Intra-accumbal injection of CART (cocaine-amphetamine regulated transcript) peptide reduces cocaine-induced locomotor activity.
Evidence suggests that CART (cocaine-amphetamine regulated transcript) peptides are mediators or modulators of the actions of psychostimulant drugs. In this study, the effects of intra-accumbal injections of rat long form (rl) CART 55-102 were examined. Injection of the peptide alone had no effect, but pretreatment with the peptide blunted or reduced the locomotor-inducing effects of cocaine after an i.p. injection. This effect was dose related and time limited, as expected. rlCART 1-27, a CART peptide fragment not active in other studies, was without effect on cocaine-induced locomotor activity. Because the actions of cocaine involve dopamine, the effect of rlCART 55-102 on dopamine-induced locomotor activity was examined. Intraaccumbal injection of dopamine produced a dose-related and time-limited increase in locomotor activity, as expected. Coinjection of rlCART 55-102 with dopamine blunted the effect. In summary, these data suggest that CART peptides in the nucleus accumbens would tend to oppose the actions of cocaine.
Jaworski
Jason N
JN
Division of Neuroscience, Yerkes National Primate Research Center of Emory University, 954 Gatewood Road NE, Atlanta, GA 30329, USA. jjawors@rmy.emory.edu
Kozel
Marie A
MA
Philpot
Kelly B
KB
Kuhar
Michael J
MJ
D000818:Animals; D003042:Cocaine / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D004298:Dopamine / Q000378:metabolism / Q000502:physiology; D018765:Dopamine Uptake Inhibitors / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D007267:Injections; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D009419:Nerve Tissue Proteins / Q000494:pharmacology*; D009714:Nucleus Accumbens / Q000033:anatomy & histology / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein
D018765:Dopamine Uptake Inhibitors; D009419:Nerve Tissue Proteins; D000098882:Cocaine- and Amphetamine-Regulated Transcript Protein; D003042:Cocaine; D004298:Dopamine