The demands of lactation promote differential regulation of lipid stores in fasting elephant seals
Fasting animals must ration stored reserves appropriately for metabolic demands. Animals that experience fasting concomitant with other metabolically demanding activities are presented with conflicting demands of energy conservation and expenditure. Our objective was to understand how fasting northe...
Published in: | General and Comparative Endocrinology |
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Language: | English |
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Online Access: | http://hdl.handle.net/2078.1/169107 https://doi.org/10.1016/j.ygcen.2015.09.024 |
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ftunivlouvain:oai:dial.uclouvain.be:boreal:169107 2024-05-19T07:39:43+00:00 The demands of lactation promote differential regulation of lipid stores in fasting elephant seals Fowler, Melinda A. Debier, Cathy Champagne, Cory D. Crocker, Daniel E. Costa, Daniel P. UCL - SST/ISV - Institut des sciences de la vie 2016 http://hdl.handle.net/2078.1/169107 https://doi.org/10.1016/j.ygcen.2015.09.024 eng eng Academic Press boreal:169107 http://hdl.handle.net/2078.1/169107 doi:10.1016/j.ygcen.2015.09.024 urn:ISSN:0016-6480 urn:EISSN:1095-6840 info:eu-repo/semantics/openAccess General and Comparative Endocrinology, Vol. 225, p. 125-132 (janvier 2016) info:eu-repo/semantics/article 2016 ftunivlouvain https://doi.org/10.1016/j.ygcen.2015.09.024 2024-04-24T01:26:47Z Fasting animals must ration stored reserves appropriately for metabolic demands. Animals that experience fasting concomitant with other metabolically demanding activities are presented with conflicting demands of energy conservation and expenditure. Our objective was to understand how fasting northern elephant seals regulate the mobilization of lipid reserves and subsequently milk lipid content during lactation. We sampled 36 females early and 39 at the end of lactation. To determine the separate influences of lactation from fasting, we also sampled fasting but non-lactating females early and late (8 and 6 seals, respectively) in their molting fasting period. Mass and adiposity were measured, as well as circulating non-esterified fatty acid (NEFA), triacylglycerol (TAG), cortisol, insulin and growth hormone levels. Milk was collected from lactating females. Milk lipid content increased from 31% in early to 51% in late lactation. In lactating females plasma NEFA was positively related to cortisol and negatively related to insulin, but in molting seals, only variation in cortisol was related to NEFA. Milk lipid content varied with mass, adiposity, NEFA, TAG, cortisol and insulin. Surprisingly, growth hormone concentration was not related to lipid metabolites or milk lipid. Suppression of insulin release appears to be the differential regulator of lipolysis in lactating versus molting seals, facilitating mobilization of stored lipids and maintenance of high NEFA concentrations for milk synthesis. Milk lipid was strongly impacted by the supply of substrate to the mammary gland, indicating regulation at the level of mobilization of lipid reserves Article in Journal/Newspaper Elephant Seals DIAL@UCLouvain (Université catholique de Louvain) General and Comparative Endocrinology 225 125 132 |
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DIAL@UCLouvain (Université catholique de Louvain) |
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ftunivlouvain |
language |
English |
description |
Fasting animals must ration stored reserves appropriately for metabolic demands. Animals that experience fasting concomitant with other metabolically demanding activities are presented with conflicting demands of energy conservation and expenditure. Our objective was to understand how fasting northern elephant seals regulate the mobilization of lipid reserves and subsequently milk lipid content during lactation. We sampled 36 females early and 39 at the end of lactation. To determine the separate influences of lactation from fasting, we also sampled fasting but non-lactating females early and late (8 and 6 seals, respectively) in their molting fasting period. Mass and adiposity were measured, as well as circulating non-esterified fatty acid (NEFA), triacylglycerol (TAG), cortisol, insulin and growth hormone levels. Milk was collected from lactating females. Milk lipid content increased from 31% in early to 51% in late lactation. In lactating females plasma NEFA was positively related to cortisol and negatively related to insulin, but in molting seals, only variation in cortisol was related to NEFA. Milk lipid content varied with mass, adiposity, NEFA, TAG, cortisol and insulin. Surprisingly, growth hormone concentration was not related to lipid metabolites or milk lipid. Suppression of insulin release appears to be the differential regulator of lipolysis in lactating versus molting seals, facilitating mobilization of stored lipids and maintenance of high NEFA concentrations for milk synthesis. Milk lipid was strongly impacted by the supply of substrate to the mammary gland, indicating regulation at the level of mobilization of lipid reserves |
author2 |
UCL - SST/ISV - Institut des sciences de la vie |
format |
Article in Journal/Newspaper |
author |
Fowler, Melinda A. Debier, Cathy Champagne, Cory D. Crocker, Daniel E. Costa, Daniel P. |
spellingShingle |
Fowler, Melinda A. Debier, Cathy Champagne, Cory D. Crocker, Daniel E. Costa, Daniel P. The demands of lactation promote differential regulation of lipid stores in fasting elephant seals |
author_facet |
Fowler, Melinda A. Debier, Cathy Champagne, Cory D. Crocker, Daniel E. Costa, Daniel P. |
author_sort |
Fowler, Melinda A. |
title |
The demands of lactation promote differential regulation of lipid stores in fasting elephant seals |
title_short |
The demands of lactation promote differential regulation of lipid stores in fasting elephant seals |
title_full |
The demands of lactation promote differential regulation of lipid stores in fasting elephant seals |
title_fullStr |
The demands of lactation promote differential regulation of lipid stores in fasting elephant seals |
title_full_unstemmed |
The demands of lactation promote differential regulation of lipid stores in fasting elephant seals |
title_sort |
demands of lactation promote differential regulation of lipid stores in fasting elephant seals |
publisher |
Academic Press |
publishDate |
2016 |
url |
http://hdl.handle.net/2078.1/169107 https://doi.org/10.1016/j.ygcen.2015.09.024 |
genre |
Elephant Seals |
genre_facet |
Elephant Seals |
op_source |
General and Comparative Endocrinology, Vol. 225, p. 125-132 (janvier 2016) |
op_relation |
boreal:169107 http://hdl.handle.net/2078.1/169107 doi:10.1016/j.ygcen.2015.09.024 urn:ISSN:0016-6480 urn:EISSN:1095-6840 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1016/j.ygcen.2015.09.024 |
container_title |
General and Comparative Endocrinology |
container_volume |
225 |
container_start_page |
125 |
op_container_end_page |
132 |
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1799479306104078336 |