镍和镉对人外周血淋巴细胞的DNA损伤作用.doc

镍和镉对人外周血淋巴细胞的DNA损伤作用    蔡颖庄志雄【摘要】目的了解不同类型DNA损伤在镍、镉遗传毒理中的不同意义。方法分别用NiCl2和CdCl2对人外周血淋巴细胞进行体外染毒,再用单细胞凝胶电泳法,测定其DNA单链、双链断裂和DNA-蛋白质交联水平,同时用[3H]-NAD参入法测定了这些细胞的聚(腺苷二磷酸-核糖)聚合酶(PARP)活性。结果尽管在两种金属处理过的细胞中DNA单链、双链断裂和DNA-蛋白质交联水平与对照相比均有明显增高,~~。两种金属在低浓度时(~,)还能通过诱导DNA断裂而激活PARP,高浓度时(~,~)反而不激活该酶。结论 DNA双链断裂的形成和PARP激活的受阻可能在镍和镉的致癌和致突变机制中起着重要的作用。【关键词】镍镉 DNA损伤 NAD+ADP核糖转移酶DNADamageinHumanPeripheralBloodLymphocyteCausedbyNickelandCadmium CAIYing*,ZHUANGZhixiong. *LaboratoryCenter,ShantouBureauofHealthQuarantineService,Guangdong515031 【Abstract】 Objective -anddouble-strandbreaksandDNA-proteincrosslinksinhumanperipherallymphocyteweredeterminedwithsinglecellgelelectrophoresis(SCGE).Activityofpoly(ADP-ribose)polymerase(PARP)wasdeterminedby[3H]- LevelsofDNAsingle-anddouble-strandbreaksandDNA-proteincrosslinksinhumanperipherallymphocytetreatedwithnickelandcadmiumweresignificantlyhigherthanthoseuntreated,butdose-~~(~0