title: [Effects of overdosed fluoride on rat's incisor expression of matrixmetalloproteinase-20 and tissue inhibitors of metalloproteinase-2].
abstract: OBJECTIVE
  To investigate the effects of overdosed fluoride on the expression of MMP-20 and TIMP-2 in rat incisor.
  
  
  METHODS
  20 Wistar rats were randomly divided into experiment group and control group. The distilled water was given in control group. 100 mg/L fluoride- was given in experiment group. After 8 weeks treatment, the rats were killed. Immunohistochemical staining was used to observe the expression of MMP-20 and TIMP-2 in rat incisors.
  
  
  RESULTS
  Immunohistochemical results demonstrated the presence of MMP-20 and TIMP-2 protein in ameloblasts, odontoblasts, stratum intermedium and the stellate reticulum of rat incisor. The imagination analysis results showed that the expression of MMP-20 was reduesed in experiment group (P<0.01), and the expression of TIMP-2 had no significant difference (P>0.05).
  
  
  CONCLUSIONS
  The overdosed fluoride inhibits the secretion of MMP-20 and leads to the disturbed balance between MMP-20, TIMP-2 in rat incisor, which leads to the delay of the amelogenin removal and the enamel demineralization.
authors.affiliation: Oral Medicine, Hospital of Stomatology, Tongji University, Shanghai 200072, China.
authors.forename: Feng-Qiu
authors.initials: FQ
authors.lastname: Jing
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
authors.forename: Tian-Lin
authors.initials: TL
authors.lastname: Liu
authors.forename: Li-Ying
authors.initials: LY
authors.lastname: Guo
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
mesh_terms: D000565:Ameloblasts; D000818:Animals; D003743:Dental Enamel; D005459:Fluorides; D009050:Fluorosis, Dental; D007180:Incisor; D045726:Metalloproteases; D010710:Phosphates; D051381:Rats; D017208:Rats, Wistar; D019716:Tissue Inhibitor of Metalloproteinase-2
chemical_list: D010710:Phosphates; C560823:TIMP2 protein, human; D019716:Tissue Inhibitor of Metalloproteinase-2; C012980:fluorophosphate; D045726:Metalloproteases; D005459:Fluorides