彗星试验与微核测试评价硝酸铈铵对蚕豆根尖细胞的遗传毒性

Evaluation of Genotoxicity of Vicia faba Root Tip Cells Induced by Ammonium Ceric Nitrate Using Comet Assay and Micronucleus Test

设置1、4、16、64、128、256mgL^(-1)共6个浓度梯度的硝酸铈铵溶液,双蒸水作对照,以微核率、染色体畸变率、头部DNA百分率、尾部DNA百分率、尾距和Olive尾距等来评价硝酸铈铵对蚕豆根尖细胞DNA的损伤.随硝酸铈铵浓度的升高,与对照组相比,染毒组的微核率和染色体畸变率升高,有丝分裂指数降低,具有良好的剂量–效应关系,当硝酸铈铵≥4mgL^(-1)时,3个指标均表现为显著性或极显著性变化(P<0.05或P<0.01).染毒组的尾距和Olive尾距与对照组相比均具有极显著性增加;随硝酸铈铵浓度的增加,头部DNA百分率减小,尾部DNA百分率增加,各染毒组均表现为极显著性变化.研究表明一定浓度(≥4mgL^(-1))的硝酸铈铵具有一定的细胞毒性和遗传毒性.

Six concentrations of ammonium ceric nitrate （0, 1, 4, 16, 64, 128 and 256 mgL^（-1）） and control group （double distilled water） were designed to study the genotoxicity of ammonium ceric nitrate in the root tip cells of Vicia faba. Micronucleus test and Comet assay were employed to detect DNA damage of the root tip cells based on the parameters of the head DNA percentage, tail DNA percentage, tail moment, olive tail moment, and the frequency of micronucleus （FMN） and frequency of chromosomal aberrations （CAF）. The results showed that the FMN and CAF of the treated groups were significantly increased with the rising of ammonium ceric nitrate concentration compared with the control group, but mitosis index was decreased, with an excellent relationship between dosage and effect. When the concentration of ammonium ceric nitrate was 4mgL^（-1） or more, the three indexes signif icantly differed from the control （P0.05 or P0.01）, while the tail moment and olive tail moment of all the treated groups signifi cantly increased compared with those of the control （P0.01）. The head DNA percentage of the treated groups were decreased signif icantly with the increasing of ammonium ceric nitrate concentration, compared with the control group, but the tail DNA percentage was on the contrary. Both the head DNA percentage and tail DNA percentage differed from the control signifi cantly （P0.01）. It was suggested that the ammonium ceric nitrate at certain concentration （≥4 mgL^（-1）） would produce genotoxicity and cytotoxicity to root tip cells of V. faba. Fig3, Tab2, Ref21