褪黑素减弱小鼠对吗啡的精神和身体依赖性

目的：观察褪黑素（ｍ ｅｌａｔｏｎｉｎ，ＭＴ）对吗啡依赖小鼠精神依赖性和身体依赖性的抑制作用。方法：用小鼠条件性位置偏爱（ｃｏｎｄｉｔｉｏｎｅｄ ｐｌａｃｅ ｐｒｅｆｅｒｅｃｅ，ＣＰＰ）模型及吗啡身体依赖进行观察。结果：单纯ＭＴ组小鼠在偏爱侧（黑箱）的停留时间给药前后差异无显著性。与吗啡同时ｉｐ ＭＴ１０ ｍ ｇ／ｋｇ ５ ｄ，显示出抑制吗啡精神依赖性反应的作用（Ｐ＜ ０．０１）。单次ｉｐ 给药，ＭＴ１０和２０ ｍ ｇ／ｋｇ，或连续与吗啡一同给予ＭＴ １０和２０ ｍ ｇ／ｋｇ，可剂量依赖地减少小鼠的跳跃次数（Ｐ＜ ０．０５）。结论：在一定的剂量范围内，ＭＴ具有抗小鼠对吗啡精神依赖和身体依赖的作用，且本身未显示精神依赖性反应。

Melatonin attenuated the dependence to morphine in mice

Objective: To study effects of melatonin(MT) on psychical and physical dependence induced by morphine(Mor) in mice. Methods: Effects of MT on the dependence of Mor were tested by using conditioned place preference(CPP) model and jumping test charllenged by naloxone in morphine dependent mice. Results: MT ip 10 mg/kg(MT 10 ) combined with sc Mor 10 mg/kg for 5 days could attenuate CPP response guided by Mor in dose related manner ( P <0.01). Jumping numbers and the number of mice jumping( P <0.05) were markly decreased when single MT 10(MT 10 ) and 20 mg/kg(MT 20 ), and 10(MT 10 ) and 20 mg/kg(MT 20 ) combined with Mor were injected. There were no significant differences between the time of pre and post MT in the biassed side in only MT treated. Conclusion: MT could attenuate effects of psychical and physical dependence induced by Mor, and itself psychical and physical dependence have not been expressed in the experiments.