氟化钠对实验性小鼠骨皮质微结构的影响

Effect of sodium fluoride on microstructure of bone cortex in experimental mice

目的了解氟化钠(NaF)对实验性小鼠骨皮质微结构和骨结构强度的影响。方法30只ICR雄性小鼠按照体质量均衡的原则随机分为3组:对照组常规饮用自来水,低氟组给予含25 mg/L NaF的自来水,高氟组饮用含50 mg/L NaF的自来水。各组均自由饮食,饲养20周后,观察各组氟斑牙发生情况,Micro-CT扫描左侧股骨,记录2D和3D物理参数,氟离子电极法测骨氟,左侧胫骨行三点弯曲试验。结果低、高氟组均有小鼠出现氟斑牙。与对照组比较,低氟组的骨氟含量[(1023.37±175.42)μg/g]、结构直径和高氟组的骨氟含量[(1135.23±69.01)μg/g]、截面厚度、结构厚度及结构直径均增加,而高氟组的骨结构强度降低。与低氟组比较,高氟组的截面厚度[(0.138±0.004)mm]、结构厚度[(0.091±0.003)mm]、结构直径[(0.181±0.006)mm]、骨皮质密度[(1.978±0.009)g/cm3]、骨体积分数[(87.267±0.379)%]及骨结构强度[(3.74±1.00)kg]均降低。结论高剂量的氟化钠可破坏实验性小鼠骨皮质微结构,降低骨结构强度。

Objective To investigate the effects of sodium fluoride(NaF)on the microstructure and strength of bone cortex in experimental mice.Methods 30 ICR male mice were randomly divided into three groups according to the principle of weight balance:the control group was given tap water regularly,the low fluoride group was given tap water containing 25 mg/L NaF,and the high fluoride group was given tap water containing 50 mg/L NaF.All groups were given free diet.After 20 weeks of feeding,the incidence of dental fluorosis in each group was observed.The left femur was scanned by the Micro CT,and 2D and 3D physical parameters were recorded.The bone fluoride was measured with fluoride ion electrode.The three-point bending test was performed on the left tibia.Results The mice in both low and high fluoride groups had dental fluorosis.Compared with the control group,the bone fluoride content[(1023.37±175.42)μg/g]and the structural diameter in the low fluoride group and the bone fluoride content[(1135.23±69.01)μg/g],section thickness,structural thickness,and structural diameter in the high fluoride group increased significantly,while the bone structural strength in the high fluoride group decreased significantly.Compared with the low fluoride group,the section thickness[(0.138±0.004)mm],structure thickness[(0.091±0.003)mm],structure diameter[(0.181±0.006)mm],bone cortex density[(1.978±0.009)g/cm3],bone volume fraction[(87.267±0.379)%]and bone structure strength[(3.74±1.00)kg]in the high fluoride group were significantly reduced.Conclusion The high dose sodium fluoride can destroy the microstructure of bone cortex in experimental mice and reduce the strength of bone structure.