氨基酸型营养素药理学机制及作用

氨基酸型营养素不仅参与合成机体蛋白质，还调节患者免疫功能和代谢。氨基酸型营养素包括：谷氨酰胺，能改善肠屏障功能，减轻炎性反应，促进免疫功能恢复，但不同疾病的临床应用仍无一致结论：精氨酸。两种代谢方式相互竞争，对不同疾病具体影响仍需进一步研究；亮氢酸，主要促进肌肉蛋白质合成，对代谢的影响尚存争议；蛋氨酸和半胱氨酸，能促进伤口愈合，对脂质代谢的益处正受重视。本综述回顾上述氨基酸型营养素对机体作用的有益生理机制及其临床应用，并简单介绍不同营养素间及营养素同机体的相互影响。

Pharmacological mechanisms and effects of amino acid nutrients

Common amino acid nutrients mainly contain glutamine, arginine, leucine, methionine and eysteine, which are not only the components participating in body protein synthesis, but also regulate the patients＇ immune system and metabolism. Glutamine can improve the intestinal barrier, reduce inflammatory reaction, and promote immunity recovery, but the clinical effects of different patients with different diseases are still lack of clear conclusions. The catabolism of arginine can produce NO, promoting the inflammatory reaction, and can also generate ornithine, alleviating inflammatory reaction and promoting wound healing. Two competing ways coexist, but the specific effects on different diseases have no clear conclusions yet. Leucine promotes muscle protein synthesis mainly through mTOR pathway, however, the influence on metabolism is still debating. Sulfur-containing amino acids methionine and cysteine can promote the synthesis of connective tissue and collagen conducive to wound healing, and their beneficial effects on lipid metabolism are of value. The purpose of this review is to cover potential beneficial physiological mechanisms of amino acid nutrients, to describe their results of clinical applications and to evaluate the interactions among individual nutrients or between individual nutrients and body.