Body Temperature during Hibernation Is Highly Correlated with a Decrease in Circulating Innate Immune Cells in the Brown Bear (Ursus arctos): A Common Feature among Hibernators?

• Published in: International Journal of Medical Sciences
• Main Authors: Sahdo, Berolla, Evans, Alina L., Arnemo, Jon M., Fröbert, Ole, Särndahl, Eva, Blanc, Stéphane
• Format: Text
• Language: English
• Published: Ivyspring International Publisher 2013
• Subjects: Research Paper; Arctic; brown bear; Ursus arctos
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3607235; http://www.ncbi.nlm.nih.gov/pubmed/23532623; https://doi.org/10.7150/ijms.4476

Background: Hibernation involves periods of severely depressed metabolism (torpor) and decreases in body temperature (Tb). Small arctic mammals (<5kg), in which Tb generally drop drastically, display leukopenia during hibernation. This raised the question of whether the decreased leukocyte counts in mammalian hibernators is due to torpor per se or is secondary to low Tb. The present study examined immune cell counts in brown bears (Ursus arctos), where torpor is only associated with shallow decreases in Tb. The results were compared across hibernator species for which immune and Tb data were available.