Using blubber explants to investigate adipose function in grey seals : glycolytic, lipolytic and gene expression responses to glucose and hydrocortisone
Abstract
Adipose tissue is fundamental to energy balance, which underpins fitness and survival. Knowledge of adipose regulation in animals that undergo rapid fat deposition and mobilisation aids understanding of their energetic responses to rapid environmental change. Tissue explants can be used to investigate adipose regulation in wildlife species with large fat reserves, when opportunities for organismal experimental work are limited. We investigated glucose removal, lactate, glycerol and NEFA accumulation in media, and metabolic gene expression in blubber explants from wild grey seals. Glycolysis was higher in explants incubated in 25 mM glucose (HG) for 24 h compared to controls (C: 5.5 mM glucose). Adipose-derived lactate likely contributes to high endogenous glucose production in seals. Lipolysis was not stimulated by HG or high hydrocortisone (HC: 500 nM hydrocortisone) and was lower in heavier animals. HC caused NEFA accumulation in media to decrease by ~30% relative to C in females, indicative of increased lipogenesis. Lipolysis was higher in males than females in C and HG conditions. Lower relative abundance of 11-β-hydroxysteroid dehydrogenase 1 mRNA in HG explants suggests glucose involvement in blubber cortisol sensitivity. Our findings can help predict energy balance responses to stress and nutritional state in seals, and highlight the use of explants to study fat tissue function in wildlife.
Citation
Bennett , K A , Robinson , K J , Moss , S E W , Millward , S & Hall , A J 2017 , ' Using blubber explants to investigate adipose function in grey seals : glycolytic, lipolytic and gene expression responses to glucose and hydrocortisone ' , Scientific Reports , vol. 7 , 7731 . https://doi.org/10.1038/s41598-017-06037-x
Publication
Scientific Reports
Status
Peer reviewed
ISSN
2045-2322Type
Journal article
Rights
© The Author(s) 2017. Open Access. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
Description
This work was funded by an early career grant to KAB from the Royal Society and Natural Environment Research Council National Capability funding to AJH (grant number SMRU/1001).Collections
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