title: Low-level laser therapy stimulates tissue repair and reduces the extracellular matrix degradation in rats with induced arthritis in the temporomandibular joint.
abstract: The objective of this study was to characterize morphological and biochemistry action of low-level laser therapy (LLLT) on induced arthritis in the temporomandibular joint (TMJ) of rats. Twenty-four male Wistar rats were randomly divided into groups with 12 animals each: (AG) group with arthritis induced in the left TMJ and (LG) group with arthritis induced in the left TMJ and treated with LLLT (830 nm, 30 mW, 3 J/cm(2)). Right TMJs in the AG group were used as noninjected control group (CG). Arthritis was induced by intra-articular injection of 50 μl Complete Freund's Adjuvant (CFA) and LLLT began 1 week after arthritis induction. Histopathological analysis was performed using sections stained with hematoxylin-eosin, Toluidine Blue, and picrosirius. Biochemical analysis was determined by the total concentration of sulfated glycosaminoglycans (GAGs) and evaluation of matrix metalloproteinases (MMP-2 and MMP-9). Statistical analysis was performed using paired and unpaired t tests, with p < 0.05. Compared to AG, LG had minor histopathological changes in the TMJ, smaller thickness of the articular disc in the anterior (p < 0.0001), middle (p < 0.0001) and posterior regions (p < 0.0001), high birefringence of collagen fibers in the anterior (p < 0.0001), middle (p < 0.0001) and posterior regions (p < 0.0001) on the articular disc, and statistically lower activity of MMP-2 latent (p < 0.0001), MMP-2 active (P = 0.02), MMP-9 latent (p < 0.0001), and MMP-9 active (p < 0.0001). These results suggest that LLLT can increase the remodeling and enhancing tissue repair in TMJ with induced arthritis.
authors.affiliation: Department of Structural and Functional Biology, Institute of Biology, University of Campinas - UNICAMP, Charles Darwin, s/n, CP 6109, 13083-970, Campinas, SP, Brazil. lemos.george@yahoo.com.br.
authors.forename: George Azevedo
authors.initials: GA
authors.lastname: Lemos
authors.affiliation: Department of Structural and Functional Biology, Institute of Biology, University of Campinas - UNICAMP, Charles Darwin, s/n, CP 6109, 13083-970, Campinas, SP, Brazil.
authors.forename: Renato
authors.initials: R
authors.lastname: Rissi
authors.affiliation: Department of Structural and Functional Biology, Institute of Biology, University of Campinas - UNICAMP, Charles Darwin, s/n, CP 6109, 13083-970, Campinas, SP, Brazil.
authors.forename: Ivan Luiz
authors.initials: IL
authors.lastname: de Souza Pires
authors.affiliation: Department of Structural and Functional Biology, Institute of Biology, University of Campinas - UNICAMP, Charles Darwin, s/n, CP 6109, 13083-970, Campinas, SP, Brazil.
authors.forename: Letícia Prado
authors.initials: LP
authors.lastname: de Oliveira
authors.affiliation: Department of Structural and Functional Biology, Institute of Biology, University of Campinas - UNICAMP, Charles Darwin, s/n, CP 6109, 13083-970, Campinas, SP, Brazil.
authors.forename: Andrea Aparecida
authors.initials: AA
authors.lastname: de Aro
authors.affiliation: Department of Structural and Functional Biology, Institute of Biology, University of Campinas - UNICAMP, Charles Darwin, s/n, CP 6109, 13083-970, Campinas, SP, Brazil.
authors.forename: Edson Rosa
authors.initials: ER
authors.lastname: Pimentel
authors.affiliation: Department of Structural and Functional Biology, Institute of Biology, University of Campinas - UNICAMP, Charles Darwin, s/n, CP 6109, 13083-970, Campinas, SP, Brazil.
authors.forename: Evanisi Teresa
authors.initials: ET
authors.lastname: Palomari
mesh_terms: D000818:Animals; D001168:Arthritis / Q000532:radiotherapy*; D004195:Disease Models, Animal; D005109:Extracellular Matrix; D005620:Freund's Adjuvant / Q000627:therapeutic use; D006025:Glycosaminoglycans / Q000378:metabolism; D028022:Low-Level Light Therapy / Q000379:methods; D008297:Male; D020782:Matrix Metalloproteinases / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D013704:Temporomandibular Joint; D014945:Wound Healing
chemical_list: D006025:Glycosaminoglycans; D005620:Freund's Adjuvant; D020782:Matrix Metalloproteinases
keywords: Arthritis; Inflammation; Low-level laser therapy; Temporomandibular joint disorders