Functional and morphological evidence for a ventricular conduction system in zebrafish and Xenopus hearts.

Détails

ID Serval
serval:BIB_F12DD05A8ACD
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Functional and morphological evidence for a ventricular conduction system in zebrafish and Xenopus hearts.
Périodique
American Journal of Physiology. Heart and Circulatory Physiology
Auteur⸱e⸱s
Sedmera D., Reckova M., deAlmeida A., Sedmerova M., Biermann M., Volejnik J., Sarre A., Raddatz E., McCarthy R.A., Gourdie R.G., Thompson R.P.
ISSN
0363-6135 (Print)
ISSN-L
0363-6135
Statut éditorial
Publié
Date de publication
2003
Peer-reviewed
Oui
Volume
284
Numéro
4
Pages
H1152-H1160
Langue
anglais
Résumé
Zebrafish and Xenopus have become popular model organisms for studying vertebrate development of many organ systems, including the heart. However, it is not clear whether the single ventricular hearts of these species possess any equivalent of the specialized ventricular conduction system found in higher vertebrates. Isolated hearts of adult zebrafish (Danio rerio) and African toads (Xenopus laevis) were stained with voltage-sensitive dye and optically mapped in spontaneous and paced rhythms followed by histological examination focusing on myocardial continuity between the atrium and the ventricle. Spread of the excitation wave through the atria was uniform with average activation times of 20 +/- 2 and 50 +/- 2 ms for zebrafish and Xenopus toads, respectively. After a delay of 47 +/- 8 and 414 +/- 16 ms, the ventricle became activated first in the apical region. Ectopic ventricular activation was propagated significantly more slowly (total ventricular activation times: 24 +/- 3 vs. 14 +/- 2 ms in zebrafish and 74 +/- 14 vs. 35 +/- 9 ms in Xenopus). Although we did not observe any histologically defined tracts of specialized conduction cells within the ventricle, there were trabecular bands with prominent polysialic acid-neural cell adhesion molecule staining forming direct myocardial continuity between the atrioventricular canal and the apex of the ventricle; i.e., the site of the epicardial breakthrough. We thus conclude that these hearts are able to achieve the apex-to-base ventricular activation pattern observed in higher vertebrates in the apparent absence of differentiated conduction fascicles, suggesting that the ventricular trabeculae serve as a functional equivalent of the His-Purkinje system.
Mots-clé
Animals, Atrial Function, Electrocardiography, Female, Heart/anatomy & histology, Heart/physiology, Heart Atria/anatomy & histology, Heart Conduction System/anatomy & histology, Heart Conduction System/physiology, Heart Rate, Heart Ventricles/anatomy & histology, Immunohistochemistry, Myocardium/chemistry, Myosins/analysis, Ventricular Function, Xenopus laevis/anatomy & histology, Xenopus laevis/physiology, Zebrafish/anatomy & histology, Zebrafish/physiology
Pubmed
Web of science
Création de la notice
24/01/2008 14:19
Dernière modification de la notice
20/08/2019 17:18
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