CHOLINERGIC MECHANISMS OF ANALGESIA

镇痛的胆碱能机制

• 批准号: 3415520
• 负责人: EDGAR T IWAMOTO
• 金额: $ 13.87万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-08-01 至 1997-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3415520
• 关键词: acetylcholine; analgesics; anticholinergic agent; arginine; autoradiography; central neural pathway /tract; cholinergic agents; cholinergic receptors; cyclic GMP; drug interactions; experimental brain lesion; high performance liquid chromatography; immunocytochemistry; in situ hybridization; inhibitor /antagonist; laboratory rat; mesencephalon; muscarinic receptor; neuropharmacology; nitric oxide; norepinephrine; pain threshold; serotonin; spinal cord; stimulant /agonist; tegmentum

The long-term objectives of this research proposal are to continue to use a multidisciplinary approach to characterize the transmitters and receptors of the cholinergic pain suppression systems of the pedunculopontine tegmental nucleus-to-rostral ventromedial medulla (PPTg- to-RVM) cholinergic pathway and the lumbar spinal cord of rats. Experiments are designed to test the hypothesis that L-arginine/nitric oxide (NO)/cyclic GMP cascades mediate muscarinic cholinergic antinociception. It is proposed that cholinergic agonists stimulate muscarinic M1 receptors on NO synthesizing (NOergic) cells present in the PPTg, RVM, and lumbar spinal cord resulting in the production of NO which then diffuses by volume transmission to activate its specific receptor, guanylyl cyclase. It is predicted that agents which inhibit NO synthesis will decrease, and agents which enhance NO or cyclic GMP production will increase cholinergic antinociception as measured using the hot-plate and tail-flick tests in rats. It is also predicted that the proposed target cells for cholinergic analgesics have M1 receptors and contain NO synthase and m1 mRNA, and that these cells are In close proximity to putative NO target neurons containing guanylyl cyclase mRNA. These experiments utilize neuropharmacologic, immunocytochemical, autoradiographic and molecular biological approaches. The Specific Aims are (i) To determine whether inhibitors of NO and cyclic GMP synthesis decrease, and agents which enhance NO or cyclic GMP production increase the antinociception produced by cholinergic stimulation of the PPTg, RVM and the lumbar spinal cord; (2) To determine whether the PPTg-to-RVM pathway sends cholinergic axons terminating on NOergic cells in the RVM, and whether these NOergic perikarya are in close proximity to cells containing guanylyl cyclase; (3) To determine whether intrathecally administered (+)-cis-methyldioxolan releases serotonin and norepinephrin in the lumbar spinal cord by a NO- dependent mechanism; (4) To determine the locations of M1 and M2 receptors in relation to the cholinergic, NOergic, and guanylyl cyclase-containing neurons in the superficial dorsal horn of the lumbar-spinal cord. This research will increase knowledge of the brain and spinal cord's cholinergic pain suppression systems, and will provide an avenue for the development of new, nonopioid pain interventions and therapeutic agents.

本研究计划的长期目标是继续使用 多学科方法来表征发射机和 胆碱能疼痛抑制系统的受体 脚桥被盖核到头端腹内侧延髓 (PPTg- to-RVM）胆碱能通路和大鼠腰脊髓。 实验旨在检验 L-精氨酸/硝酸的假设 氧化物 (NO)/环状 GMP 级联介导毒蕈碱胆碱能 抗伤害作用。 建议胆碱能激动剂刺激 存在于 NO 合成（NOergic）细胞上的毒蕈碱 M1 受体 PPTg、RVM 和腰脊髓导致 NO 的产生 然后通过体积传输扩散以激活其特定受体， 鸟苷酸环化酶。据预测，抑制NO合成的药物 将会减少，而增强 NO 或环 GMP 生产的药物将会 增加使用热板测量的胆碱能抗伤害作用和 大鼠甩尾试验。另据预测，拟议目标 胆碱能镇痛细胞具有 M1 受体并含有 NO 合酶 和 m1 mRNA，并且这些细胞与假定的 NO 非常接近 含有鸟苷酸环化酶 mRNA 的靶神经元。这些实验利用 神经药理学、免疫细胞化学、放射自显影和分子 生物学方法。具体目标是 (i) 确定是否 NO 和环 GMP 合成的抑制剂减少，并且药物 增强 NO 或循环 GMP 的产生，增加产生的镇痛作用 通过 PPTg、RVM 和腰脊髓的胆碱能刺激； (2) 确定PPTg-to-RVM通路是否发送胆碱能轴突 终止于 RVM 中的 NOergic 细胞，以及这些 NOergic 细胞是否 核周体与含有鸟苷酸环化酶的细胞非常接近； (3) 确定是否鞘内给药 (+)-顺式甲基二氧戊环 通过一氧化氮在腰脊髓中释放血清素和去甲肾上腺素 依赖机制； (4)确定M1和M2受体的位置 与含有胆碱能、NO能和鸟苷酸环化酶有关 腰脊髓浅表背角的神经元。这 研究将增加对大脑和脊髓的了解 胆碱能疼痛抑制系统，并将提供一个途径 开发新的非阿片类疼痛干预措施和治疗药物。