Hewett Karen, Dickenson Anthony H, McQuay Henry J
Department of Pharmacology, University College London, LondonUK Nuffield Department of Anaesthetics, University of Oxford, OxfordUK.
Pain. 1993 Apr;53(1):59-63. doi: 10.1016/0304-3959(93)90056-U.
Previous studies have shown that morphine-3-glucuronide (M3G), a metabolite of morphine, may functionally antagonize the antinociceptive action of morphine. The interaction between morphine and M3G was therefore investigated in the halothane-anaesthetised rat. Extracellular unit recordings were made of the innocuous A-beta fibre and noxious C-fibre evoked responses of convergent dorsal horn neurones. Intrathecal M3G (5 micrograms, 100 micrograms and 500 micrograms) alone did not show any antinociceptive effect. There was a slight, but not statistically significant, decrease in the antinociceptive effect of 5 micrograms morphine in the M3G-pretreated groups. However, M3G pretreatment (5 micrograms, 100 micrograms and 500 micrograms) had no effect on the higher dose of morphine (50 micrograms) used. We conclude that M3G has, at most, a minor effect on the spinal antinociceptive effects of morphine.
先前的研究表明，吗啡的代谢产物吗啡-3-葡萄糖醛酸苷（M3G）可能在功能上拮抗吗啡的镇痛作用。因此，在氟烷麻醉的大鼠中研究了吗啡与M3G之间的相互作用。对无害的A-β纤维和伤害性C纤维诱发的会聚背角神经元反应进行细胞外单位记录。鞘内注射单独的M3G（5微克、100微克和500微克）未显示出任何镇痛作用。在M3G预处理组中，5微克吗啡的镇痛作用略有下降，但无统计学意义。然而，M3G预处理（5微克、100微克和500微克）对所用较高剂量的吗啡（50微克）没有影响。我们得出结论，M3G对吗啡的脊髓镇痛作用至多有轻微影响。
