^(32)P后标法分析二氯胺基酚-DNA加合物

DETECTION OF DICHLOROAMINOPHENOL-DNA ADDUCTS USING 32 P-POSTLABELLING ASSAY

本研究以核酸酶Ｐ１和正丁醇增强的３２Ｐ后标法分析了２，４—二氯—６—胺基酚（ＤＣＡＰ）染毒的Ｖ７９细胞ＤＮＡ加合物。试验结果：在核酸酶Ｐ１富集方式下，观察到４种ＤＣＡＰ诱发的ＤＮＡ加合物，其含量分别为３８．７、７１．５、８５．７和２２．４／１０８单核苷酸；而正丁醇萃取法，未检出加合物。该结果表明：ＤＣＡＰ具有与哺乳动物细胞ＤＮＡ产生共价结合的能力，与ＤＮＡ共价结合可能是ＤＣＡＰ产生遗传危害和致癌的基本途径。由于ＤＣＡＰ是致癌性农药（８３—１除草剂）在体内的主要代谢产物，ＤＮＡ加合物分析可能成为８３—１除草剂暴露人群监测的重要生物标志。本文还对两种富集方法的敏感性进行了讨论，提出：化合物的极性可能是选用正丁醇富集法的主要依据。

A detection of DNA adducts in V79 cells treated by 2,4-dichloro-6-aminophenol(DCAP) was carried out using 32 P-postlabelling assay with the nuclease P 1 and the butanol enhancement methods.Results showed that with the nuclease P 1 enhancement 4 DNA adducts induced by DCAP were observed and the amount of the DNA adducts were 38.7, 71.5 ,85.7,and 22.4/10 8 nucleotides respectively,and that with butanol enhancement no one was detected.The results indicated that DCAP was capable of forming covalent bonds to DNA in mammalian cells and the covalent binding to DNA might be an essential pathway by which DCAP resulted in genotoxic and carcinogenic effects.Because DCAP is a major metabolite of the 83-1 herbicide,an animal carcinogen,the DNA adduct analyses could be applied as a biomarker for biomonitoring of human exposure to the herbicide.The sensitivity of two enhancement methods has also been discussed and it was suggested that the polarity of chemicals was the most important factor for selecting the butanol enhancement method.