PUBLICATION
Excitation-contraction coupling in zebrafish ventricular myocardium is regulated by trans-sarcolemmal Ca2+ influx and sarcoplasmic reticulum Ca2+ release
- Authors
- Haustein, M., Hannes, T., Trieschmann, J., Verhaegh, R., Köster, A., Hescheler, J., Brockmeier, K., Adelmann, R., Khalil, M.
- ID
- ZDB-PUB-150506-15
- Date
- 2015
- Source
- PLoS One 10: e0125654 (Journal)
- Registered Authors
- Keywords
- none
- MeSH Terms
-
- Adrenergic beta-Agonists/pharmacology
- Animals
- Calcium/metabolism
- Calcium Channels/metabolism
- Calcium Signaling/drug effects
- Excitation Contraction Coupling/drug effects
- Excitation Contraction Coupling/physiology*
- Extracellular Space/metabolism
- Heart Ventricles/drug effects
- Heart Ventricles/metabolism*
- Immunohistochemistry
- Myocardial Contraction/drug effects
- Myocardial Contraction/physiology
- Myocardium/metabolism*
- Sarcoplasmic Reticulum/metabolism
- Temperature
- Zebrafish
- PubMed
- 25938412 Full text @ PLoS One
Citation
Haustein, M., Hannes, T., Trieschmann, J., Verhaegh, R., Köster, A., Hescheler, J., Brockmeier, K., Adelmann, R., Khalil, M. (2015) Excitation-contraction coupling in zebrafish ventricular myocardium is regulated by trans-sarcolemmal Ca2+ influx and sarcoplasmic reticulum Ca2+ release. PLoS One. 10:e0125654.
Abstract
Zebrafish (Danio rerio) have become a popular model in cardiovascular research mainly due to identification of a large number of mutants with structural defects. In recent years, cardiomyopathies and other diseases influencing contractility of the heart have been studied in zebrafish mutants. However, little is known about the regulation of contractility of the zebrafish heart on a tissue level. The aim of the present study was to elucidate the role of trans-sarcolemmal Ca2+-flux and sarcoplasmic reticulum Ca2+-release in zebrafish myocardium. Using isometric force measurements of fresh heart slices, we characterised the effects of changes of the extracellular Ca2+-concentration, trans-sarcolemmal Ca2+-flux via L-type Ca2+-channels and Na+-Ca2+-exchanger, and Ca2+-release from the sarcoplasmic reticulum as well as beating frequency and β-adrenergic stimulation on contractility of adult zebrafish myocardium. We found an overall negative force-frequency relationship (FFR). Inhibition of L-type Ca2+-channels by verapamil (1 μM) decreased force of contraction to 22±7% compared to baseline (n=4, p<0.05). Ni2+ was the only substance to prolong relaxation (5 mM, time after peak to 50% relaxation: 73±3 ms vs. 101±8 ms, n=5, p<0.05). Surprisingly though, inhibition of the sarcoplasmic Ca2+-release decreased force development to 54±3% in ventricular (n=13, p<0.05) and to 52±8% in atrial myocardium (n=5, p<0.05) suggesting a substantial role of SR Ca2+-release in force generation. In line with this finding, we observed significant post pause potentiation after pauses of 5 s (169±7% force compared to baseline, n=8, p<0.05) and 10 s (198±9% force compared to baseline, n=5, p<0.05) and mildly positive lusitropy after β-adrenergic stimulation. In conclusion, force development in adult zebrafish ventricular myocardium requires not only trans-sarcolemmal Ca2+-flux, but also intact sarcoplasmic reticulum Ca2+-cycling. In contrast to mammals, FFR is strongly negative in the zebrafish heart. These aspects need to be considered when using zebrafish to model human diseases of myocardial contractility.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping