甲醛和丝裂霉素C的DNA交联作用研究

目的：探讨用彗星试验检测DNA交联剂作用的时间－效应关系及验证其应用的可行性。方法：以过氧化氢（H2O2）作标准DNA断裂剂，用慧星试验对甲醛诱导TK6细胞DNA交联作用的时间－ 效应关系进行了探讨，并用甲醛和丝裂霉素C进行验证。结果：在一定浓度范围内，随着甲醛和丝裂霉素C浓度的增加，由H2O2造成的TK6细胞DNA迁移距离逐渐减少，时间效应的研究表明，在H2O2浓度一定时，随着甲醛染毒 时间的延长，其DNA交联作用增加，结论：彗星试验既可检测DNA－蛋白质交联又可检测DNA－DNA交联，对DNA－蛋白质交联的检测更敏感。

STUDY ON THE EFFECTS OF DNA CROSSLINKS OF FORMALDEHYDE AND MITOMYCINE C

Purpose: To explore the time course effects in detecting DNA crosslinks with comet assay and to prove the feasibility of comet assay for detecting DNA crosslinks. Method: Hydrogen peroxide (H-2O-2) was used as standard DNA breaking agent, the relationship of time effects of DNA crosslinks in TK6 cells induced by formaldehyde (FA) was studied using comet assay. Meanwile, two kinds of DNA crosslinking agents (FA and mitomycine c) were tested and verified. Results: The length of DNA migration caused by H-2O-2 decreased with the increase in the dosage of FA and MMC within the doses given. The investigation of time course effects of DNA crosslinks showed that the action of DNA crosslinks increased with increase in the exposure time of FA. Conclusion: The comet assay could detect both DNA protein crosslinks and DNA DNA crosslinks. The comet assay was more sensitive for detecting DNA protein crosslinks than detecting DNA DNA crosslinks.