Response of embryonic heart to hypoxia and reoxygenation: an in vitro model

Détails

ID Serval
serval:BIB_44450E6E13F3
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Response of embryonic heart to hypoxia and reoxygenation: an in vitro model
Périodique
Experimental and Clinical Cardiology
Auteur(s)
Raddatz  E., de Ribaupierre  Y., Kucera  P.
ISSN
1205-6626 (Print)
ISSN-L
1918-1515 (Electronic)
Statut éditorial
Publié
Date de publication
1998
Volume
2
Numéro
2
Pages
128-134
Langue
anglais
Résumé
OBJECTIVES: To define properly the consequences of oxygen deprivation and readmission for the functioning of the developing heart.
METHODS: Spontaneously beating hearts excised from three-day-old chick embryos were loaded with a drop of viscous nontoxic silicone oil and cultured in a special chamber in which variations of PO2 at the tissue level could be strictly controlled. All parts of the hearts were simultaneously submitted to identical changes in PO2. Instantaneous heart rate, myocardial shortening, velocities of contraction and relaxation, and mechanical propagation along the heart tube were determined photometrically.
RESULTS: The hearts, submitted to a PO2 ramp (0 to 9.3 kPa) or absolute anoxia, reacted rapidly, reversibly and reproducibly. Under sustained anoxia, ventricular activity stopped after 3.8±0.7 mins (n=4) and then resumed intermittently in the form of tachycardic bursts. Brief anoxia (1 min) provoked tachycardia followed by bradycardia, induced contracture, depressed contractility and retarded atrioventricular propagation. Upon reoxygenation, ventricular contractions ceased suddently for 20±11 s (n=5), whereas a residual atrial activity could persist. The duration of this arrest and the rate of recovery depended on duration of the preceding anoxia. Such a dysfunction constitutes the embryonic analogue of the oxygen paradox observed in adult hearts. Initial impulses, including arrhythmic activity, originated exclusively from the atrium, and no ventricular ectopic beats were detected whatever the conditions of oxygenation.
CONCLUSIONS: This in vitro model seems promising for studying the pathophysiological mechanisms associated with hypoxia and reoxygenation in the developing heart.
Mots-clé
Anoxia, arrhythmias, chick embryo, developmental cardiology, in vitro moel, oxygen paradox
Création de la notice
24/01/2008 13:19
Dernière modification de la notice
20/08/2019 13:48
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