Hanelt S, Helbig R, Hartmann A, Lang M, Seidel A, Speit G
Universität Ulm, Abteilung Medizinische Genetik, Germany.
Mutat Res. 1997 Apr 24;390(1-2):179-88. doi: 10.1016/s0165-1218(97)00019-0.
Genotoxic effects of benzo[a]pyrene (BP) and its reactive metabolites (+/-)-anti-benzo[a]pyrene-7,8-diol 9,10-oxide ((+/-)-anti-BPDE) were comparatively investigated in vitro with the permanent human fibroblast cell line MRC5CV1. Induced DNA adducts were measured by 32P-postlabeling, DNA strand breakage was determined by the comet assay and the HPRT gene mutation test was used to detect cytotoxicity and mutagenicity. Treatment of MRC5CV1 cells with S9 mix-activated BP or with (+/-)-anti-BPDE resulted in a concentration-dependent increase in DNA adducts and strand breaks. Genotoxic effects of BP and (+/-)-anti-BPDE were detected by 32P-postlabeling and the comet assay with similar sensitivity. However, under the same experimental conditions, a clear induction of gene mutations was only found after (+/-)-anti-BPDE treatment. The relationship between the induction of primary DNA alterations like DNA strand breaks and DNA adducts and the induction of gene mutations is discussed.
利用永生化人成纤维细胞系MRC5CV1，在体外比较研究了苯并[a]芘（BP）及其活性代谢产物（±）-反式苯并[a]芘-7,8-二醇-9,10-环氧化物（（±）-反式-BPDE）的遗传毒性作用。通过32P后标记法测定诱导的DNA加合物，通过彗星试验测定DNA链断裂，并使用次黄嘌呤磷酸核糖转移酶（HPRT）基因突变试验检测细胞毒性和致突变性。用S9混合物激活的BP或（±）-反式-BPDE处理MRC5CV1细胞，导致DNA加合物和链断裂呈浓度依赖性增加。通过32P后标记法和彗星试验以相似的灵敏度检测到BP和（±）-反式-BPDE的遗传毒性作用。然而，在相同的实验条件下，仅在（±）-反式-BPDE处理后发现明显的基因突变诱导。讨论了DNA链断裂和DNA加合物等原发性DNA改变的诱导与基因突变诱导之间的关系。
