French Polar Institute Literature Database
Home
|
Show All
|
Simple Search
|
Advanced Search
Login
Quick Search:
Field:
main fields
author
title
publication
keywords
abstract
programme
type
contains:
...
1–1 of 1 record found matching your query (
RSS
|
history
):
Search within Results:
Field:
author
title
year
keywords
abstract
programme
type
publication
abbrev_journal
volume
issue
pages
publisher
place
editor
series_title
language
area
notes
contains:
...
Exclude matches
Display Options:
Field:
all fields
keywords & abstract
additional fields
records per page
Select All
Deselect All
<<
1
>>
List View
|
Citations
|
Details
Record
Links
Author
Monternier Pierre-Axel, Marmillot Vincent, Rouanet Jean-Louis, Roussel Damien,
Title
Mitochondrial phenotypic flexibility enhances energy savings during winter fast in king penguin chicks
Type
Journal Article
Year
2014
Publication
The Journal of Experimental Biology
Abbreviated Journal
J. Exp. Biol.
Volume
217
Issue
15
Pages
2691 -2697
Keywords
Abstract
Energy conservation is a key priority for organisms that live in environments with seasonal shortages in resource supplies or that spontaneously fast during their annual cycle. The aim of this study was to determine whether the high fasting endurance of winter-acclimatized king penguin chicks (Aptenodytes patagonicus) is associated with an adjustment of mitochondrial bioenergetics in pectoralis muscle, the largest skeletal muscle in penguins. The rates of mitochondrial oxygen consumption, and ATP synthesis and mitochondrial efficiency (ATP/O ratio) were measured in winter-acclimatized chicks. We used pyruvate/malate and palmitoyl-l-carnitine/malate as respiratory substrates and results from naturally fasted chicks were compared to experimentally re-fed chicks. Bioenergetics analysis of pectoralis muscle revealed that mitochondria are on average 15% more energy efficient in naturally fasted than in experimentally fed chicks, indicating that fasted birds consume less nutrients to sustain their energy-demanding processes. We also found that moderate reductions in temperature from 38°C to 30°C further increase by 23% the energy coupling efficiency at the level of mitochondria, suggesting that king penguin chicks realize additional energy savings while becoming hypothermic during winter. It has been calculated that this adjustment of mitochondrial efficiency in skeletal muscle may contribute to nearly 25% of fasting-induced reduction in mass-specific metabolic rate measured in vivo. The present study shows that the regulation of mitochondrial efficiency triggers the development of an economical management of resources, which would maximize the conservation of endogenous fuel stores by decreasing the cost of living in fasted winter-acclimatized king penguin chicks.
Programme
131
Campaign
Address
Corporate Author
Thesis
Publisher
Place of Publication
Editor
Language
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
0022-0949
ISBN
Medium
Area
Expedition
Conference
Notes
Approved
yes
Call Number
Serial
5179
Permanent link to this record
Select All
Deselect All
<<
1
>>
List View
|
Citations
|
Details
Home
Show Record
|
Help