Editing Tryptamine (section)

===Effects in animals and humans===
In a published clinical study, tryptamine, at a total dose of 23 to 277{{nbsp}}mg by [[intravenous therapy|intravenous infusion]], produced [[hallucinogen]]ic effects or perceptual disturbances similar to those of small doses of [[lysergic acid diethylamide]] (LSD).<ref name="MartinSloan1977">{{cite book | last1=Martin | first1=W. R. | last2=Sloan | first2=J. W. | title=Drug Addiction II | chapter=Pharmacology and Classification of LSD-like Hallucinogens | publisher=Springer Berlin Heidelberg | publication-place=Berlin, Heidelberg | year=1977 | isbn=978-3-642-66711-4 | doi=10.1007/978-3-642-66709-1_3 | pages=305–368 | quote=MARTIN and SLOAN (1970) found that intravenously infused tryptamine increased blood pressure, dilated pupils, enhanced the patellar reflex, and produced perceptual distortions. [...] Tryptamine, but not DMT, increases locomotor activity in the mouse, while both antagonize reserpine depression (V ANE et al., 1961). [...] In the rat, tryptamine causes backward locomotion, Straub tail, bradypnea and dyspnea, and clonic convulsions (TEDESCHI et al., 1959). [...] Tryptamine produces a variety of changes in the cat causing signs of sympathetic activation including mydriasis, retraction of nictitating membrane, piloerection, motor signs such as extension of limbs and convulsions and affective changes such as hissing and snarling (LAIDLAW, 1912). [...]}}</ref><ref name="ShulginShulgin1997">{{cite book | last=Shulgin | first=A. | title=Tihkal: The Continuation | publisher=Transform Press | year=1997 | isbn=978-0-9630096-9-2 | url=https://books.google.com/books?id=jl_ik66IumUC | access-date=17 August 2024 | at=[https://www.erowid.org/library/books_online/tihkal/tihkal53.shtml #53. T] | quote = (with 250 mg, intravenously) "Tryptamine was infused intravenously over a period of up to 7.5 minutes. Physical changes included an increases in blood pressure, in the amplitude of the patellar reflex, and in pupillary diameter. The subjective changes are not unlike those seen with small doses of LSD. A point-by-point comparison between the tryptamine and LSD syndromes reveals a close similarity which is consistent with the hypothesis that tryptamine and LSD have a common mode of action."}}</ref><ref name="BloughLandavazoDecker2014">{{cite journal | vauthors = Blough BE, Landavazo A, Decker AM, Partilla JS, Baumann MH, Rothman RB | title = Interaction of psychoactive tryptamines with biogenic amine transporters and serotonin receptor subtypes | journal = Psychopharmacology (Berl) | volume = 231 | issue = 21 | pages = 4135–4144 | date = October 2014 | pmid = 24800892 | pmc = 4194234 | doi = 10.1007/s00213-014-3557-7 | url = | quote = [Tryptamine (T): [...] Psychoactive effects: Psychoactive, short acting due to metabolism, increased blood pressure, similar to LSD}}</ref><ref name="MartinSloan1970">{{cite journal | vauthors = Martin WR, Sloan JW | title = Effects of infused tryptamine in man | journal = Psychopharmacologia | volume = 18 | issue = 3 | pages = 231–237 | date = 1970 | pmid = 4922520 | doi = 10.1007/BF00412669 | url = }}</ref> It also produced other LSD-like effects, including [[pupil dilation]], increased [[blood pressure]], and increased force of the [[patellar reflex]].<ref name="MartinSloan1977" /><ref name="BloughLandavazoDecker2014" /><ref name="ShulginShulgin1997" /><ref name="MartinSloan1970" /> Tryptamine produced [[side effect]]s including [[nausea]], [[vomiting]], [[dizziness]], [[tingling]] sensations, [[sweating]], and bodily heaviness among others as well.<ref name="MartinSloan1977" /><ref name="MartinSloan1970" /> Conversely, there were no changes in [[heart rate]] or [[respiratory rate]].<ref name="MartinSloan1970" /> The [[onset of action|onset]] of the effects was rapid and the [[duration of action|duration]] was very short.<ref name="Jones1982" /><ref name="BloughLandavazoDecker2014" /><ref name="ShulginShulgin1997" /><ref name="MartinSloan1970" /> This can be attributed to the very rapid [[drug metabolism|metabolism]] of tryptamine by [[monoamine oxidase]] (MAO) and its very short [[elimination half-life]].<ref name="Jones1982" /><ref name="BloughLandavazoDecker2014" /><ref name="ShulginShulgin1997" /><ref name="MartinSloan1970" />

