Reduced feeding response to neuropeptide Y in senescent fischer 344 rats

Cynthia A. Blanton, Barbara A Horwitz, James E. Blevins, Jock S. Hamilton, Eduardo J. Hernandez, Roger B. McDonald

Research output: Contribution to journalArticle

36 Scopus citations

Abstract

The anorexia of aging syndrome in humans is characterized by spontaneous body weight loss reflecting diminished food intake. We reported previously that old rats undergoing a similar phenomenon of progressive weight loss (i.e., senescent rats) also display altered feeding behavior, including reduced meal size and duration. Here, we tested the hypothesis that blunted responsiveness to neuropeptide Y (NPY), a feeding stimulant, occurs concurrently with senescence-associated anorexia/hypophagia. Young (8 mo old, n = 9) and old (24-30 mo old, n = 11) male Fischer 344 rats received intracerebroventricular NPY or artificial cerbrospinal fluid injections. In response to a maximum effective NPY dose (10 μg), the net increase in size of the first meal after injection was similar in old weight-stable (presenescent) and young rats (10.85 ± 1.73 and 12.63 ± 2.52 g/kg body wt0.67, respectively). In contrast, senescent rats that had spontaneously lost ∼10% of body weight had significantly lower net increases at their first post-NPY meal (1.33 ± 0.33 g/kg body wt0.67) than before they began losing weight. Thus altered feeding responses to NPY occur in aging rats concomitantly with spontaneous decrements in food intake and body weight near the end of life.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume280
Issue number4 49-4
StatePublished - 2001

Keywords

  • Anorexia of aging
  • Corticosterone
  • Food intake
  • Leptin

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

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    Blanton, C. A., Horwitz, B. A., Blevins, J. E., Hamilton, J. S., Hernandez, E. J., & McDonald, R. B. (2001). Reduced feeding response to neuropeptide Y in senescent fischer 344 rats. American Journal of Physiology - Regulatory Integrative and Comparative Physiology, 280(4 49-4).