[Study on acting mechanism of anti-morphine conditioned place preference between aqueous extract of Corydalis yanhusuo and L-THP and comparison of their effects].
OBJECTIVE
To study the acting mechanism of anti-morphine conditioned place preference (CPP) between aqueous extract of Corydalis yanhusuo and L-THP and compare their effects.


METHODS
The CPP model was established by injecting morphine in rats with a increasing dose for 10 days, with the initial dose of 10 g x kg(-1) and the final dose of 100 g x kg(-1), 10 mg x kg(-1) was increased each day, thus 100 mg x kg(-1) was injected by d 10. Having been treated with differential doses (2, 1 and 0.5 g x kg(-1)) of C. yanhusuo (containing L-THP: 0.153, 0.077 and 0.038 mg x kg(-1) respectively) and L-THP (3.76, 1.88 and 0.94 mg x kg(-1)) for six days, the CPP effect in rats was detected. Both colorimetry and immunohistochemistry methods were adopted to detect the content of glutamate neurotransmitter in each brain region and the expression of NR2B in VTA-NAc-PFC neuroanatomical circuit.


RESULTS
Compared with the physiological saline treatment group, C. yanhusuo (2, 1 g x kg(-1)) and L-THP (3.76 and 1.88 mg x kg(-1)) groups showed a notably shorter retention period of rats in white boxes (morphine-accompanied boxes) (P < 0.05 or P < 0.01) and remarkably lower glutamic acid content in VTA, NAc and PFC and NR2B expression.


CONCLUSIONS
Both C. yanhusuo and L-THP can substantially inhibit the effect of morphine CPP, reduce the increasing glutamic acid content in VTA-NAc-PFC neuroanatomical circuit and down-regulated NR2B expression, which may be one of mechanisms on reducing the effect of morphine CPP. C. yanhusuo preparations containing L-THP (1 x ) showed 24-fold effect of L-THP monomer of single application in terms of the behaviouristics of inhibitory effect on CPP as well as the similarity in terms of transmitter glutamic acid of in VTA-NAc-PFC neuroanatomical circuit and pharmacological mechanism of NR2B.
Department of Cell Biology and Genetics, Zunyi Medical College, Zunyi 563099, China. swx_100@163.com
Su-Yuan
SY
Luo
Ping
P
Guo
Gang
G
Qian
Ming-Li
ML
Yang
Xin
X
Lin
Pei-Run
PR
Yang
D000818:Animals; D001600:Berberine Alkaloids / Q000627:therapeutic use*; D003216:Conditioning, Operant / Q000187:drug effects*; D031311:Corydalis / Q000737:chemistry*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004365:Drugs, Chinese Herbal / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D009020:Morphine / Q000037:antagonists & inhibitors*; D009021:Morphine Dependence / Q000188:drug therapy* / Q000523:psychology; D051381:Rats; D017207:Rats, Sprague-Dawley
D001600:Berberine Alkaloids; D004365:Drugs, Chinese Herbal; C014215:tetrahydropalmatine; D009020:Morphine