甲醛和甲苯联合染毒对小鼠骨髓细胞的遗传毒性研究

Joint Genotoxicity of Formaldehyde and Toluene Inhalation to Bone-marrow Cells of Mice

目的研究甲醛和甲苯联合吸入染毒对小鼠骨髓细胞的遗传毒性作用。方法 72只健康清洁级昆明纯系小鼠,雌雄各半,按3×3析因设计随机分为9组,每组8只,分别为:对照组(清洁空气),低甲醛(1 mg/m3)、高甲醛(5 mg/m3)剂量组,低甲苯(400 mg/m3)、高甲苯(2 000 mg/m3)剂量组,低甲醛+低甲苯(1 mg/m3+400 mg/m3)、低甲醛+高甲苯(1 mg/m3+2 000 mg/m3)、高甲醛+低甲苯(5 mg/m3+400 mg/m3)、高甲醛+高甲苯(5 mg/m3+2 000 mg/m3)剂量组。采用静式吸入染毒,每天2 h,连续14 d。染毒结束次日处死小鼠,采用微核试验和彗星试验检测甲醛和甲苯联合染毒致骨髓细胞的遗传毒性作用。结果微核试验结果显示,甲醛和甲苯致小鼠骨髓细胞微核的形成具有统计学意义(P<0.05),且随着染毒浓度的增加微核率增大,二者在高浓度时微核率最高(33.83‰),甲醛和甲苯对小鼠骨髓细胞微核率的影响有交互作用(P<0.05)。彗星试验结果显示,甲醛和甲苯对骨髓细胞彗星尾部DNA含量、彗星细胞尾矩形成均有影响(P<0.05);二者联合染毒对小鼠骨髓彗星细胞尾部DNA含量、尾矩形成均有交互作用(P<0.05)。结论甲醛和甲苯对小鼠骨髓细胞均有遗传损伤作用,二者联合吸入对小鼠骨髓细胞的遗传损伤具有一定的协同作用。

Objective To study the joint genotoxicity of formaldehyde and toluene inhalation to bone-marrow cells of the mice.Methods Seventy-two healthy and clean Kunming inbred strain mice were randomly divided into nine groups,the control groups were exposed at clean air,the formaldehyde treatment groups were exposed at dosage of 1 mg/m3,5 mg/m3,the toluene treatment groups were exposed at dosage of 400 mg/m3,2 000 mg/m3 and the joint treatment groups of formaldehyde and toluene were exposed at dosage of 1＋400 mg/m3,1＋2 000 mg/m3,5＋400 mg/m3,5＋2 000 mg/m3 respectively.The mice were exposed to formaldehyde and toluene for 14 days,2 hours a day,then killed them on 15th day.The joint genotoxicity of formaldehyde and toluene was tested by micronuclei and single cell gel electrophoresis.Results Micronucleus tests showed,When the mice were exposed to formaldehyde and toluene,the micronucleus rate was increased with the increasing of formaldehyde and toluene,the highest rate was the nine group（33.83%）,the two substances could induced micronucleus rate significantly（P0.05）,and there was interaction between formaldehyde and toluene in micronucleus rate（P0.05）.The comet assay displayed that the formaldehyde and toluene have significant affect in tail DNA% and tail moment of comet（P0.05）.The two substances existed interaction in tail DNA% and tail moment（P0.05）.Conclusion Inhaling formaldehyde and toluene can induce genetic damage in bone-marrow cells of the mice.The joint exposure to formaldehyde and toluene has synergistic effect on bone-marrow cells in genotoxicity.