苯并(a)芘对健康人胚肝细胞DNA损伤作用的研究

Study on DNA damage induced by benzoa pyrene in human embryo hepatocytes

目的探讨苯并(a)芘[B(a)P]在体外实验条件下致健康人胚肝细胞(L-02细胞)DNA损伤的作用,建立B(a)P致肝细胞DNA损伤的体外实验研究模型。方法对L-02细胞分别用高(50μM)、低(25μM)剂量的B(a)P染毒2h,然后用单细胞凝胶电泳(SCGE)技术检测细胞DNA的损伤情况,选用Oliver尾矩值作为DNA损伤的分析指标,并依据尾部DNA含量/总DNA含量统计DNA损伤分级。结果在本试验条件下,高低剂量的B(a)P均能引起L-02细胞明显的DNA单链断裂损伤,其Oliver尾矩值与溶剂对照组相比差异有统计学意义(P<0·01),并且高、低剂量的B(a)P对L-02细胞的DNA损伤差异也具有统计学意义(P<0·01),随着B(a)P剂量升高,引起肝细胞损伤的Oliver尾矩值也增大。实验组的总彗星样细胞数均较对照组高(P<0·01),高、低剂量的B(a)P引起的总彗星样细胞数间差异没有显著性。高、低剂量的B(a)P诱导不同损伤级别的细胞数不同(P<0·01),B(a)P组与溶剂对照组相比,无损伤及轻度损伤细胞数较少,而中、重度损伤细胞数增多。结论低剂量的B(a)P即可引起L-02细胞DNA的明显损伤。

Objective To explore DNA damage in human healthy embryo hepatoeytes（L-02 cells） induced by benzo[ a]pyrene [B（a）P] in vitro and to estabolish a model of DNA damage induced by B（a）P.Methods Single cell gel electrophoresis （SCGE） was performed to assay DNA damages after L-02 cells were stimulated by a low and high concentration of 25,50 μM B（a）P for 2 h incuhation respectively. Olive tail moment was selected as the index of DNA damage and the grade of DNA damages were analyzed according to DNA contents of the tail/the all.Results Under the condition,B（a）P obviously induced DNA single strand breaks at both concentrations,the Olive tail moment was significantly higher than the control （P〈0.01）.A difference was also observed in both low and high dosage groups （P 〈 0.01）, and as the increase of concentration, the Olive tail moment was increased. The rotes of comet ceils in the B（a）P treated groups were higher than that of control （P〈0.01） ,and there was no difference between low and high dose groups. The proportion of damage grade in all groups was different （ P 〈 0.01）. Compared with the control, there was a little of the amount of undamped and tiny damaged ceils in B（a）P grouop,and the amount of medium and severe damaged calls increased.Conclusion B（a）P at low concentration may cause DNA damage in L-02 cells.