Anesthetics: Cellular and Molecular Actions

描述(申请人提供)：全身麻醉药达到临床预期效果的机制尚未完全了解。本计划中提出的工作旨在定义麻醉剂类固醇的分子靶点(S)，并阐明在这些靶点上的作用导致麻醉的方式。其基本思想是，类固醇麻醉剂作用于蛋白质上的特定位置，特别是参与神经元之间信息传递的蛋白质。拟议的研究将建立在该计划前几个时期取得的一系列进展的基础上，这些进展为类固醇的作用部位和作用机制提供了见解。该计划的一个目标是确定类固醇与特定靶点GABA-A受体相互作用的结构基础。这项工作将包括对类固醇类似物构效关系的补充研究和受体结构的突变研究，以及识别由特定部位的光激活类固醇类似物标记的残基。该计划的第二个目标是阐明类固醇对其分子靶标的作用机制，包括对靶蛋白的功能影响的研究和类固醇访问的检查。第三个目标是检查类固醇在决定类固醇作用的时间进程和大小方面在细胞膜池中的作用。最终目标是将药理学和生理学结果与麻醉的产生或仅在整个动物水平上定义的其他状态相关联。虽然主要的重点是对GABA-A受体的研究，但将对谷氨酸、甘氨酸和GABA-C受体进行比较研究。每个项目都涉及麻醉剂类固醇在细胞和分子水平上的作用的一个或另一个方面。作为一个整体，该计划将整合这些互补性研究，并为继续开发新化合物和分析药物对行为状态的影响提供资源。

DESCRIPTION (provided by applicant): The mechanisms by which general anesthetics have their clinically desired effects are not yet fully understood. The work proposed in this Program is designed to define the molecular target(s) for anesthetic steroids and to clarify the way in which action at these targets results in anesthesia. The underlying idea is that steroid anesthetics act at defined sites on proteins and, in particular, the proteins involved in information transfer between neurons. The proposed research will build on a series of advances made in preceding periods of the Program, which have provided insights into the sites and mechanisms of action for steroids. One objective of the Program is to define the structural basis for steroid interaction with a specific target, the GABA-A receptor. This work will involve complementary studies of the structure-activity relationship for steroid analogues and mutational studies of receptor structure coupled with identification of the residues labeled by site-specific photo-activated steroid analogues. The second objective of the Program is to clarify the mechanisms by which steroids have their actions on their molecular targets, including studies of functional effects on target proteins and examination of steroid access. The third objective is to examine the role of steroid partitioning among cellular membrane pools in determining the time course and magnitude of steroid action. The final objective is to correlate the pharmacological and physiological results with the production of anesthesia or other states defined only at the level of the whole animal. Although a major focus is on studies of the GABA-A receptor, comparative studies of glutamatergic, glycinergic and GABA-C receptors will be performed. Each project addresses one or another aspect of the action of anesthetic steroids at the cellular and molecular level. The Program as a whole will integrate these complementary studies and provide the resources for continued development of novel compounds and for assays of drug effects on behavioral states.