Oxidative and glycogenolytic cCapacities within the developing chick heart.

Details

Serval ID
serval:BIB_7214F4CFA3BB
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Oxidative and glycogenolytic cCapacities within the developing chick heart.
Journal
Pediatric research
Author(s)
Romano R., Rochat A.C., Kucera P., De Ribaupierre Y., Raddatz E.
ISSN
0031-3998 (Print)
ISSN-L
0031-3998
Publication state
Published
Issued date
03/2001
Peer-reviewed
Oui
Volume
49
Number
3
Pages
363-372
Language
english
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't
Publication Status: ppublish
Abstract
Cardiac morphogenesis and function are known to depend on both aerobic and anaerobic energy-producing pathways. However, the relative contribution of mitochondrial oxidation and glycogenolysis, as well as the determining factors of oxygen demand in the distinct chambers of the embryonic heart, remains to be investigated. Spontaneously beating hearts isolated from stage 11, 20, and 24HH chick embryos were maintained in vitro under controlled metabolic conditions. O(2) uptake and glycogenolytic rate were determined in atrium, ventricle, and conotruncus in the absence or presence of glucose. Oxidative capacity ranged from 0.2 to 0.5 nmol O(2)/(h.microg protein), did not depend on exogenous glucose, and was the highest in atria at stage 20HH. However, the highest reserves of oxidative capacity, assessed by mitochondrial uncoupling, were found at the youngest stage and in conotruncus, representing 75 to 130% of the control values. At stage 24HH, glycogenolysis in glucose-free medium was 0.22, 0.17, and 0.04 nmol glucose U(h.microg protein) in atrium, ventricle, and conotruncus, respectively. Mechanical loading of the ventricle increased its oxidative capacity by 62% without altering glycogenolysis or lactate production. Blockade of glycolysis by iodoacetate suppressed lactate production but modified neither O(2) nor glycogen consumption in substrate-free medium. These findings indicate that atrium is the cardiac chamber that best utilizes its oxidative and glycogenolytic capacities and that ventricular wall stretch represents an early and major determinant of the O(2) uptake. Moreover, the fact that O(2) and glycogen consumptions were not affected by inhibition of glyceraldehyde-3-phosphate dehydrogenase provides indirect evidence for an active glycerol-phosphate shuttle in the embryonic cardiomyocytes.
Keywords
Animals, Chick Embryo, Glycogen/metabolism, Heart/embryology, Morphogenesis, Myocardium/metabolism, Oxidation-Reduction
Pubmed
Web of science
Open Access
Yes
Create date
24/01/2008 13:19
Last modification date
11/09/2019 5:10
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