Potential importance of leucine in treatment of obesity and the metabolic syndrome
Potential importance of leucine in treatment of obesity and the metabolic syndrome
复制标题
DOI：
10.1093/jn/136.1.319s
复制
发表时间：
2006-01-01
影响因子：
4.2
通讯作者：
Walker, DA
中科院分区：
文献类型：
--
作者：
Layman, DK;Walker, DA
总蛋白质摄入量> 1.5 g.kg(-1).d(-1) 和碳水化合物摄入量< 150 g/d 的饮食可有效治疗肥胖、2 型糖尿病和代谢综合征。这些饮食可以改善身体成分并增强血糖控制。在减肥过程中，富含蛋白质的饮食可以减少瘦肉组织的损失并增加体内脂肪的损失。解释这些临床结果的具体机制仍有待充分阐明。我们认为，理解膳食蛋白质和碳水化合物之间关系的关键是支链氨基酸亮氨酸与胰岛素和葡萄糖代谢之间的关系。已知亮氨酸与胰岛素信号通路相互作用，刺激蛋白质合成的下游信号控制，从而在能量摄入受限期间维持肌肉蛋白质。亮氨酸似乎还可以调节骨骼肌的胰岛素信号传导和葡萄糖使用。虽然总蛋白对于提供糖异生的底物很重要，但亮氨酸似乎通过葡萄糖-丙氨酸循环刺激葡萄糖循环来调节骨骼肌对葡萄糖的氧化利用。这些机制产生蛋白质节约，并在能量限制期间提供稳定的葡萄糖环境和低胰岛素反应。
Diets with total protein intake > 1.5 g.kg(-1).d(-1) and carbohydrate intake < 150 g/d are effective for treatment of obesity, type 2 diabetes, and the Metabolic Syndrome. These diets improve body composition and enhance glycemic control. During weight loss, protein-rich diets reduce loss of lean tissue and increase loss of body fat. Specific mechanisms to explain each of these clinical outcomes remain to be fully elucidated. We propose that keys to understanding the relationship between dietary protein and carbohydrates are the relationships between the branched-chain amino acid leucine and insulin and glucose metabolism. Leucine is known to interact with the insulin signaling pathway to stimulate downstream signal control of protein synthesis, resulting in maintenance of muscle protein during periods of restricted energy intake. Leucine also appears to modulate insulin signaling and glucose use by skeletal muscle. Whereas total protein is important in providing substrates for gluconeogenesis, leucine appears to regulate oxidative use of glucose by skeletal muscle through stimulation of glucose recycling via the glucose-alanine cycle. These mechanisms produce protein sparing and provide a stable glucose environment with low insulin responses during energy-restricted periods.