THERAPEUTIC NA+ CHANNEL BLOCKERS: RECEPTOR & DRUG DESIGN

治疗性 NA 通道阻断剂：受体

• 批准号: 6630298
• 负责人: GING K WANG
• 金额: $ 27.54万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-08-01 至 2004-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6630298
• 关键词: amitriptyline; drug design /synthesis /production; drug metabolism; drug receptors; ion channel blocker; laboratory rat; local anesthetics; receptor binding; sciatic nerve; sheep; site directed mutagenesis; sodium channel; tissue /cell culture; voltage /patch clamp; voltage gated channel

The long term objective of this renewal application is to develop therapeutic Na+ channel blockers pertinent to pain management. Traditional local anesthetics are often unsuited for treatment of chronic or intractable cancer pain because of their insufficient duration of nerve block. There are 4 specific aims: 1. To study the structure-activity relationship of various potent Na+ channel blockers in vitro; 2. To design and synthesize their amphipathic derivatives; 3. To test selected blockers suitable for prolonged nerve block in vivo; and 4. To map their receptor site within the Na+ channel alpha subunit. The first agent to be tested is the tricyclic antidepressant amitryptyline, which is a potent sodium channel blocking agent in addition to its actions at other receptors. With bupivacaine as a standard for comparison, the binding affinities of various tricyclics and other potent sodium channel blockers will be determined in voltage clamp studies on HEK cells transiently transfected with rat skeletal muscle and human heart sodium channel clones; native neuronal sodium channels in rat pituitary GH3 cells will also be used. Elements to be characterized include use-dependence of block and IC50 for resting and inactivated channel block. The working hypothesis for this phase of the studies is that duration of block in vivo will correlate positively with use dependence and negatively with IC50 for inactivated channel states. The in vivo studies will employ behavioral endpoints to examine both sensory and motor nerve block of sciatic nerve following a single injection of each agent in rats; drugs effective in rats will also be tested in the cauda equina space in sheep to model spinal routes of therapy. Drug design and synthesis will initially employ amitryptiline derivatives. Studies of the receptor site in the sodium channel will probe for the locations of two hydrophobic domains using point mutations and studies of drug potency on the mutated channels in HEK cells, with a special emphasis on residues which may be responsible for high-affinity binding of the tricyclic ring. Eventually the studies will be extended to other classes of drugs including phenylacetamides, calcium channel blockers, and a potassium channel blocker that also potently blocks sodium channels. Like tricyclic antidepressants, these agents have multiple phenyl rings but they are separated into two large hydrophobic domains rather than one.

本次更新申请的长期目标是发展 与疼痛管理相关的治疗性Na+通道阻滞剂。传统 局部麻醉剂通常不适用于治疗慢性或难治性的 癌症疼痛是因为神经阻滞的持续时间不足。有4 具体目标：1.为了研究不同的构效关系， 体外有效的Na+通道阻断剂; 2.设计并合成它们的 两亲衍生物; 3.为了测试选定的阻滞剂适用于长期 体内神经阻滞; 4.绘制它们在Na+通道内的受体位点 α亚基第一个被测试的药物是三环类抗抑郁药 阿米替林是一种强效钠通道阻滞剂， 它对其他受体的作用以布比卡因为对照品， 各种三环化合物和其他有效钠通道的结合亲和力 阻断剂将在HEK细胞的电压钳研究中瞬时测定 用大鼠骨骼肌和人心脏钠通道克隆转染; 还将使用大鼠垂体GH 3细胞中的天然神经元钠通道。 待表征的元素包括阻断的使用依赖性和IC 50， 静息和失活通道阻滞。这一阶段的工作假设 研究表明，体内阻滞的持续时间与 使用依赖性，并且与失活通道状态的IC 50呈负相关。的in 体内研究将采用行为终点来检查感觉和运动 坐骨神经的神经阻滞后，单次注射每种药物， 大鼠;在大鼠中有效的药物也将在 绵羊来模拟脊椎治疗的路径。药物设计和合成将 最初使用阿米替林衍生物。受体位点的研究 钠通道将探测两个疏水结构域的位置， HEK中突变通道的点突变和药物效力研究 细胞，特别强调可能负责 三环的高亲和力结合。最终，这些研究将 扩展到其他类别的药物，包括苯乙酰胺，钙通道， 阻断剂和钾通道阻断剂，也有效地阻断钠 渠道像三环类抗抑郁药，这些药物有多个苯基 环，但它们被分成两个大的疏水结构域，而不是 一个.