L-Leucine 研究方向

L-亮氨酸拥有单一氨基酸中体量最大的研究文献之一，原因有两条且彼此无关。在细胞生物学中，它是与 mTORC1 营养感应通路联系最紧密的氨基酸，由此形成了独立于营养学之外的结构生物学与分子机制文献；在药剂学中，它是喷雾干燥吸入粉体中被充分表征的辅料。介于两者之间的，是老年人群与运动科学领域一大批存在争议的临床营养文献——其中「单一亮氨酸」与「复配产品」的结果并不一致。

亮氨酸文献中的剂量选择集中在两处：急性肌肉蛋白合成研究中克级的单次剂量，以及老年人群试验中每日数克的摄入量。2024 年一项对 10 名健康年轻男性的指示氨基酸氧化法研究，将亮氨酸平均需要量定为 33.6 mg/kg/天（95% CI 26.2-41.0）。还需注意，同一研究报告较高亮氨酸摄入伴随血浆缬氨酸与异亮氨酸下降——这正是复配产品采用固定比例而非只用亮氨酸的技术依据。若客户询问吸入级，预期对方关注的是粒子工程与杂质，而非仅含量测定的规格。

仅为研究背景。以下每一条描述的是某项已发表研究考察了什么、报告了什么，不构成对本原料的宣称，也不构成对任何成品的宣称。法规与标签口径应由把产品投放市场的品牌方自行判断。

1. A crystallographic study reported the 2.7 angstrom structure of Sestrin2 in complex with leucine and described a single binding pocket with a lid-latch loop; a structure-guided mutation lowering leucine affinity raised the leucine concentration needed to activate mTORC1 in cells. Saxton RA, Knockenhauer KE, Wolfson RL, et al. Science. 2016;351(6268):53-8. PMID 26586190DOI 10.1126/science.aad2087
2. A critical review argued that the theoretical maximum stimulation of post-absorptive muscle protein synthesis from BCAAs alone is bounded by the supply of other essential amino acids, and reported that an extensive literature search identified no human study quantifying the muscle protein synthesis response to orally ingested BCAAs alone. Wolfe RR. J Int Soc Sports Nutr. 2017;14:30. PMID 28852372DOI 10.1186/s12970-017-0184-9
3. A narrative review critically examined the acute and longitudinal literature on isolated leucine and BCAA supplementation for muscular strength and hypertrophy and described the efficacy of BCAAs as an ongoing source of controversy in sports nutrition. Plotkin DL, Delcastillo K, Van Every DW, Tipton KD, Aragon AA, Schoenfeld BJ. Int J Sport Nutr Exerc Metab. 2021;31(3):292-301. PMID 33741748DOI 10.1123/ijsnem.2020-0356
4. A biochemical review examined the evidence for and against an anabolic effect of isolated branched-chain amino acid intake on muscle protein synthesis in humans and described the evidence for BCAAs alone as equivocal. Santos CS, Nascimento FEL. Einstein (Sao Paulo). 2019;17(3):eRB4898. PMID 31508659DOI 10.31744/einstein_journal/2019RB4898
5. A quantitative systematic review reported that ingested leucine dose was associated with the magnitude of the postprandial post-exercise muscle protein synthesis response in older adults but not in younger adults, and that no single plasma leucine variable had substantial predictive capacity. Wilkinson K, Koscien CP, Monteyne AJ, Wall BT, Stephens FB. Physiol Rep. 2023;11(15):e15775. PMID 37537134DOI 10.14814/phy2.15775
6. A systematic review and meta-analysis of 17 randomised controlled trials in 1,418 older adults reported no pooled effect of leucine-isolated supplementation on total lean mass, handgrip strength or leg press, and reported statistically significant pooled differences for handgrip strength and gait speed where leucine was combined with vitamin D. Guo Y, Fu X, Hu Q, Chen L, Zuo H. Front Nutr. 2022;9:929891. PMID 35845777DOI 10.3389/fnut.2022.929891
7. An indicator amino acid oxidation study in ten healthy young adult males tested seven leucine intakes from 10 to 75 mg/kg/day and determined a mean leucine requirement of 33.6 mg/kg/day (95% CI 26.16-41.04), reporting that higher leucine intakes were accompanied by decreased plasma valine and isoleucine. Szwiega S, Pencharz PB, Xu L, et al. Am J Clin Nutr. 2024;120(5):1063-1070. PMID 39209155DOI 10.1016/j.ajcnut.2024.08.022
8. A review surveyed leucine as an excipient in spray-dried inhalation powders, covering its reported effects on aerosolisation and physical stability, the formulation and processing parameters governing its behaviour during drying, and its regulatory status. Alhajj N, O'Reilly NJ, Cathcart H. Drug Discov Today. 2021;26(10):2384-2396. PMID 33872799DOI 10.1016/j.drudis.2021.04.009