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[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 investigate the effects of three CYP2E1 Ras I genotypes on CYP2E1 enzyme activity and DNA damage induced by phenol in human immortalized human lymphocytes. [Method] The immortalized human lymphocytes with different genotypes of CYP2E1 Ras I were exposed to different concentrations of phenol for 24-72 h. The cytotoxicity was determined by MTT and the cytotoxicity was determined Phenol dose. Aniline spectrophotometry was used to measure the activity of CYP2E1. Single cell gel electrophoresis (SCGE) was used to determine DNA damage. [Result] The 24 h exposure of 0.05% phenol had inhibitory effect on the growth of CYP2E1 Ras I wild-type, heterozygous and mutant genotype cells. The maximum concentration-effect concentration of phenol on cells exposed to 24-72 h was 0.01% . The enzymatic activity of all genotypes was increased after being induced by certain concentration of phenol (P <0.05). The increase of enzyme activity appeared in wild-type cells exposed to 0.005% and 0.01% Type and heterozygous cells exposed to 0.01% concentration increased enzyme activity can occur, and 72 hours after exposure, 0.01% phenol dose of CYP2E1 enzyme activity in each genotype were significantly different , And the CYP2E1 activity of wild-type cells was significantly higher than that of mutant and heterozygous genotypes (P <0.05). The genomic cells exposed to phenol at a certain concentration showed the DNA damage effect. Compared with the control, the tailing DNA content and the tail length of the cells were significantly increased (P <0.05) At 72 h, the DNA damage effect of wild-type genotype cells was more obvious than that of mutant and heterozygous cells (P <0.05). Phenol-induced cell DNA damage and CYP2E1 enzyme activity showed a significant positive correlation between. [Conclusion] The different genotypes of CYP2E1 Ras I significantly affect the induction activity of CYP2E1 enzyme on human lymphocytes and DNA damage degree. Among them, CYP2E1 Ras I wild type cells have the most obvious effect.