DIHYDRODIOL DEHYDROGENASE & PAH DETOXIFICATION

此应用程序请求对研究职业的支持 发展奖，以表彰对 二氢二醇脱氢酶在大豆脱毒中的作用 多环芳烃的近致癌物质和最终致癌物质 碳氢化合物(PAH)。研究项目包括化学品， 生化、细胞和人体研究旨在提供 关于这种酶在多环芳烃代谢中的作用的信息。 我们已经证明了均相二氢二醇脱氢酶 从大鼠肝脏胞浆中氧化多种非K区反式 致癌的多环芳烃的二氢二醇与相应的邻位 能够以巯基乙醇加合物形式被捕获的喹酮类化合物。至 获取有关这条可选途径的信息 致癌物代谢，非K区邻位反应性- 将检查针对细胞亲核分子的苯醌产品， 湾区甲基化对反应性的影响将是 测定了谷胱甘肽提高酶解率的能力 捕获邻苯二酚对反式二氢二醇氧化的影响 将对产品进行评估，推测的苯二酚的结构- 谷胱甘肽加合物将被阐明，这些加合物的能力 邻苯二酚产品作为高纯度的底物 大鼠肝脏谷胱甘肽转移酶的制备 下定决心。 均相二氢二醇脱氢酶参与血管紧张素转换酶的表达 最终的致癌物代谢将通过使用 稳定的萘、菲抗二醇环氧化物及 以苯并(A)芘(BP)为底物的抗二醇环氧化物。 细胞研究将利用这一发现，即大鼠肝癌 细胞系(H-4II-e)含有二氢二醇脱氢酶，即 对吲哚美辛和6-氨基丁酸的抑制非常敏感 醋酸甲羟孕酮。通过研究人的新陈代谢 BP在这些细胞中的(~3H)-7，8-反式二氢二醇 而没有这些药物，二氢二醇的贡献 脱氢酶对全细胞内多环芳烃的脱毒作用 评估过了。如果这种酶发挥重要作用，这些药物 应评估抗二醇环氧化物和BP-DNA加合物的水平。 确定二氢二醇脱氢酶是否在PAH中起作用 人体的新陈代谢，肝脏尸检样本将被分析 这种酶的活性，活性会被 氧化反式-7，8-羟色胺的层析和同工酶 对BP的二氢二醇进行了表征。

This application requests support for a Research Career Development Award for continuation of a systematic study of the role of dihydrodiol dehydrogenase in the detoxification of proximate and ultimate carcinogens of polycyclic aromatic hydrocarbons (PAH). The research programs includes chemical, biochemical, cellular and human studies designed to provide information on the role of this enzyme in PAH metabolism. We have shown that the homogeneous dihydrodiol dehydrogenase from rat liver cytosol oxidizes a variety of non-K-region-trans dihydrodiols of carcinogenic PAH to the corresponding ortho- quinones which can be trapped as mercaptoethanol adducts. To obtain information on this alternative pathway of proximate carcinogen metabolism, the reactivity of non-K-region ortho- quinone products towards cellular nucleophiles will be examined, the influence of bay-region methylation on reactivity will be determined, the ability of glutathione to enhance enzymatic rates of trans-dihydrodiol oxidation by trapping the ortho-quinone products will be assessed, structures of putative quinone- glutathione adducts will be elucidated, and the ability of these ortho-quinone products to act as substrates for highly purified preparations of rat liver glutathione transferases will be determined. The involvement of the homogeneous dihydrodiol dehydrogenase in ultimate carcinogen metabolism will be explored by using the stable anti-diol-epoxides of naphthalene and phenanthrene and the anti-diol epoxide of benzo(a)pyrene (BP) as substrates. Cellular studies will exploit the findings that the rat hepatoma cell line (H-4II-e) contains dihydrodiol dehydrogenase that is exquisitely sensitive to inhibition by indomethacin and 6- medroxyprogesterone acetate. By studying the metabolism of the (3H)-7,8-trans-dihydrodiol of BP in these cells, in the presence and absence of these drugs, the contribution of dihydrodiol dehydrogenase to the detoxification of PAH in whole cells will be assessed. If this enzyme plays a significant role these drugs should evaluate levels of anti-diol epoxides and BP-DNA adducts. To determine if dihydrodiol dehydrogenase plays a role in PAH metabolism in humans, liver autopsy samples will b analyzed for this enzyme activity, activities will be separated by chromatography and isozymes which oxidize the trans-7,8- dihydrodiol of BP will be characterized.