Phillips D H, Hemminki K, Alhonen A, Hewer A, Grover P L
Chester Beatty Laboratories, Institute of Cancer Research, London, Great Britain.
Mutat Res. 1988 Mar;204(3):531-41. doi: 10.1016/0165-1218(88)90047-x.
Blood samples were volunteered by workers in a Finnish iron foundry who were occupationally exposed to polycyclic aromatic hydrocarbons and from control subjects not known to be occupationally exposed to this class of chemical carcinogens. DNA was isolated from peripheral white blood cells and digested with micrococcal nuclease, spleen phosphodiesterase and nuclease P1. The DNA digest was then incubated with [gamma-32P]ATP and polynucleotide kinase. Aromatic adducts present in the digest that were resistant to nuclease P1 were thus 32P-labelled while unmodified nucleotides were not. The 32P-labelled adducts were resolved by t.l.c. and detected by autoradiography. Foundry workers were classified as belonging to high, medium or low exposure groups according to their exposure to airborne benzo[a]pyrene (high greater than 0.2, medium 0.05-0.2, low less than 0.05 microgram BP/m3 air). Aromatic adducts were found to be present in DNA from 3/4 samples from the high exposure group, 8/10 samples from the medium exposure group. 4/18 samples from the low exposure group and 1/9 samples from the unexposed controls. The levels of adducts found in the high and medium group samples ranged up to 1 adduct in 10(7) nucleotides but the levels formed in the low exposure group samples were not significantly different from those in unexposed controls. No differences related to the smoking habits of the subjects were observed. Most of the DNA adducts detected had chromatographic mobilities distinct from those formed when the 7,8-diol 9,10-oxide of BP reacted with DNA. The results indicate that highly-exposed individuals are more likely to contain aromatic DNA adducts in their white blood cells, but large interindividual variations were evident. In addition, multiple samples from the same subjects indicate that qualitative and quantitative changes in adduct patterns occur with time. This pilot study suggests that 32P-postlabelling may be useful in monitoring human exposure to known and to previously unidentified environmental genotoxic agents.
血样由芬兰一家铸铁厂的工人自愿提供，这些工人在职业上接触多环芳烃，同时还采集了已知未职业接触此类化学致癌物的对照对象的血样。从外周血白细胞中分离出DNA，并用微球菌核酸酶、脾脏磷酸二酯酶和核酸酶P1进行消化。然后将DNA消化物与[γ-32P]ATP和多核苷酸激酶一起孵育。这样，消化物中对核酸酶P1有抗性的芳香族加合物就被32P标记，而未修饰的核苷酸则没有。32P标记的加合物通过薄层层析分离，并用放射自显影检测。根据铸造工人对空气中苯并[a]芘的接触情况（高接触组大于0.2微克/立方米，中接触组0.05 - 0.2微克/立方米，低接触组小于0.05微克/立方米），将他们分为高、中、低接触组。结果发现，高接触组4份样本中的3份、中接触组10份样本中的8份、低接触组18份样本中的4份以及未接触对照组9份样本中的1份的DNA中存在芳香族加合物。在高接触组和中接触组样本中发现的加合物水平最高可达每10^7个核苷酸中有1个加合物，但低接触组样本中形成的加合物水平与未接触对照组的水平没有显著差异。未观察到与受试者吸烟习惯相关的差异。检测到的大多数DNA加合物的色谱迁移率与BP的7,8 - 二醇9,10 - 环氧化物与DNA反应时形成的加合物不同。结果表明，高暴露个体的白细胞中更有可能含有芳香族DNA加合物，但个体间差异很大。此外，同一受试者的多个样本表明，加合物模式会随时间发生定性和定量变化。这项初步研究表明，32P后标记法可能有助于监测人类对已知和先前未识别的环境遗传毒性剂的暴露情况。
