吗啡依赖大鼠脊髓和脑干一氧化氮含量和合酶活力分析

本文检测了吗啡依赖大鼠脊髓和脑干一氧化氮合酶（ＮＯｓ）活力，一氧化氮（ＮＯ）以及ｃＧＭＰ含量。结果显示吗啡依赖大鼠脊髓ＮＯｓ活力，ＮＯ和ｃＧＭＰ含量较正常对照组降低，脑干中ＮＯｓ活力轻度降低，而ＮＯ和ｃＧＭＰ含量降低。纳洛酮激发戒断症状后大鼠脊髓和脑干ＮＯｓ活力，ＮＯ以及ｃＧＭＰ含量急剧升高。ＮＯｓ抑制剂Ｌ－Ｎ－硝基精氨酸甲酯（Ｌ－ＮＡＭＥ）处理可以抑制大鼠吗啡戒断反应，同时减少脊髓和脑干ＮＯ含量。结果表明吗啡戒断反应与脊髓和脑干的ＮＯ－ｃＧＭＰ途径的兴奋有关。

THE ROLE OF NITRIC OXIDE PRODUCTION IN SPINAL CORD AND STEM DURING MORPHINE WITHDRAWAL IN RATS

The present results showed that the activities of nitric oxide synthase (NOs) in morphine dependent rats were 1.3 nmolmin-1g-1s 0.27 nmolmin-1g-1 tissue in spinal cord which was lower than that of the activities of NOs (2.9 nmolmin-1g-1s 0.51 nmolmin-1g-1,n=5,P<0.05) in control animals, and the activities of NOs in stem were decreased slightly in morphine dependent rats,while the activities of NOs in spinal cord and stem in morphine withdrawal rats precipitated by naloxone were both increased significantly compared with morphine dependent rats. The NO2-/NO3-(the end products of NO) levels and cGMP contents in spinal cord and stem in morphine dependent rats were decreased compared with the control animals,and during morphine withdrawal the NO levels and cGMP contents were increased over those of morphine dependent rats. L-N-nitroarginine methyl-ester(L-NAME),a competitive inhibitor of NOs, was administered as a single injection (10 mgkg-1,ip) 1 hour before the injection of naloxone in morphine dependent rats, it was revealed that L-NAME reduced the total ratings of withdrawal signs, and also decreased the NO production in spinal cord and stem. The data indicated that the excitement of NO-cGMP pathway in spinal cord and stem may play an important role in mediating the process of morphine withdrawal.