Hormonal regulation of glucose clearance in lactating northern elephant seals (Mirounga angustirostris)
Northern elephant seals exhibit the rare strategy of fasting and lactating concomitantly. We investigated hormonal regulation of glucose clearance in northern elephant seals using glucose tolerance tests (GTT) performed early in lactation and again just prior to weaning. For comparison, identical me...
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fthighwire:oai:open-archive.highwire.org:jexbio:211/18/2943 2023-05-15T16:05:35+02:00 Hormonal regulation of glucose clearance in lactating northern elephant seals (Mirounga angustirostris) Fowler, Melinda A. Champagne, Cory D. Houser, Dorian S. Crocker, Daniel E. 2008-09-15 00:00:00.0 text/html http://jeb.biologists.org/cgi/content/short/211/18/2943 https://doi.org/10.1242/jeb.018176 en eng Company of Biologists http://jeb.biologists.org/cgi/content/short/211/18/2943 http://dx.doi.org/10.1242/jeb.018176 Copyright (C) 2008, Company of Biologists Research Article TEXT 2008 fthighwire https://doi.org/10.1242/jeb.018176 2015-02-28T13:01:44Z Northern elephant seals exhibit the rare strategy of fasting and lactating concomitantly. We investigated hormonal regulation of glucose clearance in northern elephant seals using glucose tolerance tests (GTT) performed early in lactation and again just prior to weaning. For comparison, identical measurements were made on separate females late in the molt fast. Serial blood samples were used to assess glucose clearance and hormone responses for 3 h post glucose injection. Plasma glucose remained elevated at the end of the sampling period in all groups. Glucose clearance rates were not significantly different among test groups. A significant insulin response was observed in early lactation, no significant response was observed late in lactation and an intermediate response was observed late in the molt fast. The insulin response to a glucose load decreased with adipose tissue proportions. Plasma glucagon decreased significantly following GTT in early and late lactation, although the magnitude of the depression was small in comparison to other species. Hypoinsulemia may be critical to facilitate net lipolysis late in lactation. Consistently low glucose clearance among test groups suggests insulin insensitivity within peripheral tissues. Glucagon suppression independent of insulin release suggests modification of the typical insulin–glucagon counter-regulation. These findings suggest that metabolic features of diabetic-like conditions may be adaptive in the context of long-term fasting. Text Elephant Seals HighWire Press (Stanford University) Journal of Experimental Biology 211 18 2943 2949 |
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HighWire Press (Stanford University) |
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English |
topic |
Research Article |
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Research Article Fowler, Melinda A. Champagne, Cory D. Houser, Dorian S. Crocker, Daniel E. Hormonal regulation of glucose clearance in lactating northern elephant seals (Mirounga angustirostris) |
topic_facet |
Research Article |
description |
Northern elephant seals exhibit the rare strategy of fasting and lactating concomitantly. We investigated hormonal regulation of glucose clearance in northern elephant seals using glucose tolerance tests (GTT) performed early in lactation and again just prior to weaning. For comparison, identical measurements were made on separate females late in the molt fast. Serial blood samples were used to assess glucose clearance and hormone responses for 3 h post glucose injection. Plasma glucose remained elevated at the end of the sampling period in all groups. Glucose clearance rates were not significantly different among test groups. A significant insulin response was observed in early lactation, no significant response was observed late in lactation and an intermediate response was observed late in the molt fast. The insulin response to a glucose load decreased with adipose tissue proportions. Plasma glucagon decreased significantly following GTT in early and late lactation, although the magnitude of the depression was small in comparison to other species. Hypoinsulemia may be critical to facilitate net lipolysis late in lactation. Consistently low glucose clearance among test groups suggests insulin insensitivity within peripheral tissues. Glucagon suppression independent of insulin release suggests modification of the typical insulin–glucagon counter-regulation. These findings suggest that metabolic features of diabetic-like conditions may be adaptive in the context of long-term fasting. |
format |
Text |
author |
Fowler, Melinda A. Champagne, Cory D. Houser, Dorian S. Crocker, Daniel E. |
author_facet |
Fowler, Melinda A. Champagne, Cory D. Houser, Dorian S. Crocker, Daniel E. |
author_sort |
Fowler, Melinda A. |
title |
Hormonal regulation of glucose clearance in lactating northern elephant seals (Mirounga angustirostris) |
title_short |
Hormonal regulation of glucose clearance in lactating northern elephant seals (Mirounga angustirostris) |
title_full |
Hormonal regulation of glucose clearance in lactating northern elephant seals (Mirounga angustirostris) |
title_fullStr |
Hormonal regulation of glucose clearance in lactating northern elephant seals (Mirounga angustirostris) |
title_full_unstemmed |
Hormonal regulation of glucose clearance in lactating northern elephant seals (Mirounga angustirostris) |
title_sort |
hormonal regulation of glucose clearance in lactating northern elephant seals (mirounga angustirostris) |
publisher |
Company of Biologists |
publishDate |
2008 |
url |
http://jeb.biologists.org/cgi/content/short/211/18/2943 https://doi.org/10.1242/jeb.018176 |
genre |
Elephant Seals |
genre_facet |
Elephant Seals |
op_relation |
http://jeb.biologists.org/cgi/content/short/211/18/2943 http://dx.doi.org/10.1242/jeb.018176 |
op_rights |
Copyright (C) 2008, Company of Biologists |
op_doi |
https://doi.org/10.1242/jeb.018176 |
container_title |
Journal of Experimental Biology |
container_volume |
211 |
container_issue |
18 |
container_start_page |
2943 |
op_container_end_page |
2949 |
_version_ |
1766401490092556288 |