Abstract
The 5-HT1B agonist RU24969 when given either systemically (1 mg/kg SC) or by infusion (0.5, 1.0, 2.0 μg) into the region of the paraventricular nucleus of the hypothalamus caused dose-dependent hypophagia in rats previously deprived of food for 18 h. Similar results were obtained at the above dosages of 1-[3-(trifluoromethyl) phenyl] piperazine (TFMPP), which acts on 5-HT1B and possibly also on 5-HT1C receptors. Neither drug significantly affected locomotion following central administration. Food intake was significantly decreased when the 5-HT1A agonist 8-OH-DPAT was given systemically (1 mg/kg SC) to rats previously deprived of food but was unaffected when 8-OH-DPAT (1 μg) was infused into the paraventricular nucleus of both food-deprived and free feeding rats. Therefore, hypophagia occurs when hypothalamic 5-HT1B (and possibly 5-HT1C) but not 5-HT1A receptors are activated.
This is a preview of subscription content, log in via an institution to check access.
References
Dourish CT, Hutson PH, Curzon G (1985) Characteristics of feeding induced by the serotonin agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT). Brain Res 15:377–384
Hoyer D, Engel G, Kalkman HO (1985) Molecular pharmacology of 5-HT1 and 5-HT2 recognition sites in rat and pig brain membranes: radioligand binding studies with [3H]5-HT, [3H]8-OH-DPAT, (-)[125I]-iodocyanopindolol, [3H] mesulergine and [3H] ketanserin. Eur J Pharmacol 118:13–23
Hutson PH, Dourish CT, Curzon G (1986) Neurochemical and behavioural evidence for mediation of the hyperphagic action of 8-OH-DPAT by 5HT cell body autoreceptors. Eur J Pharmacol 129:347–352
Kennett GA, Curzon G (1988a) Evidence that mCPP and TFMPP-induced hypophagia is mediated by selective activation of 5-HT1C receptors. Br J Pharmacol (in press)
Kennett GA, Curzon G (1988b) Evidence that mCPP may have behavioural effects mediated by central 5-HT1C receptors. Br J Pharmacol 94:137–147
Kennett GA, Dourish CT, Curzon G (1987) 5HT1B agonists induce anorexia at a post synaptic site. Eur J Pharmacol 141:429–435
Kilpatrick GJ, Jones BJ, Tyers MB (1987) Identification and distribution of 5-HT3 receptors in rat brain using radioligand binding. Nature 330:746–748
Paxinos G, Watson C (1982) The rat brain in stereotaxic coordinates. Academic Press, New York
Pazos A, Probst A, Palacios JM (1987) Serotonin receptors in human brain — III Autoradiographic mapping of serotonin-1 receptors. Neuroscience 21:97–122
Shor-Posner G, Grinker JA, Marmeson C, Brown O, Leibowitz SF (1986) Hypothalamic serotonin in the control of meal patterns and macronutrient selection. Brain Res Bull 17:663–671
Sugrue MF (1987) Neuropharmacology of drugs affecting food intake. Pharmacol Ther 32:145–182
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Hutson, P.H., Donohoe, T.P. & Curzon, G. Infusion of the 5-hydroxytryptamine agonists RU24969 and TFMPP into the paraventricular nucleus of the hypothalamus causes hypophagia. Psychopharmacology 95, 550–552 (1988). https://doi.org/10.1007/BF00172974
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00172974