Hypothalamic neuropeptide gene expression during recovery from food restriction superimposed on short-day photoperiod-induced weight loss in the Siberian hamster

Zoë A. Archer, Kim-Marie Moar, Tracy Logie, Laura Reilly, Valerie Joan Stevens, Peter John Morgan, Julian Mercer

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Previously, 40% food restriction of male Siberian hamsters over 21 days in short-day (SD) photoperiod induced characteristic changes in expression of hypothalamic arcuate nucleus energy balance genes; mRNAs for neuropeptide Y, agouti-related peptide, and leptin receptor were upregulated, and those of proopiomelanocortin and cocaine- and amphetamine-regulated transcript were depressed. The present study examined the effect of refeeding hamsters for 6 days (approximately 50% recovery of weight differential) or 19 days (resumption of appropriate weight trajectory). Hyperphagia continued throughout refeeding, but differences in fat pad weights and leptin levels had disappeared after 19 days. Cocaine- and amphetamine-regulated transcript gene expression was depressed by prior restriction in both refed groups. The depressive effect of prior restriction on proopiomelanocortin gene expression had disappeared after 19 days of refeeding. There was no effect of prior food restriction on neuropeptide Y or agouti-related peptide gene expression. Expression of the anorexigenic brain-derived neurotrophic factor was downregulated in the ventromedial nucleus after SD exposure for 12 wk. In the SD food restriction study, there were effects of photoperiod on brain-derived neurotrophic factor gene expression but not of prior food restriction. Hypothalamic energy balance genes in the hamster respond asynchronously to return to a seasonally appropriate body weight. The achievement of this weight rather than the weight at which caloric restriction was imposed is the critical factor. The differential responses of hypothalamic energy balance genes to food restriction and refeeding are poorly characterized in any species, a critical issue given their potential relevance to human weight loss strategies that involve caloric restriction.
Original languageEnglish
Pages (from-to)R1094-R1101
Number of pages8
JournalAmerican Journal of Physiology-Regulatory Integrative and Comparative Physiology
Volume293
Issue number3
DOIs
Publication statusPublished - Sep 2007

    Fingerprint

Keywords

  • animals
  • body weight
  • brain-derived neurotrophic factor
  • caloric restriction
  • cricetinae
  • eating
  • gene expression
  • hypothalamus
  • leptin
  • male
  • neuropeptides
  • organ size
  • phodopus
  • photoperiod
  • radioimmunoassay
  • weight loss

Cite this