Effects of fluoride on osteoclastic activity of rats in vitro / 中华预防医学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the effects of fluoride on activities of tartrate-resistant acid phosphate (TRAP) and matrix metalloproteinase-9 (MMP-9) in rat osteoclasts cultured in vitro.</p><p><b>METHODS</b>Osteoclast was isolated mechanically from long bones of neonatal rats and cultured in vitro. Histochemical stain was applied to detect the effects of fluoride on activities of TRAP and in-situ hybridization was used to study the expression of MMP-9 mRNA in rat osteoclasts in vitro.</p><p><b>RESULTS</b>Number of TRAP positive cells was 154.2, 160.0, 170.6, 179.0 and 180.0 per cm(2), respectively for the rats with varied doses of fluoride, in a dose-response pattern but without statistical significance. The expression of MMP-9 mRNA increased with elevating dose of fluoride, especially in the rats with 1.00, 2.00 and 4.00 mg/L of fluoride, to 94.50, 94.64 and 104.97, respectively, significantly different from those in control group.</p><p><b>CONCLUSIONS</b>Fluoride can enhance the MMP-9 mRNA expression in cultured osteoclasts of rats.</p>