NPY-leptin: opposing effects on appetitive and consummatory ingestive behavior and sexual behavior

AA Ammar, F Sederholm, TR Saito, AJW Scheurink, AE Johnson, P. Södersten

Research output: Contribution to journalArticleAcademicpeer-review

95 Citations (Scopus)

Abstract

Many studies have indicated that neuropeptide Y (NPY) stimulates and leptin inhibits food intake. In line with this, intracerebroventricular injection of NPY (10 mu g) stimulated and leptin (10 mu g) inhibited intake of a sucrose solution when female rats were required to obtain the solution from a bottle. However, NPY inhibited and leptin stimulated intake if the solution was infused intraorally. Thus NPY stimulates the responses used to obtain food but inhibits those used to consume food, and leptin has the opposite effects. To test the specificity of these responses the sexual behavior of male rats was examined. NPY-treated males showed minor deficits in sexual behavior but chose to ingest a sucrose solution rather than copulate with a female if offered the choice. By contrast, leptin-treated males ingested little sucrose and displayed an increase in ejaculatory frequency if given the same choice. It is suggested that NPY is not merely an orexigenic peptide, but one that directs attention toward food. Similarly, leptin may not be an anorexic peptide, but one that diverts attention away from food toward alternate stimuli.

Original languageEnglish
Pages (from-to)R1627-R1633
Number of pages7
JournalAmerican journal of physiology-Regulatory integrative and comparative physiology
Volume278
Issue number6
Publication statusPublished - Jun-2000

Keywords

  • food intake
  • reproduction
  • peptides
  • behavioral choice
  • CORTICOTROPIN-RELEASING FACTOR
  • NEUROPEPTIDE-Y
  • BODY-WEIGHT
  • CENTRAL NUCLEUS
  • PARAVENTRICULAR NUCLEUS
  • MESSENGER-RNA
  • RATS
  • AMYGDALA
  • BRAIN
  • COLOCALIZATION

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