低剂量镉诱导细胞氧化损伤的机理研究  

Mechanism of low-dosage cadmium on cellular oxidative damage

作　　者：罗松年[1] 张迎梅[1] 任培丽[1] 

机构地区：[1]兰州大学生命科学学院,兰州730000

出　　处：《安全与环境学报》2006年第3期77-79,共3页Journal of Safety and Environment

基　　金：国家自然科学基金项目(30470302)

摘　　要：镉是一种有毒重金属,能诱导酿酒酵母的氧化损伤。为了研究低剂量镉诱导细胞氧化损伤的作用,通过有葡萄糖和无葡萄糖的酵母培养基,用浓度2μmol/L和10μmol/L的CdCl2染毒酿酒酵母10h后,统计酿酒酵母细胞的存活率,并用HPLC EC法测定酿酒酵母线粒体DNA中8OH dG/105dG比值。结果表明:无葡萄糖条件下,10μmol/L的CdCl2染毒时酿酒酵母对Cd2+的耐受性比有葡萄糖时明显高(P<0.01),而且线粒体DNA氧化损伤程度也明显低(P<0.01);但2μmol/L的CdCl2染毒时,酿酒酵母对Cd2+的耐受性和线粒体DNA氧化损伤程度与有葡萄糖条件下相比差异不显著(P>0.05)。因此,本文认为低浓度Cr主要对酿酒酵母细胞质中蛋白造成氧化损伤,浓度升高时则对线粒体DNA也产生氧化损伤。The present paper is aimed at introducing the author＇ s study of the oxidative damage in yeast Saccharomyces cerevisiae caused by Cadmium. As is known, Cadmium is a kind of toxic heavy metal that can induce oxidative damage. When exposed to CdCl2 dosed 2 μmol/L and 10 μmol/L for 10 hours and when yeast cells were collected for survival assay, oxidative damage of mitochondrial DNA （mDNA） could be found with the level of 8-OH-dG/105dG by HPLE-EC. And when the results were compared between the situations with or without glucose in the medium, it can be concluded that the tolerance of yeast to Cd^2 ＋ would be higher in glucose-free medium than that in glucose-sufficient medium（ P 〈 0.01）. This proves that the yeast in glucose-free medium has had a low level of oxidative damage in mDNA （ P 〈 0.01） at the exposure of 10 μmol/L CdCl2. However, at the exposure of 2 μmol/L CdCl2, there were no signifi- cant differences between the Cd^2＋ tolerance and mDNA oxidative damage （ P 〉 0.05）. Therefore, cadmium with low-dosage can be the main reason for the oxidative damage of cytoplasm protein, however, with the increase of concentration, cadmium would result in the oxidative damage of mDNA.

关 键 词：环境毒理 镉 酿酒酵母 氧化损伤 线粒体DNA 葡萄糖 

分 类 号：Q935[生物学—微生物学]