The Effect Of Fluoride On Osteoblasts Of New Born Rats In Viro

Objective : To study the effect of fluoride on osteoblasts. Methods: Osteoblasts were obtained from the calvaria of 24-h new born wister rat by using primary culture. The effect of NaF(10-7mol/L~ 10-3mol/L) on the cell proliferation, the activity of alkaline phosphatase(ALP), Osterocalcin, the cell protein ,the expression level of TGF-β1mRNA and COL-1mRNA of osteoblasts were observed. Results: Low doses of NaF(10-7mol/L ~ 10-5mol/L) promoted proliferation, ALP activity and content of protein of osteoblasts(P<0.05); while high doses of NaF(10-4mol/L,10-3mol/L) decreased them(P<0.05). As compared with control group, all concentrations of NaF stimulated the secretion of osterocaclcin(P < 0.05). All concentrations of NaF had no effect on the expression of TGF-β1mRNA(P>0.05), but the expression of TGF-β1mRNA had tendency to change with the concentration of NaF. That is, low doses of NaF increased the expression of TGF-β1mRNA; high doses of NaF decreased the expression of it. The expression of COL-lmRNA was not effected by the 10-7mol/L and 10-6mol/L NaF, but the expression of COL-lmRNA was increased significantly by 10-5mol/L NaF (P<0.05); while the expression of COL-lmRNA was decreased by high 10-4mol/L and 10-3mol/L NaF (P<0.05). Conclusions: The effect of NaF on the proliferation, early differentiation and the content of protein of osteoblasts were regulated in a double-phase manner. Low doses of NaF increased them, vice versa at high doses. But the action on the late differentiation was single. All concentrations of NaF promoted the secretion of osterocaclcin. 10-5mol/L NaF promoted the expression of COL-lmRNA while overdose NaF inhibited the expression of COL-lmRNA.