肪饲粮（脂肪含量为20% w/w），或在AP饲粮中添加与HP饲粮亮氨酸含量相当的L-亮氨酸（6%亮氨酸，AP+L）。测定大鼠的体重和组成、能量消耗、葡萄糖耐量、肝脏甘油三酯（TG）、血浆参数以及各组织mRNA和蛋白质的表达水平。与AP相比，HP喂养导致体重、体脂和肝脏TG积累减少，胰岛素敏感性增加。这与总能量消耗和静息能量消耗（REE）增加、饲料能量效率降低、骨骼肌（SM）蛋白质合成增加、肝脏脂肪生成减少和白色脂肪分解增加有关。补充亮氨酸对体成分、肝脏TG含量、胰岛素敏感性、稀土元素和饲料能量效率的影响介于HP和AP之间，对SM蛋白合成的影响与HP相似。然而，HP和AP+L均未在SM中激活雷帕霉素途径的哺乳动物靶点。与AP相比，添加亮氨酸对肝脏脂肪生成和白色脂肪分解没有影响。由此可见，必需氨基酸亮氨酸能够模拟HP日粮的部分有益代谢作用，但不是全部。(C) 2012爱思唯尔公司版权所有。
High-protein diets have been shown to promote weight loss, to improve glucose homeostasis and to increase energy expenditure and fat oxidation. We aimed to study whether leucine supplementation is able to mimic the alleviating effects of high-protein diets on metabolic syndrome parameters in mice fed high-fat diet.Male C57BL/6 mice were fed for 20 weeks with semisynthetic high-fat diets (20% w/w of fat) containing either an adequate (10% protein, AP) or high (50% protein, HP) amount of whey protein, or an AP diet supplemented with L-Ieucine corresponding to the leucine content of the HP diet (6% leucine, AP+L). Body weight and composition, energy expenditure, glucose tolerance, hepatic triacylglycerols (TG), plasma parameters as well as expression levels of mRNA and proteins in different tissues were measured. HP feeding resulted in decreased body weight, body fat and hepatic TG accumulation, as well as increased insulin sensitivity compared to AP. This was linked to an increased total and resting energy expenditure (REE), decreased feed energy efficiency, increased skeletal muscle (SM) protein synthesis, reduced hepatic lipogenesis and increased white fat lipolysis. Leucine supplementation had effects that were intermediate between HP and AP with regard to body composition, liver TG content, insulin sensitivity, REE and feed energy efficiency, and similar effects as HP on SM protein synthesis. However, neither HP nor AP+L showed an activation of the mammalian target of rapamycin pathway in SM. Leucine supplementation had no effect on liver lipogenesis and white fat lipolysis compared to AP. It is concluded that the essential amino acid leucine is able to mimic part but not all beneficial metabolic effects of HP diets. (C) 2012 Elsevier Inc. All rights reserved.