Wettstein J G, Martin W R
Drug Alcohol Depend. 1985 Aug;15(4):353-60. doi: 10.1016/0376-8716(85)90013-4.
Naltrexone (0.01-2.0 mg/kg, i.v.) produced dose-dependent EEG slowing in the conscious dog as did morphine (0.5-8 mg/kg, i.v.) and fentanyl (5-20 micrograms/kg, i.v.). However, the dose-response curve for naltrexone was not parallel to the morphine or fentanyl dose-response curves. Morphine and fentanyl but not naltrexone also produced dose-dependent miosis and increased the skin twitch reflex latency. When administered into the fourth cerebral ventricle naltrexone (60 micrograms), morphine (80 micrograms) and ethylketazocine (30 micrograms) produced EEG slowing. Again, naltrexone did not alter the skin twitch latency whereas morphine lengthened it and ethylketazocine reduced it. The pharmacological profiles obtained from different routes of administration indicate that naltrexone is clearly different from morphine, fentanyl and ethylketazocine. However, naltrexone may act as a partial agonist in the production of EEG slowing at a previously unidentified opioid receptor.
纳曲酮（0.01 - 2.0毫克/千克，静脉注射）在清醒犬中产生剂量依赖性的脑电图减慢，吗啡（0.5 - 8毫克/千克，静脉注射）和芬太尼（5 - 20微克/千克，静脉注射）也是如此。然而，纳曲酮的剂量 - 反应曲线与吗啡或芬太尼的剂量 - 反应曲线不平行。吗啡和芬太尼而非纳曲酮还产生剂量依赖性的瞳孔缩小并增加皮肤抽搐反射潜伏期。当注入第四脑室时，纳曲酮（60微克）、吗啡（80微克）和乙基酮佐辛（30微克）产生脑电图减慢。同样，纳曲酮不改变皮肤抽搐潜伏期，而吗啡使其延长，乙基酮佐辛使其缩短。从不同给药途径获得的药理学特征表明，纳曲酮明显不同于吗啡、芬太尼和乙基酮佐辛。然而，纳曲酮可能在一个先前未确定的阿片受体产生脑电图减慢过程中作为部分激动剂起作用。
