Metabolic Changes in Summer Active and Anuric Hibernating Free-Ranging Brown Bears (Ursus arctos)
The brown bear (Ursus arctos) hibernates for 5 to 6 months each winter and during this time ingests no food or water and remains anuric and inactive. Despite these extreme conditions, bears do not develop azotemia and preserve their muscle and bone strength. To date most renal studies have been limi...
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ftpubmed:oai:pubmedcentral.nih.gov:3767665 2023-05-15T18:41:57+02:00 Metabolic Changes in Summer Active and Anuric Hibernating Free-Ranging Brown Bears (Ursus arctos) Stenvinkel, Peter Fröbert, Ole Anderstam, Björn Palm, Fredrik Eriksson, Monica Bragfors-Helin, Ann-Christin Qureshi, Abdul Rashid Larsson, Tobias Friebe, Andrea Zedrosser, Andreas Josefsson, Johan Svensson, My Sahdo, Berolla Bankir, Lise Johnson, Richard J. 2013-09-09 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3767665 https://doi.org/10.1371/journal.pone.0072934 en eng Public Library of Science http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3767665 http://dx.doi.org/10.1371/journal.pone.0072934 This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. CC-BY Research Article Text 2013 ftpubmed https://doi.org/10.1371/journal.pone.0072934 2013-09-15T00:58:12Z The brown bear (Ursus arctos) hibernates for 5 to 6 months each winter and during this time ingests no food or water and remains anuric and inactive. Despite these extreme conditions, bears do not develop azotemia and preserve their muscle and bone strength. To date most renal studies have been limited to small numbers of bears, often in captive environments. Sixteen free-ranging bears were darted and had blood drawn both during hibernation in winter and summer. Samples were collected for measurement of creatinine and urea, markers of inflammation, the calcium-phosphate axis, and nutritional parameters including amino acids. In winter the bear serum creatinine increased 2.5 fold despite a 2-fold decrease in urea, indicating a remarkable ability to recycle urea nitrogen during hibernation. During hibernation serum calcium remained constant despite a decrease in serum phosphate and a rise in FGF23 levels. Despite prolonged inactivity and reduced renal function, inflammation does not ensue and bears seem to have enhanced antioxidant defense mechanisms during hibernation. Nutrition parameters showed high fat stores, preserved amino acids and mild hyperglycemia during hibernation. While total, essential, non-essential and branched chain amino acids concentrations do not change during hibernation anorexia, changes in individual amino acids ornithine, citrulline and arginine indicate an active, although reduced urea cycle and nitrogen recycling to proteins. Serum uric acid and serum fructose levels were elevated in summer and changes between seasons were positively correlated. Further studies to understand how bears can prevent the development of uremia despite minimal renal function during hibernation could provide new therapeutic avenues for the treatment of human kidney disease. Text Ursus arctos PubMed Central (PMC) PLoS ONE 8 9 e72934 |
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Research Article |
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Research Article Stenvinkel, Peter Fröbert, Ole Anderstam, Björn Palm, Fredrik Eriksson, Monica Bragfors-Helin, Ann-Christin Qureshi, Abdul Rashid Larsson, Tobias Friebe, Andrea Zedrosser, Andreas Josefsson, Johan Svensson, My Sahdo, Berolla Bankir, Lise Johnson, Richard J. Metabolic Changes in Summer Active and Anuric Hibernating Free-Ranging Brown Bears (Ursus arctos) |
topic_facet |
Research Article |
description |
The brown bear (Ursus arctos) hibernates for 5 to 6 months each winter and during this time ingests no food or water and remains anuric and inactive. Despite these extreme conditions, bears do not develop azotemia and preserve their muscle and bone strength. To date most renal studies have been limited to small numbers of bears, often in captive environments. Sixteen free-ranging bears were darted and had blood drawn both during hibernation in winter and summer. Samples were collected for measurement of creatinine and urea, markers of inflammation, the calcium-phosphate axis, and nutritional parameters including amino acids. In winter the bear serum creatinine increased 2.5 fold despite a 2-fold decrease in urea, indicating a remarkable ability to recycle urea nitrogen during hibernation. During hibernation serum calcium remained constant despite a decrease in serum phosphate and a rise in FGF23 levels. Despite prolonged inactivity and reduced renal function, inflammation does not ensue and bears seem to have enhanced antioxidant defense mechanisms during hibernation. Nutrition parameters showed high fat stores, preserved amino acids and mild hyperglycemia during hibernation. While total, essential, non-essential and branched chain amino acids concentrations do not change during hibernation anorexia, changes in individual amino acids ornithine, citrulline and arginine indicate an active, although reduced urea cycle and nitrogen recycling to proteins. Serum uric acid and serum fructose levels were elevated in summer and changes between seasons were positively correlated. Further studies to understand how bears can prevent the development of uremia despite minimal renal function during hibernation could provide new therapeutic avenues for the treatment of human kidney disease. |
format |
Text |
author |
Stenvinkel, Peter Fröbert, Ole Anderstam, Björn Palm, Fredrik Eriksson, Monica Bragfors-Helin, Ann-Christin Qureshi, Abdul Rashid Larsson, Tobias Friebe, Andrea Zedrosser, Andreas Josefsson, Johan Svensson, My Sahdo, Berolla Bankir, Lise Johnson, Richard J. |
author_facet |
Stenvinkel, Peter Fröbert, Ole Anderstam, Björn Palm, Fredrik Eriksson, Monica Bragfors-Helin, Ann-Christin Qureshi, Abdul Rashid Larsson, Tobias Friebe, Andrea Zedrosser, Andreas Josefsson, Johan Svensson, My Sahdo, Berolla Bankir, Lise Johnson, Richard J. |
author_sort |
Stenvinkel, Peter |
title |
Metabolic Changes in Summer Active and Anuric Hibernating Free-Ranging Brown Bears (Ursus arctos) |
title_short |
Metabolic Changes in Summer Active and Anuric Hibernating Free-Ranging Brown Bears (Ursus arctos) |
title_full |
Metabolic Changes in Summer Active and Anuric Hibernating Free-Ranging Brown Bears (Ursus arctos) |
title_fullStr |
Metabolic Changes in Summer Active and Anuric Hibernating Free-Ranging Brown Bears (Ursus arctos) |
title_full_unstemmed |
Metabolic Changes in Summer Active and Anuric Hibernating Free-Ranging Brown Bears (Ursus arctos) |
title_sort |
metabolic changes in summer active and anuric hibernating free-ranging brown bears (ursus arctos) |
publisher |
Public Library of Science |
publishDate |
2013 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3767665 https://doi.org/10.1371/journal.pone.0072934 |
genre |
Ursus arctos |
genre_facet |
Ursus arctos |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3767665 http://dx.doi.org/10.1371/journal.pone.0072934 |
op_rights |
This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1371/journal.pone.0072934 |
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PLoS ONE |
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8 |
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9 |
container_start_page |
e72934 |
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