Open AccessEffects of l ‐tetrahydropalmatine on locomotor sensitization to oxycodone in mice
Author(s) -
LIU Yanli,
LIANG Jianhui,
YAN Lingdi,
SU Ruibin,
WU Chunfu,
GONG Zehui
Publication year - 2005
Publication title -
acta pharmacologica sinica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.514
H-Index - 90
eISSN - 1745-7254
pISSN - 1671-4083
DOI - 10.1111/j.1745-7254.2005.00101.x
Subject(s) - oxycodone , sensitization , pharmacology , agonist , opioid , partial agonist , morphine , chemistry , medicine , opioid receptor , tetrahydropalmatine , receptor , immunology , alternative medicine , traditional chinese medicine , pathology , corydalis
Aim: Recent studies have shown that l‐tetrahydropalmatine ( l ‐THP), an active component of Corydolis yanhusuo , can inhibit the development of the conditional place preference induced by opioid receptor agonists, but the effects of l THP on locomotor sensitivity induced by opioid receptor agonists have not beendocumented. In the present study, the effects of l ‐THP on locomotor sensitization to oxycodone, which is an opioid receptor agonist, were studied. Methods: Mice treated daily for 7 d with 5 mg/kg oxycodone and challenged with the same dose after 5 days of washout showed locomotor sensitization. In order to study the effects of l ‐THP on locomotor sensitization induced by oxycodone, l ‐THP was administered at doses of 6.25, 12.5, and 18.75 mg/kg, 40 min prior to treatment of oxycodone. Results:l ‐THP per se did not affect the locomotor activity at the doses of 6.25, 12.5, and 18.75 mg/kg, but could antagonize the hyperactivity induced by oxycodone (5 mg/kg). Co‐administration of l ‐THP (18.75 mg/kg), 40 min prior to oxycodone, could inhibit the development of sensitization to oxycodone. In addition, l ‐THP (6.25, 12.5, and 18.75 mg/kg, ig) dose‐dependently prevented the expression of oxycodone sensitization. Conclusion: These results suggested that l ‐THP could attenuate the locomotor‐stimulating effects of oxycodone and inhibit the development and expression of oxycodone behavioral sensitization.