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High Final Energy of Low‐Level Gallium Arsenide Laser Therapy Enhances Skeletal Muscle Recovery without a Positive Effect on Collagen Remodeling
Author(s) -
Freitas Carlos Eduardo Assumpção,
Bertaglia Raquel Santilone,
Vechetti Júnior Ivan José,
Mareco Edson Assunção,
Salomão Rondinelle Artur Simões,
Paula Tassiana Gutierrez,
Nai Gisele Alborghetti,
Carvalho Robson Francisco,
Pacagnelli Francis Lopes,
DalPaiSilva Maeli
Publication year - 2015
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/php.12446
Subject(s) - myogenin , myod , skeletal muscle , extracellular matrix , low level laser therapy , wound healing , lesion , chemistry , medicine , muscle tissue , laser , endocrinology , pathology , surgery , laser therapy , myogenesis , biochemistry , physics , optics
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.