title: Low-level laser therapy modulates pro-inflammatory cytokines after partial tenotomy.
abstract: Tendon injuries give rise to substantial morbidity, and current understanding of the mechanisms involved in tendon injury and repair is limited. This lesion remains a clinical issue because the injury site becomes a region with a high incidence of recurrent rupture and has drawn the attention of researchers. We already demonstrated that low-level laser therapy (LLLT) stimulates the synthesis and organization of collagen I, MMP-9, and MMP-2 and improved the gait recovery of the treated animals. The aim of this study was to evaluate the effects of LLLT in the nitric oxide and cytokines profile during the inflammatory and remodeling phases. Adult male rats were divided into the following groups: G1--intact, G2-- injured, G3--injured + LLLT (4 J/cm(2) continuous), G4--injured + LLLT (4 J/cm(2)-20 Hz--pulsed laser). According to the analysis, the animals were euthanized on different dates (1, 4, 8, or 15 days after injury). ELISA assay of TNF-α, IL-1β, IL-10, and TGF-β was performed. Western blotting of isoform of nitric oxide synthase (i-NOS) and nitric oxide dosage experiments was conducted. Our results showed that the pulsed LLLT seems to exert an anti-inflammatory effect over injured tendons, with reduction of the release of proinflammatory cytokines, such as TNF-α and the decrease in the i-NOS activity. Thanks to the pain reduction and the facilitation of movement, there was a stimulation in the TGF-β and IL-1β release. In conclusion, we believe that pulsed LLLT worked effectively as a therapy to reestablish the tendon integrity after rupture.
authors.affiliation: Department of Anatomy, Institute of Biomedical Science, Federal University of Alfenas - UNIFAL-MG, 37130-000, Alfenas, MG, Brazil. dgflavia@yahoo.com.br.
authors.forename: Flávia
authors.initials: F
authors.lastname: Da Ré Guerra
authors.affiliation: Department of Structural and Functional Biology, Institute of Biology, CP 6109, University of Campinas - UNICAMP, 13083-970, Campinas, SP, Brazil.
authors.forename: Cristiano Pedrozo
authors.initials: CP
authors.lastname: Vieira
authors.affiliation: Department of Structural and Functional Biology, Institute of Biology, CP 6109, University of Campinas - UNICAMP, 13083-970, Campinas, SP, Brazil.
authors.forename: Letícia Prado
authors.initials: LP
authors.lastname: Oliveira
authors.affiliation: Department of Biochemistry, Institute of Biomedical Science, Federal University of Alfenas - UNIFAL-MG, 37130-000, Alfenas, MG, Brazil.
authors.forename: Petrus Pires
authors.initials: PP
authors.lastname: Marques
authors.affiliation: Department of Anatomy, Institute of Biomedical Science, Federal University of Alfenas - UNIFAL-MG, 37130-000, Alfenas, MG, Brazil.
authors.forename: Marcos
authors.initials: M
authors.lastname: dos Santos Almeida
authors.affiliation: Department of Structural and Functional Biology, Institute of Biology, CP 6109, University of Campinas - UNICAMP, 13083-970, Campinas, SP, Brazil.
authors.forename: Edson Rosa
authors.initials: ER
authors.lastname: Pimentel
mesh_terms: D000818:Animals; D024042:Collagen Type I / Q000378:metabolism; D016207:Cytokines / Q000097:blood*; D054023:Lasers, Semiconductor / Q000627:therapeutic use*; D028022:Low-Level Light Therapy / Q000379:methods; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013708:Tendon Injuries / Q000097:blood / Q000532:radiotherapy*; D013710:Tendons / Q000378:metabolism / Q000528:radiation effects; D058971:Tenotomy; D016896:Treatment Outcome; D014945:Wound Healing / Q000528:radiation effects
chemical_list: D024042:Collagen Type I; D016207:Cytokines; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat
keywords: IL-1β; Inflammatory; TGF-β; TNF-α; i-NOS