Branched‐chain amino acids (BCAAs) appear to influence several synthetic and catabolic cellular signaling cascades leading to altered phenotypes in mammals. BCAAs are most notably known to increase protein synthesis through modulating protein translation, explaining their appeal to resistance and endurance athletes for muscle hypertrophy, expedited recovery, and preservation of lean body mass. In addition to anabolic effects, BCAAs may increase mitochondrial content in skeletal muscle and adipocytes, possibly enhancing oxidative capacity. However, elevated circulating BCAA levels have been correlated with severity of insulin resistance. It is hypothesized that elevated circulating BCAAs observed in insulin resistance may result from dysregulated BCAA degradation. This review summarizes original reports that investigated the ability of BCAAs to alter glucose uptake in consequential cell types and experimental models. The review also discusses the interplay of BCAAs with other metabolic factors, and the role of excess lipid (and possibly energy excess) in the dysregulation of BCAA catabolism. Lastly, this article provides a working hypothesis of the mechanism(s) by which lipids may contribute to altered BCAA catabolism, which often accompanies metabolic disease.

中文翻译：

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BCAA代谢和胰岛素敏感性–是否受代谢状态调节？

支链氨基酸（BCAA）似乎会影响几种合成的和分解代谢的细胞信号传导级联反应，从而导致哺乳动物的表型发生变化。BCAA最著名的是通过调节蛋白质翻译来增加蛋白质合成，这说明它们对抵抗力和耐力运动员的肌肉肥大，加快恢复速度和保持瘦体重具有吸引力。除合成代谢作用外，BCAA还可能增加骨骼肌和脂肪细胞中的线粒体含量，可能增强氧化能力。但是，循环中的BCAA水平升高与胰岛素抵抗的严重程度相关。假设胰岛素抵抗中观察到的循环BCAA升高可能是由于BCAA降解失调导致的。这篇综述总结了原始报告，这些报告调查了BCAAs改变相应细胞类型和实验模型中葡萄糖摄取的能力。该评论还讨论了BCAA与其他代谢因子的相互作用，以及过多的脂质（可能还有能量过多）在BCAA分解代谢失调中的作用。最后，本文提供了脂质可能导致改变的BCAA分解代谢（通常伴随代谢性疾病）的机制的有效假设。