碲化镉量子点对小鼠肝脏氧化应激及DNA损伤效应初探

目的探讨碲化镉量子点(CdTe QDs)对小鼠肝脏的氧化应激及其DNA损伤作用。方法将30只雄性ICR小鼠随机分成5组,每组6只动物,尾静脉注射染毒。其中小鼠肝脏自由基检测试验设阴性对照组和低、中、高3个剂量组,即0、3.75、37.5及375nmol/ml CdTe QDs溶液组;小鼠单细胞凝胶电泳试验组别同前,另设阳性对照组(20mg/ml环磷酰胺)。每只动物注射0.2ml实验溶液,对照组注射等体积的生理盐水。染毒24h后断头处死动物。用低温电子顺磁共振(EPR)检测小鼠肝脏组织自由基水平的变化;用单细胞凝胶电泳(SCGE)检测小鼠肝细胞DNA损伤。结果染毒24h时后,随着CdTe QDs染毒剂量的增加,低、中、高染毒组的小鼠肝脏组织自由基水平与阴性对照组比较有统计学意义的增高(P<0.05,P<0.01);小鼠肝细胞SCGE检测彗星尾长、Olive尾矩、尾DNA%、头尾比显著高于阴性对照组(P<0.01)。结论 CdTe QDs可导致小鼠肝细胞产生氧化应激和DNA损伤,并有一定的剂量-效应关系。

Effects of CdTe QDs on oxidative stress and DNA damage of liver cells in mice

Objective To investigate the effects of CdTe QDs(cadmium telluride quantum dots) on oxidative stress and DNA damage of liver cells in mice.Methods Thirty ICR male mice were randomly divided into 5 groups: one negative control(normal saline) group.three CdTe QDs groups(exposed by intravenous injection of 0.2 ml of CdTe QDs at the concentration of 3.75,37.5 and 375 nmol/ml respectively) for electron paramagnetic resonance(EPR) test,and another positive control group(exposed by intravenous injection of 0.2 ml of cyclophosphamide 20mg/ml) for single cell gel electrophoresis(SCGE) test.All mice were decapitated 24h after the injection,free radicals and DNA damage of liver cells were detected by EPR and SCGE.Results The levels of oxygen free radicals detected by EPR were increased with the increase of CdTe QDs.The tail length,olive tail moment,tail DNA(%) and the ratio of tail/head examined by SCGE were also increased with the increase of the dosage of CdTe QDs(P<0.01).Conclusion CdTe QDs could induce oxidative stress and DNA damage of liver cells in mice with a dose-effect relationship.