Apnea Stimulates the Adaptive Response to Oxidative Stress in Elephant Seal Pups
Extended breath-hold (apnea) bouts are routine during diving and sleeping in seals. These apneas result in oxygen store depletion and blood flow redistribution towards obligatory oxygen-dependent tissues, exposing seals to critical levels of ischemia and hypoxemia. The subsequent reperfusion/reoxyge...
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Journal of Experimental Biology
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ftcalifstateuniv:oai:scholarworks:js956g52f 2024-09-30T14:34:22+00:00 Apnea Stimulates the Adaptive Response to Oxidative Stress in Elephant Seal Pups José Pablo Vázquez-Medina Tania Zenteno-Savín Michael S. Tift Henry Jay Forman Daniel E. Crocker Rudy M. Ortiz 2011 http://hdl.handle.net/10211.3/118183 English eng Journal of Experimental Biology J.P.V.-M. is supported by fellowships from The University of California Institute for Mexico and The United States (UC MEXUS), Mexicoʼs Consejo Nacional de Ciencia y Tecnología (CONACYT), Mexicoʼs Ministry of Education (SEP) and the University of California Miguel Velez Scholarship Fund. This research was funded by UC MEXUS, CONACYT and the National Institutes of Health (NHLBI R01- HL09176). Deposited in PMC for release after 6 months. http://hdl.handle.net/10211.3/118183 apnea antioxidant reperfusion hypoxemia elephant seal ischemia oxidative stress Article 2011 ftcalifstateuniv 2024-09-10T17:06:15Z Extended breath-hold (apnea) bouts are routine during diving and sleeping in seals. These apneas result in oxygen store depletion and blood flow redistribution towards obligatory oxygen-dependent tissues, exposing seals to critical levels of ischemia and hypoxemia. The subsequent reperfusion/reoxygenation has the potential to increase oxidant production and thus oxidative stress. The contributions of extended apnea to oxidative stress in adapted mammals are not well defined. To address the hypothesis that apnea in seals is not associated with increased oxidative damage, blood samples were collected from northern elephant seal pups (N=6) during eupnea, rest- and voluntary submersion-associated apneas, and post-apnea (recovery). Plasma 4-hydroxynonenal (HNE), 8-isoprostanes (8-isoPGF2a), nitrotyrosine (NT), protein carbonyls, xanthine and hypoxanthine (HX) levels, along with xanthine oxidase (XO) activity, were measured. Protein content of XO, superoxide dismutase 1 (Cu,ZnSOD), catalase and myoglobin (Mb), as well as the nuclear content of hypoxia inducible factor 1 (HIF-1 ) and NF-E2-related factor 2 (Nrf2), were measured in muscle biopsies collected before and after the breath-hold trials. HNE, 8-iso PGF2 , NT and protein carbonyl levels did not change among eupnea, apnea or recovery. XO activity and HX and xanthine concentrations were increased at the end of the apneas and during recovery. Muscle protein content of XO, CuZnSOD, catalase, Mb, HIF-1 and Nrf2 increased 25–70% after apnea. Results suggest that rather than inducing the damaging effects of hypoxemia and ischemia/reperfusion that have been reported in non-diving mammals, apnea in seals stimulates the oxidative stress and hypoxic hormetic responses, allowing these mammals to cope with the potentially detrimental effects associated with this condition. Published by and copyright of The Company of Biologists. The definitive version of this article is available at: http://jeb.biologists.org/content/214/24/4193.full.pdf+html Vázquez-Medina, José Pablo, ... Article in Journal/Newspaper Elephant Seal Scholarworks from California State University Medina ENVELOPE(-66.233,-66.233,-68.453,-68.453) Pablo ENVELOPE(-63.717,-63.717,-64.283,-64.283) |
institution |
Open Polar |
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Scholarworks from California State University |
op_collection_id |
ftcalifstateuniv |
