title: Low-level laser therapy in experimental model of collagenase-induced tendinitis in rats: effects in acute and chronic inflammatory phases.
abstract: A variety of treatments for tendinopathies is currently used or has been trialed. However, in fact, there is a remarkably little evidence that any conventional therapies are effective. In the last years, low-level laser therapy (LLLT) has been showing interesting results in inflammatory modulation in different musculoskeletal disorders, but the optimal parameters and mechanisms behind these effects are not fully understood. The aim of this study is to investigate if the LLLT modulates the acute and chronic phase of collagenase-induced tendinitis in rat by interfering in mRNA expression for matrix metalloproteinases (MMP13 and MMP1), vascular endothelial growth factor (VEGF), and anti-inflammatory mediator (interleukin (IL)-10). For such, tendinitis was induced by collagenase injection in male Wistar rats. Animals were treated with LLLT (780 nm, potency of 22 mW, 107 mW/cm(2), energy density of 7.5 J/cm(2), and energy delivered of 1.54 J) with different number of treatments in accordance with the inflammatory phase analyzed. LLLT was able to modulate mRNA gene expression of IL-10, VGEF, MMP1, and MMP13 both in acute than in chronic inflammatory phase (p<0.05). Our results suggest that LLLT with parameters employed in the present study was able to modulate IL-10, VEGF, MMP1, and MMP13 mRNA gene expression both in acute than in chronic tendon inflammation. However, further studies are needed to establish optimal parameters for LLLT.
authors.affiliation: Post Graduate Program in Rehabilitation Sciences, Nove de Julho University (UNINOVE), Rua Vergueiro, 235, 01504-001, São Paulo, SP, Brazil.
authors.forename: Heliodora Leão
authors.initials: HL
authors.lastname: Casalechi
authors.forename: Ernesto Cesar Pinto
authors.initials: EC
authors.lastname: Leal-Junior
authors.forename: Murilo
authors.initials: M
authors.lastname: Xavier
authors.forename: José Antônio
authors.initials: JA
authors.lastname: Silva
authors.forename: Paulo de Tarso Camillo
authors.initials: Pde T
authors.lastname: de Carvalho
authors.forename: Flávio
authors.initials: F
authors.lastname: Aimbire
authors.forename: Regiane
authors.initials: R
authors.lastname: Albertini
mesh_terms: D000208:Acute Disease; D000818:Animals; D002908:Chronic Disease; D017364:Collagenases / Q000008:administration & dosage; D004195:Disease Models, Animal; D015870:Gene Expression / Q000528:radiation effects; D007249:Inflammation / Q000209:etiology / Q000235:genetics / Q000532:radiotherapy; D018836:Inflammation Mediators / Q000378:metabolism; D016753:Interleukin-10 / Q000235:genetics; D028022:Low-Level Light Therapy; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000235:genetics; D053509:Matrix Metalloproteinase 13 / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D052256:Tendinopathy / Q000209:etiology / Q000235:genetics / Q000532:radiotherapy*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics
chemical_list: D018836:Inflammation Mediators; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; C467498:vascular endothelial growth factor A, rat; D016753:Interleukin-10; D017364:Collagenases; D053509:Matrix Metalloproteinase 13; C507083:Mmp13 protein, rat; C576840:MMP1 protein, rat; D020781:Matrix Metalloproteinase 1