A hypoxic episode during cardiogenesis downregulates the adenosinergic system and alters the myocardial anoxic tolerance.

Details

Serval ID
serval:BIB_CFC7D3FCB690
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
A hypoxic episode during cardiogenesis downregulates the adenosinergic system and alters the myocardial anoxic tolerance.
Journal
American Journal of Physiology. Regulatory, Integrative and Comparative Physiology
Author(s)
Robin E., Marcillac F., Raddatz E.
ISSN
1522-1490 (Electronic)
ISSN-L
0363-6119
Publication state
Published
Issued date
2015
Peer-reviewed
Oui
Volume
308
Number
7
Pages
R614-R626
Language
english
Notes
Publication types: Journal Article Publication Status: ppublish
Abstract
To what extent hypoxia alters the adenosine (ADO) system and impacts on cardiac function during embryogenesis is not known. Ectonucleoside triphosphate diphosphohydrolase (CD39), ecto-5'-nucleotidase (CD73), adenosine kinase (AdK), adenosine deaminase (ADA), equilibrative (ENT1,3,4), and concentrative (CNT3) transporters and ADO receptors A1, A2A, A2B, and A3 constitute the adenosinergic system. During the first 4 days of development chick embryos were exposed in ovo to normoxia followed or not followed by 6 h hypoxia. ADO and glycogen content and mRNA expression of the genes were determined in the atria, ventricle, and outflow tract of the normoxic (N) and hypoxic (H) hearts. Electrocardiogram and ventricular shortening of the N and H hearts were recorded ex vivo throughout anoxia/reoxygenation ± ADO. Under basal conditions, CD39, CD73, ADK, ADA, ENT1,3,4, CNT3, and ADO receptors were differentially expressed in the atria, ventricle, and outflow tract. In H hearts ADO level doubled, glycogen decreased, and mRNA expression of all the investigated genes was downregulated by hypoxia, except for A2A and A3 receptors. The most rapid and marked downregulation was found for ADA in atria. H hearts were arrhythmic and more vulnerable to anoxia-reoxygenation than N hearts. Despite downregulation of the genes, exposure of isolated hearts to ADO 1) preserved glycogen through activation of A1 receptor and Akt-GSK3β-GS pathway, 2) prolonged activity and improved conduction under anoxia, and 3) restored QT interval in H hearts. Thus hypoxia-induced downregulation of the adenosinergic system can be regarded as a coping response, limiting the detrimental accumulation of ADO without interfering with ADO signaling.
Pubmed
Web of science
Create date
11/05/2015 13:43
Last modification date
20/08/2019 16:50
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