language |
English |
topic |
apnea antioxidant reperfusion hypoxemia elephant seal ischemia oxidative stress |
spellingShingle |
apnea antioxidant reperfusion hypoxemia elephant seal ischemia oxidative stress José Pablo Vázquez-Medina Tania Zenteno-Savín Michael S. Tift Henry Jay Forman Daniel E. Crocker Rudy M. Ortiz Apnea Stimulates the Adaptive Response to Oxidative Stress in Elephant Seal Pups |
topic_facet |
apnea antioxidant reperfusion hypoxemia elephant seal ischemia oxidative stress |
description |
Extended breath-hold (apnea) bouts are routine during diving and sleeping in seals. These apneas result in oxygen store depletion and blood flow redistribution towards obligatory oxygen-dependent tissues, exposing seals to critical levels of ischemia and hypoxemia. The subsequent reperfusion/reoxygenation has the potential to increase oxidant production and thus oxidative stress. The contributions of extended apnea to oxidative stress in adapted mammals are not well defined. To address the hypothesis that apnea in seals is not associated with increased oxidative damage, blood samples were collected from northern elephant seal pups (N=6) during eupnea, rest- and voluntary submersion-associated apneas, and post-apnea (recovery). Plasma 4-hydroxynonenal (HNE), 8-isoprostanes (8-isoPGF2a), nitrotyrosine (NT), protein carbonyls, xanthine and hypoxanthine (HX) levels, along with xanthine oxidase (XO) activity, were measured. Protein content of XO, superoxide dismutase 1 (Cu,ZnSOD), catalase and myoglobin (Mb), as well as the nuclear content of hypoxia inducible factor 1 (HIF-1 ) and NF-E2-related factor 2 (Nrf2), were measured in muscle biopsies collected before and after the breath-hold trials. HNE, 8-iso PGF2 , NT and protein carbonyl levels did not change among eupnea, apnea or recovery. XO activity and HX and xanthine concentrations were increased at the end of the apneas and during recovery. Muscle protein content of XO, CuZnSOD, catalase, Mb, HIF-1 and Nrf2 increased 25–70% after apnea. Results suggest that rather than inducing the damaging effects of hypoxemia and ischemia/reperfusion that have been reported in non-diving mammals, apnea in seals stimulates the oxidative stress and hypoxic hormetic responses, allowing these mammals to cope with the potentially detrimental effects associated with this condition. Published by and copyright of The Company of Biologists. The definitive version of this article is available at: http://jeb.biologists.org/content/214/24/4193.full.pdf+html Vázquez-Medina, José Pablo, ... |
format |
Article in Journal/Newspaper |
author |
José Pablo Vázquez-Medina Tania Zenteno-Savín Michael S. Tift Henry Jay Forman Daniel E. Crocker Rudy M. Ortiz |
author_facet |
José Pablo Vázquez-Medina Tania Zenteno-Savín Michael S. Tift Henry Jay Forman Daniel E. Crocker Rudy M. Ortiz |
author_sort |
José Pablo Vázquez-Medina |
title |
Apnea Stimulates the Adaptive Response to Oxidative Stress in Elephant Seal Pups |
title_short |
Apnea Stimulates the Adaptive Response to Oxidative Stress in Elephant Seal Pups |
title_full |
Apnea Stimulates the Adaptive Response to Oxidative Stress in Elephant Seal Pups |
title_fullStr |
Apnea Stimulates the Adaptive Response to Oxidative Stress in Elephant Seal Pups |
title_full_unstemmed |
Apnea Stimulates the Adaptive Response to Oxidative Stress in Elephant Seal Pups |
title_sort |
apnea stimulates the adaptive response to oxidative stress in elephant seal pups |
publisher |
Journal of Experimental Biology |
publishDate |
2011 |
url |
http://hdl.handle.net/10211.3/118183 |
long_lat |
ENVELOPE(-66.233,-66.233,-68.453,-68.453) ENVELOPE(-63.717,-63.717,-64.283,-64.283) |
geographic |
Medina Pablo |
geographic_facet |
Medina Pablo |
genre |
Elephant Seal |
genre_facet |
Elephant Seal |
op_relation |
http://hdl.handle.net/10211.3/118183 |
_version_ |
1811637995988582400 |