Fasting metabolism in Antarctic fur seal (Arctocephalus gazella) pups
The metabolism of 52–73-day old Antarcticfursealpups from Bird Island, South Georgia, was investigated during fasting periods of normal duration while their mothers were at sea foraging. Body mass decreased exponentially with pups losing 3.5–3.8% of body mass per day. Resting metabolic rate also dec...
Published in: | Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology |
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2001
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ftnerc:oai:nora.nerc.ac.uk:18354 2023-05-15T13:45:12+02:00 Fasting metabolism in Antarctic fur seal (Arctocephalus gazella) pups Arnould, J.P.Y. Green, J.A. Rawlins, D.R. 2001 http://nora.nerc.ac.uk/id/eprint/18354/ http://www.sciencedirect.com/science/article/pii/S1095643301003397 unknown Elsevier Arnould, J.P.Y.; Green, J.A.; Rawlins, D.R. 2001 Fasting metabolism in Antarctic fur seal (Arctocephalus gazella) pups. Comparative Biochemistry and Physiology, 129A (4). 829-841. https://doi.org/10.1016/S1095-6433(01)00339-7 <https://doi.org/10.1016/S1095-6433(01)00339-7> Publication - Article PeerReviewed 2001 ftnerc https://doi.org/10.1016/S1095-6433(01)00339-7 2023-02-04T19:31:42Z The metabolism of 52–73-day old Antarcticfursealpups from Bird Island, South Georgia, was investigated during fasting periods of normal duration while their mothers were at sea foraging. Body mass decreased exponentially with pups losing 3.5–3.8% of body mass per day. Resting metabolic rate also decreased exponentially from 172–197 ml (O2)·min−1 at the beginning of the fast and scaled to Mb0.74 at 2.3 times the level predicted for adult terrestrial mammals of similar size. While there was no significant sex difference in RMR, female pups had significantly higher (F1,18=6.614, P<0.019) mass-specific RMR than male pups throughout the fasting period. Fasting FMR was also significantly (t15=2.37, P<0.035) greater in females (823 kJ·kg−1·d−1) than males (686 kJ·kg−1·d−1). Average protein turnover during the study period was 19.3 g·d−1 and contributed to 5.4% of total energy expenditure, indicating the adoption of a protein-sparing strategy with a reliance on primarily lipid catabolism for metabolic energy. This is supported by observed decreases in plasma BUN, U/C, glucose and triglyceride concentrations, and an increase in β-HBA concentration, indicating that Antarcticfursealspups adopt this strategy within 2–3 days of fasting. Mean RQ also decreased from 0.77 to 0.72 within 3 days of fasting, further supporting a rapid commencement of protein-sparing. However, RQ gradually increased thereafter to 0.77, suggesting a resumption of protein catabolism which was not substantiated by changes in plasma metabolites. Female pups had higher TBL (%) than males for any given mass, which is consistent with previous findings in this and other furseal species, and suggests sex differences in metabolic fuel use. The observed changes in plasma metabolites and protein turnover, however, do not support this. Article in Journal/Newspaper Antarc* Antarctic Antarctic Fur Seal Arctocephalus gazella Bird Island Natural Environment Research Council: NERC Open Research Archive Antarctic Bird Island ENVELOPE(-38.060,-38.060,-54.004,-54.004) Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology 129 4 829 841 |
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Open Polar |
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Natural Environment Research Council: NERC Open Research Archive |
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ftnerc |
language |
unknown |
description |
The metabolism of 52–73-day old Antarcticfursealpups from Bird Island, South Georgia, was investigated during fasting periods of normal duration while their mothers were at sea foraging. Body mass decreased exponentially with pups losing 3.5–3.8% of body mass per day. Resting metabolic rate also decreased exponentially from 172–197 ml (O2)·min−1 at the beginning of the fast and scaled to Mb0.74 at 2.3 times the level predicted for adult terrestrial mammals of similar size. While there was no significant sex difference in RMR, female pups had significantly higher (F1,18=6.614, P<0.019) mass-specific RMR than male pups throughout the fasting period. Fasting FMR was also significantly (t15=2.37, P<0.035) greater in females (823 kJ·kg−1·d−1) than males (686 kJ·kg−1·d−1). Average protein turnover during the study period was 19.3 g·d−1 and contributed to 5.4% of total energy expenditure, indicating the adoption of a protein-sparing strategy with a reliance on primarily lipid catabolism for metabolic energy. This is supported by observed decreases in plasma BUN, U/C, glucose and triglyceride concentrations, and an increase in β-HBA concentration, indicating that Antarcticfursealspups adopt this strategy within 2–3 days of fasting. Mean RQ also decreased from 0.77 to 0.72 within 3 days of fasting, further supporting a rapid commencement of protein-sparing. However, RQ gradually increased thereafter to 0.77, suggesting a resumption of protein catabolism which was not substantiated by changes in plasma metabolites. Female pups had higher TBL (%) than males for any given mass, which is consistent with previous findings in this and other furseal species, and suggests sex differences in metabolic fuel use. The observed changes in plasma metabolites and protein turnover, however, do not support this. |
format |
Article in Journal/Newspaper |
author |
Arnould, J.P.Y. Green, J.A. Rawlins, D.R. |
spellingShingle |
Arnould, J.P.Y. Green, J.A. Rawlins, D.R. Fasting metabolism in Antarctic fur seal (Arctocephalus gazella) pups |
author_facet |
Arnould, J.P.Y. Green, J.A. Rawlins, D.R. |
author_sort |
Arnould, J.P.Y. |
title |
Fasting metabolism in Antarctic fur seal (Arctocephalus gazella) pups |
title_short |
Fasting metabolism in Antarctic fur seal (Arctocephalus gazella) pups |
title_full |
Fasting metabolism in Antarctic fur seal (Arctocephalus gazella) pups |
title_fullStr |
Fasting metabolism in Antarctic fur seal (Arctocephalus gazella) pups |
title_full_unstemmed |
Fasting metabolism in Antarctic fur seal (Arctocephalus gazella) pups |
title_sort |
fasting metabolism in antarctic fur seal (arctocephalus gazella) pups |
publisher |
Elsevier |
publishDate |
2001 |
url |
http://nora.nerc.ac.uk/id/eprint/18354/ http://www.sciencedirect.com/science/article/pii/S1095643301003397 |
long_lat |
ENVELOPE(-38.060,-38.060,-54.004,-54.004) |
geographic |
Antarctic Bird Island |
geographic_facet |
Antarctic Bird Island |
genre |
Antarc* Antarctic Antarctic Fur Seal Arctocephalus gazella Bird Island |
genre_facet |
Antarc* Antarctic Antarctic Fur Seal Arctocephalus gazella Bird Island |
op_relation |
Arnould, J.P.Y.; Green, J.A.; Rawlins, D.R. 2001 Fasting metabolism in Antarctic fur seal (Arctocephalus gazella) pups. Comparative Biochemistry and Physiology, 129A (4). 829-841. https://doi.org/10.1016/S1095-6433(01)00339-7 <https://doi.org/10.1016/S1095-6433(01)00339-7> |
op_doi |
https://doi.org/10.1016/S1095-6433(01)00339-7 |
container_title |
Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology |
container_volume |
129 |
container_issue |
4 |
container_start_page |
829 |
op_container_end_page |
841 |
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1766216660123910144 |