BENEFICIAL ROLE OF PHYSICAL ACTIVITY IN COUNTERACTING MUSCULOSKELETAL DISORDERS INDUCED BY EARLY MOVEMENT RESTRICTION
Résumé
Physical hypoactivity during childhood, due to sedentary lifestyle, extended bed rest or developmental coordination disorders, induces sensorimotor and behavioral disturbances and increases risk of non-communicable diseases in the future. On the other hand, physical activity is widely recognized for its positive impact on health and is necessary for the harmonious maturation of the neuromuscular system. However, whether physical activity can counteract the deleterious effects of sensorimotor restriction (SMR) remains to be demonstrated. This study aimed to assess whether physical activity can reverse the muscle alterations induced by early SMR in rats. Pups were assigned to Control (CTRL) or SMR groups at birth. SMR was obtained by immobilizing hindlimbs from birth to postnatal day 28 (P28). From P28 to P60, animals were housed in standard (sedentary group, SED) or enriched cages with access to activity wheel one hour/day (activity group, ACT). At P60 hindlimb muscles (soleus – SOL; extensor digitorum longus – EDL; tibialis anterior – TA) were removed to determine morphological parameters by immunohistochemistry. We emphasized a strong atrophy of the SOL in the SMR-SED group compared to CTRL-SED group, that was partially reversed by physical activity (SMR-ACT). Interestingly, activity had no effect on the CTRL group. SOL and TA fibre type was not affected by SMR, whereas a fast-to-slow transition was observed in the EDL of SMR-SED group. In conclusion, early SMR has persistent detrimental effects that are only partially reversed by activity. Nevertheless, physical activity seems to be an interesting countermeasure to reverse some of the changes induced by early RSM.
Domaines
MorphogenèseOrigine | Fichiers produits par l'(les) auteur(s) |
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