期刊
BRAIN RESEARCH
卷 958, 期 1, 页码 28-35出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/S0006-8993(02)03394-2
关键词
morphine analgesia and tolerance; physical dependence; naloxone-precipitated withdrawal; protein kinase; phosphatidylinositol cascade
资金
- NIDA NIH HHS [DA-01647-25, T32-DA-07027] Funding Source: Medline
The phosphatidylinositol (PI) cascade plays a pivotal role in mediating behavioral tolerance to the antinociceptive effects of morphine, Earlier we reported that antinociceptive tolerance was completely reversed 30 min after the administration of inhibitors of each step in the PI cascade. The aim of this study was to determine whether injection of a single dose of protein kinase C (PKC) inhibitor would elicit a prolonged reversal of morphine tolerance for up to 24 h. Three days after implantation of placebo- or 75-mg morphine pellets, mice received intracerebroventricular (i.c.v.) injections of vehicle or PKC inhibitor drug. Morphine challenge doses were then administered 4, 8 and 24 h later to test for tolerance reversal. In non-tolerant mice, Go-7874 and sangivamycin had no effect on the potency of morphine. However, Go-7874 and sangivamycin significantly reversed morphine tolerance at 4, 8 and 24 h. In addition, the role of PKC in morphine physical dependence was determined. Go-7874 and sangivamycin by themselves did not precipitate spontaneous morphine withdrawal. Therefore, experiments were conducted to determine whether the PKC inhibitors would block naloxone-precipitated withdrawal. However, neither a 30-min nor a 24-h pretreatment with Go-7874 or sangivamycin blocked naloxone withdrawal. Our results along with other publications indicate that PKC is a pivotal kinase essential for maintaining animals in an opioid tolerant state. Finally, the use of persistent PKC inhibitors that lasted for 24 h demonstrated that the neuronal systems in these animals did not adapt by increasing the activity of other protein kinase cascades to re-establish morphine tolerance. (C) 2002 Elsevier Science B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据