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Early Deconditioning of Human Skeletal Muscles and the Effects of a Thigh Cuff Countermeasure
- Source :
- International Journal of Molecular Sciences, International Journal of Molecular Sciences, 2021, 22 (21), 19p. ⟨10.3390/ijms222112064⟩, International Journal of Molecular Sciences, MDPI, 2021, 22 (21), 19p. ⟨10.3390/ijms222112064⟩, International Journal of Molecular Sciences, Vol 22, Iss 12064, p 12064 (2021), Volume 22, Issue 21
- Publication Year :
- 2021
- Publisher :
- MDPI, 2021.
-
Abstract
- Le déconditionnement musculaire se produit suite à l'inactivité (vols spatiaux, sédentarité). Les changements apparaissant les premiers jours seraient déterminants pour mettre au point des méthodes de prévention. Une expérience d'immersion sèche de 5 jours a été menée au CNES. Dix-huit volontaires ont été divisés en groupe « témoin » et groupe avec une contremesure vasculaire, un brassard de cuisse ou « cuffs ». Des biopsies musculaires ont été réalisées sur le vaste latéral. La force de contraction du genou (MVC) diminue de 17% et la section transversale des fibres musculaires de 22%. L'équilibre protéique est altéré (activation réduite de la voie mTOR), ainsi que la capacité oxydative (diminution des niveaux de PGC1-α). L'utilisation des cuffs n'a pas empêché le déconditionnement. Ces résultats devraient permettre une meilleure compréhension de la fonte musculaire lors des maladies musculaires, du vieillissement etc... Muscle deconditioning is a major consequence of a wide range of conditions from spaceflight to a sedentary lifestyle, and occurs as a result of muscle inactivity, leading to a rapid decrease in muscle strength, mass, and oxidative capacity. The early changes that appear in the first days of inactivity must be studied to determine effective methods for the prevention of muscle deconditioning. To evaluate the mechanisms of muscle early changes and the vascular effect of a thigh cuff, a five-day dry immersion (DI) experiment was conducted by the French Space Agency at the MEDES Space Clinic (Rangueil, Toulouse). Eighteen healthy males were recruited and divided into a control group and a thigh cuff group, who wore a thigh cuff at 30 mmHg. All participants underwent five days of DI. Prior to and at the end of the DI, the lower limb maximal strength was measured and muscle biopsies were collected from the vastus lateralis muscle. Five days of DI resulted in muscle deconditioning in both groups. The maximal voluntary isometric contraction of knee extension decreased significantly. The muscle fiber cross-sectional area decreased significantly by 21.8%, and the protein balance seems to be impaired, as shown by the reduced activation of the mTOR pathway. Measurements of skinned muscle fibers supported these results and potential changes in oxidative capacity were highlighted by a decrease in PGC1-α levels. The use of the thigh cuff did not prevent muscle deconditioning or impact muscle function. These results suggest that the major effects of muscle deconditioning occur during the first few days of inactivity, and countermeasures against muscle deconditioning should target this time period. These results are also relevant for the understanding of muscle weakness induced by muscle diseases, aging, and patients in intensive care. 22;21
- Subjects :
- Male
[SDV]Life Sciences [q-bio]
Isometric exercise
Thigh
law.invention
Dry immersion
0302 clinical medicine
Deconditioning
law
Countermeasure
Biology (General)
Spectroscopy
0303 health sciences
General Medicine
Thigh cuff
3. Good health
Computer Science Applications
Chemistry
Muscular Atrophy
medicine.anatomical_structure
Muscle deconditioning
Anesthesia
Cuff
medicine.symptom
Adult
Restraint, Physical
QH301-705.5
Vastus lateralis muscle
Spaceflight
Article
Catalysis
Inorganic Chemistry
03 medical and health sciences
Intensive care
Isometric Contraction
medicine
Humans
Muscle Strength
Physical and Theoretical Chemistry
countermeasure
dry immersion
muscle deconditioning
spaceflight
thigh cuff
Muscle, Skeletal
QD1-999
Molecular Biology
030304 developmental biology
business.industry
Organic Chemistry
Muscle weakness
Space Flight
Case-Control Studies
Sedentary Behavior
business
030217 neurology & neurosurgery
Subjects
Details
- Language :
- English
- ISSN :
- 16616596 and 14220067
- Database :
- OpenAIRE
- Journal :
- International Journal of Molecular Sciences, International Journal of Molecular Sciences, 2021, 22 (21), 19p. ⟨10.3390/ijms222112064⟩, International Journal of Molecular Sciences, MDPI, 2021, 22 (21), 19p. ⟨10.3390/ijms222112064⟩, International Journal of Molecular Sciences, Vol 22, Iss 12064, p 12064 (2021), Volume 22, Issue 21
- Accession number :
- edsair.doi.dedup.....e9573bdbcfe1f0cdd0e6eeb8b70ad694