1
|
Falchi-Carvalho M, Wießner I, Silva SRB, O Maia L, Barros H, Laborde S, Arichelle F, Tullman S, Silva-Costa N, Assunção A, Almeida R, Pantrigo ÉJ, Bolcont R, Costa-Macedo JV, Arcoverde E, Galvão-Coelho N, Araujo DB, Palhano-Fontes F. Safety and tolerability of inhaled N,N-Dimethyltryptamine (BMND01 candidate): A phase I clinical trial. Eur Neuropsychopharmacol 2024; 80:27-35. [PMID: 38141403 DOI: 10.1016/j.euroneuro.2023.12.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 12/11/2023] [Accepted: 12/14/2023] [Indexed: 12/25/2023]
Abstract
Psychedelics are being increasingly examined for their therapeutic potential in mood disorders. While the acute effects of ayahuasca, psilocybin, and lysergic acid diethylamide (LSD) last over several hours, inhaled N,N-Dimethyltryptamine (DMT) effects last around 10 min, which might provide a cost- and time-effective alternative to the clinical application of oral psychedelics. We aimed at investigating the safety and tolerability of inhaled DMT (BMND01 candidate). We recruited 27 healthy volunteers to receive a first, lower dose and a second, higher dose (5/20 mg, 7.5/30 mg, 10/40 mg, 12.5/50 mg, or 15/60 mg) of inhaled DMT in an open-label, single-ascending, fixed-order, dose-response study design. We investigated subjective experiences (intensity, valence, and phenomenology), physiological effects (blood pressure, heart rate, respiratory rate, blood oxygen saturation, body temperature), biochemical markers (liver, kidney, and metabolic functions), and adverse events during the acute and post-acute effects of DMT. DMT dose-dependently increased intensity, valence and perceptual ratings. There was a mild, transient, and self-limited increase in blood pressure and heart rate. There were no changes in safety blood biomarkers and no serious adverse events. DMT dose-dependently enhanced subjective experiences and positive valence. Inhaled DMT might be an efficient, non-invasive, safe route of administration, which might simplify the clinical use of this substance. This is the first clinical trial to test the effects of inhaled DMT (BMND01 candidate).
Collapse
Affiliation(s)
- Marcelo Falchi-Carvalho
- Biomind Labs, Brookfield Place, 181 Bay Street, Suite 1800, Toronto, ON M5J 2T9, Canada; Department of Clinical Medicine, Health Science Center, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Isabel Wießner
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Sérgio Ruschi B Silva
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Lucas O Maia
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Handersson Barros
- Graduate Program in Health Sciences, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Sophie Laborde
- Graduate Program in Health Sciences, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Flávia Arichelle
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Sam Tullman
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Natan Silva-Costa
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Aline Assunção
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Raissa Almeida
- Department of Physiology and Behavior, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Érica J Pantrigo
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Raynara Bolcont
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | | | - Emerson Arcoverde
- University Hospital Onofre Lopes, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Nicole Galvão-Coelho
- Department of Physiology and Behavior, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Draulio B Araujo
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil; Graduate Program in Health Sciences, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil.
| | - Fernanda Palhano-Fontes
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil.
| |
Collapse
|
2
|
Eckernäs E, Macan-Schönleben A, Andresen-Bergström M, Birgersson S, Hoffmann KJ, Ashton M. N, N-dimethyltryptamine forms oxygenated metabolites via CYP2D6 - an in vitro investigation. Xenobiotica 2023; 53:515-522. [PMID: 37916667 DOI: 10.1080/00498254.2023.2278488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 10/30/2023] [Indexed: 11/03/2023]
Abstract
N, N-dimethyltryptamine (DMT) is a psychedelic compound that has shown potential in the treatment of depression. Aside from the primary role of monoamine oxidase A (MAO-A) in DMT metabolism, the metabolic pathways are poorly understood. Increasing this understanding is an essential aspect of ensuring safe and efficacious use of DMT.This work aimed to investigate the cytochrome 450 (CYP) mediated metabolism of DMT by incubating DMT with recombinant human CYP enzymes and human liver microsomes (HLM) followed by analysis using high-resolution mass spectrometry for metabolite identification.DMT was rapidly metabolised by CYP2D6, while stable with all other investigated CYP enzymes. The metabolism of DMT in HLM was reduced after inclusion of harmine and SKF-525A whereas quinidine did not affect the metabolic rate, likely due to MAO-A residues present in HLM. Analysis of the CYP2D6 incubates showed formation of mono-, di- and tri-oxygenated metabolites, likely as a result of hydroxylation on the indole core.More research is needed to investigate the role of this metabolic pathway in vivo and any pharmacological activity of the proposed metabolites. Our findings may impact on safety issues following intake of ayahuasca in slow CYP2D6 metabolizers or with concomitant use of CYP2D6 inhibitors.
