RESUMO
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 γ-irradiation,the mRNA and 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 irradiation.Conclusions 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.