中文摘要：

目的观察多氯联苯（PCBs）153和苯并[a]芘（B[a]P）单独及联合处理对人肝肿瘤细胞HepG2的DNA损伤作用。方法以HepG2细胞为靶细胞，以DMSO为溶剂对照，PCB153设4个剂量组：0．1、1、10和100μmol／L，B[a]P设4个剂量组：12．5、25、50和100。应用单细胞凝胶电泳试验检测和B[a]μmol／LPCB153P单独和联合处理对Helz．G2细胞DNA损伤的影响；通过荧光分光光度法分别测定PCB153对HepG2细胞CYP1A1（EROD）、CYP281（PROD）酶活性的影响。结果与溶剂对照相比，B[a]P各剂量组Olive尾矩均显著增加（P〈0．01）：而PCB153各剂量组均不引起Olive尾矩显著增加，与50μmol／LB[a]P单独作用相比，0．1—10μmol／L的PCB153与50μmol／LB[a]P联合作用可使Olive尾矩增加，但只有10μmol／LPCB153与50μmol／LB[a]P联合作用极显著增加Olive尾矩（P〈0．01）；100μmol／LPCB153与50μmol／LB[a]P联合作用与50μmol／LB[a]P单独作用相比，Olive尾矩则显著降低（P〈0．01）。酶活性分析表明，PCB153各剂量组均可诱导EROD、PROD活性显著增加，差异有统计学意义。结论PCB153在一定浓度范围内使B[a]P诱导的HepG2细胞DNA损伤作用显著增强，可能与其诱导的CYP1A1、CYP281酶活性升高有关。

英文摘要：

Objective To explore effects of polychlorinated biphenyl, PCB153 on DNA damage induced by benzo（a） pyrene （B[ a] P） in HepG2 cells. Methods As target cell, HepG2 cells were treated at the concentrations of 0.1, 1, 10 and 100μmol/L with PCB153 and at the concentrations of 12.5, 25, 50 and 100μmol/L B[ a] P respectively. DMSO was used as solvent control. Single cell gel electrophoresis （SCGE） was applied for quantitative analysis of DNA damage which was caused by treating alone or co-treating with PCB153 and B[ a] P, CYP1 A1 （EROD） and CYP2B1 （PROD） activities were detected by using fluorescence spectrophotometry. Results When compared with the solvent control, the DNA oliver tail moments were increased significantly （P 〈 0.01 ） in HepG2 cells treated with all the concentrations of B[ a] P, while no significant DNA damage was observed in HepG2 cells treated with all the concentrations of PCB153. When compared with B[a]P treated alone, the DNA oliver tail moments showed a increase tendency in HepG2 cells co-treated with PCB153 （0.1, 1, 10μmol/L） and B[a] P （50μmol/L）. But DNA oliver tail moments were increased significantly only when co- treated with 10μmol/L of PCB153 and 50μmol/L of B[ a]P （ P 〈 0.01 ）, while decreased significantly after co-exposuring to 100μmol/L of PCB153 and 50μmol/L of B[a] P （ P 〈 0.01 ）. All concentrations of PCB153 induced significant increase in EROD and PROD activities in HepG2 cells. Conclusion It was suggested that the enhancement of DNA damage induced by B[a]P could be associated with the increases of CYP1A1 and CYP2B1 activities induced by PCB153 in HepG2 cells.