Effects of cobalt and chromium ions on osteoblasts:cytotoxicity and the releasion of RANKL and OPG

[Objective]To investigate the cytotoxicity of cobalt(Co2+) and chromium(Cr3+)ions on mice osteoblast(MC3T3E1)and the effects on the secretion of RANKL/OPG from osteoblast because of the stimulation of Co2+ and Cr3+ ions. [Methods]The osteoblast in vitri was cultured.The cell viability was assured by MTT test.ELISA method was applied to detect RANKL(receptor activator of nuclear factor-kB ligand),OPG(osteoprotegerin) content in serum supernatant.[Results]Compared to the control,MTT test demonstrated that Co2+ and Cr3+ ions can obviously decrease the cell viability of osteoblast.When osteoblast were exposed to Co2+ and Cr3+ ions for 24 and 48 hours,the releasion of OPG increased by 32.1% and 17.8% as compared with the control(P0.05);the RANKL were 61.6-fold,13.8-fold growth(P0.05);and the ratios of RANKL/OPG proteins were upregulated by 51.4-fold and 12.3-fold.[Conclusion]Co2+ and Cr3+ ions have a cytotoxic effect on osteoblasts and stimulate the releasion of RANKL and OPG from osteoblast,upregulate the the ratios of RANKL/OPG proteins.