中文摘要：

为了观察氟对体外培养的小鼠成骨细胞中OPG/RANKL mRNA表达的影响,取30只出生24 h以内的昆明小鼠,无菌条件下取其头盖骨,去除筋膜和结缔组织,用胰蛋白酶-胶原酶消化法进行原代成骨细胞的培养。取其第2代成骨细胞,分成试验组和对照组,试验组培养液中分别加入不同浓度的氟化钠（10^-12、10^-11、10^-10、10^-9、10^-8mol/L）,培养40 h,收集细胞板中贴壁的细胞提取总RNA,采用荧光定量RT-PCR法检测细胞中OPG/RANKL mRNA的变化。结果试验组中OPG/RANKL mRNA的比值显著升高,且随着氟化钠浓度的增加先升高,后降低,10^-10mol/L氟化钠达到最大值（P〈0.01）。说明微量氟可以减少破骨细胞的成熟分化,使骨吸收能力减弱,相应地增加了骨形成的过程。

英文摘要：

The receptor activator of nuclear factor kappa B ligand （RANKL） and its decoy receptor, osteoprotegerin （OPG）, play an important role in bone metabolism, which directly control osteoclastogenesis. Here we investigate the expression of OPG and RANKL mRNA using an in vitro osteoblast culture assay. The osteoblasts were derived from mouse calvarial bone and isolated by complete trypsinization and collagenase digestion and cultured in DMEM supplemented with 15% FBS at 37℃ containing 5% CO2, and the osteoblasts were exposed to the different concentrations of sodium fluoride （0, 10^-12, 10-^11, 10-^10, 10^-9 and 10^-8 mol/L） for 40 h at 37℃ containing 5 % CO2, and the total RNA was extracted and reverse transcribed into first-strand cDNA. The cDNA was amplified using OPG, RANKL and β-actin primers by real-time fluorescent quantitative PCR （FQ-PCR） in DNA Engine OpticonTM2 continuous fluorescence detection system. The results indicated that OPG mRNA expression of mouse osteoblasts in sodium fluoride treated groups were up-regulated and the RANKL mRNA expression also increased excepting the group of 10^-12 mol/L sodium fluoride. When exposed to sodium fluoride of 1.0×10^-12to 1.0 × 10^-8mol/L, the relative expression level of OPG/RANKL mRNA was also up-regulated. Particularly the ratio of OPG/RANKL increased significantly from 1.0 × 10^-12 to 1.0 × 10^-10 mol/L sodium fluoride（P〈0.01）. Thereafter, it was decreased gradually from 1.0×10^-10to 1.0×10^-8 mol/L sodium fluoride（P〈0.05）. In conclusion, these in vitro data demonstrated that traces of sodium fluoride could decrease osteoclastogenesis.