Naloxone pretreatment blocks acute morphine-induced sensitization to naltrexone.
Naloxone pretreatment blocks acute morphine-induced sensitization to naltrexone.
复制标题
纳洛酮预处理可阻断吗啡引起的急性纳曲酮过敏。
DOI：
10.1007/bf02244840
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发表时间：
1994
影响因子：
3.4
通讯作者：
Holtzman,S
中科院分区：
文献类型：
--
作者：
White-Gbadebo,D;Holtzman,S
本实验旨在探讨纳洛酮能否阻断单剂量吗啡对纳曲酮的急性增敏作用。剥夺食物的雄性Spraogue-Dawley大鼠被训练为按固定间隔3分钟的多次试验对食物做出反应。增援取决于在固定间隔3分钟后的10-S有限保留期内的反应。一项试验包括三个固定的间隔，中间有10分钟的超时时间，在此期间没有加强反应。阿片类拮抗剂纳曲酮的减速作用采用累积给药法。吗啡(3.0 mg/kg，SC)预处理后，对纳曲酮降低应答率的敏感性较生理盐水预处理增加70倍。吗啡前10min给予纳洛酮可剂量依赖性地阻断这种敏感性的增加。将吗啡预处理剂量增加到10 mg/kg可克服纳洛酮的拮抗作用。这些结果进一步证明，急性激动剂对纳曲酮减速作用的增敏作用是通过阿片受体介导的。
The present experiment was designed to examine whether the acute sensitization to naltrexone that is induced by a single dose of morphine could be blocked by pretreatment with naloxone. Food-deprived male Sprague-Dawley rats were trained to respond for food on a multiple-trial fixed interval 3-min schedule. Reinforcement was contingent upon a response within a 10-s limited hold period following a fixed interval of 3 min. A trial consisted of three fixed intervals separated by a 10-min timeout period during which responses were not reinforced. The rate decreasing effects of the opioid antagonist naltrexone were determined by cumulative dosing. Pretreatment with morphine (3.0 mg/kg, SC) resulted in a 70-fold increase in sensitivity to the response rate decreasing effect of naltrexone compared with saline pretreatment. The increased sensitivity was dose-dependently blocked by naloxone administration 10 min before morphine. The blockade by naloxone was overcome by increasing the pretreatment dose of morphine to 10 mg/kg. The results provide further evidence that acute agonist-induced sensitization to the rate-reducing effects of naltrexone is mediated by opioid receptors.