Hormonal responses to extreme fasting in subantarctic fur seal (Arctocephalus tropicalis) pups
Surviving prolonged fasting implies closely regulated alterations in fuel provisioning to meet metabolic requirements, while preserving homeostasis. Little is known, however, of the endocrine regulations governing such metabolic adaptations in naturally fasting free-ranging animals. The hormonal res...
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ftdeakinunifig:oai:figshare.com:article/20974729 2023-05-15T13:22:34+02:00 Hormonal responses to extreme fasting in subantarctic fur seal (Arctocephalus tropicalis) pups D Verrier S Atkinson C Guinet R Groscolas John Arnould 2012-04-15T00:00:00Z http://hdl.handle.net/10536/DRO/DU:30049635 https://figshare.com/articles/journal_contribution/Hormonal_responses_to_extreme_fasting_in_subantarctic_fur_seal_Arctocephalus_tropicalis_pups/20974729 unknown http://hdl.handle.net/10536/DRO/DU:30049635 https://figshare.com/articles/journal_contribution/Hormonal_responses_to_extreme_fasting_in_subantarctic_fur_seal_Arctocephalus_tropicalis_pups/20974729 All Rights Reserved Uncategorized starvation leptin cortisol thyroid hormones insulin Science & Technology Life Sciences & Biomedicine Physiology NORTHERN ELEPHANT SEAL LIONS EUMETOPIAS-JUBATUS THYROID-HORMONE AMSTERDAM ISLAND PLASMA-CORTISOL MIROUNGA-ANGUSTIROSTRIS HEPATIC GLUCONEOGENESIS MILK CONSUMPTION LEPTIN LEVELS SERUM LEPTIN Text Journal contribution 2012 ftdeakinunifig 2022-11-17T22:02:36Z Surviving prolonged fasting implies closely regulated alterations in fuel provisioning to meet metabolic requirements, while preserving homeostasis. Little is known, however, of the endocrine regulations governing such metabolic adaptations in naturally fasting free-ranging animals. The hormonal responses to natural prolonged fasting and how they correlate to the metabolic adaptations observed, were investigated in subantarctic fur seal (Arctocephalus tropicalis) pups, which, because of the intermittent pattern of maternal attendance, repeatedly endure exceptionally long fasting episodes throughout their development (1–3 mo). Phase I fasting was characterized by a dramatic decrease in plasma insulin, glucagon, leptin, and total L-thyroxine (T4) associated with reductions in mass-specific resting metabolic rate (RMR), plasma triglycerides, glycerol, and urea-to-creatine ratio, while nonesterified fatty acids (NEFA) and β-OHB increased. In contrast, the metabolic steady-state of phase II fasting reached within 6 days was associated with minimal concentrations of insulin, glucagon, and leptin; unchanged cortisol and triiodothyronine (T3); and moderately increased T4. The early fall in insulin and leptin may mediate the shift to the strategy of energy conservation, protein sparing, and primary reliance on body lipids observed in response to the cessation of feeding. In contrast to the typical mammalian starvation response, nonelevated cortisol and minimal glucagon levels may contribute to body protein preservation and downregulation of catabolic pathways, in general. Furthermore, thyroid hormones may be involved in a process of energy conservation, independent of pups' nutritional state. These original hormonal settings might reflect an adaptation to the otariid repeated fasting pattern and emphasize the crucial importance of a tight physiological control over metabolism to survive extreme energetic constraints. Other Non-Article Part of Journal/Newspaper Amsterdam Island Elephant Seal DRO - Deakin Research Online |
institution |
Open Polar |
collection |
DRO - Deakin Research Online |
op_collection_id |
ftdeakinunifig |
language |
unknown |
topic |
Uncategorized starvation leptin cortisol thyroid hormones insulin Science & Technology Life Sciences & Biomedicine Physiology NORTHERN ELEPHANT SEAL LIONS EUMETOPIAS-JUBATUS THYROID-HORMONE AMSTERDAM ISLAND PLASMA-CORTISOL MIROUNGA-ANGUSTIROSTRIS HEPATIC GLUCONEOGENESIS MILK CONSUMPTION LEPTIN LEVELS SERUM LEPTIN |
spellingShingle |