Collapse
Affiliation(s)
- Emma Eckernäs
- Unit for Pharmacokinetics and Drug Metabolism, Department of Pharmacology, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | | | - Moa Andresen-Bergström
- Laboratory of Clinical Chemistry, Sahlgrenska University Hospital, Gothenburg, Sweden
- Department of Laboratory Medicine, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Sofia Birgersson
- Unit for Pharmacokinetics and Drug Metabolism, Department of Pharmacology, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Kurt-Jürgen Hoffmann
- Unit for Pharmacokinetics and Drug Metabolism, Department of Pharmacology, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Michael Ashton
- Unit for Pharmacokinetics and Drug Metabolism, Department of Pharmacology, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| |
Collapse
|
3
|
Abstract
N,N-dimethyltryptamine (DMT) is a potent psychedelic naturally produced by many plants and animals, including humans. Whether or not DMT is significant to mammalian physiology, especially within the central nervous system, is a debate that started in the early 1960s and continues to this day. This review integrates historical and recent literature to clarify this issue, giving special attention to the most controversial subjects of DMT's biosynthesis, its storage in synaptic vesicles and the activation receptors like sigma-1. Less discussed topics, like DMT's metabolic regulation or the biased activation of serotonin receptors, are highlighted. We conclude that most of the arguments dismissing endogenous DMT's relevance are based on obsolete data or misleading assumptions. Data strongly suggest that DMT can be relevant as a neurotransmitter, neuromodulator, hormone and immunomodulator, as well as being important to pregnancy and development. Key experiments are addressed to definitely prove what specific roles DMT plays in mammalian physiology.
Collapse
Affiliation(s)
- Javier Hidalgo Jiménez
- ICEERS Foundation (International Center for Ethnobotanical Education, Research and Services), Barcelona, Spain
| | - José Carlos Bouso
- ICEERS Foundation (International Center for Ethnobotanical Education, Research and Services), Barcelona, Spain
| |
Collapse
|
4
|
Mavlyutov TA, Epstein ML, Liu P, Verbny YI, Ziskind-Conhaim L, Ruoho AE. Development of the sigma-1 receptor in C-terminals of motoneurons and colocalization with the N,N'-dimethyltryptamine forming enzyme, indole-N-methyl transferase. Neuroscience 2012; 206:60-8. [PMID: 22265729 PMCID: PMC3321351 DOI: 10.1016/j.neuroscience.2011.12.040] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 12/22/2011] [Accepted: 12/22/2011] [Indexed: 11/17/2022]
Abstract
The function of the sigma-1 receptor (S1R) has been linked to modulating the activities of ion channels and G-protein-coupled receptors (GPCR). In the CNS, the S1R is expressed ubiquitously but is enriched in mouse motoneurons (MN), where it is localized to subsurface cisternae of cholinergic postsynaptic densities, also known as C-terminals. We found that S1R is enriched in mouse spinal MN at late stages of embryonic development when it is first visualized in the endoplasmic reticulum. S1Rs appear to concentrate at C-terminals of mouse MN only on the second week of postnatal development. We found that indole-N-methyl transferase (INMT), an enzyme that converts tryptamine into the sigma-1 ligand dimethyltryptamine (DMT), is also localized to postsynaptic sites of C-terminals in close proximity to the S1R. This close association of INMT and S1Rs suggest that DMT is synthesized locally to effectively activate S1R in MN.
