代谢
这项研究旨在确定有机过氧化物,包括叔丁基过氧化氢、异丙苯过氧化氢和叔丁基过氧苯甲酸,是否会被人类皮肤鳞状细胞癌细胞代谢生成自由基。将来自皮肤鳞状细胞癌的角蛋白细胞在含有去铁胺的磷酸盐缓冲液(pH 7.4)中与叔丁基过氧化氢、异丙苯过氧化氢和叔丁基过氧苯甲酸一起培养,并在存在自旋陷阱(3,5-二溴硝基苯磺酸)的情况下,产生了相应的甲基自由基加合物。将细胞预先加热至100摄氏度后,消除了自由基加合物的生成。向反应混合物中添加乙醇也抑制了自由基加合物的形成。这些数据首次直接证明了人类皮肤癌细胞可以从有机过氧化物生成自由基。由于自由基被认为参与肿瘤促进过程中发生的一系列事件,这种代谢能力可能是人类对过氧化物癌症风险的重要决定因素。
...This study was designed to determine whether the organic hydroperoxides, tert-butyl hydroperoxide, cumene hydroperoxide and tert-butyl peroxybenzoate are metabolized by human carcinoma skin keratinocytes to free radicals. Incubation of keratinocytes prepared from cutaneous squamous cell carcinoma in phosphate-buffered saline (pH 7.4) containing desferrioxamine with tert-butyl hydroperoxide, cumene hydroperoxide and tert-butyl peroxybenzoate in the presence of spin trap (3,5-dibromonitrosobenzene sulfonic acid) resulted in the generation of corresponding methyl radical adducts. Prior heating of the cells to 100 degrees C abolished the generation of radical adducts. The addition of ethanol to the reaction mixture also inhibited formation of radical adducts. These data provide the first direct evidence that human carcinoma skin cells can generate free radicals from organic hydroperoxides. Since free radicals are suggested to be involved in the cascade of events occurring during tumor promotion this metabolic capacity may be an important determinant of human cancer risk for hydroperoxides.
来源:Hazardous Substances Data Bank (HSDB)