In animals, tryptamine, alone and/or in combination with a [[monoamine oxidase inhibitor]] (MAOI), produces behavioral changes such as [[hyperlocomotion]] and reversal of [[reserpine]]-induced [[hypoactivity|behavioral depression]].<ref name="MartinSloan1977" /><ref name="Jones1982" /><ref name="KellarCascio1986" /><ref name="MurphyTamarkinGarrick1985" /> In addition, it produces effects like [[hyperthermia]], [[tachycardia]], [[myoclonus]], and [[seizure]]s or [[convulsion]]s, among others.<ref name="MartinSloan1977" /><ref name="Jones1982" /><ref name="KellarCascio1986" /><ref name="MurphyTamarkinGarrick1985" /> Findings on tryptamine and the [[head-twitch response]] in rodents have been mixed, with some studies reporting no effect,<ref name="Jones1981" /><ref name="YamadaSugimotoHorisaka1987">{{cite journal | vauthors = Yamada J, Sugimoto Y, Horisaka K | title = The behavioural effects of intravenously administered tryptamine in mice | journal = Neuropharmacology | volume = 26 | issue = 1 | pages = 49–53 | date = January 1987 | pmid = 3561719 | doi = 10.1016/0028-3908(87)90043-8 | url = }}</ref> some studies reporting induction of head twitches by tryptamine,<ref name="HaberzettlBertFink2013">{{cite journal | vauthors = Haberzettl R, Bert B, Fink H, Fox MA | title = Animal models of the serotonin syndrome: a systematic review | journal = Behav Brain Res | volume = 256 | issue = | pages = 328–345 | date = November 2013 | pmid = 24004848 | doi = 10.1016/j.bbr.2013.08.045 | url = | doi-access = free }}</ref><ref name="SugimotoYamadaHorisaka1986">{{cite journal | vauthors = Sugimoto Y, Yamada J, Horisaka K | title = Effect of tryptamine on the behavior of mice | journal = J Pharmacobiodyn | volume = 9 | issue = 1 | pages = 68–73 | date = January 1986 | pmid = 2940357 | doi = 10.1248/bpb1978.9.68 | url = }}</ref><ref name="OrikasaSloley1988">{{cite journal | vauthors = Orikasa S, Sloley BD | title = Effects of 5,7-dihydroxytryptamine and 6-hydroxydopamine on head-twitch response induced by serotonin, p-chloroamphetamine, and tryptamine in mice | journal = Psychopharmacology (Berl) | volume = 95 | issue = 1 | pages = 124–131 | date = 1988 | pmid = 3133691 | doi = 10.1007/BF00212780 | url = }}</ref> and others reporting that tryptamine actually antagonized [[5-hydroxytryptophan]] (5-HTP)-induced head twitches.<ref name="KellarCascio1986" /><ref name="Jones1981">{{cite journal | vauthors = Jones RS | title = In vivo pharmacological studies on the interactions between tryptamine and 5-hydroxytryptamine | journal = Br J Pharmacol | volume = 73 | issue = 2 | pages = 485–493 | date = June 1981 | pmid = 6972243 | pmc = 2071674 | doi = 10.1111/j.1476-5381.1981.tb10447.x | url = }}</ref> Another study found that combination of tryptamine with an MAOI dose-dependently produced head twitches.<ref name="IronsRobinsonMarsden1984">{{cite book | last1=Irons | first1=Jane | last2=Robinson | first2=C. M. | last3=Marsden | first3=C. A. | title=Neurobiology of the Trace Amines | chapter=5ht Involvement in Tryptamine Induced Behaviour in Mice | publisher=Humana Press | publication-place=Totowa, NJ | date=1984 | isbn=978-1-4612-9781-9 | doi=10.1007/978-1-4612-5312-9_35 | pages=423–427}}</ref> Head twitches in rodents are a behavioral proxy of psychedelic-like effects.<ref name="CanalMorgan2012">{{cite journal | vauthors = Canal CE, Morgan D | title = Head-twitch response in rodents induced by the hallucinogen 2,5-dimethoxy-4-iodoamphetamine: a comprehensive history, a re-evaluation of mechanisms, and its utility as a model | journal = Drug Test Anal | volume = 4 | issue = 7–8 | pages = 556–576 | date = 2012 | pmid = 22517680 | pmc = 3722587 | doi = 10.1002/dta.1333 | url = }}</ref><ref name="KozlenkovGonzález-Maeso2013">{{cite book | last1=Kozlenkov | first1=Alexey | last2=González-Maeso | first2=Javier | title=The Neuroscience of Hallucinations | chapter=Animal Models and Hallucinogenic Drugs | publisher=Springer New York | publication-place=New York, NY | date=2013 | isbn=978-1-4614-4120-5 | doi=10.1007/978-1-4614-4121-2_14 | pages=253–277}}</ref> Many of the effects of tryptamine can be reversed by [[serotonin receptor antagonist]]s like [[metergoline]], [[metitepine]] (methiothepin), and [[cyproheptadine]].<ref name="Jones1982" /><ref name="KellarCascio1986" /><ref name="MurphyTamarkinGarrick1985" /><ref name="MartinSloan1977" /> Conversely, the effects of tryptamine in animals are profoundly augmented by MAOIs due to inhibition of its metabolism.<ref name="Jones1982" /><ref name="MurphyTamarkinGarrick1985" /><ref name="MartinSloan1977" />

Tryptamine seems to also elevate [[prolactin]] and [[cortisol]] levels in animals and/or humans.<ref name="MurphyTamarkinGarrick1985" />

The {{Abbrlink|LD<sub>50</sub>|median lethal dose}} values of tryptamine in animals include 100{{nbsp}}mg/kg i.p. in mice, 500{{nbsp}}mg/kg s.c. in mice, and 223{{nbsp}}mg/kg i.p. in rats.<ref name="PubChem" />