Influence of l-tetrahydropalmatine on morphine-induced conditioned place preference / 中国药理学通报

ABSTRACT

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