Collapse
Affiliation(s)
- T A Mavlyutov
- Department of Neuroscience, University of Wisconsin, School of Medicine and Public Health, 1300 University Ave, Madison, WI 53706, USA.
| | | | | | | | | | | |
Collapse
|
5
|
Abstract
N,N-dimethyltryptamine (DMT) is a hallucinogen found endogenously in human brain that is commonly recognized to target the 5-hydroxytryptamine 2A receptor or the trace amine-associated receptor to exert its psychedelic effect. DMT has been recently shown to bind sigma-1 receptors, which are ligand-regulated molecular chaperones whose function includes inhibiting various voltage-sensitive ion channels. Thus, it is possible that the psychedelic action of DMT might be mediated in part through sigma-1 receptors. Here, we present a hypothetical signaling scheme that might be triggered by the binding of DMT to sigma-1 receptors.
Collapse
Affiliation(s)
- Tsung-Ping Su
- Cellular Pathobiology Section, Cellular Neurobiology Research Branch, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, USA.
| | | | | |
Collapse
|
6
|
Fontanilla D, Johannessen M, Hajipour AR, Cozzi NV, Jackson MB, Ruoho AE. The hallucinogen N,N-dimethyltryptamine (DMT) is an endogenous sigma-1 receptor regulator. Science 2009; 323:934-7. [PMID: 19213917 PMCID: PMC2947205 DOI: 10.1126/science.1166127] [Citation(s) in RCA: 377] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The sigma-1 receptor is widely distributed in the central nervous system and periphery. Originally mischaracterized as an opioid receptor, the sigma-1 receptor binds a vast number of synthetic compounds but does not bind opioid peptides; it is currently considered an orphan receptor. The sigma-1 receptor pharmacophore includes an alkylamine core, also found in the endogenous compound N,N-dimethyltryptamine (DMT). DMT acts as a hallucinogen, but its receptor target has been unclear. DMT bound to sigma-1 receptors and inhibited voltage-gated sodium ion (Na+) channels in both native cardiac myocytes and heterologous cells that express sigma-1 receptors. DMT induced hypermobility in wild-type mice but not in sigma-1 receptor knockout mice. These biochemical, physiological, and behavioral experiments indicate that DMT is an endogenous agonist for the sigma-1 receptor.
Collapse
Affiliation(s)
- Dominique Fontanilla
- Department of Pharmacology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
| | - Molly Johannessen
- Department of Physiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
| | - Abdol R. Hajipour
- Pharmaceutical Research Laboratory, Department of Chemistry, Isfahan University of Technology, Isfahan 84156, IR Iran
| | - Nicholas V. Cozzi
- Department of Pharmacology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
| | - Meyer B. Jackson
- Department of Physiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
| | - Arnold E. Ruoho
- Department of Pharmacology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA
| |
Collapse
|
7
|
Nicasio MDP, Villarreal ML, Gillet F, Bensaddek L, Fliniaux MA. Variation in the accumulation levels of n,n-dimethyltryptamine in micro-propagated trees and in in vitro cultures of Mimosa tenuiflora. Nat Prod Res 2006; 19:61-7. [PMID: 15700647 DOI: 10.1080/14786410410001658860] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The present article reports the accumulation of N,N-dimethyltryptamine and its metabolic precursors (tryptophan, tryptamine) in different organs of micropropagated Mimosa tenuiflora trees (leaves, flowers and bark) subjected to seasonal variations (January and June), as well as in in vitro cultures (plantlets and calluses) of this plant species. The accumulation of all the tested compounds varied according to the organ, the month of collection, and age of the plant material. In all cases, the neurotoxic compound N,N-dimethyltryptamine (DMT) was detected with the lowest concentration 0.01% dry weight (DW) in flowers, and the highest 0.33% DW in bark. For the in vitro cultures, DMT was present in high yields in plantlets (0.1-0.2% DW), while in calluses this compound was initially detected but its concentration decreased significantly in the subsequent subcultures.
