Recovery of skeletal muscle mass after extensive injury: positive effects of increased contractile activity
| Autor: | Nathalie Koulmann, Brigitte Crassous, Sébastien Banzet, Hélène Richard-Bulteau, Xavier Bigard, André Peinnequin, Bernard Serrurier |
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| Přispěvatelé: | Centre de Recherches du Service de Santé des Armées (CRSSA), Service de Santé des Armées, Sinniger, Valérie |
| Rok vydání: | 2008 |
| Předmět: |
Physiology
MESH: Muscle Contraction Muscle Fibers Skeletal Muscle Proteins MESH: Physical Conditioning Animal MESH: Ribosomal Protein S6 Kinases 70-kDa 0302 clinical medicine AMP-activated protein kinase MESH: Up-Regulation MESH: Animals Phosphorylation MESH: Muscle Skeletal 0303 health sciences MESH: Muscle Fibers Skeletal biology TOR Serine-Threonine Kinases MESH: Regeneration Ribosomal Protein S6 Kinases 70-kDa MESH: Recovery of Function MESH: Eukaryotic Initiation Factor-4E Exercise Therapy Up-Regulation Muscle regeneration Female Muscle Contraction medicine.medical_specialty MESH: Rats Neurotoxins Physical activity Muscle mass MESH: Muscle Proteins 03 medical and health sciences Physical Conditioning Animal Proliferating Cell Nuclear Antigen Internal medicine [SDV.BBM] Life Sciences [q-bio]/Biochemistry Molecular Biology medicine Animals Regeneration MESH: Exercise Therapy [SDV.BBM]Life Sciences [q-bio]/Biochemistry Molecular Biology Rats Wistar Muscle Skeletal MESH: Protein Kinases MESH: Elapid Venoms MyoD Protein MESH: Neurotoxins 030304 developmental biology Elapid Venoms MESH: Phosphorylation MESH: Proto-Oncogene Proteins c-akt MESH: MyoD Protein Recovery of Function MESH: Rats Wistar Cell Biology Skeletal muscle mass Rats Eukaryotic Initiation Factor-4E MESH: Proliferating Cell Nuclear Antigen Endocrinology biology.protein Protein Kinases Proto-Oncogene Proteins c-akt MESH: Female 030217 neurology & neurosurgery |
| Zdroj: | American Journal of Physiology-Cell Physiology American Journal of Physiology-Cell Physiology, American Physiological Society, 2008, 294 (2), pp.C467-76. ⟨10.1152/ajpcell.00355.2007⟩ |
| ISSN: | 1522-1563 0363-6143 |
| DOI: | 10.1152/ajpcell.00355.2007 |
| Popis: | The present study was designed to test the hypothesis that increasing physical activity by running exercise could favor the recovery of muscle mass after extensive injury and to determine the main molecular mechanisms involved. Left soleus muscles of female Wistar rats were degenerated by notexin injection before animals were assigned to either a sedentary group or an exercised group. Both regenerating and contralateral intact muscles from active and sedentary rats were removed 5, 7, 14, 21, 28 and 42 days after injury ( n = 8 rats/group). Increasing contractile activity through running exercise during muscle regeneration ensured the full recovery of muscle mass and muscle cross-sectional area as soon as 21 days after injury, whereas muscle weight remained lower even 42 days postinjury in sedentary rats. Proliferator cell nuclear antigen and MyoD protein expression went on longer in active rats than in sedentary rats. Myogenin protein expression was higher in active animals than in sedentary animals 21 days postinjury. The Akt-mammalian target of rapamycin (mTOR) pathway was activated early during the regeneration process, with further increases of mTOR phosphorylation and its downstream effectors, eukaryotic initiation factor-4E-binding protein-1 and p70s6k, in active rats compared with sedentary rats ( days 7–14). The exercise-induced increase in mTOR phosphorylation, independently of Akt, was associated with decreased levels of phosphorylated AMP-activated protein kinase. Taken together, these results provided evidence that increasing contractile activity during muscle regeneration ensured early and full recovery of muscle mass and suggested that these beneficial effects may be due to a longer proliferative step of myogenic cells and activation of mTOR signaling, independently of Akt, during the maturation step of muscle regeneration. |
| Databáze: | OpenAIRE |
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