左旋四氢巴马汀对吗啡条件性位置偏爱的影响

目的探讨不同剂量的左旋四氢巴马汀(lTetrahydropalmatine,lTHP)对吗啡诱导的条件性位置偏爱(CPP)的影响以及自身能否产生CPP效应。方法本实验采用倾向性实验程序,①对♂SD大鼠sc吗啡(5.00mg·kg-1)或生理盐水(NS)训练8d,d9测定大鼠对伴药侧的偏爱效应或测试前40minipNS或不同剂量的lTHP(1.25～5.00mg·kg-1),观察这些预处理对该效应的影响;②测量不同剂量的lTHP(1.25～5.00mg·kg-1)慢性用药(每天1次,ip)对CPP效应消退的影响;③测试ipNS或lTHP(1.25～5.00mg·kg-1)能否诱导大鼠对伴药侧产生偏爱(方法同吗啡)。结果5.00mg·kg-1吗啡诱导大鼠对伴药盒产生明显的CPP;测试前ip2.50mg·kg-1或5.00mg·kg-1的lTHP明显降低吗啡诱导的CPP效应的表达(P<0.05),其慢性给药明显加速吗啡CPP效应的消退;3个剂量的lTHP均不能诱导大鼠形成CPP。结论lTHP能抑制吗啡的奖赏效应,可在吗啡成瘾的治疗中发挥一定的作用。

Influence of l-tetrahydropalmatine on morphine-induced conditioned place preference

Aim To study the effect of different doses of l-Tetrahydropalmatine( l-THP) on morphine-induced conditioned place preference(CPP) and observe whether l-THP itself induces CPP.Methods ①♂SD rats were administered with morphine (5.00 mg·kg -1 ,sc) or saline and trained for 8 days;on d 9,the rats were tested CPP with no treatment or 40 min after they were given different doses of l-THP(1.25～5.00 mg·kg -1,ip) to observe the effect of l-THP on morphine-induced CPP;② With daily injection of l-THP (ip) at different doses,effect on the extinguishment of morphine-induced CPP was tested weekly; ③ Normal saline (NS) or l-THP (1.25～5.00 mg·kg -1 , ip) was used as a training drug to test whether l-THP could induce CPP in the rats. Results 5.00 mg·kg -1 morphine (sc) induced CPP; l-THP of 2.50 mg·kg -1 and 5.00 mg·kg -1 administered prior to the testing reduced the expression of morphine-induced CPP significantly (P<0.05) and chronic administration of these agents both accelerated the extinguishment of morphine-induced CPP obviously. None of the three doses of l-THP induced CPP. Conclusion l-THP can inhibit the rewarding effect induced by morphine and may play a role in the treatment of morphine addiction.