A focus on leucine in the nutritional regulation of human skeletal muscle metabolism in ageing, exercise and unloading states.

Autor: Ely IA; Centre of Metabolism, Ageing & Physiology (COMAP), MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham NIHR Biomedical Research Centre, Derby, DE22 3DT, UK., Phillips BE; Centre of Metabolism, Ageing & Physiology (COMAP), MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham NIHR Biomedical Research Centre, Derby, DE22 3DT, UK., Smith K; Centre of Metabolism, Ageing & Physiology (COMAP), MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham NIHR Biomedical Research Centre, Derby, DE22 3DT, UK., Wilkinson DJ; Centre of Metabolism, Ageing & Physiology (COMAP), MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham NIHR Biomedical Research Centre, Derby, DE22 3DT, UK., Piasecki M; Centre of Metabolism, Ageing & Physiology (COMAP), MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham NIHR Biomedical Research Centre, Derby, DE22 3DT, UK., Breen L; School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK., Larsen MS; Arla Foods Ingredients Group P/S, Denmark., Atherton PJ; Centre of Metabolism, Ageing & Physiology (COMAP), MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and Nottingham NIHR Biomedical Research Centre, Derby, DE22 3DT, UK. Electronic address: philip.atherton@nottingham.ac.uk.
Jazyk: angličtina
Zdroj: Clinical nutrition (Edinburgh, Scotland) [Clin Nutr] 2023 Oct; Vol. 42 (10), pp. 1849-1865. Date of Electronic Publication: 2023 Aug 12.
DOI: 10.1016/j.clnu.2023.08.010
Abstrakt: Muscle protein synthesis (MPS) and muscle protein breakdown (MPB) are influenced through dietary protein intake and physical (in)activity, which it follows, regulate skeletal muscle (SKM) mass across the lifespan. Following consumption of dietary protein, the bio-availability of essential amino acids (EAA), and primarily leucine (LEU), drive a transient increase in MPS with an ensuing refractory period before the next MPS stimulation is possible (due to the "muscle full" state). At the same time, MPB is periodically constrained via reflex insulin actions. Layering exercise on top of protein intake increases the sensitivity of SKM to EAA, therefore extending the muscle full set-point (∼48 h), to permit long-term remodelling (e.g., hypertrophy). In contrast, ageing and physical inactivity are associated with a premature muscle full set-point in response to dietary protein/EAA and contractile activity. Of all the EAA, LEU is the most potent stimulator of the mechanistic target of rapamycin complex 1 (mTORC1)-signalling pathway, with the phosphorylation of mTORC1 substrates increasing ∼3-fold more than with all other EAA. Furthermore, maximal MPS stimulation is also achieved following low doses of LEU-enriched protein/EAA, negating the need for larger protein doses. As a result, LEU supplementation has been of long term interest to maximise muscle anabolism and subsequent net protein accretion, especially when in tandem with resistance exercise. This review highlights current knowledge vis-à-vis the anabolic effects of LEU supplementation in isolation, and in enriched protein/EAA sources (i.e., EAA and/or protein sources with added LEU), in the context of ageing, exercise and unloading states.
Competing Interests: Conflict of Interest The authors declare no conflict of interests. Bethan E Phillips has received research funding from Abbott Nutrition and Arla Foods Ltd. Leigh Breen has received speaking/consultancy honoraria from Dairy UK and the European Whey Processors Association and research grant funding from Volac LTD, Myprotein and Biomega Ltd. Philip J Atherton has received consultancy and research funding from Abbott Nutrition, Arla Foods Ltd and Fresenius-Kabi.
(Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)
Databáze: MEDLINE
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