COVALENT BINDING IN DRUG-INDUCED LIVER INJURY

该项目的目标是获得关于下列人员身份的资料： 某些治疗剂的反应性肝毒性代谢物， 研究它们与蛋白质的相互作用。 待研究药物 包括对乙酰氨基酚、异烟肼、异丙肼和丙戊酸。 的 在这项研究中采用的实验方法是新颖的，因为它需要 反应性药物代谢物不可逆结合的优点 蛋白质，以“陷阱”这些短命的有毒物种。 的直接 和间接方法将被用来表征的结构， 由此产生的共价加合物，反过来，将揭示的身份， 反应中间体本身。 现代色谱和质谱技术将发挥重要作用。 在拟议的研究和发展改进的 药物蛋白分离鉴定的分析方法学 药物-氨基酸结合物将是这一研究的关键特征 调查 这种方法很可能在实地得到广泛应用 生物化学毒理学及相关学科。 本项目的具体目标是：（1）鉴定共价键 蛋白质之间在体外形成的加合物，具有肝毒性和 非肝毒性药物，（2）比较形成的共价加合物类型 （3）研究不同类型的 蛋白质之间发生相互作用，有毒和无毒 代谢产物，（4）研究保护作用的物种差异 抗坏血酸对醋氨酚肝损伤的影响，（5）鉴定 丙戊酸的肝毒性代谢物，和（6）开发多功能和 灵敏的分析方法，用于识别痕量的 肝组织和血红蛋白中的药物蛋白加合物。 本项目所要求的这类信息对于 建立健全的实验基础， 药物性肝炎的治疗性和预防性治疗， 最后，根据其预测新治疗药物的潜在毒性， 剂.

The objective of this project is to obtain information on the identities of reactive hepatotoxic metabolites of certain therapeutic agents and to investigate their interaction with proteins. The drugs to be studied include acetaminophen, isoniazid, iproniazid and valproic acid. The experimental approach to be adopted in this study is novel in that it takes advantage of the irreversible binding of reactive drug metabolites to protein in order to "trap" these short-lived toxic species. Both direct and indirect methods will be used to characterize the structures of the resulting covalent adducts which, in turn, will reveal the identities of the reactive intermediates themselves. Modern chromatographic and mass spectrometric techniques will play a central role in the proposed studies and the development of improved analytical methodology for the isolation and identification of drug-protein and drug-amino acid conjugates will be a key feature of this investigation. Such methods are likely to find widespread use in the field of biochemical toxicology and related disciplines. The specific aims of this project are: (1) to identify the covalent adducts formed in vitro between proteins and both hepatotoxic and non-hepatotoxic agents, (2) to compare the types of covalent adduct formed in vivo with those produced in vitro, (3) to study the different types of interaction which take place between proteins and both toxic and non-toxic metabolites, (4) to investigate species differences in the protective effect of ascorbate on acetaminophen-induced liver injury, (5) to identify hepatotoxic metabolites of valproic acid, and (6) to develop versatile and sensitive analytical methodology for the identification of trace amounts of drug-protein adducts in liver tissue and in hemoglobin. Information of the type sought in this project is necessary for the construction of a sound experimental basis from which to develop rational therapeutic and prophylactic treatments of drug-induced hepatitis and, ultimately, from which to predict the potential toxicity of new therapeutic agents.