Bromocriptine produces decreases in cocaine self-administration in the rat.
The effect of bromocriptine pretreatment was investigated in rats trained to self-administer intravenous cocaine on a fixed-ratio (FR) 5 schedule of reinforcement. Bromocriptine, a dopamine agonist, produced dose-dependent decreases in cocaine self-administration at doses of 4.0, 8.0, 16.0, and 32.0 mg/kg. In a separate group of rats trained on a DRL 20-second schedule of food reinforcement used to produce the same overall rate of responding for food as for cocaine on the FR 5 schedule, bromocriptine did not produce a significant effect on overall response rate, number of reinforced responses, or percent of responses that were reinforced. Given that bromocriptine produced a specific effect on cocaine-maintained responding, the present results suggest that bromocriptine is interacting with the neurochemical substrate mediating the reinforcing effects of cocaine. The potential effectiveness of bromocriptine as a pharmacotherapy for cocaine dependence is discussed.
Hubner
C B
CB
Research Institute of Scripps Clinic, Department of Neuropharmacology, La Jolla, California 92037.
Koob
G F
GF
D000818:Animals; D001971:Bromocriptine / Q000494:pharmacology*; D003042:Cocaine / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012054:Reinforcement, Psychology; D012646:Self Administration
D001971:Bromocriptine; D003042:Cocaine