[Effects of overdosed fluoride on rat's incisor expression of matrixmetalloproteinase-20 and tissue inhibitors of metalloproteinase-2].
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.
Jing
Feng-Qiu
FQ
Oral Medicine, Hospital of Stomatology, Tongji University, Shanghai 200072, China.
Wang
Qiang
Q
Liu
Tian-Lin
TL
Guo
Li-Ying
LY
Liu
Hui
H
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
D010710:Phosphates; C560823:TIMP2 protein, human; D019716:Tissue Inhibitor of Metalloproteinase-2; C012980:fluorophosphate; D045726:Metalloproteases; D005459:Fluorides