Collapse
Affiliation(s)
- María Del Pilar Nicasio
- Centro de Investigación Biomédica del Sur Instituto Mexicano del Seguro Social, Xochitepec, Morelos, México
| | | | | | | | | |
Collapse
|
8
|
Glennon RA, Dukat M, Grella B, Hong S, Costantino L, Teitler M, Smith C, Egan C, Davis K, Mattson MV. Binding of beta-carbolines and related agents at serotonin (5-HT(2) and 5-HT(1A)), dopamine (D(2)) and benzodiazepine receptors. Drug Alcohol Depend 2000; 60:121-32. [PMID: 10940539 DOI: 10.1016/s0376-8716(99)00148-9] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A large series of beta-carbolines was examined for their ability to bind at [3H]agonist-labeled 5-HT(2A) serotonin receptors. Selected beta-carbolines were also examined at 5-HT(2C) serotonin receptors, 5-HT(1A) serotonin receptors, dopamine D(2) receptors, and benzodiazepine receptors. Indolealkylamines and phenylisopropylamines were also evaluated in some of these binding assays. The beta-carbolines were found to bind with modest affinity at 5-HT(2A) receptors, and affinity was highly dependent upon the presence of ring substituents and ring saturation. The beta-carbolines displayed little to no affinity for 5-HT(1A) serotonin receptors, dopamine D(2) receptors and, with the exception of beta-CCM, for benzodiazepine receptors. Examples of beta-carbolines, indolealkylamines (i.e. N,N-dimethyltryptamine analogs), and phenylisopropylamines have been previously shown to produce common stimulus effects in animals trained to discriminate the phenylisopropylamine hallucinogen DOM (i.e. 1-(2, 5-dimethoxy-4-methylphenyl)-2-aminopropane) from vehicle. Although the only common receptor population that might account for this action is 5-HT(2A), on the basis of a lack of enhanced affinity for agonist-labeled 5-HT(2A) receptors, as well as on their lack of agonist action in the PI hydrolysis assay, it is difficult to conclude that the beta-carbolines behave in a manner consistent with that of other classical hallucinogens.
Collapse
Affiliation(s)
- R A Glennon
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Box 980540, Richmond, VA 23298-0540, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Sitaram BR, Talomsin R, Blackman GL, McLeod WR. Study of metabolism of psychotomimetic indolealkylamines by rat tissue extracts using liquid chromatography. Biochem Pharmacol 1987; 36:1503-8. [PMID: 3472525 DOI: 10.1016/0006-2952(87)90117-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The use of a series of liquid chromatographic techniques involving cation-exchange, reverse-phase and normal-phase chromatography has permitted the separation and characterisation of a number of metabolites of the psychotomimetic indolealkylamines N,N-dimethyltryptamine and 5-methoxy-N,N-dimethyltryptamine which were isolated following incubation of these compounds with rat tissue extracts. In liver, kidney and brain tissue extracts the routes of metabolism identified included oxidative deamination, N-demethylation, O-demethylation and N-oxidation. The quantitative significance of individual routes of metabolism in these tissues was assessed using N,N-dimethyltryptamine as a substrate.
Collapse
|
10
|
Sitaram BR, Lockett L, Talomsin R, Blackman GL, McLeod WR. In vivo metabolism of 5-methoxy-N,N-dimethyltryptamine and N,N-dimethyltryptamine in the rat. Biochem Pharmacol 1987; 36:1509-12. [PMID: 3472526 DOI: 10.1016/0006-2952(87)90118-3] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Following intraperitoneal administration, 5-methoxy-N,N-dimethyltryptamine and N,N-dimethyltryptamine are subject to both a very rapid uptake into, and clearance from, all tissues examined. The current studies in vivo confirm previous in vitro observations that the routes involved in the metabolism of these compounds include oxidative deamination, N-demethylation, O-demethylation, and N-oxidation. The analysis of metabolic profiles in various tissues led to the identification of the N-oxides as major metabolites. The successful inhibition and redirection of metabolism away from the indole acids towards the parent compounds and their structurally unique metabolites were demonstrated in animals pretreated with iproniazid.
Collapse
|
11
|
Yanai K, Ido T, Ishiwata K, Hatazawa J, Takahashi T, Iwata R, Matsuzawa T. In vivo kinetics and displacement study of a carbon-11-labeled hallucinogen, N,N-[11C]dimethyltryptamine. Eur J Nucl Med 1986; 12:141-6. [PMID: 3489620 DOI: 10.1007/bf00276707] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The endogenous hallucinogen, N,N-dimethyltryptamine (DMT), was labeled with carbon-11 and its regional distribution in rat brain studied. [11C]DMT showed higher accumulation in the cerebral cortex, caudate putamen, and amygdaloid nuclei. Studies of the subcellular distribution of [11C]DMT revealed the specific localization in the fractions enriched with serotonin receptors only when a very low dose was injected into rats. The proportions of the radioactivity in receptor-rich fractions were greatly enhanced by pretreatment with the monoamine oxidase inhibitor, pargyline. Specific binding of [11C]DMT to serotonin receptors in dog brain was demonstrated by a positron emission tomographic study in which 5-methoxy-N,N-dimethyltryptamine caused approximately 20% displacement of the radioligand from the receptors.
