title: Musculoskeletal Atrophy in an Experimental Model of Knee Osteoarthritis: The Effects of Exercise Training and Low-Level Laser Therapy.
abstract: OBJECTIVE
  The aim of this study was to evaluate the effects of an exercise training protocol and low-level laser therapy (and the association of both treatments) on musculoskeletal atrophy using an experimental model of knee osteoarthritis (OA).
  
  
  METHODS
  Fifty male Wistar rats were randomly divided into five groups: control group, knee OA control group, OA plus exercise training group, OA plus low-level laser therapy group, and OA plus exercise training associated with low-level laser therapy group. The exercise training and the laser irradiation started 4 wks after the surgery, 3 days per week for 8 wks. The exercise was performed at a speed of 16 m/min, 3 days per week, 50 mins per day, for 8 wks. Laser irradiation was applied at two points of the left knee joint (medial and lateral), for 24 sessions.
  
  
  RESULTS
  The results showed that both trained groups (irradiated or not) presented a significant increase in the muscle cross-sectional area and a decrease in muscle fiber density compared with the knee OA control group. Moreover, both trained and laser-irradiated groups demonstrated decreased muscle-specific ring-finger protein 1 and atrogin-1 immunoexpression.
  
  
  CONCLUSIONS
  These results suggest that exercise training and low-level laser therapy were effective in preventing musculoskeletal alterations related to atrophy caused by the degenerative process induced by knee OA.
authors.affiliation: From the Department of Bioscience, Federal University of São Paulo, Santos, Sao Paulo, Brazil.
authors.forename: Livia
authors.initials: L
authors.lastname: Assis
authors.forename: Thais
authors.initials: T
authors.lastname: Almeida
authors.forename: Luiz Paulo
authors.initials: LP
authors.lastname: Milares
authors.forename: Nayara
authors.initials: N
authors.lastname: dos Passos
authors.forename: Bruna
authors.initials: B
authors.lastname: Araújo
authors.forename: Caroline
authors.initials: C
authors.lastname: Bublitz
authors.forename: Suellen
authors.initials: S
authors.lastname: Veronez
authors.forename: Ana Claudia Muniz
authors.initials: AC
authors.lastname: Renno
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D003131:Combined Modality Therapy; D007150:Immunohistochemistry; D028022:Low-Level Light Therapy; D008297:Male; D008853:Microscopy; D023421:Models, Animal; D018485:Muscle Fibers, Skeletal / Q000378:metabolism / Q000473:pathology; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000473:pathology; D009133:Muscular Atrophy / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D020370:Osteoarthritis, Knee / Q000150:complications*; D010805:Physical Conditioning, Animal; D063150:Polycomb Repressive Complex 1 / Q000378:metabolism; D011897:Random Allocation; D017208:Rats, Wistar; D044843:SKP Cullin F-Box Protein Ligases / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism
chemical_list: D009124:Muscle Proteins; C486691:Fbxo32 protein, mouse; D063150:Polycomb Repressive Complex 1; C570469:Ring1 protein, rat; D044843:SKP Cullin F-Box Protein Ligases; D044767:Ubiquitin-Protein Ligases