中文摘要：

目的研究电离辐射对成骨细胞RANKL和OPG表达的影响，探讨辐射导致骨损伤的分子机制。方法采用MC3T3-E1细胞诱导分化为成骨细胞，经0、2和4Gy137cs1射线照射后，采用实时定量PCR及Westernblot方法检测电离辐射对于成骨细胞RANKL和OPGmRNA及其蛋白水平表达的影响。结果4Gy照射可以导致成骨细胞RANKLmRNA（t=5．41，P〈0．05）及其蛋白（t=68．37，P〈0．01）表达水平上调；2和4Gy照射可以导致成骨细胞OPGmRNA（t=5．20、7．02，P〈0．05）及其蛋白（t=7．78、9．45，P〈0．05）表达水平下调。结论2和4Gy电离辐射可以导致成骨细胞中RANKL／RANK／OPG通路发生改变，促进破骨细胞的分化和成熟，进而促进破骨细胞的骨吸收作用。

英文摘要：

Objective To investigate the effect of radiation on the expressions of RANKL and OPG in osteoblasts in order to disclose the molecular mechanism of bone injury induced by ionizing radiation. Methods The osteoblasts were differentiated from MC3T3-E1 cells. After 2 or 4 Gy137 Cs T- irradiation, the mRNA a1nd protein expression levels of RANKL and OPG of osteoblast precursor and osteoblast were detected by real-time PCR and Western blot. Results The expressions of RANKL mRNA （t = 5.41, P 〈 0.05） and protein （t = 68.37, P 〈 0. 01 ） were up-regulated after 4 Gy irradiation, while the expressions of OPG mRNA （ t = 5.20,7.02, P 〈 0. 05 ） and protein （ t = 7.78,9.45, P 〈 0.05 ） were down-regulated after 2 and 4 Gy iITadiation. Conclllsions 2 and 4 Gy ionizing radiation alters RANKL/ RANK/OPG pathway in osteoblasts, which may promote the osteoclast differentiation and maturation and hence promote bone resorption of osteoclasts.