The work presented here was carried out in collaboration between all authors. KA, BS, and OF defined the research subject. ALE and JMA designed and supervised capture and fieldwork. ALE carried out and supervised sampling of bears shot during hunting. BS carried out blood sample laboratory experiments and UB designed and carried out histologypathology. KA and OF analyzed the data, interpreted the results and wrote the paper. All authors have contributed to, seen and approved the manuscript.
Brown Bears (Ursus arctos) Seem Resistant to Atherosclerosis Despite Highly Elevated Plasma Lipids during Hibernation and Active State
Article first published online: 10 JAN 2012
© 2012 Wiley Periodicals, Inc.
Clinical and Translational Science
Volume 5, Issue 3, pages 269–272, June 2012
How to Cite
Arinell, K., Sahdo, B., Evans, A. L., Arnemo, J. M., Baandrup, U. and Fröbert, O. (2012), Brown Bears (Ursus arctos) Seem Resistant to Atherosclerosis Despite Highly Elevated Plasma Lipids during Hibernation and Active State. Clinical and Translational Science, 5: 269–272. doi: 10.1111/j.1752-8062.2011.00370.x
- Issue published online: 11 JUN 2012
- Article first published online: 10 JAN 2012
- hibernation physiology;
Hibernation is an extreme physiological challenge for the brown bear (Ursus arctos) in which metabolism is based mainly on lipids. The study objective was to compare plasma lipids in hibernating and active free-ranging brown bears and relate them to arterial histopathology. Blood was drawn from seven immobilized free-ranging brown bears (three females, 2–3 years old) during hibernation in February and from the same bears while active in June and analyzed by enzymatic and automated hematology methods within 48 hours of sampling. Left anterior descending coronary arteries and aortic arches from 12 bears (six females, 1.5–12 years old) killed in hunting were examined by histopathology. Total plasma cholesterol decreased from hibernation to the active period (11.08 ± 1.04 mmol/L vs. 7.89 ± 1.96 mmol/L, P= 0.0028) as did triglyceride (3.16 ± 0.62 mmol/L vs. 1.44 ± 0.27 mmol/L, P= 0.00012) and LDL cholesterol (4.30 ± 0.71 mmol/L vs. 2.02 ± 1.03 mmol/L, P= 0.0075), whereas HDL cholesterol was unchanged. No atherosclerosis, fatty streaks, foam cell infiltration, or inflammation were seen in any arterial samples. Brown bears tolerate elevated cholesterol levels, obesity, physical inactivity, and circulatory slow flow during hibernation without signs of atherosclerosis. This species might serve as a reverse translational model for atherosclerosis resistance. Clin Trans Sci 2012; Volume 5: 269–272