Horita A, Carino M A, Yamawaki S
Neuropharmacology. 1983 Oct;22(10):1183-6. doi: 10.1016/0028-3908(83)90078-3.
Morphine was administered by the intracerebroventricular (i.c.v.) route to pentobarbital-anesthetized rabbits. Small doses of morphine (less than 150 micrograms) potentiated, but larger doses (greater than 250 micrograms) shortened, the duration of anesthesia. In naltrexone-pretreated animals, all doses of morphine employed acted only as an analeptic. Atropine, but not atropine methylbromide, blocked the analeptic effect of morphine, indicating that a central cholinergic mechanism was involved in this response. Tolerance to the analeptic effect was not evident. These results suggest that morphine exerts an arousal action which is usually masked by the dominant narcotic properties, but which becomes evident when administered intracerebroventricularly or in the presence of naltrexone.
将吗啡经脑室内（i.c.v.）途径给予戊巴比妥麻醉的家兔。小剂量吗啡（小于150微克）可增强麻醉持续时间，但大剂量（大于250微克）则缩短麻醉持续时间。在经纳曲酮预处理的动物中，所用的所有剂量吗啡仅起兴奋作用。阿托品而非甲基溴化阿托品可阻断吗啡的兴奋作用，表明该反应涉及中枢胆碱能机制。对兴奋作用的耐受性不明显。这些结果表明，吗啡发挥的觉醒作用通常被其主要的麻醉特性所掩盖，但在经脑室内给药或存在纳曲酮的情况下会变得明显。