Uncategorized starvation leptin cortisol thyroid hormones insulin Science & Technology Life Sciences & Biomedicine Physiology NORTHERN ELEPHANT SEAL LIONS EUMETOPIAS-JUBATUS THYROID-HORMONE AMSTERDAM ISLAND PLASMA-CORTISOL MIROUNGA-ANGUSTIROSTRIS HEPATIC GLUCONEOGENESIS MILK CONSUMPTION LEPTIN LEVELS SERUM LEPTIN D Verrier S Atkinson C Guinet R Groscolas John Arnould Hormonal responses to extreme fasting in subantarctic fur seal (Arctocephalus tropicalis) pups |
topic_facet |
Uncategorized starvation leptin cortisol thyroid hormones insulin Science & Technology Life Sciences & Biomedicine Physiology NORTHERN ELEPHANT SEAL LIONS EUMETOPIAS-JUBATUS THYROID-HORMONE AMSTERDAM ISLAND PLASMA-CORTISOL MIROUNGA-ANGUSTIROSTRIS HEPATIC GLUCONEOGENESIS MILK CONSUMPTION LEPTIN LEVELS SERUM LEPTIN |
description |
Surviving prolonged fasting implies closely regulated alterations in fuel provisioning to meet metabolic requirements, while preserving homeostasis. Little is known, however, of the endocrine regulations governing such metabolic adaptations in naturally fasting free-ranging animals. The hormonal responses to natural prolonged fasting and how they correlate to the metabolic adaptations observed, were investigated in subantarctic fur seal (Arctocephalus tropicalis) pups, which, because of the intermittent pattern of maternal attendance, repeatedly endure exceptionally long fasting episodes throughout their development (1–3 mo). Phase I fasting was characterized by a dramatic decrease in plasma insulin, glucagon, leptin, and total L-thyroxine (T4) associated with reductions in mass-specific resting metabolic rate (RMR), plasma triglycerides, glycerol, and urea-to-creatine ratio, while nonesterified fatty acids (NEFA) and β-OHB increased. In contrast, the metabolic steady-state of phase II fasting reached within 6 days was associated with minimal concentrations of insulin, glucagon, and leptin; unchanged cortisol and triiodothyronine (T3); and moderately increased T4. The early fall in insulin and leptin may mediate the shift to the strategy of energy conservation, protein sparing, and primary reliance on body lipids observed in response to the cessation of feeding. In contrast to the typical mammalian starvation response, nonelevated cortisol and minimal glucagon levels may contribute to body protein preservation and downregulation of catabolic pathways, in general. Furthermore, thyroid hormones may be involved in a process of energy conservation, independent of pups' nutritional state. These original hormonal settings might reflect an adaptation to the otariid repeated fasting pattern and emphasize the crucial importance of a tight physiological control over metabolism to survive extreme energetic constraints. |
format |
Other Non-Article Part of Journal/Newspaper |
author |
D Verrier S Atkinson C Guinet R Groscolas John Arnould |
author_facet |
D Verrier S Atkinson C Guinet R Groscolas John Arnould |
author_sort |
D Verrier |
title |
Hormonal responses to extreme fasting in subantarctic fur seal (Arctocephalus tropicalis) pups |
title_short |
Hormonal responses to extreme fasting in subantarctic fur seal (Arctocephalus tropicalis) pups |
title_full |
Hormonal responses to extreme fasting in subantarctic fur seal (Arctocephalus tropicalis) pups |
title_fullStr |
Hormonal responses to extreme fasting in subantarctic fur seal (Arctocephalus tropicalis) pups |
title_full_unstemmed |
Hormonal responses to extreme fasting in subantarctic fur seal (Arctocephalus tropicalis) pups |
title_sort |
hormonal responses to extreme fasting in subantarctic fur seal (arctocephalus tropicalis) pups |
publishDate |
2012 |
url |
http://hdl.handle.net/10536/DRO/DU:30049635 https://figshare.com/articles/journal_contribution/Hormonal_responses_to_extreme_fasting_in_subantarctic_fur_seal_Arctocephalus_tropicalis_pups/20974729 |
genre |
Amsterdam Island Elephant Seal |
genre_facet |
Amsterdam Island Elephant Seal |
op_relation |
http://hdl.handle.net/10536/DRO/DU:30049635 https://figshare.com/articles/journal_contribution/Hormonal_responses_to_extreme_fasting_in_subantarctic_fur_seal_Arctocephalus_tropicalis_pups/20974729 |
op_rights |
All Rights Reserved |
_version_ |
1766365522370232320 |