混合重金属离子诱导的鲫鱼DNA损伤与基因表达

DNA DAMAGE AND ITS GENE EXPRESSION OF FISH INDUCED BY MIXTURE-METALS

本研究结果表明 ,混合重金属离子诱导了鲫鱼鱼鳃、肝脏组织产生脂质过氧化作用 (LPO) ;鱼鳃、肝脏组织中的LPO产物丙二醛 (MDA)含量与暴露浓度呈指数效应关系 ;鱼鳃、肝脏的指数方程分别为Y =e- 2 87X + 0 6 87和Y =e- 2 19X + 0 115;LPO引发了DNA链的断裂损伤 ;3H TdR在鱼鳃、肝脏细胞DNA中大量掺入 ,并与重金属离子暴露浓度间呈双向效应 ;重金属离子的暴露极大地提高了鲫鱼肝脏DNA的总甲基化水平 ;重金属离子的毒性作用干扰了鲫鱼细胞的正常生理周期和基因的表达 ,是引发水生生物基因毒性作用的主要机制。

DNA damage and its gene expression in fish( Carassius auratus ) after exposed in mixture\|metals of 0 00～0 54mg/L were studied.The results demonstrated that the lipid superoxide was induced in the fish gill and liver tissues.The exponential relation was found between the MDA(LPO product) content and exposure concentration.The equations for the gill and liver were Y =e -2 87X+0 687 and Y =e -2 19X+0 115 respectively.LPO caused the breakage of DNA strand and 3H TdR incorporation increased greatly in the gill and liver DNA. A double effect was shown between the 3H TdR incorporation and exposure concentration.The mixture\|metals also improved significantly the methylation level in the liver DAN.The toxicity of the mixture\|metals disturbed the normal physiological circle and inhibited the gene expression of the fish cell,which was the main genotoxicity mechanism to the aquatic organism.