Collapse
|
12
|
Abstract
The present study deals with the measurement of the brain levels of the two potent hallucinogens N,N-dimethyltryptamine (DMT) and 5-methoxy-N,N-dimethyltryptamine (OMB), the biogenic amine tryptamine (TA), and its condensation product 1,2,3,4-tetrahydro-beta-carboline (THBC) in rats of various ages. Using gas chromatography-mass spectrometry with isotope dilution, we detected DMT, OMB, and THBC in neonatal rats from birth. DMT levels remained low until days 12 and 17 at which time they increased significantly and then returned to the initial low levels for all subsequent ages. The levels of OMB were higher than those measured for DMT with the highest levels being observed at days 12 and 17, and also on day 31. However, the levels for OMB showed much more variation. Although elevated levels of DMT and OMB have been correlated with stress, there are no known functions for these compounds. TA levels remained below detection limits until day 19. THBC levels were observed to be highest on days 22 and 31. The role that THBC plays in mammalian tissues is not known.
Collapse
|
13
|
Barker SA, Beaton JM, Christian ST, Monti JA, Morris PE. In vivo metabolism of alpha,alpha,beta,beta-tetradeutero-N, N-dimethyltryptamine in rodent brain. Biochem Pharmacol 1984; 33:1395-400. [PMID: 6587850 DOI: 10.1016/0006-2952(84)90404-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The metabolism of alpha,alpha,beta,beta- tetradeutero -N,N -dimethyltryptamine ( D4DMT ) in rat brain in vivo as a function of time and dose was examined. Quantification of D4DMT and its respective deutero-metabolites was accomplished using gas chromatographic/mass spectrometric/selected ion monitoring/isotope dilution techniques. The results of this study indicate that D4DMT is metabolized to the corresponding deutero-N-methyltryptamine, tryptamine, 1,2,3,4-tetrahydro-beta-carboline, and 2-methyl-1, 2,3,4-tetrahydro-beta-carboline in rat brain. The subcellular distribution of D4DMT and the aforementioned metabolites is also reported.
Collapse
|
14
|
Barker SA, Beaton JM, Christian ST, Monti JA, Morris PE. Comparison of the brain levels of N,N-dimethyltryptamine and alpha, alpha, beta, beta-tetradeutero-N-N-dimethyltryptamine following intraperitoneal injection. The in vivo kinetic isotope effect. Biochem Pharmacol 1982; 31:2513-6. [PMID: 6812592 DOI: 10.1016/0006-2952(82)90062-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A comparison of the brain levels (microgram/g wet weight of tissue) of the hallucinogen N,N-dimethyltryptamine (DMT) and its deuterated analog alpha, alpha, beta, beta-tetradeutero-DMT (D4DMT) as a function of time and dose is reported. It was observed that the presence of deuterium in the alpha- and beta-positions of the ethylamine side-chain led to a potentiation of the level of DMT in brain. Strikingly different dynamics of uptake and clearance were also noted. We propose that these results are due to primary kinetic isotope effect, illustrating the importance of the alpha-position in the metabolism of DMT.
Collapse
|
15
|
|
16
|
Barker SA. GC/MS quantification and identification of endogenous tetrahydro-beta-carbolines in rat brain and adrenal. Prog Clin Biol Res 1982; 90:113-124. [PMID: 6810379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
|
17
|
Abstract
The transepithelial potential recorded across the salivary gland of the blowfly Calliphora responded to 5-hydroxytryptamine (5-HT) with a complex depolarising response characterised by oscillatory activity at low doses. A rapid screening procedure for characterizing the electrophysiological response of the gland to 5-HT and its analogues was developed. It consisted of recording the potential during the gradual addition of the agent in the form of a ramp. 5-HT gave a characteristic electrophysiological signature which was then compared with that of other analogues. Tryptamine, bufotenine and dimethyltryptamine gave potential signatures very similar to those of 5-HT. Histamine, 4- and 5-fluoro-alpha-methyltryptamine gave s predominantly hyperpolarising response which is characteristic of the effect produced by cyclic AMP. Analogues with substituents at the 5-position (methyl, methoxy, chloro) and 4-hydroxytryptamine gave a depolarising response indicative of a predominantly calcium effect. It is concluded that 5-HT acts through separate transducing mechanisms. The depolarizing response seems to indicate an action through calcium whereas the hyperpolarizing response might be mediated through cyclic AMP. Whether or not these separate responses are linked to different 5-HT receptors remains to be determined.
