LaVelle J M, Witmer C M
Environ Mutagen. 1984;6(3):311-20. doi: 10.1002/em.2860060307.
A fluctuation test using Salmonella typhimurium strain 1535 has been used in an experimental protocol to assess biological effects of interactions between chromium (VI), such as K2CrO4, and two DNA-damaging agents, ethyl methanesulfonate (EMS), and sodium azide. Mutagenicity, expressed as the average number of mutations induced over a parallel control, was determined for the compounds alone and in combination. The significance of the differences between the "expected" response, calculated by simple addition of the responses from the individual tests, and the observed response when the combination was tested, were estimated by chi square. For the combination of K2CrO4 and NaN3, the response was significantly greater than expected suggesting a possible potentiation of mutagenesis. The opposite (a less-than-additive response) was found for the K2CrO4/EMS combination. Both effects were found to be dose related to the concentration of potassium chromate used. Toxicity of the compounds or their combinations to the bacteria could not explain the results.
在一项实验方案中，使用鼠伤寒沙门氏菌1535菌株进行了波动试验，以评估六价铬（如铬酸钾）与两种DNA损伤剂甲磺酸乙酯（EMS）和叠氮化钠之间相互作用的生物学效应。单独及组合测定了这些化合物的诱变性，以平行对照中诱导的平均突变数表示。通过简单相加各个试验的反应来计算“预期”反应，将其与组合试验时观察到的反应之间的差异显著性用卡方检验进行估计。对于铬酸钾和叠氮化钠的组合，反应显著大于预期，表明可能存在诱变增强作用。而铬酸钾/EMS组合则出现相反情况（反应小于相加效应）。发现这两种效应均与所用铬酸钾的浓度存在剂量相关性。化合物或其组合对细菌的毒性无法解释这些结果。
