title: Evidence that MK-801 stimulates intraoral intake by acting on hepatic afferents.
abstract: Satiety signals from the gastrointestinal tract travel via vagal afferents to the nucleus of the solitary tract (NTS) in the brain stem, the first central relay in a neural network which controls food intake. The non-competitive NMDA antagonist MK-801 facilitates food intake in rats by acting on the NTS. Here we report that hepatic portal vein infusion of MK-801 (25 or 50 microg/kg) increases intake of an intraorally infused 1 M solution of sucrose (by 113 +/- 9 and 132 +/- 11%, respectively) and that this effect is prevented by hepatic vagotomy. By contrast, jugular vein infusion of MK-801 fails to increase sucrose intake but induces forward locomotion, indicating activation of a central mechanism. These data suggest that MK-801 can stimulate food intake by acting peripherally on hepatic vagal afferents.
authors.affiliation: Section of Applied Neuroendocrinology, Karolinska Institutet, Huddinge, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Qian
authors.forename: S W
authors.initials: SW
authors.lastname: Zhu
authors.forename: A E
authors.initials: AE
authors.lastname: Johnson
authors.forename: P
authors.initials: P
authors.lastname: Södersten
mesh_terms: D000818:Animals; D016291:Dizocilpine Maleate / Q000494:pharmacology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology*; D005247:Feeding Behavior / Q000187:drug effects*; D008099:Liver / Q000294:innervation*; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009475:Neurons, Afferent / Q000187:drug effects* / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D018691:Excitatory Amino Acid Antagonists; D016291:Dizocilpine Maleate