Collapse
|
18
|
Abstract
Mice pretreated with the monoamine oxidase inhibitor pargyline showed a dose-dependent increase in hyperactivity for up to 2 h following injections of N,N-dimethyltryptamine (DMT: 0.5-8.0 mg/kg). Hyperactivity was related to a linear increase in whole brain concentrations of DMT as measured by a new sensitive gas chromatographic assay. The duration of this behaviour paralleled the concentration of DMT in the brain from 15-120 min. However, at 15 min, there was no significant difference in brain DMT concentrations between mice receiving pargyline and those given distilled water at the two dose levels of DMT studied (2.0 and 8.0 mg/kg). Pre-treatment with the microsomal enzyme inhibitor SKF-525A, alone or in combination with pargyline, had no effect on the DMT-induced behaviour or on the brain levels of DMT.
Collapse
|
19
|
|
20
|
Abstract
This article reviews the major hallucinogenic fungi both for their historical as well as neurochemical import. Despite voluminous literature on them, relatively little study has focused on psilocybin related substances that could relate to forms of psychotic illness. Some metabolic pathways are reviewed which illustrate the need for more study of indole compounds such as baeocystin.
Collapse
|
21
|
|
22
|
Sangiah S, Gomez MV, Domino EF. Accumulation of N,N-dimethyltryptamine in rat brain cortical slices. Biol Psychiatry 1979; 14:925-36. [PMID: 41604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
14C-DMT accumulates in rat brain cortical slices incubated at 37 C. This process has many of the properties of an active uptake mechanism. It is temperature-sensitive, sodium-dependent, saturable, and is inhibited by metabolic inhibitors. Tryptamine derivatives were more effective than the catecholamines in competing for 14C-DMT accumulation. A number of psychotropic drugs were inhibitors of 14C-DMT accumulation. In general, irrespective of pharmacologic class, the tertiary amines were more potent than the secondary or primary amines, although there were some exceptions. Most of the accumulated 14C-DMT was associated with the cytoplasmic fraction. Of the portion associated with the crude mitochondrial fraction, 54.4% was associated with nerve-ending fraction.
Collapse
|
23
|
Ruffing D, Kovacic B, Demetriou S, Domino EF. Naloxone enhancement of DMT and LSD-25 induced suppression of food-rewarded bar pressing behavior in the rat. Psychopharmacology (Berl) 1979; 62:207-10. [PMID: 111285 DOI: 10.1007/bf00431949] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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.
Collapse
|
24
|
Checkley SA, Oon MC, Rodnight R, Murphy MP, Williams RS, Birley JL. Urinary excretion of dimethyltryptamine in liver disease. Am J Psychiatry 1979; 136:439-41. [PMID: 284722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The urinary excretion of N,N-dimethyltryptamine (DMT) was higher in patients with severe liver disease than in normal subjects. This difference remained significant when patients with all grades of hepatic encephalopathy were excluded. Patients with liver disease whose mental states were normal excreted amounts of DMT similar to those of patients with a hospital diagnosis of schizophrenia.
Collapse
|
25
|
Räisänen M, Kärkkäinen J. Quantitative assay of the N-methylated metabolites of tryptamine and serotonin by gas chromatography mass spectrometry as applied to the determination of lung indoleethylamine N-methyltransferase activity. Biomed Mass Spectrom 1978; 5:596-600. [PMID: 284808 DOI: 10.1002/bms.1200051010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A specific and sensitive method is described for the identifcation and quantification of the N-mono- and dimethylated derivatives of tryptamine and serotonin by gas chromatography mass spectrometry. Deuterated analogues of the amines have been prepared for use as internal standards. The technique has been applied to the determination of indoleethylamine N-methyltransferase activity in rabbit and human lung. No interference from the beta-carboline formation or other side reactions between the substrates and the methyl donor was observed.
