MODULATION OF THE ACTION OF PCP BY MG2+ AND POLYAMINES

苯环利定(PCP)在脑内的主要作用部位是N-氨基丁酸。 谷氨酸受体的甲基-D-天冬氨酸(NMDA)亚型。PCP绑定到 NMDA受体受镁离子和多胺的调节。然而，尽管 多胺和镁离子对结合有显著的调节作用。 PCP，这些调节剂改变受体的位置和机制 人们对其功能知之甚少。本研究的长期目标是 要了解这些调节子在结合中的作用机制 将PCP结合到NMDA受体上，并将这些调控位点作为靶点 对于会改变或阻断五氯苯酚的药理作用的药物。我们 将采取三种融合的方法，使用合成化学， 分子生物学和药理学来实现这一目标。具体目标 该项目的主要内容包括： 1.寻求多胺类拮抗剂的合理设计和合成。vbl.使用 阿卡因作为先导化合物和系统修饰大小、构象 和疏水性，我们将开发多胺 比目前更强大和/或更有选择性的对手 可获得的药物。 2.对新型多胺配体进行药理学表征。我们将使用 配基结合实验和细胞内钙离子实验 新合成的多胺类药物的活性和特异性。我们 还将确定可以修改PCP操作的程度 多胺拮抗剂。 3.测定多胺激动剂和拮抗剂对配体的影响 与哺乳动物中表达的重组NMDA受体亚单位的结合 细胞。我们将评估多胺对已定义的NMDA受体亚单位的作用 组合，提供了一种更具体的方法来研究 该调节剂对NMDA受体复合体的作用机制。 4.测定细胞内游离镁离子浓度升高对血管内皮细胞生长的影响 PCP位点配体对NMDA受体的抑制作用我们将使用钙离子- 依赖和不依赖于钙离子的方法将细胞内[镁]升高到 检验升高的[镁]离子会减少PCP与 NMDA受体。 理解镁离子和多胺的分子机制 影响五氯苯酚的行动将提供关于 这种重要的滥用物质的分子作用机制。 该项目还将重点放在预防影响的战略上。 在NMDA受体上的PCP，从而提供了治疗的靶点 五氯酚滥用的治疗。

The principal site of action of phencyclidine (PCP) in the brain is the N- methyl-D-aspartate (NMDA) subtype of glutamate receptor. PCP binding to the NMDA receptor is modulated by Mg2+ and polyamines. However, although polyamines and Mg2+ have substantial modulatory effects on the binding of PCP, the sites and mechanisms by which these modulators alter receptor function is poorly understood. The long term goal of the present study is to understand the mechanism of action of these modulators one the binding of PCP to the NMDA receptor, and to use these modulator sites as targets for drugs that will alter or block the pharmacological effects of PCP. We will take three convergent approaches, using synthetic chemistry, molecular biology and pharmacology to achieve this goal. The specific aims of this project are: 1. To pursue rational design and synthesis of polyamine antagonists. Using arcaine as a lead compound and systematically modifying size, conformation and hydrophobicity of novel bisguanidines we will develop polyamine antagonists that are more potent and/or more selective than the currently available drugs. 2. To pharmacologically characterize novel polyamine ligands. We will use ligand binding assays and intracellular Ca2+ assays to establish the activity and specificity of newly synthesized polyamine site drugs. We will also determine the extent to which PCP action can be modified by polyamine antagonists. 3. To determine the effect of polyamine agonists and antagonists on ligand binding to recombinant NMDA receptor subunits expressed in mammalian cells. We will assess polyamine action on defined NMDA receptor subunit combinations, which offers a more specific approach to investigating the mechanism of action of this modulator on the NMDA receptor complex. 4. To determine the effects of elevated intracellular free Mg2+ on inhibition of NMDA receptors by PCP site ligands. We will use Ca2+- dependent and Ca2+-independent methods to elevate intracellular [Mg2+] to test the hypothesis that elevated [Mg2+] will decrease PCP binding to the NMDA receptor. Understanding the molecular mechanisms by which Mg2+ and polyamines influence the actions of PCP will provide important new information about the molecular mechanisms of action of this important substance of abuse. This project will also focus on strategies that will prevent the effects of PCP on the NMDA receptor, and thereby offer a therapeutic target for the treatment of PCP abuse.