摘要
[目的]研究3种CYP2E1 Ras I基因型对苯酚诱导永生化人淋巴细胞的CYP2E1酶活性及DNA损伤作用的影响。[方法]加入不同浓度的苯酚对CYP2E1 Ras I不同基因型的永生化人淋巴细胞进行24～72 h染毒,采用四甲基偶氮唑蓝法(Methyl Thiazolyl Tetrazolium,MTT)测定细胞毒性并确定苯酚染毒剂量;采用苯胺分光光度法测定CYP2E1酶活性;采用单细胞凝胶电泳(SCGE)法测定DNA损伤作用。[结果]0．05％苯酚24 h染毒对CYP2E1 Ras I野生、杂合及突变基因型细胞均产生生长抑制作用,苯酚对细胞24～72 h染毒的最大无作用浓度为0．01％。各基因型细胞经一定浓度苯酚诱导后酶活性升高(P<0．05),其中野生型细胞经0．005％和0．01％浓度的苯酚染毒可出现酶活性增高的效应,突变型和杂合型细胞经0．01％浓度染毒可出现酶活性增高的效应,且染毒72 h时,在0．01％苯酚染毒剂量下各基因型细胞的CYP2E1酶活力出现明显差异,其中野生基因型细胞的CYP2E1酶活力显著高于突变型、杂合型基因型细胞(P<0．05)。各基因型细胞经一定浓度苯酚染毒后可出现DNA损伤效应,与对照相比,细胞的拖尾率、尾DNA含量及尾长显著升高(P<0．05),且染毒48 h、72 h时,野生基因型细胞的DNA损伤效应与突变型、杂合型细胞相比更为明显(P<0．05)。苯酚诱导后细胞的DNA损伤与CYP2E1酶活性之间呈现明显正相关性。[结论]CYP2E1 Ras I不同基因型明显影响苯酚对人淋巴细胞CYP2E1酶的诱导活性和DNA的损伤程度,其中CYP2E1 Ras I野生基因型细胞的作用最为明显。
[ Objective ] To observe the CYP2E1 enzyme activity and DNA damage of immortalized human lymphoeytes with three genotypes （ wild, heterozygosis and mutant at 5＇-flanking region Ras I of CYP2E1 gene ）after exposure to phenol, an intermediate of benzene. [ Methods ] The immortalized human lymphocytes with different genotypes were exposed to phenol of different dose for 24 to 72 hours. MTT assay was used to detect the cytotoxicity of phenol to lymphocytes. The CYP2E1 enzyme activity was assessed by spectmphotometry. The DNA damage of the lymphocytes was assessed by single cell gel electrophoresis （ SCGE ）. [ Results ] The cellular growth inhibiting effect was observed on immortalized human lymphocytes of three genotypes exposed to 0.05% phenol and the maximal no-effect concentration of phenol to human lymphocytes was 0.01%. The CYP2E1 enzyme activity of the cells with each genotype could be induced while exposing to phenol（ P〈0.05 ）, the enzyme activity of wild genotype lymphocytes was increased significantly while exposed to 0.005% and 0.01% phenol, as well as heterozygosis and mutant genotype lymphocytes while exposing to 0.01% phenol. The enzyme induction activity of cells with wild genotype was the highest among three genotypes while exposing to 0.01% phenol for 72 hours（ P〈0.05 ）. The DNA damages were observed on the cells with each genotype after exposed to phenol, as the frequencies of comet, tail DNA content and tail length of cells were increased significantly compared to controls （ P〈0.05 ）. The most significant damage effect was present on the cells with wild genotype while exposing to 0.005% and 0.01% phenol for 48 to 72 hours （ P〈0.05 ）. A positive correlation was found between CYP2E1 enzyme activity and DNA damages of immortalized human lymphocytos exposed to phenol. [ Conclusion ] CYP2E1 enzyme activity and DNA damage of immortalized human lymphocytes induced by phenol were obviously influenced by genotypes of CYP2E1 Ras I site. The highest enzyme activity and most se
出处
《环境与职业医学》
CAS
北大核心
2007年第2期170-173,共4页
Journal of Environmental and Occupational Medicine
基金
国家自然科学基金(编号:30671731)
江苏省医学科研基金(编号:H200538)
江苏省研究生创新基金(编号:苏教研2005-7号)
