硒对大鼠肝脏抗氧化酶活性及基因表达的影响

Effects of selenium on activities of antioxidant enzymes and gene expression in rat's livers

目的 探讨补硒对大鼠肝脏抗氧化酶活性及基因表达的影响。方法 给大鼠补充不同剂量的硒 ,观察补硒对大鼠肝脏硒、丙二醛 (MDA)含量 ,超氧化物歧化酶 (SOD)、过氧化氢酶 (CAT)、谷胱甘肽过氧化物酶 (GSH -Px)、硫氧还蛋白还原酶 (TR)活性及TRmRNA表达的影响。结果 补硒 2 0 μg/kg能显著降低MDA含量 ,增强SOD、CAT、GSH -Px的活性 ,而补硒 40 ,80 μg/kg却显著增加MDA含量 ,降低CAT、GSH -Px和TR的活性 ,并能降低TRmRNA表达水平。硒的含量则表现出剂量依赖性。结论 硒对机体有双重作用 ,适当剂量硒增强机体抗氧化功能 。

Objective To explore the effects of selenium(Se) supplementation on the activities of antioxidant enzymes and gene expression in rat's livers.Methods Different levels of selenium were given to the rats and the changes of some parameters were observed in rat's livers which included the contents of Se and malondialdehyde(MDA),the activities of superoxide dismutase(SOD),catalase(CAT),glutathione peroxidase(GSH-Px),thioredoxin reductase(TR) and TR mRNA expression.Results 20 μg/kg Se supplementation could decreased MDA content and upregulated the activities of SOD,CAT,GSH-Px significantly in rat's livers,whereas 40,80 μg/kg Se supplementation increased MDA content and decreased the activities of CAT,GSH-Px,TR and TR mRNA level.Se levels were elevated dose-dependently.Conclusion Appropriate dosage of selenium showed good effects on antioxidant function and Se overexposure can result in chronic Se intoxication.