青风藤及青藤碱对吗啡依赖小鼠位置偏爱效应及cAMP水平的影响

目的观察中药青风藤及其有效成分青藤碱对吗啡诱导的小鼠位置偏爱效应的影响及其与中枢cAMP水平的关系.方法连续给予吗啡 (9mg/kg, 1次/d,sc) 5d,引起小鼠产生显著的条件性位置偏爱效应.用两种方式给予青风藤醇提液(5,10g/kg, ig)和青藤碱 (60mg/kg, ig) ,即在训练阶段每天sc吗啡前 45min给予和在d 6测定位置偏爱前45min仅给药一次.大脑皮层cAMP含量采用放射免疫法测定. 结果吗啡对照组小鼠在伴药箱中停留的时间明显延长, 小鼠脑组织的cAMP水平亦显著升高. 青风藤或青藤碱连续用药可显著抑制吗啡引起的小鼠位置偏爱的形成,对小鼠已形成的条件性位置偏爱效应也具有一定的抑制作用.并能降低脑内cAMP含量.结论青风藤及青藤碱能消除吗啡产生的条件性位置偏爱,其作用机制与降低中枢cAMP水平有关.

Effects of Caulis Sinomenii and sinomenine on morphine-induced place preference and cyclic AMP level in mice

OBJECTIVE To explore the effects of Caulis Sinomenii and sinomenine on the conditioned place preference induced by morphine in mice and its relation to cAMP level of the brain. METHOD Morphine was injected (9mg/kg, one time/day, sc) to mice for 5 days. The strong place preference was observed in mice. Mice were pretreated 45 min before each injection of morphine during 5 d training phase and treated only once 45 min before the testing phase at d 6 with Caulis Sinomenii(5,10g/kg, ig)and sinomenine(60mg/kg, ig), respectively. Cyclic AMP content in the brain cortex of mice was measured by RIA.RESULTS The time of staying in morphine-paired compartment and the cAMP level in brain of mice in morphine group were significantly increased. After treatment with Caulis Sinomenii and sinomenine, the time of staying in morphine-paired compartment and the cAMP level in mice were significantly reduced.CONCLUSION Caulis Sinomenii and sinomenine could suppress the acquisition and expression of place preference induced by morphine. Their mechanism may be related to decrease of cAMP level in the brain.