Fuente: PubMed "industrial biotechnology" J Int Soc Sports Nutr. 2025 Dec 31;22(1):2590102. doi: 10.1080/15502783.2025.2590102. Epub 2025 Nov 30.ABSTRACTBACKGROUND: Amino acids activate neutrophil phagocytosis and free radical release in vitro.AIM: We examined the effects of amino acid supplementation on post-exercise accumulation of myeloperoxidase-positive (MPO⁺) cells in human skeletal muscle using a randomized, double-blind, placebo-controlled crossover design.METHODS: Ten young men (22 ± 2.8 years) consumed either amino acids (15 g) or an isocaloric placebo before resistance exercise. Biopsies of the vastus lateralis muscle were collected at baseline, immediately after exercise (0 h), and 24 h post-exercise.RESULTS: Resistance exercise increased MPO⁺ cell infiltration (+161%, p = 0.02) and 8-hydroxy-2-deoxyguanosine (8-OHdG) levels (+66%, p = 0.02) at 24 h. Amino acid supplementation accelerated MPO⁺ cell infiltration to 0 h (+100%, p = 0.03), which diminished by 24 h post-exercise (+53%, p = 0.06). Immunofluorescence co-staining revealed that MPO⁺ cells exhibited markedly higher mitochondrial density (TOM20-labeled) and integrated with the injured regions of adjacent myofibers showing lower mitochondria. Other infiltrating MPO-negative cells also contributed mitochondria to exercised muscle tissue, resulting in an overall ~2-fold increase in mitochondrial content during 24-h recovery (p < 0.001), similar under both supplementation conditions. Cellular senescence marker p16Ink4a mRNA decreased by 58% at 24 h post-exercise, with an earlier reduction observed under amino acid treatment (0 h: -49%, p = 0.05).CONCLUSION: These findings indicate that amino acid supplementation accelerates the resolution of inflammation in exercised human skeletal muscle. Immunofluorescence evidence further suggests that infiltrating bone marrow-derived cells contribute to fast mitochondrial gains as part of the muscle damage-response following exercise.PMID:41320288 | DOI:10.1080/15502783.2025.2590102