Effect of oxyradical on glucocorticoid-induced osteoporosis in rabbit.

Reactive oxygen species play an important role in the pathogenesis of many diseases.The aims of this study are to compare serum antioxidant enzyme activities,lipid peroxidation and nitric oxide levels in rabbit with glucocorticoid-induced osteoporosis to assess the relationship between bone mineral density and these oxidant/antioxidant parameters.Twenty-four mature female New Zealand white rabbits(2.5 to 2.8 kg) in three groups were injected with prednisolone acetate (0.5 mg/kg),both prednisolone acetate(0.5 mg/kg) and vitamin C(100 mg/kg) or saline every two days for nine weeks,respectively.The results demonstrated that Glucocorticoid-induced osteoporosis rabbits had significantly lower superoxide dismutase、BMD and higher levels of alkaline phosphatase,hydrogen peroxide,hydroxy radical,nitric oxide and malondialdehyde than thoseot the control animals.Serum hydrogen peroxide,nitric oxide and malondialdehyde levels significantly decreased,but hydroxy radical increased in vitamin C injected group compared with that in prednisolone acetate injected group.In conclusion:Reactive oxygen species could increase glucocorticoid-induced bone loss,and the increase could be inhibited by anti-oxidant(vitamin C).