褪黑素对吗啡依赖大鼠复吸行为的抑制作用

目的 :研究褪黑素对吗啡依赖大鼠复吸行为的抑制作用。方法 :以剂量递增法连续皮下注射 (sc)吗啡 6d建立吗啡诱导的大鼠条件性位置偏爱 (CPP)模型 ,d7用生理盐水替代吗啡训练大鼠 10d ,以使形成的CPP逐渐消退。单次sc 4mg·kg- 1 吗啡以唤起消退的CPP的恢复。部分大鼠在注射吗啡前 30min分别腹腔注射 (ip)褪黑素 2 0、4 0和 80mg·kg- 1 进行治疗。结果 :与吗啡依赖组相比 ,在sc 4mg·kg- 1 吗啡引燃刺激前 30min应用褪黑素 4 0和 80mg·kg- 1 急性治疗 ,可以使大鼠在伴药箱的停留时间明显缩短 ,(P <0 0 5、P <0 0 1) ;而褪黑素 2 0mg·kg- 1 急性治疗亦使大鼠在伴药箱的停留时间缩短 ,但无统计学意义 ,P >0 0 5。结论 :褪黑素在一定程度上可以抑制吗啡引燃的吗啡依赖大鼠的复吸行为

THE INHIBITION OF MELATONIN ON RELAPSE BEHAVIOR IN MORPHINE- DEPENDENT RATS

Objective: To study the inhibitory efficacy of melatonin (Mel) on relapse behavior in morphine-dependent rats. Methods: Morphine was administered via subcutaneous injection at gradually increasing doses (from 10 mg·kg -1 to 60 mg·kg -1 ) for 6 days to establish morphine conditioned place preference(CPP). From Day 7, the rats were administered saline instead of morphine for 10 days to induce CPP extinction. The rats then were given a single priming injection of morphine 4 mg·kg -1 to reinstate the morphine CPP. Some rats were treated by ip melatonin (20, 40 and 80 mg·kg -1 ) prior to priming injection of morphine. Results: After priming injection of morphine 4 mg·kg -1 , the time spent on the drug-paired side was significantly reduced because of the treatment with Mel(40 and 80 mg·kg -1 ), compared with Mor Group P<0 05, P<0 01. No significant statistical differences were observed between Mor Group and Mel 20 Group (P> 0 05). Conclusion: Mel has some effects on the inhibitory of relapse behavior induced by priming injection of morphine in morphine-dependent rats.