Garberg P, Akerblom E L, Bolcsfoldi G
AB Astra, Safety Assessment, Södertälje, Sweden.
Mutat Res. 1988 Jun;203(3):155-76. doi: 10.1016/0165-1161(88)90101-x.
A rapid genotoxicity test, based on the measurement of the proportion of single- to double-stranded DNA by alkaline unwinding and hydroxyapatite elution in mouse lymphoma cells treated in vitro with various chemicals, was evaluated. Seventy-eight compounds from diverse chemical groups, including commonly tested mutagens, toxic compounds not usually tested for genotoxicity and non-toxic compounds not thought to be genotoxic were tested. The results obtained were compared with those from the mouse lymphoma TK locus forward-mutation assay, providing a basis for assessing the relative sensitivity of the 2 assays using the same cells exposed to chemicals under similar conditions. Clear evidence of DNA-damaging activity was obtained with 43 of the compounds, while 4 gave equivocal results. Of the remaining 31 compounds, 14 were toxic without inducing DNA damage while the rest were non-toxic and did not induce any DNA damage. Results were available from both the alkaline unwinding assay and the mouse lymphoma assay for 61 compounds; they showed a concordance between the 2 assays of 77%. Of the 47 compounds that were positive or equivocal in the alkaline unwinding assay, only carbon tetrachloride and prednisolone were negative in the mouse lymphoma assay, while 12 of the 19 compounds that were negative in the alkaline unwinding assay were positive in the mouse lymphoma assay. These included 3 compounds that interfere with nucleic acid metabolism, and 3 crosslinking agents, which would be expected to produce mutations to a greater extent than strand breaks. The other 6 compounds were anthranilic acid, benzoquinone, p-chloroaniline, diethylmaleate, glucose and procarbazine HCl. Of these only the last is a known carcinogen. It is concluded from the present study that there was good overall agreement between the results of the DNA alkaline unwinding and mouse lymphoma TK locus assays, but that the sensitivity of the alkaline unwinding assay is lower for some classes of compounds. Bearing this in mind, the alkaline unwinding assay is considered suitable as a rapid screen for genotoxic activity in eukaryotic cells.
一种快速遗传毒性试验，基于通过碱性解旋和羟基磷灰石洗脱来测量体外经各种化学物质处理的小鼠淋巴瘤细胞中单链与双链DNA的比例，该试验得到了评估。测试了78种来自不同化学组的化合物，包括常用的诱变剂、通常不进行遗传毒性测试的有毒化合物以及被认为无遗传毒性的无毒化合物。将所得结果与小鼠淋巴瘤TK位点正向突变试验的结果进行比较，为评估在相似条件下用相同细胞暴露于化学物质时这两种试验的相对敏感性提供了依据。43种化合物获得了DNA损伤活性的明确证据，而4种给出了模棱两可的结果。在其余31种化合物中，14种有毒但未诱导DNA损伤，其余无毒且未诱导任何DNA损伤。对于61种化合物，碱性解旋试验和小鼠淋巴瘤试验均有结果；它们显示两种试验的一致性为77%。在碱性解旋试验中呈阳性或模棱两可的47种化合物中，只有四氯化碳和泼尼松龙在小鼠淋巴瘤试验中为阴性，而在碱性解旋试验中为阴性的19种化合物中有12种在小鼠淋巴瘤试验中为阳性。这些包括3种干扰核酸代谢的化合物和3种交联剂，预计它们产生突变的程度会比链断裂更大。其他6种化合物是邻氨基苯甲酸、苯醌、对氯苯胺、马来酸二乙酯、葡萄糖和盐酸丙卡巴肼。其中只有最后一种是已知的致癌物。从本研究得出的结论是，DNA碱性解旋试验和小鼠淋巴瘤TK位点试验的结果总体上有良好的一致性，但碱性解旋试验对某些类别的化合物敏感性较低。考虑到这一点，碱性解旋试验被认为适合作为真核细胞遗传毒性活性的快速筛选方法。
