Buprenorphine-cocaine interactions in mice: effect on locomotor activity and hole-dipping behaviour
Jackson, H.C.; Griffin, I.J.; Nutt, D.J.
Journal of Pharmacy and Pharmacology 45(7): 636-640
1993
ISSN/ISBN: 0022-3573 PMID: 8105060 Document Number: 412529
The effect of cocaine and the mixed mu-opioid partial agonist/kappa-antagonist buprenorphine on locomotor activity and hole-dipping behavior was investigated in mice. The drugs were given alone and in combination. Cocaine (7.5, 15, 30 mg kg-1, i.p.) significantly increased locomotion in a dose-related manner in the hour following injection. The two highest doses also increased hole-dipping although this response was not consistently seen. Buprenorphine (0.5, 5 mg kg-1, i.p.) produced an increase in locomotion which occurred 30-60 min after injection but did not alter hole-dipping behavior. A lower dose (0.05 mg kg-1) had no effect on either parameter. The locomotion induced by cocaine (15 mg kg-1, i.p.) was not modified by buprenorphine (0.05, 0.5, 1, 5 mg kg-1, i.p.; 5 min pretreatment). However, hole-dipping was almost completely abolished in animals given combinations of cocaine and buprenorphine (0.05-5 mg kg-1, i.p.), although neither drug decreased hole-dipping when given alone. This observation, which was not simply due to the emergence of stereotyped behavior, suggests an interaction between buprenorphine and cocaine.