Atrophy Resistant vs. Atrophy Susceptible Skeletal Muscles: “aRaS” as a Novel Experimental Paradigm to Study the Mechanisms of Human Disuse Atrophy

Frontiers in Physiology

Edward J. O. Hardy¹  Ken Smith²  Bethan E. Phillips²  Mathew Piasecki²  Philip J. Atherton²  Daniel J. Wilkinson²  Joseph J. Bass²  Thomas B. Inns²  Craig Sale³  Abi Spicer⁴  Robert H. Morris⁴ 

[1] Department of Surgery and Anaesthetics, Royal Derby Hospital, Derby, United Kingdom;MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research and National Institute for Health Research (NIHR), Nottingham Biomedical Research Centre (BRC), University of Nottingham, Nottingham, United Kingdom;Musculoskeletal Physiology Research Group, Sport, Health and Performance Enhancement Research Centre, Nottingham Trent University, Nottingham, United Kingdom;School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom;

关键词: skeletal muscle atrophy;    aRaS;    disuse atrophy;    tibialis anterior muscle;    medial gastrocnemius muscle;   

DOI  :  10.3389/fphys.2021.653060

来源: DOAJ

【 摘 要 】

ObjectiveDisuse atrophy (DA) describes inactivity-induced skeletal muscle loss, through incompletely defined mechanisms. An intriguing observation is that individual muscles exhibit differing degrees of atrophy, despite exhibiting similar anatomical function/locations. We aimed to develop an innovative experimental paradigm to investigate Atrophy Resistant tibialis anterior (TA) and Atrophy Susceptible medial gastrocnemius (MG) muscles (aRaS) with a future view of uncovering central mechanisms.MethodSeven healthy young men (22 ± 1 year) underwent 15 days unilateral leg immobilisation (ULI). Participants had a single leg immobilised using a knee brace and air-boot to fix the leg (75° knee flexion) and ankle in place. Dual-energy X-ray absorptiometry (DXA), MRI and ultrasound scans of the lower leg were taken before and after the immobilisation period to determine changes in muscle mass. Techniques were developed for conchotome and microneedle TA/MG muscle biopsies following immobilisation (both limbs), and preliminary fibre typing analyses was conducted.ResultsTA/MG muscles displayed comparable fibre type distribution of predominantly type I fibres (TA 67 ± 7%, MG 63 ± 5%). Following 15 days immobilisation, MG muscle volume (–2.8 ± 1.4%, p < 0.05) and muscle thickness decreased (−12.9 ± 1.6%, p < 0.01), with a positive correlation between changes in muscle volume and thickness (R2 = 0.31, p = 0.038). Importantly, both TA muscle volume and thickness remained unchanged.ConclusionThe use of this unique “aRaS” paradigm provides an effective and convenient means by which to study the mechanistic basis of divergent DA susceptibility in humans, which may facilitate new mechanistic insights, and by extension, mitigation of skeletal muscle atrophy during human DA.

【 授权许可】

Unknown