Naloxone enhancement of DMT and LSD-25 induced suppression of food-rewarded bar pressing behavior in the rat

✍ Scribed by Diane Ruffing; Beverly Kovacic; Sandra Demetriou; Edward F. Domino

• Publisher: Springer
• Year: 1979
• Tongue: English
• Weight: 388 KB
• Volume: 62
• Category: Article
• ISSN: 0033-3158
• DOI: 10.1007/bf00431949

✦ Synopsis

The narcotic antagonist naloxone was tested to determine its possible interaction with N,Ndimethyltryptamine (DMT) and lysergic acid diethylamide-25 (LSD) in adult male Holtzman rats trained to press a bar on a fixed-ratio four schedule (FR4), i.e., every fourth press earned a reward of 0.01ml sugar sweetened milk. LSD (0.1mg/kg) or increasing doses of DMT (1.0, 3.2, and 10.0mg/kg) were administered i.p. to disrupt food-rewarded fixed ratio bar pressing in a dose related fashion. Pretreatment (5-10 min) with behaviorally ineffective doses of naloxone (l.0-5.6mg/kg) dramatically enhanced the effects of DMT and LSD. The content of DMT in the brain and liver of rats injected with DMT alone (10mg/kg) and with a 5min pretreatment of naloxone (3.2 mg/kg) was determined by radiochemical analysis at 30 and 90min after 14C-DMT injection. There was no significant difference for either brain or liver I~C-DMT levels when control DMT rats were compared with the naloxone pretreated rats. These results seem to rule out interference by naloxone with the metabolism of DMT as a mechanism of the observed behavioral potentiation.