利用牙鲆和牙鲆鳃细胞(FG)检测除草剂丁草胺的急性毒性和遗传毒性

Study on the Acute Toxicity and Genotoxicity of Herbicide Butachlor in Flounder,Paralichihys Olivaceus,and Flounder Gill(FG) Cells

为科学评价丁草胺对牙鲆的毒性效应,本文采用生态毒理学方法研究丁草胺对牙鲆和体外培养的牙鲆鳃细胞(FG)的急性毒性以及对牙鲆血细胞的微核化和FG细胞的DNA的片断化诱导作用。结果表明:中性红(NR)吸收、MTT(四唑盐)检测和细胞蛋白含量分析测得丁草胺对FG细胞的24 h-IC_(50)分别是43.32、43.86和44.91μmol/L;低于10μmol/L的丁草胺对FG细胞没有毒性,20～80μmol/L的丁草胺对FG细胞的毒性表现为浓度依赖性;丁草胺对牙鲆的96 h-LC_(50)为6.55 nmol/L,约为体外培养FG细胞24 h-IC_(50)的1/7000;30μmol/L丁草胺处理FG细胞8 h后,FG细胞基因组DNA出现明显的片断化,并且随着处理时间的延长,DNA片断化越来越严重;1.28～3.84 nmol/L丁草胺处理牙鲆96 h后,牙鲆血细胞的微核率均明显升高。以上结果表明丁草胺对牙鲆高毒并且具有遗传毒性。

In this study the acute in vivo and in vitro toxicity of butachlor in flounder,Paralichihys olivaceus,and flounder gill cells(FG),as well as the genotoxicity of butachlor in the induction of micronucleus of the erythro- cytes of flounder,and fragmentation of genomic DNA of FG cells,were investigated for the risk assessment of butachlor to marine fish species.It was found that,the 24 h-IC_(50)values(median inhibition concentration)of butachlor in FG cells were 43.32,43.86 and 44.91μmol/L for neutral red(NR)uptake,MTT assay and cell protein assay,respectively;no acute cytotoxicity was observed in FG cells exposed to butachlor,which was lower than 10μmol/L.Above 20μmol/L,the cytotoxicity of butachlor to FG cells was obvious and dose-de- pendent;the fragmentation of genomie DNA of FG cells exposed to 30μmol/L butachlor was first observed af- ter 8 h exposure,and with the increase of the exposure time,the DNA damage became more severe;the ratios of micronucleus in the erythrocytes of flounder exposed to 1.28～3.84 nmol/L butachlor for 96 h were signifi- cantly increased in contrast to the control.Taken together,butachlor has a high acute lethal toxicity and geno- toxicity to flounder.