DICATIONIC DRUGS--METABOLISM AND TOXICITY

该计划的目标是了解作用机制， 结构/活性关系和毒性机制 双阳离子类抗微生物剂（喷他脒类似物）。 双阳离子 分子是重要的治疗（或潜在的治疗）剂， 与艾滋病相关的机会性病原体的治疗。 这类 这些药物以前已经显示出抗卡氏肺孢子虫的效力， 是艾滋病患者中最严重的感染者， 对另外两种与艾滋病有关的机会性病原体的活性;弓形虫 gondii和隐孢子虫（Cryptosporidium parvum）。 虽然dicationic代理 这在艾滋病患者的临床管理中被认为很重要， 在不了解其行动方式的情况下取得了地位， 代谢或毒性。 在这项提案中，我们在综合方面的专长 喷他脒类似物的化学治疗应用将用于 获得的分子相互作用和代谢命运的理解， 这些化合物在受感染的病人体内。 这种基本的理解， 双阳离子药物治疗机会性药物的作用方式 将允许合理设计具有改善的治疗效果的新药 指数和使用范围。 上述问题将分三个部分来解决。 独立的项目。 以下项目标题清楚地表明了该计划的重点， 一个整体和每个项目的责任领域：项目一。 双阳离子药物：代谢和毒性;项目II。指示性药物： 行动机制;项目三。双阳离子分子对C. parvum 和T.刚地。 项目I将确定体外和体内 喷他脒和选定喷他脒的结构/毒性特征 类似物 此外，该项目将继续我们的初步 喷他脒的药代动力学/代谢研究，并启动类似的 对已证明具有毒性模式的选定类似物的研究 和/或活性不同于母体药物。 项目二将 集中在两个先前描述的双阳离子剂，DNA 使用多种生物化学方法结合和抑制DNA拓扑异构酶 技术. 这些研究将试图确定上述药物是否- 靶向相互作用具有治疗意义。 此外，项目 II将使用放射性标记配体结合试验和抗独特型抗体 针对抗药物抗体以表征另外的药物 病原体和人体细胞中的结合位点。 项目三将依靠 两名高级研究人员的专业知识，以建立药物模型， 测试T。gondii和C.并提供微生物 项目二研究。 项目III将使用放射性标记药物和电子 显微镜以鉴定喷他脒类似物的结合位点， 确定其生理意义。 密切互动， 三个项目将得到保证，并监测该计划的进展情况 通过积极的行政核心。 藤泽制药 (FPC)将作为赞助商。 因此，FPC将获得专利， 开发小组的关键发现，每年投入135，000美元 预算和提供全面的动物毒性研究， 化合物.

The goal of this program is to understand the mechanism(s) of action, structure/activity relationships, and mechanism(s) of toxicity of the dicationic class of antimicrobial agents (pentamidine analogs). Dicationic molecules are important therapeutic (or potential therapeutic) agents in the treatment of opportunistic agents associated with AIDS. This class of agents has previously demonstrated potency against Pneumocystis carinii, the most serious infection in AIDS patients, and has recently demonstrated activity against two other AIDS-related opportunistic pathogens; Toxoplasma gondii, and Cryptosporidium parvum. Although dicationic agents are accepted as important in the clinical management of the AIDS patient, this status has been achieved with no understanding of their mode of action, metabolism, or toxicity. In this proposal, our expertise in the synthesis and chemotherapeutic applications of pentamidine analogs will be used to obtain an understanding of the molecular interactions and metabolic fate of these compounds in the infected patient. This basic understanding of the mode(s) of action of dicationic agents in treating opportunistic agents will allow the rational design of new drugs with improved therapeutic indices and spectra of use. The above questions will be addressed in three separate projects. The following project titles clearly indicate the focus of the program as a whole and the areas of responsibility for each project: Project I. Dicationic Drugs: Metabolism and Toxicity; Project II. Dicationic Drugs: Mechanism(s) of Action; Project III. Dicationic Molecules Against C. parvum and T. gondii. Project I will determine the in vitro and in vivo structure/toxicity profiles for pentamidine and selected pentamidine analogs. In addition, this project will continue our preliminary pharmacokinetic/metabolism studies for pentamidine, and initiate similar studies on selected analogs that have demonstrated patterns of toxicity and/or activity different from those of the parent drug. Project II will focus on two previously described activities of dicationic agents, DNA binding and inhibition of DNA topoisomerases using a variety of biochemical techniques. Such studies will attempt to determine if the above drug- target interactions are of therapeutic significance. In addition, Project II will use radiolabeled ligand binding assays and antiidiotype antibodies directed toward anti-drug antibodies to characterize additional drug binding sites in both pathogens and human cells. Project III will rely on the expertise of the two senior investigators to establish models for drug testing against T. gondii and C. parvum and to provide organisms for Project II studies. Projects III will use radiolabeled drug and electron microscopy to identify binding sites of the pentamidine analogs and determine their physiological significance. Close interaction between the three Projects will be assured and the progress of the Program monitored through an active Administrative Core. Fujisawa Pharmaceutical Company (FPC) will serve as the corporate sponsor. As such, FPC will patent and develop key discoveries by the group, commit $135,000/yr to the total budget and provide comprehensive animal toxicity studies on selected compounds.