中文摘要：

目的研究三氯乙烯（TCE）对人角质形成细胞（KC）一氧化氮（NO）合成以及细胞活力的影响，探讨三氯乙烯引起皮肤细胞毒性的机制。方法体外培养的人角质形成细胞以0.125、0.25、0.5、1.0、2.0mmol/L浓度的TCE染毒4h，另以诱导型一氧化氮合酶（iNOS）抑制剂氨基胍（AG）100μmoL／L预处理细胞30min后再行TCE处理，分别于染毒后12h、24h、48h、72h时检测细胞上清中NO的含量，MTT法观察细胞活力。结果低剂量的TCE不引起NO含量改变（与溶剂对照比较，P〉0．05），0．5、1．0、2.0mmol/L浓度的TCE染毒组NO含量分别在染毒后的24h、48h和72h开始升高（P〈0.05），对应的细胞活力则相应下降（P〈0．05）；AG预处理的0.5、1.0和2．0mmol/L TCE染毒组在处理48h后NO含量开始下降（与对应的TCE染毒组比较，P〈0.05），且回复到正常溶剂对照水平（P〉0.05），其所对应的细胞活力逐步回升（与对应的TCE染毒组比较，P〈0.05）。结论TCE以剂量和时间依赖方式诱导人KC产生NO，而过量的NO可能介导了TCE的KC细胞毒性。

英文摘要：

Objective To observe the effect of trichloroethylene （TCE） on nitric oxide （NO） and cell activity in human keratinocytes （KC）, and further explore the mechanism of dermatotoxicity caused by trichloroethylene. Methods Cultured human keratinocytes were exposed to 0, 0. 125, 0. 25, 0. 5, 1.0, 2.0 mmol/L trichloroethylene for 4 h with or without the 30min pretreatment with 100 μmol/L aminoguanidine （AG）, a specific inhibitor of iNOS. After 12 h, 24 h, 48 h and 72 h incubation, the NO concentrations in the mediums were detected, the cell viability was determined by MTT test as well. Results It was shown that there was no obvious increase in NO level when KC treated with lower concentrations of TCE such as 0. 125 mmol/L and 0. 25 mmol/L （ P 〈0. 05, compared with the controls） ; while higher doses of TCE （ such as 0. 5 to 2. 0 mmol/L） might induce the rise of NO levels （ P 〈 0. 05 ）, meanwhile, cell viability was also markedly decreased . The pretreatment with aminoguanidine might effectively lower the rise of NO level in higher dosage groups especially at 48h and the cell viahilities were also restored to baseline levels. Conclusions Trichloroethylene can induce keratinocytes to produce NO in the dose-and timedependent manner, and the overdose of NO might play a role in the cytotoxicity of TCE on keratinocytes.