title: Laser therapy reduces gelatinolytic activity in the rat trigeminal ganglion during temporomandibular joint inflammation.
abstract: OBJECTIVE
  To investigate whether low-level laser therapy (LLLT) alters the expression and activity of MMP-2 and MMP-9 in the trigeminal ganglion (TG) during different stages of temporomandibular joint (TMJ) inflammation in rats. It also evaluated whether LLLT modifies mechanical allodynia and orofacial hyperalgesia.
  
  
  METHODS
  Wistar rats (±250 g) were divided into groups that received saline (SAL) or complete Freund's adjuvant (CFA, 50 μl) in the TMJ, and that later underwent LLLT (20 J cm(-2) ) at their TMJ or not (groups SAL, SAL + LLLT, CFA, and CFA + LLLT). LLLT was applied on days 3, 5, 7, and 9 after SAL or CFA. Mechanical allodynia was evaluated on days 1, 3, 5, 7, and 10; orofacial hyperalgesia was assessed on day 10. Gelatin zymography and in situ zymography aided quantification of MMPs in the TG.
  
  
  RESULTS
  Low-level laser therapy abolished the reduction in the mechanical orofacial threshold and the increase in orofacial rubbing during the orofacial formalin test induced by CFA. LLLT also decreased the CFA-induced rise in the levels of MMP-9 and MMP-2 as well as the gelatinolytic activity in the TG.
  
  
  CONCLUSIONS
  Low-level laser therapy could constitute an adjuvant therapy to treat temporomandibular disorders and prevent inflammation-induced alterations in the levels of MMP-2 and MMP-9 and in the gelatinolytic activity in TGs.
authors.affiliation: Department of Morphology, Physiology and Basic Pathology of Dentistry School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: A C
authors.initials: AC
authors.lastname: Desiderá
authors.affiliation: Psychobiology Graduate Program, School of Philosophy, Science and Literature of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: G C
authors.initials: GC
authors.lastname: Nascimento
authors.affiliation: Department of Morphology, Physiology and Basic Pathology of Dentistry School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: R F
authors.initials: RF
authors.lastname: Gerlach
authors.affiliation: Department of Morphology, Physiology and Basic Pathology of Dentistry School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.|Psychobiology Graduate Program, School of Philosophy, Science and Literature of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: C R A
authors.initials: CR
authors.lastname: Leite-Panissi
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental / Q000628:therapy*; D017364:Collagenases / Q000096:biosynthesis* / Q000378:metabolism; D005157:Facial Pain / Q000628:therapy; D005620:Freund's Adjuvant / Q000494:pharmacology; D005780:Gelatin / Q000378:metabolism; D006930:Hyperalgesia / Q000628:therapy; D028022:Low-Level Light Therapy / Q000379:methods*; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012965:Sodium Chloride / Q000008:administration & dosage; D013704:Temporomandibular Joint / Q000187:drug effects / Q000294:innervation* / Q000601:surgery; D013705:Temporomandibular Joint Disorders / Q000201:enzymology* / Q000473:pathology / Q000628:therapy*; D012668:Trigeminal Ganglion / Q000201:enzymology* / Q000378:metabolism / Q000473:pathology
chemical_list: D012965:Sodium Chloride; D005780:Gelatin; D005620:Freund's Adjuvant; D017364:Collagenases; D020778:Matrix Metalloproteinase 2; C522363:Mmp2 protein, rat; D020780:Matrix Metalloproteinase 9
keywords: low-level laser therapy; matrix metalloproteinase 2; matrix metalloproteinase 9; orofacial pain; temporomandibular joint disorders