ETHANOL INDUCTION OF UDP-GLUCURONYLTRANSFERASE

申请者摘要：长期饮酒改变治疗效果 几种药物的疗效和药代动力学。通常，这些 变化表现为药物新陈代谢增加，导致 更短的半衰期、更高的清除度和更低的血浆浓度 浓度。这些变化可能导致治疗剂量不足。 这种作用主要可以在临床治疗中观察到。 酗酒者，但在中度酒精的影响中可能很重要 对药效的消耗。其中许多药物的葡萄糖醛酸化反应 消除的主要或唯一途径，以及诱导 UDP-葡萄糖醛酸基转移酶同工酶可导致显著增加 毒品的清除。慢性酒精暴露会导致 兔UDP-葡萄糖醛酸基转移酶(GT)同工酶的制备 肝脏微粒体，这种生化效应在 通过葡萄糖醛酸化作用增加吗啡和奥西潘在脑内的清除量 动物。这项研究的主要目标是确定准确的 控制诱导过程的分子事件和剂量要求 在兔子身上，并证明这些过程也发生在人类身上。 实现这一目标将通过以下几个方面 方法：1)兔抗体的制备及应用 乙醇诱导的免疫印迹和免疫沉淀研究 乙醇诱导的兔微粒体及其纯化的同工酶测定 诱导的时间进程和剂量要求；2)准备和 兔肝组织中编码该蛋白的DNA克隆的序列分析 乙醇诱导的GT及用基因探针筛选兔和人的mRNA 确定导致分子事件的分子水平 同工酶的产生；3)同工酶的纯化和性质 乙醇诱导的人肝组织GT蛋白(S)和cDNA。这个 这项研究的长期目标是确定 乙醇诱导的UDP-葡萄糖醛酸基转移酶同工酶 动物和人类，描述同工酶的特征并提供关于 负责它们的产生的分子事件，并与 这些生化事件对人类的治疗，在慢性暴露后 到乙醇，用这些GT同工酶代谢的药物。这些 研究代表了生物化学、分子生物学的多方面方法。 生物学和临床水平，将提供重要的新 关于长期饮酒对健康的影响的信息 人体重要的药物代谢酶。

APPLICANT'S ABSTRACT: Chronic alcohol consumption changes the therapeutic efficacies and pharmacokinetics of a number of drugs. Usually, these changes are manifest as increased metabolism of the drugs leading to shorter half-lives, increased clearance, and decreased plasma concentrations. These changes can lead to inadequate therapeutic doses. Such effects may primarily be observed in the clinical treatment of alcoholics, but may be important in the effects of moderate alcohol consumption on drug efficacies. Glucuronidation of many of these drugs is the major or only route of elimination, and induction of UDP-glucuronosyltransferase isozymes could lead to significant increases in the clearance of the drugs. Chronic alcohol exposure induces the production of a unique UDP-glucuronosyltransferase (GT) isozyme in rabbit hepatic microsomes, and this biochemical effect is manifest in the increased clearance, via glucuronidation, of morphine and oxazepam in the animals. The major goal of this research is to determine the precise molecular events and dose requirements that control this induction process in rabbits, and to demonstrate that these processes also occur in man. Realization of this goal will be accomplished through the following methods: 1) the production and use of antibodies to the rabbit ethanol-induced GT in immunoblots and immunoprecipitation studies with ethanol-induced rabbit microsomes and purified isozymes to determine the time course and dose requirements for induction; 2) preparation and sequencing of rabbit hepatic cDNA clones of the DNA coding for the ethanol-induced GT and use of cDNA probes to screen rabbit and human mRNA levels to determine the molecular events that are responsible for production of the isozyme; and 3) purification and characterization of the ethanol-induced GT protein(s) and cDNAs from human liver tissue. The long-term objectives of this research are to establish the existence of ethanol-induced UDP-glucuronosyltransferase isozymes in experimental animals and humans, characterize the isozymes and provide information about the molecular events that are responsible for their production, and relate these biochemical events to the treatment of humans, after chronic exposure to ethanol, with drugs that are metabolized by these GT isozymes. These studies represent a multifaceted approach on the biochemical, molecular biological, and clinical levels that will provide significant new information about the effects of chronic alcohol consumption on an important human drug metabolism enzyme.