中文摘要：

[目的]探讨氟砷联合作用对大鼠骨骼代谢Runt相关转录因子2（runt-related transcription factor2，Runx2）信号通路的影响。[方法]以SD大鼠为实验动物，析因设计方法随机分成9组：对照组、低氟组（5mg／kg）、高氟组（20mg／kg）、低砷组（2．5mg／kg）、高砷组（10mg／kg）、低氟低砷组、低氟高砷组、高氟低砷组、高氟高砷组，每组6只，雌雄各半。用氟化钠（NaF）、亚砷酸钠（NaAsO2）灌胃，连续染毒6个月。实验结束后，氟离子选择电极法检测尿氟（urinary fluorine，UF）浓度、氢化物发生器一电感耦合等离子体离子发射光谱法检测尿砷（urinaryarsenic，UAs）浓度；酶联免疫吸附法（enzyme-linked immunosorbnent assay，ELISA）测定血清中甲状旁腺激素（parathyroid hormone，PTH）、蛋白激酶A（proteinkinaseA，PKA）、cAMP反应原件结合蛋白（cAMP-response element binding protein，CREB）、Runx2含量。[结果]UF、UAs浓度随氟、砷染毒剂量的增加而升高（P〈O．01）；氟与Runx2呈正相关（r=0．626，P〈O．01），砷与Runx2呈负相关（仁一0．376，P〈0．05）；氟砷对Runx2具有交互作用（F=3．928，P〈O．01），且高氟低砷、高氟高砷剂量组Runx2含量低于氟、砷单独作用时的含量之和（P〈0．01o氟与PTH、PKA、CREB为正相关关系（r=0．489、0．534、O．363，P〈0．05或P〈0．01）。砷与PTH、PKA为正相关关系（r=0．336、0．374，P〈0．05或P〈0．01），但与CREB无明显相关关系。[结论]PTH．PKA-CREB-Runx2通路参与了氟致骨骼损伤的过程，而砷作用于Runx2间接参与了氟致骨骼损伤的过程。氟砷对Runx2存在交互作用，在高氟低砷、高氟高砷水平时表现为拮抗作用。

英文摘要：

[ Objective ] To examine the combined effects of sodium fluoride and sodium arsenite on the Runx2 signaling pathway of bone metabolism in rats. [ Methods ] Factorial experimental design was used. SD rats were exposed to NaF （5 mg/kg and 20 mg/kg）, NaAsO2 （2.5 mg/kg and 10 mg/kg）, and 4 combinations of NaF plus NaAsO2 by oral perfusion for 6 months respectively. The concentrations of urinary fluoride （UF） and urinary arsenic （UAs） were determined as exposure biomarkers by fluoride ion selective electrode method and inductively coupled plasma optical emission spectrometer, respectively. The concentrations of parathyroid hormone （PTH）, protein kinase A （PKA）, cAMP-response element binding protein （CREB）, and runt-related transcription factor 2 （Runx2） in serum were determined as effect biomarkers by enzyme-linked immunosorbent assay （ELISA）. [ Results ] A positive correlation was identified between the concentrations of UF ＆ UAs and the exposure dose of fluoride ＆ arsenite （P 〈 0.01）. The fluoride was positively associated with the Runx2, PTH, PKA, and CREB （r=0.626, 0.489, 0.534, 0.363, respectively, P 〈 0.05 or P〈O.O1）. The arsenite was positively associated with the PTH, and PKA （r=0.336, 0.374, respectively, P〈O.05 or P〈O.O1）, but negatively correlated with the Runx2 （r=-0.376, P〈O.05）. There was an interaction between F ＆ As and Runx2 （？＇--3.928, P〈0.O1）. Runx2 level was lower in the rats treated with 20mg/kg F＋ 2.5 mg/kg As or 20mg/kg F＋ 10mg/kg As than that in those treated with F or As separately. [ Conclusion ] The PTH-PKA-CREB-Runx2 pathway participates in the fluoride induced bone damage, while arsenite indirectly participates in this process by affecting Runx2. The combined effects of F and As on Runx2 are an antagonism effect of NaF （20mg/kg） plus NaAsO2 （2.5 mg/kg） and NaF （20mg/kg） plus NaAsO2 （lOmg/kg）.