title: Multiple Apical Periodontitis Influences Serum Levels of Cytokines and Nitric Oxide.
abstract: BACKGROUND
  This study evaluated whether apical periodontitis (AP) in a single tooth or in multiple teeth affected serum levels of inflammatory mediators and influenced blood homeostasis.
  
  
  METHODS
  Thirty male Wistar rats were divided into 3 groups of 10 rats each: control group, healthy rats; 1AP group, rats with AP in 1 tooth; and 4AP group, rats with AP in 4 teeth. After 30 days, the rats were anesthetized, and their blood was collected through cardiac puncture to quantify tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), interleukin (IL)-6, IL-17, IL-23, and nitric oxide (NO) levels. The rats were then sacrificed by administering an anesthetic overdose. Their maxillary and mandibular molars were collected and processed for histologic analysis with hematoxylin-eosin and for immunohistochemical staining of the cytokines and NO-producing enzyme nitric oxide synthase. Results of these analyses were statistically analyzed; P < .05 was considered statistically significant.
  
  
  RESULTS
  Rats in the 1AP and 4AP groups showed increased IL-6, IL-17, IL-23, TNF-α, IFN-γ, and NO synthase expression; inflammatory cell infiltration; and moderate bone resorption in affected teeth. Serum TNF-α, IL-6, IL-17, and IL-23 levels were higher in rats in the 4AP group than in those in the control group (P < .05). Serum NO levels were significantly lower in rats in the 1AP and 4AP groups than in those in the control group (P < .05). Serum IFN-γ levels were not different among rats in the 3 groups (P > .05).
  
  
  CONCLUSIONS
  These results suggested that AP affected blood homeostasis by altering the serum levels of inflammatory cytokines and NO.
authors.affiliation: Department of Endodontics, Araçatuba Dental School, Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil. Electronic address: lucianocintra@foa.unesp.br.
authors.forename: Luciano Tavares Angelo
authors.initials: LT
authors.lastname: Cintra
authors.affiliation: Department of Endodontics, Araçatuba Dental School, Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil.
authors.forename: Renata Oliveira
authors.initials: RO
authors.lastname: Samuel
authors.affiliation: Department of Endodontics, Araçatuba Dental School, Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil.
authors.forename: Mariane Maffei
authors.initials: MM
authors.lastname: Azuma
authors.affiliation: Department of Endodontics, Araçatuba Dental School, Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil.
authors.forename: Ana Olívia Silva
authors.initials: AO
authors.lastname: de Queiróz
authors.affiliation: Department of Basic Sciences, Araçatuba Dental School, Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil.
authors.forename: Edilson
authors.initials: E
authors.lastname: Ervolino
authors.affiliation: Department of Basic Sciences, Araçatuba Dental School, Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil.
authors.forename: Dóris Hissako
authors.initials: DH
authors.lastname: Sumida
authors.affiliation: Department of Clinic and Surgery and Animal Reproduction, Araçatuba Veterinary Medicine, Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil.
authors.forename: Valéria Marçal Félix
authors.initials: VM
authors.lastname: de Lima
authors.affiliation: Department of Endodontics, Araçatuba Dental School, Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil.
authors.forename: João Eduardo
authors.initials: JE
authors.lastname: Gomes-Filho
mesh_terms: D000818:Animals; D001862:Bone Resorption; D016207:Cytokines / Q000097:blood*; D007371:Interferon-gamma / Q000097:blood; D020381:Interleukin-17; D053759:Interleukin-23; D015850:Interleukin-6; D008297:Male; D008334:Mandible; D008437:Maxilla; D008963:Molar; D009569:Nitric Oxide / Q000097:blood*; D010485:Periapical Periodontitis / Q000097:blood* / Q000000981:diagnostic imaging / Q000378:metabolism*; D010486:Periapical Tissue / Q000000981:diagnostic imaging / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D044967:Serum / Q000737:chemistry*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D016207:Cytokines; D020381:Interleukin-17; D053759:Interleukin-23; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D007371:Interferon-gamma
keywords: Apical periodontitis; cytokines; nitric oxide