Neuromuscular deconditioning with disuse: should we live more on our nerves?
| Autor: | Marco V, Narici |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
muscle atrophy
Adult Male myosin myosin heavy chain nerve cell adhesion molecule bed rest fast muscle human immobilization muscle denervation neuromuscular system nonhuman Note priority journal quadriceps femoris muscle spinal cord injury denervation disuse neural cell adhesion molecule (NCAM) bed rest Myosins nerve cell adhesion molecule Isometric Contraction Humans Muscle Skeletal Weightlessness Elasticity Muscle Perspectives |
| Popis: | Our study contributes to the characterization of muscle loss and weakness processes induced by a sedentary life style, chronic hypoactivity, clinical bed rest, immobilization and microgravity. This study, by bringing together integrated and cellular evaluation of muscle structure and function, identifies the early functional markers and biomarkers of muscle deconditioning. Three days of muscle disuse in healthy adult subjects is sufficient to significantly decrease muscle mass, tone and force, and to induce changes in function relating to a weakness in aerobic metabolism and muscle fibre denervation. The outcomes of this study should be considered in the development of an early muscle loss prevention programme and/or the development of pre-conditioning programmes required before clinical bed rest, immobilization and spaceflight travel.Microgravity and hypoactivity are associated with skeletal muscle deconditioning. The decrease of muscle mass follows an exponential decay, with major changes in the first days. The purpose of the study was to dissect out the effects of a short-term 3-day dry immersion (DI) on human quadriceps muscle function and structure. The DI model, by suppressing all support zones, accurately reproduces the effects of microgravity. Twelve healthy volunteers (32 ± 5 years) completed 3 days of DI. Muscle function was investigated through maximal voluntary contraction (MVC) tests and muscle viscoelasticity. Structural experiments were performed using MRI analysis and invasive experiments on muscle fibres. Our results indicated a significant 9.1% decrease of the normalized MVC constant (P = 0.048). Contraction and relaxation modelization kinetics reported modifications related to torque generation (k |
| Databáze: | OpenAIRE |
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