用彗星试验研究饮用水中有机提取物对小鼠睾丸细胞DNA的损伤作用

Experimental study of the organic extracts of drinking water on DNA damage of testicle cells in mice by the comet assay

目的通过彗星试验探讨饮用水两种不同消毒工艺所产生的非挥发性有机提取物对小鼠睾丸细胞DNA的损伤作用。方法设对照组,低、中和高剂量组共4个组,采用彗星试验检测NZ和XC水厂丰水期和枯水期水源水、自来水水样的非挥发性有机提取物对小鼠睾丸细胞DNA的损伤,并进行比较。结果各剂量组都出现了明显的拖尾现象,NZ与XC水厂的拖尾率比较差异无统计学意义。各剂量组的平均尾长明显高于对照组,NZ水厂低剂量组中,枯水期水源水平均尾长(19.3±2.7)μm高于自来水的(16.0±2.5)μm;高剂量组中,丰水期水源水高于自来水。水源水中,枯水期低剂量组低于丰水期、中剂量组高于丰水期;自来水中,枯水期中剂量组低于丰水期,高剂量组高于丰水期。XC水厂低剂量组中,丰水期的水源水平均尾长(15.5±1.0)μm低于自来水的(24.9±2.6)μm,中剂量组中,枯水期水源水高于自来水。水源水中,丰水期低剂量组低于枯水期,中剂量组和高剂量组丰水期高于枯水期;自来水中,丰水期中剂量组高于枯水期。结论 NZ和XC水厂的丰水期和枯水期有机提取物均含有导致小鼠睾丸细胞DNA损伤的物质;水源水与自来水、丰水期与枯水期表现为不同程度的DNA损伤。

Objective Compare the DNA damage effects on testicle cells in mice of the non-volatile chlorination by-products generated from two different drinking water disinfection processes. Methods The mice were randomly divided into four groups： negative group, low-dose group, middle-dose group and high-dose group. The testicular cell DNA damages by the organic extracts from the water samples from the water source of the NZ and XC manufactories during wet season and dry season, and also the tap water sample were determined by comet assay. Results Tailing in the comet assay was observed in all the treated samples. There was no significant difference in the trailing rates of samples from NZ and XC. The average tail length of treated groups was higher than the control group. In the low-dose group, the average tail length of source water sample of NZ from the dry season was higher than that from tap water. In high-dose group, the average tail length of source water sample of NZ from wet season was higher than that from tap water. The average tail length of the source water from dry season in low-dose group was lower than that from wet season, but that in the middle-dose group was higher than that from the wet season. The average tail length of the tap water sample from dry season in middle-dose group was lower than that from wet season. In low-dose group ,the average tail length of source water sample of XC from wet season was lower than that from tap water. In middle-dose group, the average tail length of source water sample of XC from dry season was higher than that from tap water. The average tail length of the source water sample from wet season in low-dose group was lower than that from dry season. The average tail lengths of sample from wet season in middle-dose and high-dose group were higher than those from dry season. The average tail length of tap water sample from wet season in middle-dose group was higher than that from dry season. Conclusion Organic extracts of water samples from NZ and XC in wet and dry seasons contain genotoxic compounds. Water samples from different source water, tap water, wet and dry seasons showed different degree of DNA damage.