【摘要】 本文通过小鼠光辐射热甩尾实验证明毛果芸香碱对可乐定镇痛具有增强作用,而阿托品则具有拮抗作用。阿托品对可乐定镇痛的拮抗可能不是通过竞争受体的机制,因阿托品只有达10^-4M/L时方可减少（³H）-可乐定的特异性结合。给大鼠侧脑室注射密胆碱（30μg/只）明显减弱可乐定（2mg/kg,S·C）的镇痛效应。结果提示可乐定镇痛效应的充分发挥需要中枢胆碱能系统功能的完整。更多还原

【Abstract】 The relationship between the analgesia of clonidine and the central acetylcholinergic system was studied. Using the radiant heat tail flick method, intracerebroventricular administration and radioactive ligand binding test in mice and rats. The areas under the analgesic activity-time curves of clonidine were first determined, and a regression line relating these areas to log dose was calculated. This regression line was shifted to the left by pilocarpine ( 5 mg/ kg, sc)and to the right by atropine ( 5 mg/kg, sc ) in mice. The analgesic effect of clonidine (2 mg/kg, sc) was markedly weakened by pretreatmet with hemicholinum-3 (30 μg/rat. icv ) . Atropine inhibited ( 3H) -clonidine binding to the cell membrane of rat brain only at the concentration 10-4M or more. The results show that the analgesia of clonidine involves the central acetylcholinergic system and needs the existence of the intact activity of the system.更多还原