Collapse
|
26
|
Glennon RA, Liebowitz SM, Mack EC. Serotonin receptor binding affinities of several hallucinogenic phenylalkylamine and N,N-dimethyltryptamine analogues. J Med Chem 1978; 21:822-5. [PMID: 278843 DOI: 10.1021/jm00206a022] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Hallucinogenic phenylalkylamine and N,N-dimethyltryptamine analogues are known to affect serotonergic systems both in vivo and in vitro. Using a rat stomach fundus model, the 5-HT receptor binding affinities of several of these analogues were determined and compared. The most behaviorally potent analogues examined, DOB, DOM, and 5-methoxy-N,N-dimethyltryptamine, were found to possess rather high affirmities (pA2 = 7.35, 7.12, and 7.08, respectively) for the 5-HT receptors of the model system.
Collapse
|
27
|
Shah NS, Hedden MP. Behavioral effects and metabolic fate of N,N-dimethyltryptamine in mice pretreated with beta-diethylaminoethyl-diphenylpropylacetate (SKF 525-A), improniazid and chlorpromazine. Pharmacol Biochem Behav 1978; 8:351-6. [PMID: 276891 DOI: 10.1016/0091-3057(78)90070-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Behavioral aspects and metabolic fate of N,N-dimethyltryptamine (DMT) were studied in mice pretreated with beta-diethylaminoethyl-diphenylpropylacetate (SKF 525-A), iproniazid or chlorpromazine (CPZ). DMT at doses of 2.5, 10.0, and 25.0 mg/kg produced several behavioral changes in a dose-related manner: inhibition of spontaneous locomotor movement, enhanced fright responses to sound stimuli, trembling, head twitching, inco-ordinated movements of hind-legs, flat or extended tail and abnormal posture with the extension of hind-legs. Pretreatment with ipromazid (153 mg/kg; 4 hr) but not SKF 525-A (50 mg/kg; 1 hr) prolonged the behavioral effects produced by 2.5 mg/kg DMT while CPZ (15 mg/kg; 0.5 hr) completely abolished the responses induced by 25 mg/kg DMT. Earlier behavioral effects generally coincided with the brain concentrations of DMT. Dose-dependent increases with rapid uptake and disappearance in the brain, plasma and hepatic levels of DMT were measured with doses of 10 and 25 mg/kg DMT. Iproniazid but not SKF 525-A markedly enhanced tissue levels of DMT. it is concluded that DMT is metabolized chiefly by monoamine oxidase rather than by drug-metabolizing hepatic microsomal enzymes and that DMT-induced behavioral effects are due to the parent compound rather than its metabolite.
Collapse
|
28
|
Wang Lu LJ, Demetriou SK, Domino EF. Effects of various neuroleptics, phenobarbital and SKF 525-A on dimethyltryptamine content in rat brain and liver. Arch Int Pharmacodyn Ther 1978; 232:117-33. [PMID: 27150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
29
|
Luchins D, Ban TA, Lehmann HE. A review of nicotinic acid, N-methylated indoleamines and schizophrenia. Int Pharmacopsychiatry 1978; 13:16-33. [PMID: 342436 DOI: 10.1159/000468318] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The hypothesis that endogenously formed, N-methylated metabolites of indoleamines may play a role in the pathogenesis of schizophrenia was reviewed. Although N-methylated indoleamines can be produced in vivo and have significant psychotomimetic effects, there is little evidence for a specific increase in the methylation of indoleamines in schizophrenic patients. It was noted that even if the relationship between schizophrenia and N-methylated indoleamines had existed, nicotinic acid would not be an appropriate therapeutic agent.
Collapse
|
30
|
Glennon RA, Gessner PK. The electronic and serotonin receptor binding affinity properties of N,N-dimethyltryptamine analogs. Res Commun Chem Pathol Pharmacol 1977; 18:453-65. [PMID: 270770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The electronic properties of a series of N,N-dimethyltryptamines and related analogs, for which binding affinity data are available, were examined using both a pi-electron and an all-valence electron method. The results suggest that affinity is related to the ability of these compounds to donate electrons in a localized charge transfer manner from the 4-position of the indole nucleus.
