Prolonged fasting suppresses cellular insulin‐dependent activity in adipose tissue of the northern elephant seal
Throughout its life, the northern elephant seal ( Mirounga angustirostris ) experiences periods of prolonged fasting during which plasma glucose reaches hyperglycemic levels. As the fast progresses, the levels of circulating glucose decrease, despite relatively low or decreasing plasma insulin level...
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crwiley:10.1096/fasebj.24.1_supplement.1055.11 2024-06-02T08:06:00+00:00 Prolonged fasting suppresses cellular insulin‐dependent activity in adipose tissue of the northern elephant seal Viscarra, Jose Abraham Vazquez‐Medina, Jose Pablo Minas, Jacqueline Crocker, Daniel E. Ortiz, Rudy M. National Institutes of Health 2010 http://dx.doi.org/10.1096/fasebj.24.1_supplement.1055.11 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor The FASEB Journal volume 24, issue S1 ISSN 0892-6638 1530-6860 journal-article 2010 crwiley https://doi.org/10.1096/fasebj.24.1_supplement.1055.11 2024-05-03T10:55:50Z Throughout its life, the northern elephant seal ( Mirounga angustirostris ) experiences periods of prolonged fasting during which plasma glucose reaches hyperglycemic levels. As the fast progresses, the levels of circulating glucose decrease, despite relatively low or decreasing plasma insulin levels. Cellular glucose uptake is dependent on an insulin‐activated signaling cascade resulting in the translocation of the glucose transport protein, Glut4, into the plasma membrane. In order to understand how this pathway is affected by prolonged fasting PI3K, AKT and VAMP2 content, and plasma insulin were examined. Blubber biopsies as well as plasma samples were obtained from two groups of northern elephant seal pups (n = 10/group) sampled during their post weaning fast: early (2 weeks) and late (6 to 8 weeks). Tissue content of PI3K, AKT, and VAMP2 proteins was quantified by western blot. Plasma insulin did not change (1.5 ± 0.4 vs. 1.2 ± 0.2 uU/mL) between early and late fasting. While PI3K and VAMP2 also did not change, AKT decreased 29% with the fast. We have previously shown that fasting is associated with a decrease in insulin receptor (IR), but an increase in Glut 4. Because insulin stimulates PI3K and AKT, the decreases in insulin and IR may explain the lack of change in PI3K and the decrease in AKT suggesting that fasting suppresses cellular insulin‐dependent activity. Funded by NIH HL91767 and UC Startup funds. Article in Journal/Newspaper Elephant Seal Wiley Online Library The FASEB Journal 24 S1 |
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Wiley Online Library |
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English |
description |
Throughout its life, the northern elephant seal ( Mirounga angustirostris ) experiences periods of prolonged fasting during which plasma glucose reaches hyperglycemic levels. As the fast progresses, the levels of circulating glucose decrease, despite relatively low or decreasing plasma insulin levels. Cellular glucose uptake is dependent on an insulin‐activated signaling cascade resulting in the translocation of the glucose transport protein, Glut4, into the plasma membrane. In order to understand how this pathway is affected by prolonged fasting PI3K, AKT and VAMP2 content, and plasma insulin were examined. Blubber biopsies as well as plasma samples were obtained from two groups of northern elephant seal pups (n = 10/group) sampled during their post weaning fast: early (2 weeks) and late (6 to 8 weeks). Tissue content of PI3K, AKT, and VAMP2 proteins was quantified by western blot. Plasma insulin did not change (1.5 ± 0.4 vs. 1.2 ± 0.2 uU/mL) between early and late fasting. While PI3K and VAMP2 also did not change, AKT decreased 29% with the fast. We have previously shown that fasting is associated with a decrease in insulin receptor (IR), but an increase in Glut 4. Because insulin stimulates PI3K and AKT, the decreases in insulin and IR may explain the lack of change in PI3K and the decrease in AKT suggesting that fasting suppresses cellular insulin‐dependent activity. Funded by NIH HL91767 and UC Startup funds. |
author2 |
National Institutes of Health |
format |
Article in Journal/Newspaper |
author |
Viscarra, Jose Abraham Vazquez‐Medina, Jose Pablo Minas, Jacqueline Crocker, Daniel E. Ortiz, Rudy M. |
spellingShingle |
Viscarra, Jose Abraham Vazquez‐Medina, Jose Pablo Minas, Jacqueline Crocker, Daniel E. Ortiz, Rudy M. Prolonged fasting suppresses cellular insulin‐dependent activity in adipose tissue of the northern elephant seal |
author_facet |
Viscarra, Jose Abraham Vazquez‐Medina, Jose Pablo Minas, Jacqueline Crocker, Daniel E. Ortiz, Rudy M. |
author_sort |
Viscarra, Jose Abraham |
title |
Prolonged fasting suppresses cellular insulin‐dependent activity in adipose tissue of the northern elephant seal |
title_short |
Prolonged fasting suppresses cellular insulin‐dependent activity in adipose tissue of the northern elephant seal |
title_full |
Prolonged fasting suppresses cellular insulin‐dependent activity in adipose tissue of the northern elephant seal |
title_fullStr |
Prolonged fasting suppresses cellular insulin‐dependent activity in adipose tissue of the northern elephant seal |
title_full_unstemmed |
Prolonged fasting suppresses cellular insulin‐dependent activity in adipose tissue of the northern elephant seal |
title_sort |
prolonged fasting suppresses cellular insulin‐dependent activity in adipose tissue of the northern elephant seal |
publisher |
Wiley |
publishDate |
2010 |
url |
http://dx.doi.org/10.1096/fasebj.24.1_supplement.1055.11 |
genre |
Elephant Seal |
genre_facet |
Elephant Seal |
op_source |
The FASEB Journal volume 24, issue S1 ISSN 0892-6638 1530-6860 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1096/fasebj.24.1_supplement.1055.11 |
container_title |
The FASEB Journal |
container_volume |
24 |
container_issue |
S1 |
_version_ |
1800750878080106496 |