Blood oxygen depletion during rest-associated apneas of northern elephant seals (Mirounga angustirostris)
Blood gases ( P O 2, P CO 2, pH), oxygen content, hematocrit and hemoglobin concentration were measured during rest-associated apneas of nine juvenile northern elephant seals. In conjunction with blood volume determinations, these data were used to determine total blood oxygen stores, the rate and m...
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fthighwire:oai:open-archive.highwire.org:jexbio:210/15/2607 2023-05-15T16:05:41+02:00 Blood oxygen depletion during rest-associated apneas of northern elephant seals (Mirounga angustirostris) Stockard, T. K. Levenson, D. H. Berg, L. Fransioli, J. R. Baranov, E. A. Ponganis, P. J. 2007-08-01 00:00:00.0 text/html http://jeb.biologists.org/cgi/content/short/210/15/2607 https://doi.org/10.1242/jeb.008078 en eng Company of Biologists http://jeb.biologists.org/cgi/content/short/210/15/2607 http://dx.doi.org/10.1242/jeb.008078 Copyright (C) 2007, Company of Biologists Research Article TEXT 2007 fthighwire https://doi.org/10.1242/jeb.008078 2015-02-28T18:21:20Z Blood gases ( P O 2, P CO 2, pH), oxygen content, hematocrit and hemoglobin concentration were measured during rest-associated apneas of nine juvenile northern elephant seals. In conjunction with blood volume determinations, these data were used to determine total blood oxygen stores, the rate and magnitude of blood O 2 depletion, the contribution of the blood O 2 store to apneic metabolic rate, and the degree of hypoxemia that occurs during these breath-holds. Mean body mass was 66±9.7 kg (± s.d.); blood volume was 196±20 ml kg–1; and hemoglobin concentration was 23.5±1.5 g dl–1. Rest apneas ranged in duration from 3.1 to 10.9 min. Arterial P O 2 declined exponentially during apnea, ranging between a maximum of 108 mmHg and a minimum of 18 mmHg after a 9.1 min breath-hold. Venous P O 2 values were indistinguishable from arterial values after the first minute of apnea; the lowest venous P O 2 recorded was 15 mmHg after a 7.8 min apnea. O 2 contents were also similar between the arterial and venous systems, declining linearly at rates of 2.3 and 2.0 ml O 2 dl–1 min–1, respectively, from mean initial values of 27.2 and 26.0 ml O 2 dl–1. These blood O 2 depletion rates are approximately twice the reported values during forced submersion and are consistent with maintenance of previously measured high cardiac outputs during rest-associated breath-holds. During a typical 7-min apnea, seals consumed, on average, 56% of the initial blood O 2 store of 52 ml O 2 kg–1; this contributed 4.2 ml O 2 kg–1 min–1 to total body metabolic rate during the breath-hold. Extreme hypoxemic tolerance in these seals was demonstrated by arterial P O 2 values during late apnea that were less than human thresholds for shallow-water blackout. Despite such low P O 2s, there was no evidence of significant anaerobic metabolism, as changes in blood pH were minimal and attributable to increased P CO 2. These findings and the previously reported lack of lactate accumulation during these breath-holds are consistent with the maintenance of aerobic ... Text Elephant Seals HighWire Press (Stanford University) Journal of Experimental Biology 210 15 2607 2617 |
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Research Article Stockard, T. K. Levenson, D. H. Berg, L. Fransioli, J. R. Baranov, E. A. Ponganis, P. J. Blood oxygen depletion during rest-associated apneas of northern elephant seals (Mirounga angustirostris) |
topic_facet |
Research Article |
description |
Blood gases ( P O 2, P CO 2, pH), oxygen content, hematocrit and hemoglobin concentration were measured during rest-associated apneas of nine juvenile northern elephant seals. In conjunction with blood volume determinations, these data were used to determine total blood oxygen stores, the rate and magnitude of blood O 2 depletion, the contribution of the blood O 2 store to apneic metabolic rate, and the degree of hypoxemia that occurs during these breath-holds. Mean body mass was 66±9.7 kg (± s.d.); blood volume was 196±20 ml kg–1; and hemoglobin concentration was 23.5±1.5 g dl–1. Rest apneas ranged in duration from 3.1 to 10.9 min. Arterial P O 2 declined exponentially during apnea, ranging between a maximum of 108 mmHg and a minimum of 18 mmHg after a 9.1 min breath-hold. Venous P O 2 values were indistinguishable from arterial values after the first minute of apnea; the lowest venous P O 2 recorded was 15 mmHg after a 7.8 min apnea. O 2 contents were also similar between the arterial and venous systems, declining linearly at rates of 2.3 and 2.0 ml O 2 dl–1 min–1, respectively, from mean initial values of 27.2 and 26.0 ml O 2 dl–1. These blood O 2 depletion rates are approximately twice the reported values during forced submersion and are consistent with maintenance of previously measured high cardiac outputs during rest-associated breath-holds. During a typical 7-min apnea, seals consumed, on average, 56% of the initial blood O 2 store of 52 ml O 2 kg–1; this contributed 4.2 ml O 2 kg–1 min–1 to total body metabolic rate during the breath-hold. Extreme hypoxemic tolerance in these seals was demonstrated by arterial P O 2 values during late apnea that were less than human thresholds for shallow-water blackout. Despite such low P O 2s, there was no evidence of significant anaerobic metabolism, as changes in blood pH were minimal and attributable to increased P CO 2. These findings and the previously reported lack of lactate accumulation during these breath-holds are consistent with the maintenance of aerobic ... |
format |
Text |
author |
Stockard, T. K. Levenson, D. H. Berg, L. Fransioli, J. R. Baranov, E. A. Ponganis, P. J. |
author_facet |
Stockard, T. K. Levenson, D. H. Berg, L. Fransioli, J. R. Baranov, E. A. Ponganis, P. J. |
author_sort |
Stockard, T. K. |
title |
Blood oxygen depletion during rest-associated apneas of northern elephant seals (Mirounga angustirostris) |
title_short |
Blood oxygen depletion during rest-associated apneas of northern elephant seals (Mirounga angustirostris) |
title_full |
Blood oxygen depletion during rest-associated apneas of northern elephant seals (Mirounga angustirostris) |
title_fullStr |
Blood oxygen depletion during rest-associated apneas of northern elephant seals (Mirounga angustirostris) |
title_full_unstemmed |
Blood oxygen depletion during rest-associated apneas of northern elephant seals (Mirounga angustirostris) |
title_sort |
blood oxygen depletion during rest-associated apneas of northern elephant seals (mirounga angustirostris) |
publisher |
Company of Biologists |
publishDate |
2007 |
url |
http://jeb.biologists.org/cgi/content/short/210/15/2607 https://doi.org/10.1242/jeb.008078 |
genre |
Elephant Seals |
genre_facet |
Elephant Seals |
op_relation |
http://jeb.biologists.org/cgi/content/short/210/15/2607 http://dx.doi.org/10.1242/jeb.008078 |
op_rights |
Copyright (C) 2007, Company of Biologists |
op_doi |
https://doi.org/10.1242/jeb.008078 |
container_title |
Journal of Experimental Biology |
container_volume |
210 |
container_issue |
15 |
container_start_page |
2607 |
op_container_end_page |
2617 |
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1766401593628950528 |