PMID- 18077604
OWN - NLM
STAT- MEDLINE
DCOM- 20080417
LR  - 20211203
IS  - 0363-6143 (Print)
IS  - 0363-6143 (Linking)
VI  - 294
IP  - 2
DP  - 2008 Feb
TI  - Recovery of skeletal muscle mass after extensive injury: positive effects of 
      increased contractile activity.
PG  - C467-76
AB  - 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 
      p70(s6k), 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.
FAU - Richard-Bulteau, Helene
AU  - Richard-Bulteau H
AD  - Centre de Recherches du Service de Sante des Armees, La Tronche, France.
FAU - Serrurier, Bernard
AU  - Serrurier B
FAU - Crassous, Brigitte
AU  - Crassous B
FAU - Banzet, Sebastien
AU  - Banzet S
FAU - Peinnequin, Andre
AU  - Peinnequin A
FAU - Bigard, Xavier
AU  - Bigard X
FAU - Koulmann, Nathalie
AU  - Koulmann N
LA  - eng
PT  - Journal Article
DEP - 20071212
PL  - United States
TA  - Am J Physiol Cell Physiol
JT  - American journal of physiology. Cell physiology
JID - 100901225
RN  - 0 (Elapid Venoms)
RN  - 0 (Eukaryotic Initiation Factor-4E)
RN  - 0 (Muscle Proteins)
RN  - 0 (MyoD Protein)
RN  - 0 (MyoD1 myogenic differentiation protein)
RN  - 0 (Neurotoxins)
RN  - 0 (Proliferating Cell Nuclear Antigen)
RN  - 37223-96-4 (notexin)
RN  - EC 2.7.- (Protein Kinases)
RN  - EC 2.7.11.1 (Proto-Oncogene Proteins c-akt)
RN  - EC 2.7.11.1 (Ribosomal Protein S6 Kinases, 70-kDa)
RN  - EC 2.7.11.1 (TOR Serine-Threonine Kinases)
SB  - IM
MH  - Animals
MH  - Elapid Venoms
MH  - Eukaryotic Initiation Factor-4E/metabolism
MH  - Exercise Therapy
MH  - Female
MH  - Muscle Contraction/*physiology
MH  - Muscle Fibers, Skeletal/metabolism
MH  - Muscle Proteins/*metabolism
MH  - Muscle, Skeletal/immunology/*injuries/*metabolism/physiology
MH  - MyoD Protein/metabolism
MH  - Neurotoxins
MH  - Phosphorylation
MH  - Physical Conditioning, Animal/physiology
MH  - Proliferating Cell Nuclear Antigen/metabolism
MH  - Protein Kinases/metabolism
MH  - Proto-Oncogene Proteins c-akt/metabolism
MH  - Rats
MH  - Rats, Wistar
MH  - Recovery of Function/*physiology
MH  - Regeneration/*physiology
MH  - Ribosomal Protein S6 Kinases, 70-kDa/metabolism
MH  - TOR Serine-Threonine Kinases
MH  - Up-Regulation/physiology
EDAT- 2007/12/14 09:00
MHDA- 2008/04/18 09:00
CRDT- 2007/12/14 09:00
PHST- 2007/12/14 09:00 [pubmed]
PHST- 2008/04/18 09:00 [medline]
PHST- 2007/12/14 09:00 [entrez]
AID - 00355.2007 [pii]
AID - 10.1152/ajpcell.00355.2007 [doi]
PST - ppublish
SO  - Am J Physiol Cell Physiol. 2008 Feb;294(2):C467-76. doi: 
      10.1152/ajpcell.00355.2007. Epub 2007 Dec 12.