The Effect of Leucine-Enriched Essential Amino Acid Supplementation on Anabolic and Catabolic Signaling in Human Skeletal Muscle after Acute Resistance Exercise: A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Comparison Trial.

• 影响指数: 6.706
• 发表时间: Aug 2020 12
• 来源期刊: Nutrients
• DOI: 10.3390/nu12082421
• PMID: 32806711
• 文章类型: Journal Article
• 中科院分区: Q1
• 方向: 医学
• 作者列表: Takegaki J,Sase K,Yasuda J,Shindo D,Kato H,Toyoda S,Yamada T,Shinohara Y,Fujita S

关键词: LEAAs; inflammation; mTORC1; resistance exercise; ubiquitin

Mesh: Amino Acids, Essential / pharmacology; Cytokines / metabolism; Dietary Supplements; Double-Blind Method; Exercise / physiology; Healthy Volunteers; Humans; Interleukin-1beta / metabolism; Interleukin-6 / metabolism; Leucine / pharmacology; Male; Mechanistic Target of Rapamycin Complex 1 / metabolism; Muscle Proteins / metabolism; Muscle, Skeletal / metabolism; Phosphorylation / drug effects; RNA, Messenger / metabolism; Resistance Training; SKP Cullin F-Box Protein Ligases / metabolism; Signal Transduction / drug effects; Tripartite Motif Proteins / metabolism; Ubiquitin-Protein Ligases / metabolism; Young Adult

Abstract

Resistance exercise transiently activates anabolic and catabolic systems in skeletal muscle. Leucine-enriched essential amino acids (LEAAs) are reported to stimulate the muscle anabolic response at a lower dose than whey protein. However, little is known regarding the effect of LEAA supplementation on the resistance exercise-induced responses of the anabolic and catabolic systems. Here, we conducted a randomized, double-blind, placebo-controlled, parallel-group comparison trial to investigate the effect of LEAA supplementation on mechanistic target of rapamycin complex 1 (mTORC1), the ubiquitin-proteasome system and inflammatory cytokines after a single bout of resistance exercise in young men. A total of 20 healthy young male subjects were supplemented with either 5 g of LEAA or placebo, and then they performed 10 reps in three sets of leg extensions and leg curls (70% one-repetition maximum). LEAA supplementation augmented the phosphorylation of mTORSer2448 (+77.1%, p < 0.05), p70S6KThr389 (+1067.4%, p < 0.05), rpS6Ser240/244 (+171.3%, p < 0.05) and 4EBP1Thr37/46 (+33.4%, p < 0.05) after resistance exercise. However, LEAA supplementation did not change the response of the ubiquitinated proteins, MuRF-1 and Atrogin-1 expression. Additionally, the mRNA expression of IL-1β and IL-6 did not change. These data indicated that LEAA supplementation augments the effect of resistance exercise by enhancing mTORC1 signal activation after exercise.