DNA损伤修复能力与慢性苯中毒关系研究

目的探讨DNA修复能力与慢性苯中毒的关系。方法以γ射线作为诱变剂造成淋巴细胞DNA损伤,应用彗星试验和外周血淋巴细胞胞质分裂阻滞微核检测法,评价63名慢性苯中毒工人和45名同期接苯但无苯中毒表现的同工种对照工人外周血淋巴细胞DNA链断裂和染色体损伤微核形成的修复能力。结果苯中毒组的彗星尾长差[(4·64±1·57)μm]显著高于对照组[(3·77±1·30)μm](P=0·0029)。3AB指数与对照组无显著性差异。彗星尾长差>3·81μm的研究对象发生慢性苯中毒的相对危险性显著增高(OR=2·490,95%CI1·068~5·806,P=0·0346),而且,慢性苯中毒危险性与彗星尾长差之间存在显著性的趋势关系(P=0·0024)。3AB指数<0·20的研究对象发生慢性苯中毒的相对危险性与3AB指数≥0·20的研究对象无显著性差异。结论DNA链水平的修复能力与慢性苯中毒的发生关系密切,修复能力越差,发生慢性苯中毒的危险性越高。本研究未证明染色体水平的修复能力与慢性苯中毒的联系。

Study on repair capacity of DNA damage associated with chronic benzene poisoning

OBJECTIVE: To explore the repair capacity of DNA damage associated with chronic benzene poisonings. METHODS: 63 workers suffered from chronic benzene poisonings and 45 workers exposed to benzene, who were engaged in the same job title, were investigated. Comet assay and cytokinesis-block micronucleus (CBMN) detection were used to evaluate gamma-radiation-induced DNA and chromosomal damage and repair capacity in peripheral blood lymphocyte. RESULTS: The comet tail length difference of the benzene poisoning group (4.64 +/- 1.57 microm) was significantly higher than that of the control group (3.77 +/- 1.30 microm) (P = 0.0029). There was no significant difference of the 3AB index between the poisoning group and the control group. The relative risk of benzene poisoning in the subject with comet tail length difference > 3.81 was significantly higher than that in the subject with comet tail length difference < or = 3.81 microm (OR = 2.490, 95% CI:1.068 - 5.806, P = 0.0346). The relative risk increased along with the comet tail length difference, and the trend was significant (P = 0.0024). There was no significant difference between the relative risk of benzene poisoning in the subject with 3AB index < 0.20 and that in the subject with 3AB index > or = 0.20. CONCLUSION: DNA repair capacity on DNA-strand level might tightly associate with chronic benzene poisoning. The DNA repair capacity on DNA-strand level would be worse, and the benzene poisoning risk could be higher. There was no clear relation between the DNA repair capacity on chromosome level and the benzene poisoning risk.