L-02肝细胞对氢醌所致DNA损伤耐受实验模型的初步建立

Establishment of experimental model for DNA damage tolerance induced by HQ in L-02 hepatic cells

目的确定氢醌（hydroquinone，HQ）对L-02肝细胞的染毒剂量和染毒时间，从而为进一步的DNA损伤耐受机制研究提供科学依据。方法采用噻唑蓝（MTT）比色法测定不同浓度（0、5、10、20、40、80、160和320umol／L）的HQ于不同时间（6、12、24和48h）作用之后L-02肝细胞的相对存活率。结果在相同的作用时间（6、12或24h）条件下，在0-320umol／L范围内，随着HQ浓度的增加，各剂量组L-02肝细胞的存活率以剂量依赖性方式逐渐减少；其中160和320umol／L组L-02肝细胞的存活率与对照组相比较有明显地减少（P〈0．01）；而在48h时间组内，HQ染毒剂量达到80umol／L就可引起L-02肝细胞存活率的明显降低（P〈0．01）。在相同浓度（5、10、加和40umol／L）的HQ作用下，随着HQ作用时间的延长，各剂量组细胞的存活率之间差异没有统计学意义（P〉0．05）；当HQ染毒时间达到48h时，80、160和320umol／L的HQ染毒组L-02肝细胞的存活率与6h对照组比较有明显地减少（P〈0．01）。结论可以将80umol／L的HQ染毒24h作为L-02肝细胞耐受DNA损伤的最大剂量和最长时间的界限。

Objective To establish action-dose and time of HQ on L-02 hepatic cells, then to provide a scientific basis for the further studies on the mechanism of DNA damage tolerance. Method MTT assay was conducted to detect the effect of HQ with various concentrations （0, 5, 10, 20, 40, 80, 160 and 320 umol/L） on survival rate of L-02 hepatic cells at different exposure time. Result The HQ concentrations in the range of 0 -320 umol/L, at same exposure time （6, 12, or 24 h）, the viabilities of L-02 hepatic cells were gradually decreased in a dose-dependent manner, the higher exposure groups （ 160 umol/L and 320 umol/L） were significantly reduced compared to the control group （0 umot/L, P 〈0.01） ; while the 48 h exposure to HQ （ 〈 80 umol/L） could induce significant decrease of viability of L-02 hepatic cells （P〈0.01）, and at same exposure level to HQ （0, 5, 10, 20, or 40 umol/L）, there was no difference in survival level of L-02 hepatic cells （ P 〉 0.05）. When the exposure time reached 48 h, the viability of L-02 hepatic cells whether 80, 160 or 320 umol/L, were all less than that of the control （6 h, P 〈 0.01）. Conclusion It could be concluded that L-02 hepatic cells treated by HQ with 80 umol/L for 24 h might be the maximal limit of dose and time of L-02 hepatic cells to tolerate DNA damage induced by HQ.