甲醛和苯联合吸入致雄性小鼠骨髓细胞的遗传毒性
Genotoxicity of Formaldehyde and Benzene Joint Inhalation on Bone-marrow Cells of Male Mice
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摘要:
目的 研究甲醛和苯联合吸入染毒对雄性小鼠骨髓细胞的遗传毒性作用。为评价甲醛和苯的安全性提供科学依据。 方法 60只健康清洁级昆明种纯系雄性小鼠,随机分为10组,每组6只。各组分别为阴性对照组(清洁空气),甲醛低(1.0 mg/m3)、中(3.0 mg/m3)、高(5.0 mg/m3)剂量组;苯低(500.0 mg/m3)、中(1500.0 mg/m3)、高(2500.0 mg/m3)剂量组,联合染毒低(0.5 mg/m3甲醛+250.0 mg/m3苯)、中(1.5 mg/m3甲醛+750.0 mg/m3苯)、高(2.5 mg/m3甲醛+1250.0 mg/m3苯)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,采用微核试验和单细胞凝胶电泳试验(彗星试验)检测甲醛和苯单独或联合染毒致骨髓细胞的遗传毒性。 结果 与阴性对照组相比,甲醛、苯单独及联合染毒各剂量组均呈现骨髓细胞微核率升高、彗星尾部DNA含量增多、尾距增大(P < 0.05)。与相应单独染毒组相比,联合染毒各剂量组骨髓细胞微核率明显升高(P < 0.05);联合染毒低、中剂量组彗星尾部DNA含量增多、尾距增大(P < 0.05);联合染毒高剂量组彗星尾部DNA含量和尾距高于甲醛高剂量染毒组(P < 0.05),与苯高剂量染毒组比较,其差异无统计学意义。 结论 甲醛和苯联合吸入染毒对雄性小鼠骨髓细胞的遗传损伤作用大于甲醛、苯单独染毒时的作用,二者对雄性小鼠骨髓细胞的联合遗传毒性作用可能具有协同作用。 Abstract:Objective To explore genotoxicity of formaldehyde and benzene joint inhalation on bone-marrow cells of male mice, and to provide a scientific basis about evaluating the safety exposure to formaldehyde and benzene. Methods Sixty healthy and clean Kunming inbred strain male mice were randomly divided into 10 groups with 6 mice in each group. The negative control group were exposed to clean air. The 3 formaldehyde treatment groups were exposed to formaldehyde at dosage of 1.0 mg/m3 (the low dose group), 3.0 mg/m3 (the moderate dose group), or 5.0 mg/m3 (the high dose group). The benzene treatment groups were exposed to benzene at dosage of 500.0 mg/m3 (the low dose group), 1 500.0 mg/m3 (the moderate dose group), or 2 500.0 mg/m3 (the high dose group). The joint treatment groups of formaldehyde and benzene were exposed to those at dosage of 0.5+250.0 mg/m3 (formaldehyde+benzene), 1.5+750.0 mg/m3, and 2.5+1 250.0 mg/m3 respectively. The treatments were conducted by static inhaling for two consecutive weeks, two hours a day, then the mice were killed on 15th day. The genotoxicity of formaldehyde and benzene was tested by micronucleus assay and single cell gel electrophoresis (comet assay). Results Compared with the negative control group, micronucleus rate, tail DNA% and tail moment in each dose group of formaldehyde or benzene exposure groups and joint exposure groups were much higher (P < 0.05). Compared with single exposure groups, the micronucleus rate of each dose group of the joint exposure groups was much higher (P < 0.05), the tail DNA% and tail moment in the low dose group and the moderate dose group of the joint exposure groups were much higher (P < 0.05). The tail DNA% and tail moment in the high dose group of the joint exposure groups were much higher than single formaldehyde high dose group (P < 0.05), but not higher than single benzene high dose group. Conclusion The genetoxic effect of combined exposure to formaldehyde and benzene on the bone-marrow cells of the male mice was more severe than that of the single exposure, which may be caused by the synergistic toxic effect.
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