吗啡依赖与戒断大鼠伏隔核单胺、类阿片肽及下丘脑POMCmRNA改变的研究

研究了大鼠吗啡依赖与戒断状态和伏隔核类阿片肽、单胺、下丘脑ＰＯＭＣ基因表达改变之间的关系。发现在吗啡依赖状态伏隔核内β－内啡肽、脑啡肽、单胺释放以及下丘脑ＰＯＭＣ基因表达受抑制。戒断４８小时后强啡肽、ＮＥ、ＭＨＰＧ、５－ＨＴ升达高峰，后虽水平有所降低，但戒断１周时仍高于对照显著。深受抑制的ＤＡ、β－内啡肽释放以及ＰＯＭＣ基因表达在戒断后有所回升，但于戒断１周时还是显著低于对照水平。提出这些生化改变尤其是自从依赖形成后ＤＡ的持续低水平是吗啡依赖的机理之一。

Extraneuronal opioids,monoamine in the nucleus accumbens and POMC gene expression in morphine dependent rats

The relationship of morphine tolerant dependence and withdrawal states with the dynamics of opioids and monoamine in the nucleus acumbens as well as POMC gene expression in the hypothalomus was assessed in rats.Employing the techniques of push-pull,HPLC,RIA and in situ hibridization,the present study demonstrated that therewere inhibitory effects on opioids and monoamine release in the nucleus accumbens,and the expressin of POMC gene wasreduced also in morphine tolerance dependence state.The levels of NE,MHPG,5-HT and dynorphin remarkably in-creased 48 hours after withdrawal,then those concentrations rdeuced but still significantly higher compared with the con-trol.DA and POMC went up since the withdrawal occured,but the lowered leves persisted thrugh one week of with-drawal observed.The dynamics of opiods and monoamine may help to explain how morphine tolerance and dependencedevelop.