摘要目的 观察慢性氟中毒对大鼠骨组织中钙调神经磷酸酶(CaN) mRNA及其蛋白表达的影响,探讨CaN在氟骨症发病机制中的作用.方法 将36只SD大鼠按性别和体质量分为3组:对照组(饮水含氟＜0.5 mg/L)、低氟组(饮水含氟5.0 mg/L)、高氟组(饮水含氟50.0 mg/L),每组12只.实验6个月后股动脉放血处死大鼠,收集血清,用酶联免疫吸附测定法(ELISA)检测骨钙素(BGP).取大鼠股骨下端,用免疫组织化学法和原位杂交检测各组大鼠股骨组织中CaN蛋白及CaN mRNA表达.结果 各组大鼠血清BGP水平比较,差异有统计学意义(均P＜0.05),与对照组(0.15 ±0.03)μg/L比较,低、高氟组血清BGP (1.99±0.62、2.38±0.16) μg/L明显升高(均P＜0.05),且高氟组明显高于低氟组(均P＜0.05).各组大鼠骨组织CaN蛋白及mRNA相对表达水平比较,差异有统计学意义,与对照组(131.11 ±1.95、111.82 ±2.39)比较,低、高氟组大鼠骨组织CaN蛋白(142.69±1.17、157.54±1.88)和mRNA表达(121.28 ±3.27、134.63 ±3.19)明显升高(均P＜0.05),且高氟组明显高于低氟组(均P＜0.05).结论 血清BGP可作为慢性氟中毒骨骼病变的代谢指标.氟可致大鼠骨组织CaN mRNA及蛋白表达水平增高,CaN可能参与氟引起的骨骼损伤的发生机制.

abstractsObjective To investigate the changes of mRNA and protein expression of CaN in the bone of rats with chronic fluorosis,and the mechanism of skeletal fluorosis.Methods Thirty-six SD rats were divided into three groups (12 in each group,half male and half female selected according to body weight):control,low-dose and high-dose fluorosis groups.Controls were fed tap water (NaF ＜ 0.5 mg/L),experimental animals in the low-or high-dose groups were fed water containing NaF of 5.0 and 50.0 mg/L,respectively.The rats were sacrificed after 6 months of treatment with fluoride.The serum was kept for testing bone metabolic marker bone gla protein (BGP) by enzyme-linked immunosorbent assay (ELISA),the protein and mRNA levels of CaN in distal femur of the rats with chronic flurosis were assessed by immunohistochemistry and in-situ hybridization.Results The levels of BGP (1.99 ± 0.62,2.38 ± 0.16)μg/L in the low-or high-dose fluorosis groups were higher than that in the control group (0.15 ± 0.03)μg/L; and the high fluorosis group showed higher level than the low fluorosis group (all P ＜0.05).Compared to the control group (131.11 ±1.95,111.82 ±2.39),the protein and mRNA levels of CaN were higher in the low-or high-dose fluorosis groups (142.69 ± 1.17,157.54 ± 1.88 and 121.28±3.27,134.63 ± 3.19,respectively),and the high fluorosis group showed higher levels than the low fluorosis group (all P ＜0.05).Conclusions BGP content could be used as a bone metabolic index in endemic fluorosis disease.Fluoride might up-regulate the mRNA and protein expression of CaN,and the changes in CaN level may be involved in the increase of the bone turnover and could be one of the pathogenetic factors in fluorosis.