Bartoletti M, Gaiardi M, Gubellini G, Bacchi A, Babbini M
Neuropharmacology. 1983 Oct;22(10):1193-6. doi: 10.1016/0028-3908(83)90080-1.
Motility effects of excitatory and depressant doses of morphine were studied in naïve, dependent (20 mg/kg daily) and post-dependent (about 40 days after withdrawal) rats. Doses of 0.6 and 1.25 mg/kg of morphine produced a greater increase in activity in post-dependent than in naïve rats. A 20-mg/kg dose exerted an excitatory effect in dependent rats instead of the depressant one induced in naïve animals. This excitatory effect was still evident but less pronounced in post-dependent rats. The dose of 1.25 mg/kg was repeatedly challenged in post-dependent (80 mg/kg daily) rats. It was found that the increased excitatory effect of this dose persisted unchanged 160 days after ceasing treatment. The present results demonstrate that several months after the withdrawal of morphine, sensitization still exists to the excitatory effect of the drug while tolerance to the depressant action is slight or no longer present shortly after ceasing treatment.
在未接触过吗啡、依赖吗啡（每日20毫克/千克）以及戒断后（戒断约40天后）的大鼠中，研究了兴奋性和抑制性剂量吗啡的运动效应。0.6毫克/千克和1.25毫克/千克的吗啡剂量使戒断后大鼠的活动增加幅度大于未接触过吗啡的大鼠。20毫克/千克的剂量在依赖吗啡的大鼠中产生兴奋作用，而在未接触过吗啡的动物中则产生抑制作用。这种兴奋作用在戒断后大鼠中仍然明显，但程度较轻。对戒断后（每日80毫克/千克）的大鼠反复给予1.25毫克/千克的剂量。结果发现，停止给药160天后，该剂量增强的兴奋作用持续不变。目前的结果表明，吗啡戒断数月后，对药物的兴奋作用仍存在敏化现象，而对抑制作用的耐受性在停止治疗后不久则轻微或不再存在。
