GENERAL ANESTHETICS AND CLONED VOLTAGE-GATED CHANNELS

全身麻醉是一种丧失记忆和意识的状态。 伴随着痛觉的丧失。吸入性全麻药 (GA)，手术麻醉的基本助手，两者都诱导，但并不是没有 表现出一些严重的副作用。因为这与 神经传递在催眠和止痛作用中的重要作用 已被置于GA在突触的作用的研究中， 强调对配体门控受体和通道的影响。的影响 电压门控离子通道上的GA在神经元中的重要性 变速箱。电压门控离子通道在 全身麻醉中GA的许多副作用已被追溯到 这些通道在各种组织中的功能受损。一个有据可查的 GA引起的涉及电压门控通道的副作用的例子是 心脏抑制，这会使患者面临相当大的风险。这个 “理想的”全身麻醉药的设计将产生于 GA效应涉及的特定分子机制。这是长期的 本项目的目标是促进对这些机制的理解 通过提供有关G通道相互作用的新信息，了解GA的作用。 在这项建议中，挥发性麻醉剂的效果是非常有希望的 静脉麻醉剂异丙酚将通过服用 分子生物学提供的工具的优势，由高表达 系统(非洲爪哇卵母细胞)和高分辨率电生理 录音技术。通过这种方法，对 单一种类的通道的功能可以在基本上没有 其他膜蛋白的污染。具体目标是：1) 描述全身吸入性麻醉药对 克隆电压门控离子的宏观门控和电导特性 频道。切开卵母细胞电压钳技术将用于 记录表达K+、Na+或Ca~(2+)的卵母细胞的离子电流和门控电流 来自注入的CRNA的通道。2)描述全身麻醉效果 通过记录单个通道蛋白的功能 单通道电平。单通道活动将使用 膜片钳技术，3)通过比较研究确定区域 与麻醉剂相互作用的结构和/或 直接参与受影响的职能。在这些研究中，不同的 亚单位和通道子类型、嵌合体和通道的组合 变种人将接受检查。目标是确定蛋白质中的区域 与麻醉剂有特定的相互作用。所扮演的角色 将对辅助亚单位进行调查。(四)开展研究 静脉麻醉药对电压门控离子通道的作用。这些 研究将集中在异丙酚对宏观、门控的影响。 和单通道电流。该项目的成果应提供 影响遗传算法的相关结构特征的重要信息- 渠道互动。

General anesthesia is a condition in which loss of memory and consciousness is accompanied by loss of pain sensation. Inhalation general anesthetics (GA), fundamental aides in surgical anesthesia, induce both but not without displaying some serious side effects. Because of the relevance of neurotransmission in hypnotic and analgesic effects, a substantial effort has been placed in the study of the action of GA at the synapse, with emphasis on effects on ligand-gated receptors and channels. The effects of GA on voltage-gated ion channels are of no less importance in neuronal transmission. Voltage-gated ion channels play an added crucial role in general anesthesia in that many side effects of GA have been traced to impaired function of these channels in various tissues. A well-documented example of GA induced side effects involving voltage-gated channels is that of cardiac depression, which puts patients under considerable risk. The design of 'ideal' general anesthetics will emerge from the knowledge of the specific molecular mechanisms involved in GA effects. It is the long-term goal of this project to contribute to the understanding of the mechanisms of action of GA by providing novel information on G-channel interactions. In this proposal the effects of volatile anesthetics an of a very promising intravenous anesthetic, Propofol, will be studied in detail by taking advantage of the tools provided by molecular biology, by a high expression system (Xenopus oocytes) and by high resolution electrophysiological recording techniques. With this approach, new detailed studies of the function of single species of channels can be performed with essentially no contamination from other membrane proteins. The specific aims are: 1) To characterize the action of general inhalation anesthetics on the macroscopic gating and conductance properties of cloned voltage-gated ion channels. The cut-open oocyte voltage-clamp technique will be used to record ionic and gating currents from oocytes expressing K+, Na+ or Ca2+ channels from injected cRNA. 2) To characterize general anesthetic effects on the function of the individual channel proteins by recording at the single-channel level. Single-channel activity will be recorded using the patch-clamp technique, 3) To determine, from comparative studies, regions of the structure that interact with the anesthetics and/or that are directly involved in the affected functions. In these studies, different combinations of subunits and channel subtypes., chimeras and channel mutants will be examined. The goal is to identify regions in the proteins involved in specific interactions with the anesthetics. The roles played by auxiliary subunits will be investigated. (4) To initiate studies on the action of intravenous anesthetics on voltage-gated ion channels. These studies will concentrate on the effects of Propofol on macroscopic, gating and single-channel currents. The outcome of this project should provide important information on relevant structural features intervening in GA- channel interactions.