中文摘要：

目的观察内质网应激在氟中毒大鼠骨组织中的变化，探索内质网应激在氟骨症发病机制中的可能作用。方法48只Wistar大鼠，按体质量分成4组，每组12只。对照组和低钙组分别饲以常食饲料（含钙量为0．790％）和自制低钙饲料（含钙量为0．063％），饮用自来水（含NaF〈1mg／L）；高氟组和低钙高氟组分别饲以常食饲料和自制低钙饲料，饮用加氟（NaF，221mg／L）自来水。实验期间动物自由进食、进水，每周测体质量1次。实验期3个月。生化方法检测大鼠血清氧化应激酶、尿酸（URIC）和碱性磷酸酶（ALP）活性。抽提大鼠一侧股骨骨干的总RNA．利用RT—PCR技术分析内质网应激相关基因BIP、Xbp1、CHOP和PDI的表达水平。结果低钙高氟组血清丙二醛（MDA）水平高于对照组[（14．74±3．11）μmol／L比（10．15±1．96）μmol／L，P〈0．05]；高氟组血清谷胱甘肽过氧化物酶（GPx）的活性高于对照组『（3．87±0．41）×10^3U／L比（2．85±0．55）×10^3U／L，P〈0．05]；高氟组和低钙高氟组的尿酸（URIC）分别低于对照组和低钙组[（73．95±9．52）μmol／L比（110．43±25．48）μmol／L，（54．32±22．09）μmol／L比（101．71±17．01）μmol／L，P〈0．051。低钙高氟组大鼠的ALP活性高于对照组（（24．77±4．57）×10^3U／L比（12．91±3．97）×10^3U／L，P〈0．01）]。低钙组和低钙高氟组BIP／GAPDH的表达高于对照组（1．38±0．24、1．35±0．12比1．14±0．06，P〈0．05）。低钙高氟组的Xbp1／GAPDH的表达高于对照组和低钙组（1．48±0．20比1．02±0．25、1．07±0．25，P〈0．01）：低钙高氟组的CHOP／GAPDH的表达高于对照组（0．84±0．18比0．52±0．07，P〈0．05）。结论氟中毒大鼠机体内氧化应激态和骨形成有明显的增强，并伴有骨组织细胞的内质网应激，说明内质网应激与氧化应激很可能都参与了氟骨症?

英文摘要：

Objective To observe endoplasmic reticulum stress in bone tissue of fluorosis rats and further explore the pathogenesis of skeletal fluorosis. Methods 48 Wistar rats were divided into 4 groups according to their body mass, The control and low-calcium group were fed with normal diet（0.79% calcium） and low-calcium diet（0.79% calcium） respectively, and both drank tap water（sodium fluoride concentrations 〈 1 rag/L）. High- fluoride and low-calcium plus high-fluoride groups were fed with normal diet（0.79% calcium） and low-calcium diet （0.79% calcium） respectively, and both drank tap water containing sodium fluoride （sodium fluoride concentrations 221 mg/L）. During experimental period, rats were measured body mass once a week with a stand diet and water available ad libitum. The experimental period was 3 months. The biochemical techniques were used to test the indicators of oxidative stress and ALP in serum of fluorosis rats. The total RNA was extracted from the one side of the femur, and the transcription level of Bip, Xbpl, CHOP and PDI were investigated by reverse transcription- polymerase chain reaction（RT-PCR）. Results The level of MDA in serum of low-calcium plus high-fluoride group was higher than that of the control [ （ 14.74 ± 3.11 ） μmol/L vs （ 10.15 ± 1.96） μmol/L, P 〈 0.05 ] ; the activity of GPx was markedly higher in high-fluoride group compared with the control[ （3.87 ± 0.41 ） x l03 U/L vs （2.85 ±- 0.55） ×10^3 U/L, P 〈 0.05]; the level of uric acid in serum was significantly lower both in high-fluoride group and low-calcium plus high-fluoride group compared with the respective control and the low-calcium group[ （73.95 ± 9.52）μmol/L vs （110.43 ± 25.48）p, mol/L, （54.32 ± 22.09）μmol/L vs （101.71 ± 17.01）μmol/L, P〈 0.05]. The activity of ALP was obviously higher in low-calcium plus high-fluoride group compared with the control [（24.77 ± 4.57） ×10^3 U/L vs （12.91 ± 3.97） ×10^3 U/L, P 〈 0.01 ）]. The mRNA expression