INTERACTION OF ETHANOL WITH HEPATIC MICROSOMES

细胞色素P450 IIEl在肝微粒体中的作用 乙醇氧化系统（MEOS），并具有纯化的活性 从人肝制备，我们现在建议确定 这种同工酶对其他生物底物的亲和力 感兴趣物质如类维生素A、致癌物质和肝毒性物质 部分地使用了这种人类形态。 我们计划将人类 细胞色素P450 IIEl在其激活 结构多样的化学致癌物二甲基-和二乙基- 亚硝胺、亚硝基吡咯烷和氯乙烯。 我们也将 确定在所述第一感应和所述第二感应之间是否存在并行性。 乙醇特异性形式的P450和 各种溶剂（如四氯化碳）的肝毒性， 常用药物（如对乙酰氨基酚）和滥用物质 (e.g.可卡因）。 毒性将通过泄漏的 肝酶进入血液和形态学变化 通过光学和电子显微镜测定。 微粒体诱导 将通过测定总细胞色素P450进行评价， 以及通过SDS-PAGE观察各种同工酶， 这些形式中的一些使用特异性免疫定量， 抗体的其他因素（如酮）在 诱导肝微粒体和增强 还将评估肝毒性;后一项研究可能 提供了新的见解， 酒精中毒和营养不良。 抗利尿激素的相对重要性， MEOS和过氧化氢酶的总肝乙醇代谢将是 在体内和分离的肝细胞中定量，重点是 长期饮酒导致的变化。三 方法将采用：氚作为放射性示踪剂的命运 来自乙醇、氘代乙醇的还原当量 以确定路径选择性同位素效应和代谢 缺乏ADH的鹿鼠品系的研究。 我们的主要目标是确定 酗酒者和非酗酒者，并确定在何种程度上， 乙醇消费所产生的变化， 微粒体P450系统改变酒精对 生理和药理学底物， 最终影响酒精相关的病理，其预防和 治疗 我们的最终目标是用分子术语定义一些 长期使用乙醇所带来的最深远的变化 身体内部环境的消耗以及由此产生的 对环境的反应。

Having-elucidated the role of cytochrome P450IIEl in the microsomal ethanol oxidizing system (MEOS) and having purified an active preparation from human liver, we now propose to determine the affinity of this isozyme for other substrates of biological interest such as retinoids, carcinogens and hepatotoxic agents using, in part, this human form. We plan to characterize the human cytochrome P450IIEl with respect to its ability to activate the structurally diverse chemical carcinogens dimethyl- and diethyl- nitrosamines, nitrosopyrolidine and vinylchloride. We also will determine whether a parallelism exists between the induction of the ethanol specific form of P450 and the potentiation of the hepatotoxicity of various solvents (e.g. carbon tetrachloride) and commonly used drugs (such as acetaminophen) and substances of abuse (e.g. cocaine). Toxicity will be determined by the leakage of liver enzymes into the bloodstream and by morphologic changes determined by light and electron microscopy. Microsomal induction will be evaluated by the determination of total cytochrome P450 as well as the visualization of the various isozymes by SDS-PAGE and the immunoquantitation of some of these forms using specific antibodies. The role of other factors (such as ketones) in the induction of liver microsomes and the potentiation of hepatotoxicity will also be assessed; these latter studies may provide new insight into the question of interactions between ethanol toxicity and malnutrition. The relative importance of ADH, MEOS and catalase for total hepatic ethanol metabolism will be quantitated in vivo and in isolated hepatocytes, focusing on changes resulting from chronic alcohol consumption. Three approaches will be employed: tritium as a radiotracer for the fate of reducing equivalents derived from ethanol, deuterated ethanol to determine pathway-selective isotope effects and metabolic studies with a deermouse strain lacking ADH. Our broad aim is to define biochemical differences between alcoholics and non-alcoholics and to determine to what extent the changes produced by ethanol consumption in the nature of the microsomal P450 system alter the response of the alcoholic to physiologic and pharmacologic substrates in a way which may eventually affect alcohol related pathology, its prevention and treatment. Our ultimate goal is to define in molecular terms some of the most far-reaching changes brought about by chronic ethanol consumption in the internal milieu of the body and the resulting response to the environment.