Study on Effect of Sodium Fluoride on Osteoblast-like Cell in Vitro

Objective To study the effect of sodium fluoride(NaF)on the proliferation and differentiation of osteoblast-like cell. Methods Osteoblast-like cell line UMR106 were cultured in the medium containing 10 -7mol/L to 10 -3mol/L NaF.Cell proliferation was detected by cell growth curve and MTT colorimetry.Alkaline phosphatase(ALP)activity and osteocalcin production examined by P-nitrophenyl sodium phosphate(PNPP)colorimetry and radioimmunologic(RIA)assay respectively reflected cell differentiation. Results The effect of NaF on the proliferation and early differentiation of UMR106 cell was regulated in a double-phase manner:after co-cultured with cells a certain time,low concentrations of NaF(10 -7mol/L,10 -6mol/L,10 -5mol/L)promoted both proliferation and ALP activity of UMR106 cell(P0.05),while high concentrations of NaF(10 -4mol/L,10 -3mol/L)suppressed them(P0.05).However,the response of cellular late differentiation to NaF was single:all concentrations of NaF we used stimulated the secretion of osteocalcin(P0.05)and the amount of the secretion increased with the concentration of NaF. Conclusions NaF had a double influence on the proliferation of osteoblast-like cell UMR106,but the action on cell differentiation is diverse depending on the exposure time and concentration of NaF.