Central activation of the A1 adenosine receptor in fed mice recapitulates only some of the attributes of daily torpor
Mice enter bouts of daily torpor, drastically reducing metabolic rate, core body temperature (Tb), and heart rate (HR), in response to reduced caloric intake. Because central adenosine activation has been shown to induce a torpor-like state in the arctic ground squirrel, and blocking the adenosine-1...
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ftpubmed:oai:pubmedcentral.nih.gov:5493318 2023-05-15T14:31:30+02:00 Central activation of the A1 adenosine receptor in fed mice recapitulates only some of the attributes of daily torpor Vicent, Maria Alejandra Borre, Ethan D. Swoap, Steven J. 2017-04-04 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5493318/ http://www.ncbi.nlm.nih.gov/pubmed/28378088 https://doi.org/10.1007/s00360-017-1084-7 en eng http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5493318/ http://www.ncbi.nlm.nih.gov/pubmed/28378088 http://dx.doi.org/10.1007/s00360-017-1084-7 Article Text 2017 ftpubmed https://doi.org/10.1007/s00360-017-1084-7 2018-07-08T00:13:08Z Mice enter bouts of daily torpor, drastically reducing metabolic rate, core body temperature (Tb), and heart rate (HR), in response to reduced caloric intake. Because central adenosine activation has been shown to induce a torpor-like state in the arctic ground squirrel, and blocking the adenosine-1 (A1) receptor prevents daily torpor, we hypothesized that central activation of the A1 adenosine receptors would induce a bout of natural torpor in mice. To test the hypothesis, mice were subjected to four different hypothermia bouts: natural torpor, forced hypothermia (FH), isoflurane-anesthesia, and an intracerebroventricular injection of the selective A1 receptor agonist N6cyclohexyladenosine (CHA). All conditions induced profound hypothermia. Tb fell more rapidly in the FH, isoflurane-anesthesia, and CHA conditions compared to torpor, while mice treated with CHA recovered at half the rate of torpid mice. FH, isoflurane-anesthesia, and CHA-treated mice exhibited a diminished drop in HR during entry into hypothermia as compared to torpor. Mice in all conditions except CHA shivered while recovering from hypothermia, and only FH mice shivered substantially while entering hypothermia. Circulating lactate during the hypothermic bouts was not significantly different between the CHA and torpor conditions, both of which had lower than baseline lactate levels. Arrhythmias were largely absent in the FH and isoflurane-anesthesia conditions, while skipped beats were observed in natural torpor and periodic extended (>1 sec) HR pauses in the CHA condition. Lastly, the hypothermic bouts showed distinct patterns of gene expression, with torpor characterized by elevated hepatic and cardiac Txnip expression and all other hypothermic states characterized by elevated c-Fos and Egr-1 expression. We conclude that CHA-induced hypothermia and natural torpor are largely different physiological states. Text Arctic ground squirrel Arctic PubMed Central (PMC) Arctic Journal of Comparative Physiology B 187 5-6 835 845 |
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Article Vicent, Maria Alejandra Borre, Ethan D. Swoap, Steven J. Central activation of the A1 adenosine receptor in fed mice recapitulates only some of the attributes of daily torpor |
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Article |
description |
Mice enter bouts of daily torpor, drastically reducing metabolic rate, core body temperature (Tb), and heart rate (HR), in response to reduced caloric intake. Because central adenosine activation has been shown to induce a torpor-like state in the arctic ground squirrel, and blocking the adenosine-1 (A1) receptor prevents daily torpor, we hypothesized that central activation of the A1 adenosine receptors would induce a bout of natural torpor in mice. To test the hypothesis, mice were subjected to four different hypothermia bouts: natural torpor, forced hypothermia (FH), isoflurane-anesthesia, and an intracerebroventricular injection of the selective A1 receptor agonist N6cyclohexyladenosine (CHA). All conditions induced profound hypothermia. Tb fell more rapidly in the FH, isoflurane-anesthesia, and CHA conditions compared to torpor, while mice treated with CHA recovered at half the rate of torpid mice. FH, isoflurane-anesthesia, and CHA-treated mice exhibited a diminished drop in HR during entry into hypothermia as compared to torpor. Mice in all conditions except CHA shivered while recovering from hypothermia, and only FH mice shivered substantially while entering hypothermia. Circulating lactate during the hypothermic bouts was not significantly different between the CHA and torpor conditions, both of which had lower than baseline lactate levels. Arrhythmias were largely absent in the FH and isoflurane-anesthesia conditions, while skipped beats were observed in natural torpor and periodic extended (>1 sec) HR pauses in the CHA condition. Lastly, the hypothermic bouts showed distinct patterns of gene expression, with torpor characterized by elevated hepatic and cardiac Txnip expression and all other hypothermic states characterized by elevated c-Fos and Egr-1 expression. We conclude that CHA-induced hypothermia and natural torpor are largely different physiological states. |
format |
Text |
author |
Vicent, Maria Alejandra Borre, Ethan D. Swoap, Steven J. |
author_facet |
Vicent, Maria Alejandra Borre, Ethan D. Swoap, Steven J. |
author_sort |
Vicent, Maria Alejandra |
title |
Central activation of the A1 adenosine receptor in fed mice recapitulates only some of the attributes of daily torpor |
title_short |
Central activation of the A1 adenosine receptor in fed mice recapitulates only some of the attributes of daily torpor |
title_full |
Central activation of the A1 adenosine receptor in fed mice recapitulates only some of the attributes of daily torpor |
title_fullStr |
Central activation of the A1 adenosine receptor in fed mice recapitulates only some of the attributes of daily torpor |
title_full_unstemmed |
Central activation of the A1 adenosine receptor in fed mice recapitulates only some of the attributes of daily torpor |
title_sort |
central activation of the a1 adenosine receptor in fed mice recapitulates only some of the attributes of daily torpor |
publishDate |
2017 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5493318/ http://www.ncbi.nlm.nih.gov/pubmed/28378088 https://doi.org/10.1007/s00360-017-1084-7 |
geographic |
Arctic |
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Arctic |
genre |
Arctic ground squirrel Arctic |
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Arctic ground squirrel Arctic |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5493318/ http://www.ncbi.nlm.nih.gov/pubmed/28378088 http://dx.doi.org/10.1007/s00360-017-1084-7 |
op_doi |
https://doi.org/10.1007/s00360-017-1084-7 |
container_title |
Journal of Comparative Physiology B |
container_volume |
187 |
container_issue |
5-6 |
container_start_page |
835 |
op_container_end_page |
845 |
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1766305113955106816 |