Varanasi U, Reichert W L, Le Eberhart B T, Stein J E
National Marine Fisheries Service, National Oceanic & Atmospheric Administration, Seattle, WA 98112.
Chem Biol Interact. 1989;69(2-3):203-16. doi: 10.1016/0009-2797(89)90078-1.
The formation of DNA adducts from the carcinogenic environmental pollutant benzo[a]pyrene (BaP) was investigated in liver of English sole (Parophrys vetulus), a fish species that exhibits a high prevalence of liver neoplasms in several polycyclic aromatic hydrocarbon (PAH)-contaminated areas of Puget Sound, WA. Analysis by the 32P-postlabeling assay of hepatic DNA digests from English sole exposed parenterally to BaP showed the presence of BaP-diol epoxide (BaPDE)-DNA adducts. When English sole were injected with 2-15 mg BaP/kg body wt., one major adduct was detected and was identified as the anti-BaPDE-DNA adduct. Moreover, in English sole sampled at 1, 28 and 60 days post-exposure to 15 mg BaP/kg body wt., there was no significant change in the level of the anti-BaPDE-DNA adduct. The autoradiographs of 32P-labeled hepatic DNA digests from fish exposed to 100 mg BaP/kg body wt. showed an elongated spot suggesting the presence of more than one adduct. Chromatography on large polyethyleneimine sheets (20 x 20 cm) showed 2 spots with the same chromatographic characteristics as those of syn- and anti-BaPDE-deoxyguanosine adduct standards. Mild acid hydrolysis of hepatic DNA of English sole, exposed to 100 mg BaP/kg body wt., also revealed the presence of tetrols derived from both anti- and syn-BaPDE, thus confirming the presence of syn- and anti-BaPDE. In fish exposed to 2-100 mg BaP/kg body wt., a linear (0.996) dose response for anti-BaPDE-DNA adduct formation was observed. The results from this study offer the first direct evidence for the formation of the suspected ultimate carcinogen, BaPDE, in liver of English sole exposed to BaP in vivo and thus further support the hypothesis that exposure to PAHs is an important factor in the etiology of hepatic neoplasms in English sole from contaminated sites.
在英国鲽（Parophrys vetulus）肝脏中研究了致癌环境污染物苯并[a]芘（BaP）形成DNA加合物的情况。英国鲽是一种鱼类，在华盛顿州普吉特海湾几个多环芳烃（PAH）污染区域，其肝脏肿瘤的患病率很高。通过32P后标记分析法对经肠胃外途径暴露于BaP的英国鲽肝脏DNA消化产物进行分析，结果显示存在BaP - 二醇环氧化物（BaPDE）-DNA加合物。当给英国鲽注射2 - 15 mg BaP/ kg体重时，检测到一种主要加合物，并鉴定为反式BaPDE - DNA加合物。此外，在暴露于15 mg BaP/ kg体重后1天、28天和60天取样的英国鲽中，反式BaPDE - DNA加合物水平没有显著变化。对暴露于100 mg BaP/ kg体重的鱼类肝脏DNA进行32P标记消化产物的放射自显影片显示有一个拉长的斑点，表明存在不止一种加合物。在大型聚乙烯亚胺薄板（20×20 cm）上进行色谱分析，显示出2个斑点，其色谱特征与顺式和反式BaPDE - 脱氧鸟苷加合物标准品相同。对暴露于100 mg BaP/ kg体重的英国鲽肝脏DNA进行温和酸水解，也揭示了源自反式和顺式BaPDE的四醇的存在，从而证实了顺式和反式BaPDE的存在。在暴露于2 - 100 mg BaP/ kg体重的鱼类中，观察到反式BaPDE - DNA加合物形成的线性（0.996）剂量反应。本研究结果首次直接证明了在体内暴露于BaP的英国鲽肝脏中形成了疑似最终致癌物BaPDE，从而进一步支持了以下假设：暴露于PAHs是受污染地点英国鲽肝脏肿瘤病因中的一个重要因素。
