Carmichael P L, Jacob J, Grimmer G, Phillips D H
Chester Beatty Laboratories, Institute of Cancer Research, London, UK.
Carcinogenesis. 1990 Nov;11(11):2025-32. doi: 10.1093/carcin/11.11.2025.
Engine lubricating oils are known to accumulate carcinogenic polycyclic aromatic hydrocarbons (PAHs) during engine running. Oils from nine petrol-powered and 11 diesel-powered vehicles, in addition to samples of unused oil, were analysed for PAH content and ability to form DNA adducts when applied topically to mouse skin. The levels of 19 PAHs, determined by GC, were in total, approximately 22 times higher in used oils from petrol engines than in oils from diesel engines. Male Parkes mice were treated with 50 microliters of oil daily for 4 days before they were killed and DNA isolated from skin and lung tissue. DNA samples were analysed by nuclease P1-enhanced 32P-postlabelling. Used oils from both diesel and petrol engines showed several adduct spots on PEI-cellulose plates at total adduct levels of up to 0.57 fmol/microgram DNA [approximately 60 times greater than in experiments with samples of unused oil in which adduct levels (0.01-0.02 fmol adducts/microgram DNA) were close to the limit of detection]. Higher adduct levels were generally formed by petrol engine oils than by diesel engine oils. Lung DNA contained similar total adduct levels to those in skin although the adduct maps were less complex. Total adduct levels correlated with extent of oil use in the engine, the total PAH concentration in oils and with the concentrations of certain individual PAHs present in the oils. An adduct spot that co-eluted with that of the major benzo[a]pyrene-DNA adduct accounted for 9-26% of the total adducts in skin DNA, and approximately 8% of the adducts in lung DNA, of mice treated with petrol engine oils. A major, and as yet unidentified, adduct spot comprised up to 30% of the total adducts in skin DNA, and up to 89% of the total adducts in lung DNA, of these animals.
众所周知，发动机润滑油在发动机运行过程中会积累致癌性多环芳烃（PAHs）。对9辆汽油动力汽车和11辆柴油动力汽车的机油，以及未使用机油的样本进行了分析，检测其PAH含量以及局部涂抹于小鼠皮肤时形成DNA加合物的能力。通过气相色谱法测定的19种PAHs的含量，汽油发动机使用过的机油中其总量比柴油发动机机油中的约高22倍。在处死雄性帕克斯小鼠前，每天给它们涂抹50微升机油，持续4天，然后从皮肤和肺组织中分离DNA。DNA样本通过核酸酶P1增强的32P后标记法进行分析。柴油发动机和汽油发动机使用过的机油在聚乙二醛纤维素板上均显示出多个加合物斑点，总加合物水平高达0.57 fmol/μg DNA[大约比未使用机油样本的实验结果高60倍，在未使用机油样本的实验中，加合物水平（0.01 - 0.02 fmol加合物/μg DNA）接近检测限]。汽油发动机机油形成的加合物水平通常高于柴油发动机机油。肺DNA中的总加合物水平与皮肤中的相似，尽管加合物图谱没那么复杂。总加合物水平与发动机机油使用程度、机油中PAH总浓度以及机油中某些特定PAHs的浓度相关。在涂抹汽油发动机机油的小鼠中，一个与主要苯并[a]芘 - DNA加合物共洗脱的加合物斑点占皮肤DNA中总加合物的9 - 26%，占肺DNA中加合物的约8%。在这些动物中，一个主要的、尚未鉴定的加合物斑点占皮肤DNA中总加合物的30%，占肺DNA中总加合物的89%。
