Naloxone enhancement of DMT and LSD-25 induced suppression of food-rewarded bar pressing behavior in the rat.
D Ruffing, B Kovacic, S Demetriou, E F Domino
Psychopharmacology April 25, 1979 DOI: 10.1007/bf00431949 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Animal behavioral and radiochemical study Peer reviewed |
|---|---|
| Population | Adult male Holtzman rats trained on a fixed-ratio four (FR4) food-rewarded bar-pressing schedule |
| Interventions | Naloxone N N-dimethyltryptamine (DMT) lysergic acid diethylamide-25 (LSD) |
| Dose | LSD 0.1 mg/kg; DMT 1.0, 3.2, and 10.0 mg/kg; naloxone 1.0-5.6 mg/kg |
| Duration | Pretreatment 5-10 min before DMT or LSD; radiochemical measurements at 30 and 90 min after 14C-DMT injection |
| Topics | DMT LSD |
| Key points | Naloxone at behaviorally ineffective doses dramatically enhanced the bar-pressing disruption caused by DMT and LSD in rats. Brain and liver levels of 14C-DMT did not differ significantly between DMT-alone and naloxone-pretreated rats, which the authors say rules out interference with DMT metabolism as the mechanism of the behavioral potentiation. |
Abstract
The narcotic antagonist naloxone was tested to determine its possible interaction with N,N-dimethyltryptamine (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 0.01 ml sugar sweetened milk. LSD (0.1 mg/kg) or increasing doses of DMT (1.0, 3.2, and 10.0 mg/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 (1.0--5.6 mg/kg) dramatically enhanced the effects of DMT and LSD. The content of DMT in the brain and liver of rats injected with DMT alone (10 mg/kg) and with a 5 min pretreatment of naloxone (3.2 mg/kg) was determined by radiochemical analysis at 30 and 90 min after 14C-DMT injection. There was no significant difference for either brain or liver 14C-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.
Comparable studies
Other preclinical and animal studies on DMT, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| The Hallucinogen N,N -Dimethyltryptamine (DMT) Is an Endogenous Sigma-1 Receptor Regulator Mice and cell lines | 2009 | Experimental study | |
| Correlation between the potency of hallucinogens in the mouse head-twitch response assay and their behavioral and subjective effects in other species. C57BL/6J mice | 2020 | Experimental study with dose-response experiments | |
| Psychedelic N,N-dimethyltryptamine and 5-methoxy-N,N-dimethyltryptamine modulate innate and adaptive inflammatory responses through the sigma-1 receptor of human monocyte-derived dendritic cells. Human primary monocyte-derived dendritic cells | 2014 | In vitro study | |
| Inhibitory effect of chlorpromazine on the syndrome of hyperactivity produced by l‐tryptophan or 5‐methoxy‐N,N‐dimethyltryptamine in rats treated with a monoamine oxidase inhibitor Rats | 1971 | Experimental study | |
| Effects of N,N-Dimethyltryptamine on Rat Behaviors Relevant to Anxiety and Depression Adult male Sprague-Dawley rats | 2018 | Experimental study |
Citations in the library
Cited by 6
- Administration of N,N-dimethyltryptamine (DMT) in psychedelic therapeutics and research and the study of endogenous DMT Psychopharmacology January 22, 2022
- Naloxone potentiates the disruptive effects of mescaline on operant responding in the rat Pharmacology, Biochemistry, and Behavior October 1, 1980
- Effects of Psychedelics Lysergic Acid Diethylamide and R (–)-2,5-Dimethoxy-4-Iodoamphetamine on Oral Opioid Consumption and Naloxone-Precipitated Withdrawal in Male C57Bl/6J Mice Psychedelic Medicine March 28, 2026
- Opioid-hallucinogen interactions. Pharmacology, Biochemistry, and Behavior February 1986
- Naloxone alters the effects of LSD, DOM and quipazine on operant behavior of rats. Pharmacology, Biochemistry, and Behavior September 1984
and 1 more in the library
Cites 5
- The psychedelic model of schizophrenia: the case of N,N- dimethyltryptamine American Journal of Psychiatry February 1, 1976
- Hallucinogenic N-methylated indolealkylamines in the cerebrospinal fluid of psychiatric and control populations. The British Journal of Psychiatry February 1, 1978
- Dimethyltryptamine levels in blood of schizophrenic patients and control subjects Psychopharmacology 1976
- Tolerance and limited cross-tolerance to the effects of N, N-dimethyltryptamine (DMT) and lysergic acid diethylamide-25 (LSD) on food-rewarded bar pressing in the rat. Journal of Pharmacology and Experimental Therapeutics June 1, 1976
- Interaction between narcotic antagonist (naloxone) and lysergic acid diethylamide (LSD) in the rat Psychopharmacology 1977