细胞增殖和DNA损伤在大鼠氟斑牙形成中的作用研究

目的:研究在氟中毒引起氟斑牙时,氟对大鼠切牙细胞增殖和DNA损伤的影响.方法:给雄性SD大鼠饮用含10,50,100 mg/L NaF的高氟水60 d和90 d,制备氟斑牙模型.用流式细胞术检测大鼠切牙细胞增殖周期的变化,用单细胞凝胶电泳检测DNA损伤.结果:雄性SD大鼠饮用含50,100 mg/L NaF的高氟水60...

Role of Cell Proliferation and DNA Damage in the Formation Of Rat Dental Fluorosis Induced by Fluoride

Objective: To explore the role of cell proliferation and DNA damage in the formation of rat dental fluorosis induced by fluoride. Methods: Male SD rats were provided with distilled water to drink containing NaF at different doses (10, 50 and 100 mg/L respectively) for 60 or 90 days. The rat model for dental fluorosis was made. The cell cycle of proliferation was detected by flow cytometry in mandibular incisor ameloblasts and odontoblasts, and the DNA damage was also measured with single cell gel electrophoresis (or comet assay). Results: NaF at the doses of 50 and 100 mg/L for 60 d and 90 d could increase serum fluoride concentration significantly, statistical analysis yielded close relationship between the dose of NaF in water and the level of NaF in serum, and the relative coefficient was 0.995 7 (P<0.01) and 0.9880 (P<0.05) respectively. NaF at the doses of 50 and 100 mg/L could cause dental fluorosis at rat mandibular incisor obviously, but 10 mg/L NaF failed to induce dental fluorosis for 60 and 90 days. Compared with control, olive tail moment of ameloblasts and odontoblasts at the doses of 10, 50, and 100 mg/L NaF were increased significantly (P<0.05) for 60 and 90 days. At the same doses, olive tail moment of group for 90 days were more than those of 60 days obviously (P<0.05). After 60 days treatment, NaF reduced the cell number of G2/M phase in cell cycle at the dose of 10 mg/L, but increased the cell number of G2/M phase at the doses of 50 and 100 mg/L after 90 days, and the changes of cell cycle were not significant (P>0.05) in rat ameloblasts and odontoblasts. Conclusion: It was suggested that ameloblast and odontoblast proliferation as well as their DNA damage could play roles in the formation of rat dental fluorosis induced by fluoride, but the mechanisms in detail needs to be studied further.