Insecticide Action at the Local Anesthetic Receptor

局部麻醉受体的杀虫作用

• 批准号: 7530427
• 负责人: DAVID M SODERLUND
• 金额: $ 23.77万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-12-01 至 2011-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7530427
• 关键词: Alanine; Amino Acids; Analgesics; Anticonvulsants; Binding; Cells; Elements; Exhibits; Funding; Insecta; Insecticides; Kinetics; Local Anesthetics; Maps; Membrane Potentials; Molecular; Molecular Structure; Mutate; Mutation; Neuroprotective Agents; Pharmaceutical Preparations; Pharmacology; Protein Isoforms; Rattus; Research; Rest; Role; Site; Site-Directed Mutagenesis; Sodium; Sodium Channel; Sodium Channel Binding; Structure; Testing; Therapeutic; Tissues; United States; Xenopus; Xenopus oocyte; indoxacarb; insight; neurotoxic; receptor; voltage; voltage clamp

Pyrazoline-type insecticides (PTIs) are a new class of insecticides exemplified by indoxacarb, the first compound of the class registered for commercial use in the United States. PTIs exert their neurotoxic effects in insects by selectively blocking sodium channels in depolarized cells. PTIs also selectively block mammalian sodium channels at membrane potentials that promote slow sodium channel inactivation. This effect is similar in many respects to the state-dependent sodium channel block caused by several classes of therapeutic drugs (e.g., local anesthetics, antiarrhythmics, anticonvulsants, neuroprotectants and analgesics) that bind to the "local anesthetic receptor" site of sodium channels. As a result, the local anesthetic receptor has been implicated indirectly as the site of PTI action. The proposed research will test the hypothesis that PTIs block sodium channels by binding to the local anesthetic receptor site of slow-inactivated sodium channels. Specific experimental aims for the proposed funding period are: (1) to define the actions of PTIs on cloned rat sodium channel isoforms and subunit combinations expressed in Xenopus oocytes; (2) to elucidate the mechanism of voltage-dependent sodium channel block by PTIs; and (3) to map the structural determinants of PTI binding to sodium channels by site-directed mutagenesis. Cloned sodium channel isoforms will be expressed in Xenopus oocytes and the actions of PTIs on expressed channels will be assessed using electrophysiological recordings of sodium currents under voltage-clamp conditions. Results of these studies will define the differential sensitivity of sodium channel isoforms to PTIs, elucidate the mechanism of state-dependent sodium channel block by these compounds, and identify the molecular determinants of PTI binding to sodium channels. This research will provide new insight into the structure of the local anesthetic receptor and its role in the neurotoxic actions of PTIs.

吡唑啉型杀虫剂（PTIS）是一类新的杀虫剂，用IndoxaCarb示例，这是第一个 在美国注册商业用途的班级的化合物。 PTIS发挥神经毒性 通过选择性地阻断去极化细胞中的钠通道来影响昆虫。 PTI也有选择地阻止 在膜电位处的哺乳动物钠通道促进慢速钠通道失活。这 在许多方面，效应与国家依赖性钠通道块相似 治疗药物（例如局部麻醉药，抗心律失常，抗惊厥药，神经保护剂和镇痛药） 与钠通道的“局部麻醉受体”部位结合。结果，局部麻醉受体 已间接地将其视为PTI动作的部位。拟议的研究将检验以下假设 PTIS通过与缓慢灭活的钠的局部麻醉受体位点结合来阻断钠通道 频道。拟议的资助期的具体实验目的是：（1）定义PTI的作用 在克隆的大鼠钠通道上的同工型和亚基卵母细胞中表达的亚基组合； （2）至 通过PTI阐明电压依赖性钠通道块的机理； （3）映射结构 通过位置定向诱变的PTI结合与钠通道的决定因素。克隆的钠通道 同工型将以武士卵母细胞表示，PTI在表达通道上的作用将为 在电压钳条件下使用钠电流的电生理记录进行评估。结果 这些研究将定义钠通道同工型对PTI的差异敏感性，阐明 通过这些化合物的状态依赖性钠通道阻滞的机理，并识别分子 PTI与钠通道结合的决定因素。这项研究将为结构提供新的见解 局部麻醉受体及其在PTI的神经毒性作用中的作用。