摘要
为了探讨甲醛致生物机体DNA蛋白质交联作用及其修复能力,以昆明纯系小鼠和人肝癌细胞系HepG2为实验材料分别进行体内和体外实验,采用KClSDS沉淀法来检测甲醛染毒后小鼠肝细胞和HepG2细胞中DNA蛋白质交联的含量及其修复效果.体内实验结果表明,低浓度的气态甲醛(0.5mg·m-3)不能引起DNA蛋白质的交联,较高浓度的甲醛(1.0mg·m-3,3.0mg·m-3,p<0.01)可以产生明显的DNA蛋白质交联作用;由3.0mg·m-3浓度的气态甲醛产生的DNA蛋白质交联在12h内可以得到明显的修复,并在24h内恢复到空白对照水平.体外实验结果表明,经低浓度液态甲醛(25μmol·L-1和50μmol·L-1)处理后,HepG2细胞内的DPC系数虽然稍有变化,但是与空白对照组相比较无显著差异,而当甲醛浓度上升至75μmol·L-1及以上时,细胞中的DPC系数出现了极显著上升(p<0.01);采用75μmol·L-1甲醛染毒HepG2细胞,在染毒18h和24h后,细胞内的DPC水平较染毒结束时发生了极显著的下降(p<0.01),且与空白对照组相比无显著差异.以上结果显示,低浓度的甲醛不能引起DNA蛋白质的交联,较高浓度的甲醛可以引起明显的DNA蛋白质的交联作用,且甲醛所致的DNA蛋白质交联在体内修复比体外修复所需时间要短.
To explore the effects of formaldehyde induced DNA-protein crosslinks ( DPC ) and the repair process of DPC, purebred Kunming mice and HepG2 cell line were used as experimental materials in vivo and in vitro respectively, and KCI - SDS assay were applied to determine the amount of DPC and the repair process. The results in vivo showed that gaseous formaldehyde could cause DPC at high concentrations (l. 0 mg m^-3,3.0 mg· m^-3, p 〈0.01 ) , hut not happened the case at low eoneentrations (0.5 mg·m^-3 ). DPC induced by gaseous formaldehyde at 3.0 mg·m^ -3 could be removed within 12 hours. Meanwhile, the results in vitro showed that liquid formaldehyde at low concentration (25 μmol· L^-1and 50 μmol· L^- 1 ) resulted in an insignificant increase in DPC content compared with control groups. When formaldehyde concentration was up to as high as 75 μmol· L^ - 1, DPC could be formed significantly, which could be removed significantly after 18 and 24 hours, but not happend the case after 6 and 12 hours. In combination, these results suggested that formaldehyde can induce DPC at relatively high concentration, and removing of DPC in vivo requires shorter time than that in vitro.
出处
《环境科学学报》
CAS
CSCD
北大核心
2006年第2期331-336,共6页
Acta Scientiae Circumstantiae
基金
国家"十五"科技攻关项目(No.2001BA704B01)
国家自然基金项目(No.30570799)~~