Infrared Laser Improves Collagen Organization in Muscle and Tendon Tissue During the Process of Compensatory Overload

Author(s)

Lins Terena, Stella Maris ^[1] ; Santos Fernandes, Kristianne Porta ^[1] ; Bussadori, Sandra Kalil ^[2] ; Brugnera Junior, Aldo ^[3] ; Teixeira da Silva, Daniela de Fatima ^[2] ; Ramos Magalhaes, Eric Moreno ^[1] ; Mesquita Ferrari, Raquel Agnelli ^[2]

Affiliation

^[1] Univ Nove Julho UNINOVE, Dept Biophoton Appl Hlth Sci, Posgrad Program, Sao Paulo - Brazil

^[2] Univ Nove Julho UNINOVE, Dept Rehabil Sci & Biophoton Appl Hlth Sci, Posgrad Program, Rua Vergueiro 235-249, BR-01504001 Sao Paulo - Brazil

^[3] Univ Camilo Castelo Branco, Biomed Engineer Res Ctr, CEB, Sao Paulo - Brazil

• Document type: Journal article
• Source: Photomedicine and Laser Surgery; v. 36, n. 3, p. 130-136, MAR 2018.
• Web of Science Citations: 1

Abstract

Background: The photobiomodulation using the low-level laser therapy (LLLT) exerts a positive modulating effect on the synthesis of collagen in skeletal muscles and tendons. However, few studies have addressed this effect during the compensatory overload. Objective: Evaluate the effect of infrared laser on the deposition and organization of collagen fibers in muscle and tendon tissue during compensatory overload of the plantar muscle in rats. Materials and methods: Wistar rats were submitted to bilateral ablation of the synergist muscles of the hind paws and divided in groups: Control, Hypertrophy, and Hypertrophy (H)+LLLT (780nm, 40mW, 9.6J/cm(2) and 10s/point, 8 points, total energy 3.2J, daily), evaluated at 7 and 14 days. Muscle cuts were stained with Picrosirius-Red and hematoxylin-eosin and tendon cuts were submitted to birefringence for determination of collagen distribution and organization. Results: After 7 days an increase was observed in the area between beam muscles in H+LLLT (25.45%+/- 2.56) in comparison to H (20.3%+/- 3.31), in mature fibers and fibrilis in H+LLLT (29346.88m(2)+/- 2182.56; 47602.8m(2)+/- 2201.86 respectively) in comparison to H (26656.5m(2)+/- 1880.46; 45630.34m(2)+/- 2805.82 respectively) and in the collagen area in H+LLLT (2.25%+/- 0.19) in comparison to H (2.0%+/- 0.15). However, after 14 days a reduction was observed in the area between beam muscles in H+LLLT (13.88%+/- 2.54) in comparison to H (19.1%+/- 2.61), in fibrils and mature fibers in H+LLLT (17174.1m(2)+/- 2563.82; 32634.04m(2)+/- 1689.38 respectively) in comparison to H (55249.86m(2)+/- 1992.65; 44318.36m(2)+/- 1759.57) and in the collagen area in H+LLLT (1.76%+/- 0.16) in comparison to H (2.09 +/- 0.27). A greater organization of collagen fibers in the tendon was observed after 7 and 14 days in H+LLLT groups. Conclusions: Infrared laser irradiation induces an improvement in collagen organization in tendons and a reduction in the total area of collagen in muscles during compensatory atrophy following the ablation of synergist muscles. (AU)

• FAPESP's process: 14/12381-1 - Comparative analysis of the effect of previous laser therapy associated or not to post treatment on the modulation of inflammatory cytokines, oxidative stress and the determination of muscle fiber type after acute injury
• Grantee: Raquel Agnelli Mesquita Ferrari
• Support Opportunities: Regular Research Grants