Studying The Effect Of Sodium Fluoride On Bone Cell In Vitro

To study the effect of sodium fluoride (NaF) on osteoblast-like cell and osteoclast. Methods: Osteoblast-like cell line UMR106 and isolated osteoclast in vitro had been chosen for the study on the effect of different concentrations of NaF on the proliferation and differentiation of UMR106 cell line and on the biological functions of osteoclast. Results: The effect of NaF on the proliferation and early differentiation of osteoblast-like cell line UMR106 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 alkaline phosphatase (ALP) activity of UMR106 cell line (P<0.05), while high concentrations of NaF (10-4mol/L, 10-3mol/L) suppressed them (P<0.05). However, the response of cellular late differentiation to NaF is single: all concentrations of NaF we used markedly stimulated the secretion of osteocalcin (P<0.05). Furthermore, the amount of the secretion increased with the concentration of NaF. NaF (10-5mol/L, 10-4mol/L, 10-3mol/L) not only made osteoclast which was identified as tartrate resistant acid phosphatase (TRAP) staining positive multinuclear cell count significantly reduced (P<0.05), but also made osteoclast volume decreased and vacuolar developed, especially at the concentration of 10-3mol/L. In addition, compared with the control group, the number and area of lacuna formed by osteoclast resorption on bone slices markedly reduced in the group given 10-5mol/L, 10-4mol/L, 10-3mol/L NaF (P<0.05). Moreover, the border of resorptive lacuna became clouding. Conclusions: NaF had a double influence on the proliferation and early differentiation of osteoblast-like cell UMR106, but23the action on the late differentiation was single. NaF could directly injury osteoclast and inhibit bone resorptive function of osteoclast.