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

• Main Authors: Berolla Sahdo, Alina L. Evans, Jon M. Arnemo, Ole Fröbert, Eva Särndahl, Stéphane Blanc
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Arctic; brown bear; Ursus arctos
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.678.4346; http://www.medsci.org/v10p0508.pdf

licenses/by-nc-nd/3.0/). Reproduction is permitted for personal, noncommercial use, provided that the article is in whole, unmodified, and properly cited. Received: 2012.04.16; Accepted: 2013.02.10; Published: 2013.03.11 Background: Hibernation involves periods of severely depressed metabolism (torpor) and de-creases 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 de-creased 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. Methods and Results: The white blood cell counts were determined by flow cytometry in 13