title: Vitamin C administration attenuates overload-induced skeletal muscle hypertrophy in rats.
abstract: OBJECTIVE
  This study aimed to investigate the effects of vitamin C administration on skeletal muscle hypertrophy induced by mechanical overload in rats.
  
  
  METHODS
  Male Wistar rats were randomly assigned to three groups: (i) sham-operated group (n = 8), (ii) placebo-administered group (n = 8) and (iii) vitamin C-administered group (n = 8). In the placebo-administered and vitamin C-administered groups, the gastrocnemius and soleus muscles of the right hindlimb were surgically removed to overload the plantaris muscle. Vitamin C (500 mg kg(-1)) was orally administered to the vitamin C-administered group once a day for 14 days.
  
  
  RESULTS
  Synergist muscle ablation caused significant increases in wet weight and protein concentration of the plantaris muscle in both the placebo-administered (P < 0.01) and vitamin C-administered groups (P < 0.01) compared with the sham-operated group (SHA). However, the magnitude of plantaris muscle hypertrophy (expressed as a percentage of the contralateral plantaris muscle) was significantly smaller (P < 0.01) in the vitamin C-administered group (141%) than in the placebo-administered group (PLA) (152%). Compared with the SHA, only the PLA showed higher expressions of phosphorylated p70s6k and Erk1/2 (positive regulators of muscle protein synthesis) and a lower expression of atrogin-1 (a muscle atrophy marker). Concentrations of vitamin C and oxidative stress markers in the overloaded muscle were similar between the placebo-administered and vitamin C-administered groups.
  
  
  CONCLUSIONS
  Oral vitamin C administration can attenuate overload-induced skeletal muscle hypertrophy, which may have implications for antioxidant supplementation during exercise training.
authors.affiliation: Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan. maka9696@hotmail.com
authors.forename: Y
authors.initials: Y
authors.lastname: Makanae
authors.forename: S
authors.initials: S
authors.lastname: Kawada
authors.forename: K
authors.initials: K
authors.lastname: Sasaki
authors.forename: K
authors.initials: K
authors.lastname: Nakazato
authors.forename: N
authors.initials: N
authors.lastname: Ishii
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D006614:Hindlimb; D006984:Hypertrophy; D008297:Male; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D009119:Muscle Contraction; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D009929:Organ Size; D018384:Oxidative Stress / Q000187:drug effects; D010766:Phosphorylation; D005082:Physical Exertion; D051381:Rats; D017208:Rats, Wistar; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000378:metabolism; D044843:SKP Cullin F-Box Protein Ligases / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors
chemical_list: D000975:Antioxidants; D009124:Muscle Proteins; C486692:Fbxo32 protein, rat; D044843:SKP Cullin F-Box Protein Ligases; D038762:Ribosomal Protein S6 Kinases, 70-kDa; C535149:Mapk1 protein, rat; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D001205:Ascorbic Acid