Serotonin3 receptor antagonists block anorectic responses to amino acid imbalance

V. A. Hammer, D. W. Gietzen, J. L. Beverly, Quinton Rogers

Research output: Contribution to journalArticlepeer-review

46 Scopus citations


The role of serotonin3 (5-HT3) receptors in the initial food intake depression of rats ingesting amino acid imbalanced or high-protein diets was investigated. The 5-HT antagonists metergoline, pirenpirone, ICS 205-930, and MDL 72222, the dopamine antagonist pimozide, or the α-adrenergic antagonist phentolamine were injected 15-45 min before presentation of test diets. Food intake was measured at intervals for 3 days. The 5-HT3 antagonists, ICS 205-930 and MDL 72222, restored feeding of a mild isoleucine (Ile)-imbalanced diet to control levels, although MDL 72222 had a longer time course of action. ICS 205-930 also increased intake of a severe Ile-imbalanced diet and a Thr-imbalanced diet but not a high-protein (44% casein) diet. Treatment with metergoline, which blocks 5-HT1, 5-HT2, and dopamine receptor sites but not 5-HT3 sites, increased intake of the basal diet at 3 and 6 h but did not significantly alter intake of the mild Ile-imbalanced diet. Although pimozide tended to increase intake of the mild imbalanced diet, neither dopamine nor α-adrenergic receptor antagonism significantly affected imbalanced diet intake. Thus 5-HT3 receptors may mediate the anorexigenic activity of 5-HT associated with feeding an amino acid-imbalanced diet.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Issue number3 28-3
StatePublished - Jan 1 1990


  • dopamine
  • feeding behavior
  • food intake depression
  • ICS 205-930
  • MDL 72222
  • metergoline
  • phentolamine
  • pimozide
  • pirenpirone
  • serotonin
  • serotonin

ASJC Scopus subject areas

  • Physiology


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