中文摘要：

氧自由基在很多的疾病发展过程中发挥重要的调节作用。本试验的目的是通过研究糖皮质激素诱导的骨质疏松模型血清抗氧化物酶活性、脂质过氧化和NO水平变化，从而明确氧自由基是否参与调节糖皮质激素诱导的骨质疏松症的发病过程。试验将24只新西兰大白兔，随机分为3组，并分别肌肉注射醋酸泼尼松龙（0．5mg／kg）、维生素C（100mg／kg）结合醋酸泼尼松龙（0．5mg／kg）、生理盐水，历时9周。试验结果表明，醋酸泼尼松龙诱导家兔血清OH、H2O2、N0水平以及碱性磷酸酶活性相对于生理盐水注射组显著升高，而SOD活性及骨密度明显降低，而维生素C干预组血清自由基水平在明显降低的同时，骨量的丢失也减慢。结果说明，氧自由基在糖皮质激素诱导的骨质疏松症发病过程中具有正向促进作用，并且这种作用可以被抗氧化剂所消弱。

英文摘要：

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 Glueocorticoid-induced osteoporosis rabbits had significantly lower superoxide dismutase.BMD and higher levels of alkaline phosphatase,hydrogen per oxide,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 in crease glucocorticoid-induced bone loss,and the increase could be inhibited by anti-oxidant （vitamin C）.