title: Influence of antiplatelet drugs in the pathogenesis of experimental periodontitis and periodontal repair in rats.
abstract: BACKGROUND
  Platelets contain an array of biologic mediators that can modulate inflammation and repair processes including proinflammatory mediators and growth factors. Previous studies have shown that periodontitis and periodontal repair are associated with platelet activation. We hypothesized that drug-induced platelet inactivation may interfere in the processes of inflammation and repair in experimental periodontitis in rats by suppressing the release of biologic mediators from platelets to the site of injury.
  
  
  METHODS
  To measure the effects on periodontitis, ligatures were placed around first molars, and aspirin (Asp, 30 mg/kg) or clopidogrel (Clo, 75 mg/kg) was given intragastrically once daily for 15 days. Interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and thromboxane A(2) levels were measured by enzyme-linked immunosorbent assay. To evaluate the effects of antiplatelet drugs on periodontal repair, ligatures were removed after 15 days of periodontitis induction, and Asp or Clo were administered beginning the following day for 15 days. Periodontal repair was assessed by microcomputed tomography.
  
  
  RESULTS
  On periodontitis phase, Asp and Clo significantly reduced levels of TNF-α and Il-6 (P <0.05), but only Asp decreased thromboxane A(2) (P <0.05). Asp and Clo decreased inflammatory infiltration; however, this reduction was more pronounced with Clo treatment (P <0.05). Histometric analysis showed that Asp and Clo impaired alveolar bone resorption. During the repair phase and after removal of the ligatures, microcomputed tomography analysis demonstrated that treatment with Asp and Clo did not impair alveolar bone repair.
  
  
  CONCLUSIONS
  Systemic administration of Asp and Clo attenuates the inflammation associated with periodontitis without affecting the repair process when stimulus is removed.
authors.affiliation: Department of Physiology and Pathology, Faculdade de Odontologia de Araraquara, UNESP, Universidade Estadual Paulista, Araraquara, SP, Brazil.
authors.forename: Leila S
authors.initials: LS
authors.lastname: Coimbra
authors.forename: Carlos
authors.initials: C
authors.lastname: Rossa
authors.forename: Morgana R
authors.initials: MR
authors.lastname: Guimarães
authors.forename: Raquel F
authors.initials: RF
authors.lastname: Gerlach
authors.forename: Marcelo N
authors.initials: MN
authors.lastname: Muscará
authors.forename: Denise M P
authors.initials: DM
authors.lastname: Spolidorio
authors.forename: Bruno S
authors.initials: BS
authors.lastname: Herrera
authors.forename: Luis C
authors.initials: LC
authors.lastname: Spolidorio
mesh_terms: D016301:Alveolar Bone Loss / Q000209:etiology / Q000473:pathology / Q000517:prevention & control; D000818:Animals; D001241:Aspirin / Q000627:therapeutic use; D001792:Blood Platelets / Q000187:drug effects; D015519:Bone Density / Q000187:drug effects; D001861:Bone Regeneration / Q000187:drug effects; D000077144:Clopidogrel; D018836:Inflammation Mediators / Q000032:analysis; D036341:Intercellular Signaling Peptides and Proteins / Q000032:analysis; D015850:Interleukin-6 / Q000032:analysis; D007962:Leukocytes / Q000187:drug effects; D008297:Male; D008336:Mandibular Diseases / Q000209:etiology / Q000473:pathology / Q000517:prevention & control; D017622:Periodontal Attachment Loss / Q000209:etiology / Q000473:pathology / Q000517:prevention & control; D010518:Periodontitis / Q000209:etiology* / Q000473:pathology / Q000517:prevention & control; D010519:Periodontium / Q000187:drug effects* / Q000473:pathology; D015539:Platelet Activation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013928:Thromboxane A2 / Q000032:analysis; D013988:Ticlopidine / Q000031:analogs & derivatives / Q000627:therapeutic use; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000187:drug effects; D014945:Wound Healing / Q000187:drug effects; D055114:X-Ray Microtomography
chemical_list: D018836:Inflammation Mediators; D036341:Intercellular Signaling Peptides and Proteins; D015850:Interleukin-6; D010975:Platelet Aggregation Inhibitors; D014409:Tumor Necrosis Factor-alpha; D013928:Thromboxane A2; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin