PUBLICATION

Ionic channels underlying the ventricular action potential in zebrafish embryo

Authors
Alday, A., Alonso, H., Gallego, M., Urrutia, J., Letamendia, A., Callol, C., Casis, O.
ID
ZDB-PUB-140513-117
Date
2014
Source
Pharmacological research   84C: 26-31 (Journal)
Registered Authors
Callol Massot, Carles
Keywords
Cardiac development, Depolarizing current, Electrophysiology, Repolarizing current
MeSH Terms
  • Action Potentials/drug effects
  • Action Potentials/physiology*
  • Animals
  • Calcium Channel Blockers/pharmacology
  • Embryo, Nonmammalian/physiology*
  • Heart Ventricles/drug effects*
  • In Vitro Techniques
  • Ion Channels/drug effects
  • Ion Channels/physiology*
  • Sodium Channel Blockers/pharmacology
  • Zebrafish
PubMed
24747832 Full text @ Pharmacol. Res.
Abstract
Over the last years zebrafish has become a popular model in the study of cardiac physiology, pathology and pharmacology. Recently, the application of the 3Rs regulation and the characteristics of the embryo have reduced the use of adult zebrafish use in many studies. However, the zebrafish embryo cardiac physiology is poorly characterized since most works have used indirect techniques and direct recordings of cardiac action potential and ionic currents are scarce. In order to optimize the zebrafish embryo model, we used electrophysiological, pharmacological and immunofluorescence tools to identify the characteristics and the ionic channels involved in the ventricular action potentials of zebrafish embryos. The application of Na(+) or T-type Ca(+2) channel blockers eliminated the cardiac electrical activity, indicating that the action potential upstroke depends on Na(+) and T-type Ca(+2) currents. The plateau phase depends on L-type Ca(+2) channels since it is abolished by specific blockade. The direct channel blockade indicates that the action potential repolarization and diastolic potential depends on ERG K(+) channels. The presence in the embryonic heart of the Nav1.5, Cav1.2, Cav3.2 and ERG channels was also confirmed by immunofluorescence, while the absence of effect of specific blockers and immunostaining indicate that two K(+) repolarizing currents present in human heart, Ito and IKs, are absent in the embryonic zebrafish heart. Our results describe the ionic channels present and its role in the zebrafish embryo heart and support the use of zebrafish embryos to study human diseases and their use for drug testing.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping