Yang D P, Graupensperger F, Minecci L C, Rubin B A
Environ Mutagen. 1981;3(1):45-52. doi: 10.1002/em.2860030105.
The frequency of sister chromatid exchange (SCE) in WI-38 cells was estimated by the 5-bromodeoxyuridine (BrdUrd)-dye technique after one hour's exposure to cyclophosphamide (CY), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), 4-nitroquinoline-1-oxide (4NQO), and maleic hydrazide (MH) with and without the addition of rat liver microsomal suspension (S-9) fraction with cofactors (S-9 mix). CY at concentrations from 1 x 10(-5) M to 1 x 10(-3) M with S-9 mix increased the number of SCEs per cell in a dose-dependent manner. Without S-9 mix, CY at concentrations below 1 x 10(-3) M failed to produce more SCEs than the controls. MNNG at 1 x 10(-8) M and 4NQO at 1 x 10(-7) M without S-9 produced significant increases in SCEs per cell. Addition of S-9 during treatment slightly decreased the effects of MNNG and 4NQO in the formation of SCEs. MH was tested at pH 6.4 and pH 7.6. At pH 7.6, MH at 1 x 10(-3)M without S-9 mix inhibited cell multiplication, but did not cause a significant increase of SCEs per cell. There were no interactions between MH (2 x 10(-4) M) and S-9 mix nor between MH and the pH levels tested. These results indicate that in the presence of metabolic activation, SCE formation in human diploid fibroblasts in vitro may be used as a potential assay for mutagenicity.
采用5-溴脱氧尿苷（BrdUrd）-染色技术，在有或无添加含辅助因子的大鼠肝微粒体悬浮液（S-9）组分（S-9混合物）的情况下，将WI-38细胞暴露于环磷酰胺（CY）、N-甲基-N'-硝基-N-亚硝基胍（MNNG）、4-硝基喹啉-1-氧化物（4NQO）和马来酰肼（MH）1小时后，估算姐妹染色单体交换（SCE）的频率。浓度为1×10⁻⁵ M至1×10⁻³ M的CY与S-9混合物以剂量依赖方式增加了每个细胞的SCE数量。在没有S-9混合物的情况下，浓度低于1×10⁻³ M的CY未能产生比对照组更多的SCE。无S-9时，1×10⁻⁸ M的MNNG和1×10⁻⁷ M的4NQO使每个细胞的SCE显著增加。处理过程中添加S-9略微降低了MNNG和4NQO在SCE形成中的作用。在pH 6.4和pH 7.6条件下对MH进行了测试。在pH 7.6时，1×10⁻³ M无S-9混合物的MH抑制细胞增殖，但未导致每个细胞的SCE显著增加。MH（2×10⁻⁴ M）与S-9混合物之间以及MH与所测试的pH水平之间均无相互作用。这些结果表明，在存在代谢活化的情况下，体外人二倍体成纤维细胞中的SCE形成可能用作潜在的致突变性检测方法。
