Energy homeostasis regulatory peptides in hibernating grizzly bears

János Gardi, O. Lynne Nelson, Charles T. Robbins, Éva Szentirmai, Levente Kapás, James M. Krueger

Research output: Article

9 Citations (Scopus)


Grizzly bears (Ursus arctos horribilis) are inactive for up to 6. months during hibernation. They undergo profound seasonal changes in food intake, body mass, and energy expenditure. The circa-annual regulation of metabolism is poorly understood. In this study, we measured plasma ghrelin, leptin, obestatin, and neuropeptide-Y (NPY) levels, hormones known to be involved in the regulation of energy homeostasis, in ten grizzly bears. Blood samples were collected during the active summer period, early hibernation and late hibernation. Plasma levels of leptin, obestatin, and NPY did not change between the active and the hibernation periods. Plasma total ghrelin and desacyl-ghrelin concentrations significantly decreased during the inactive winter period compared to summer levels. The elevated ghrelin levels may help enhance body mass during pre-hibernation, while the low plasma ghrelin concentrations during hibernation season may contribute to the maintenance of hypophagia, low energy utilization and behavioral inactivity. Our results suggest that ghrelin plays a potential role in the regulation of metabolic changes and energy homeostasis during hibernation in grizzly bears.

Original languageEnglish
Pages (from-to)181-183
Number of pages3
JournalGeneral and Comparative Endocrinology
Issue number1
Publication statusPublished - máj. 15 2011


ASJC Scopus subject areas

  • Animal Science and Zoology
  • Endocrinology

Cite this

Gardi, J., Nelson, O. L., Robbins, C. T., Szentirmai, É., Kapás, L., & Krueger, J. M. (2011). Energy homeostasis regulatory peptides in hibernating grizzly bears. General and Comparative Endocrinology, 172(1), 181-183.