Miglécz E, Székely J I
Pharmacol Res Commun. 1985 Feb;17(2):177-87. doi: 10.1016/0031-6989(85)90063-3.
Intracerebroventricular (i.c.v.) saline treatment of unanaesthetized mice resulted in moderate but well detectable analgesia. This elevation of pain threshold (by 60-90%) could be observed already 2 min after i.c.v. injection and lasted 15-30 min. Surprisingly, the analgesic action of i.c.v. treatment was not attenuated if naloxone was administered i.c.v. instead of saline. In fact if applying it in higher doses, the opiate antagonist potentiated the antinociceptive action. However, giving naloxone subcutaneously (s.c.) before i.c.v. saline treatment, the resulting analgesia was significantly reduced. It is tentatively put forward that i.c.v. treatment is stressful and in itself may induce mobilization of endogenous opioids and the latters elevate the pain threshold via peripheral opiate mechanisms.
对未麻醉小鼠进行脑室内（i.c.v.）注射生理盐水治疗可产生中度但可明显检测到的镇痛作用。脑室内注射后2分钟即可观察到疼痛阈值升高（60 - 90%），并持续15 - 30分钟。令人惊讶的是，如果脑室内注射的是纳洛酮而非生理盐水，i.c.v.治疗的镇痛作用并未减弱。事实上，若使用更高剂量，阿片类拮抗剂会增强抗伤害感受作用。然而，在脑室内注射生理盐水治疗前皮下（s.c.）注射纳洛酮，所产生的镇痛作用会显著降低。初步推测，i.c.v.治疗具有应激性，其本身可能会诱导内源性阿片类物质的动员，而后者通过外周阿片机制提高疼痛阈值。