Collapse
|
31
|
Christian ST, Harrison R, Quayle E, Pagel J, Monti J. The in vitro identification of dimethyltryptamine (DMT) in mammalian brain and its characterization as a possible endogenous neuroregulatory agent. Biochem Med 1977; 18:164-83. [PMID: 20877 DOI: 10.1016/0006-2944(77)90088-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
32
|
Gillin JC, Wyatt RJ. Evidence for and against the involvement of N,N-dimethyl-tryptamine (DMT) and 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) in schizophrenia. Psychopharmacol Bull 1976; 12:12-3. [PMID: 1067623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
33
|
Wang Lu LJ, Domino E. Effects of iproniazid and tranylcypromine of the half-life of N,N-dimethyltryptamine in rat brain and liver. Biochem Pharmacol 1976; 25:1521-7. [PMID: 1066131 DOI: 10.1016/0006-2952(76)90071-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
34
|
Abstract
The authors review the research on N,N-dimethyltryptamine (DMT) as a possible "schizotoxin." DMT produces psychedelic effects when administered to normal subjects, the means are present to synthesize it in man, it has occasionally been found in man, and tolerance to its behavioral effects is incomplete. However, DMT concentrations have not been proven to differ significantly in schizophrenics and normal controls. Also, in vivo synthesis of DMT has not been convincingly demonstrated, and the psychological changes it produces do not closely mimic the symptoms of schizophrenia. The authors conclude that more data are necessary before the validity of this theory can be determined.
Collapse
|
35
|
Schöpf J. [Biogenic amines and schizophrenia]. Schweiz Med Wochenschr 1975; 105:1201-9. [PMID: 1061994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Three main biogenic amine hypotheses for the origin of schizophrenia are discussed. The dopamine theory of schizophrenia postulates a pathogenetic connection between the disease and changes in the activity of dopaminergic cells in the brain. The theory is mainly based on findings on the mechanism of action of neuroleptics, on the clinical features and pharmacology of the amphetamine psychosis, and on some amphetamine effects in animals. Several results are in good agreement with the assumption of a state of hyperactivity of central dopamine neurons, whereas others, e.g. the lack of an increased dopamine turnover, are not. According to another theory, schizophrenia is caused by reversible damage to central norepinephrine cells. So far the only empirical basis for this theory is the finding that the activity of dopamine-beta-hydroxylase, a marker enzyme for noradrenaline cells, is lowered in the brains of schizophrenic patients. Thus further confirmation is required. The transmethylation hypotheses assume that hallucinogenic amine metabolites are produced in the body and lead to the appearance of schizophrenic symptoms. Whether or not the occurrence of DMPEA, presumably an oxymethylation product of the dopamine metabolism, is specific for schizophrenics is still open to question; if it is, the meaning of this finding is obscure. Current results leave open the possibility that N-dimethyltryptamine or other N-methylated hallucinogenic biogenic amine metabolites cause the disease; however, this hypothesis is hardly confirmed by positive empirical results.
Collapse
|
36
|
Editorial: Recent developments in schizophrenia. Med J Aust 1975; 1:258-9. [PMID: 1055285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
37
|
Squires RF. Evidence that 5-methoxy-N, N-dimethyl tryptamine is a specific substrate for MAO-A in the rat: implications for the indoleamine dependent behavioural syndrome. J Neurochem 1975; 24:47-50. [PMID: 1053788 DOI: 10.1111/j.1471-4159.1975.tb07626.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
38
|
Rodnight R. The significance of some biochemical abnormalities in schizophrenia. Acta Neurol (Napoli) 1975; 30:85-101. [PMID: 1063539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
39
|
Editorial: Dimethyltryptamine and psychosis. Lancet 1974; 2:140-1. [PMID: 4135558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
40
|
Lin RL, Narasimhachari N. Evidence for the absence of amine-N-methylation and O-methylation in indolethylamines with methyltetrahydrofolic acid-dependent N-methyltransferase. Res Commun Chem Pathol Pharmacol 1974; 8:535-42. [PMID: 4527795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
41
|
Narasimhachari N, Lin RL. A possible mechanism for the antischizophrenic action of chlorpromazine: inhibition of the formation of dimethyltryptamine by chlorpromazine metabolites. Res Commun Chem Pathol Pharmacol 1974; 8:341-51. [PMID: 4527612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
42
|
Gillin JC, Cannon E, Magyar R, Schwartz M, Wyatt RJ. Failure of N,N-dimethyltryptamine to evoke tolerance in cats. Biol Psychiatry 1973; 7:213-20. [PMID: 4519415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
43
|
|