Assessment of the role of oxytocin receptors in phenylpropanolamine-induced anorexia in rats

L. R. McMahon, Paul J. Wellman

Research output: Contribution to journalArticle

2 Scopus citations

Abstract

The anorexic effects of phenylpropanolamine (PPA) have been attributed to activation by PPA of α1-adrenoceptors within rat hypothalamic paraventricular nucleus (PVN). The PVN, however, is a nexus for a number of ascending and descending fibers systems that release transmitters and modulators known to inhibit appetite. The focus of the present study was to assess the possibility that oxytocin activity might play a role in the anorexic action of PPA. The present study therefore examined the effects of systemic administration of the oxytocin antagonist L-366,948 on PPA-induced anorexia. Adult male rats (n = 10 per group) were pretreated (IP) with either 0, 1, or 2 mg/kg L-366,948 15 min prior to treatment injections (IP) of either 0, 5, 10 and 15 mg/kg PPA. Food and water intakes were recorded for a 30 min period (1600 h) starting 30 min after the treatment injection. Rats pretreated with vehicle and then treated with PPA exhibited a dose-dependent suppression of feeding with a maximal effect evident at 15 mg/kg PPA. Pretreatment with 1 or 2 mg/kg L-366,948 alone did not alter feeding nor did these doses alter the anorexia induced by PPA. These results suggest that direct or indirect oxytocin activity is not a factor in the anorexic action of PPA, a finding that further strengthens the notion that PPA inhibits food intake via activation of α1-adrenoceptors.

Original languageEnglish (US)
Pages (from-to)767-770
Number of pages4
JournalPharmacology Biochemistry and Behavior
Volume57
Issue number4
DOIs
StatePublished - Aug 1 1997

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Keywords

  • Feeding
  • L-366,948
  • α1-Adrenergic receptors

ASJC Scopus subject areas

  • Biochemistry
  • Toxicology
  • Pharmacology
  • Clinical Biochemistry
  • Biological Psychiatry
  • Behavioral Neuroscience

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