title: Experimental model of zymosan-induced arthritis in the rat temporomandibular joint: role of nitric oxide and neutrophils.
abstract: OBJECTIVE
  To establish a new model of zymosan-induced temporomandibular joint (TMJ) arthritis in the rat and to investigate the role of nitric oxide.
  
  
  METHODS
  Inflammation was induced by an intra-articular injection of zymosan into the left TMJ. Mechanical hypernociception, cell influx, vascular permeability, myeloperoxidase activity, nitrite levels, and histological changes were measured in TMJ lavages or tissues at selected time points. These parameters were also evaluated after treatment with the nitric oxide synthase (NOS) inhibitors L-NAME or 1400 W.
  
  
  RESULTS
  Zymosan-induced TMJ arthritis caused a time-dependent leucocyte migration, plasma extravasation, mechanical hypernociception, and neutrophil accumulation between 4 and 24 h. TMJ immunohistochemical analyses showed increased inducible NOS expression. Treatment with L-NAME or 1400 W inhibited these parameters.
  
  
  CONCLUSIONS
  Zymosan-induced TMJ arthritis is a reproducible model that may be used to assess both the mechanisms underlying TMJ inflammation and the potential tools for therapies. Nitric oxide may participate in the inflammatory temporomandibular dysfunction mechanisms.
authors.affiliation: Faculty of Dentistry, Federal University of Ceará, Sobral Campus, Avenida Comandante Maurocélio Rocha Pontes, 100 Derby, 62042-280 Sobral, CE, Brazil.
authors.forename: Hellíada Vasconcelos
authors.initials: HV
authors.lastname: Chaves
authors.forename: Ronaldo de Albuquerque
authors.initials: Rde A
authors.lastname: Ribeiro
authors.forename: André Mattos Brito
authors.initials: AM
authors.lastname: de Souza
authors.forename: Antonio Alfredo
authors.initials: AA
authors.lastname: Rodrigues e Silva
authors.forename: Antoniella Souza
authors.initials: AS
authors.lastname: Gomes
authors.forename: Mariana Lima
authors.initials: ML
authors.lastname: Vale
authors.forename: Mirna Marques
authors.initials: MM
authors.lastname: Bezerra
authors.forename: Gerly Anne de Castro
authors.initials: GA
authors.lastname: Brito
mesh_terms: D000818:Animals; D001169:Arthritis, Experimental / Q000276:immunology* / Q000378:metabolism*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D007150:Immunohistochemistry; D008297:Male; D020556:Neutrophil Infiltration; D009504:Neutrophils / Q000276:immunology*; D009569:Nitric Oxide / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013582:Synovial Fluid / Q000737:chemistry / Q000166:cytology; D013704:Temporomandibular Joint / Q000473:pathology; D013705:Temporomandibular Joint Disorders / Q000276:immunology* / Q000378:metabolism*; D015054:Zymosan
chemical_list: D009569:Nitric Oxide; D015054:Zymosan; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat