High Final Energy of Low-Level Gallium Arsenide Laser Therapy Enhances Skeletal Muscle Recovery without a Positive Effect on Collagen Remodeling.
The aim of this study was to evaluate the effects of a Gallium Arsenide (GaAs) laser, using a high final energy of 4.8 J, during muscle regeneration after cryoinjury. Thirty Wistar rats were divided into three groups: Control (C, n = 10); Injured (I, n = 10) and Injured and laser treated (Injured/LLLT, n = 10). The cryoinjury was induced in the central region of the tibialis anterior muscle (TA). The applications of the laser (904 nm, 50 mW average power) were initiated 24 h after injury, at energy density of 69 J cm(-1) for 48 s, for 5 days, to two points of the lesion. Twenty-four hours after the final application, the TA muscle was removed and frozen in liquid nitrogen to assess the general muscle morphology and the gene expression of TNF-α, TGF-β, MyoD, and Myogenin. The Injured/LLLT group presented a higher number of regenerating fibers and fewer degenerating fibers (P < 0.05) without changes in the collagen remodeling. In addition, the Injured/LLLT group presented a significant decrease in the expression of TNF-α and myogenin compared to the injured group (P < 0.05). The results suggest that the GaAs laser, using a high final energy after cryoinjury, promotes muscle recovery without changing the collagen remodeling in the muscle extracellular matrix.
Post Graduate Program in General and Applied Biology, Bioscience Institute, State University of São Paulo, UNESP, Botucatu, SP, Brazil.|Department of Physiotherapy, University of Oeste Paulista (UNOESTE), Presidente Prudente, SP, Brazil.
Carlos Eduardo Assumpção
CE
de Freitas
Post Graduate Program in General and Applied Biology, Bioscience Institute, State University of São Paulo, UNESP, Botucatu, SP, Brazil.
Raquel Santilone
RS
Bertaglia
Post Graduate Program in General and Applied Biology, Bioscience Institute, State University of São Paulo, UNESP, Botucatu, SP, Brazil.
Ivan José
IJ
Vechetti Júnior
Post Graduate Program in General and Applied Biology, Bioscience Institute, State University of São Paulo, UNESP, Botucatu, SP, Brazil.
Edson Assunção
EA
Mareco
Post Graduate Program in General and Applied Biology, Bioscience Institute, State University of São Paulo, UNESP, Botucatu, SP, Brazil.
Rondinelle Artur Simões
RA
Salomão
Post Graduate Program in General and Applied Biology, Bioscience Institute, State University of São Paulo, UNESP, Botucatu, SP, Brazil.
Tassiana Gutierrez
TG
de Paula
Department of Pathology, University of Oeste Paulista (UNOESTE), Presidente Prudente, SP, Brazil.
Gisele Alborghetti
GA
Nai
Department of Morphology, Bioscience Institute State University of São Paulo, UNESP, Botucatu, SP, Brazil.
Robson Francisco
RF
Carvalho
Department of Physiotherapy, University of Oeste Paulista (UNOESTE), Presidente Prudente, SP, Brazil.
Francis Lopes
FL
Pacagnelli
Department of Morphology, Bioscience Institute State University of São Paulo, UNESP, Botucatu, SP, Brazil.
Maeli
M
Dal-Pai-Silva
D000818:Animals; D001152:Arsenicals / Q000627:therapeutic use*; D003094:Collagen / Q000378:metabolism*; D005708:Gallium / Q000627:therapeutic use*; D053685:Laser Therapy; D008297:Male; D018482:Muscle, Skeletal / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D001152:Arsenicals; C043055:gallium arsenide; D003094:Collagen; D005708:Gallium