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Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents
Published on: July 3, 2013
Daurisoline suppressed early afterdepolarizations and inhibited L-type calcium current
Qiang-Ni Liu1, Li Zhang, Pei-Li Gong
1Department of Pharmacology, Huazhong University of Science and Technology, Wuhan, China.
The American Journal of Chinese Medicine
|February 4, 2010
Summary
Daurisoline (DS) effectively inhibits early afterdepolarizations (EADs) in hypertrophied heart cells by blocking L-type calcium currents. This finding suggests DS has potential as an antiarrhythmic agent.
Area of Science:
- Cardiology
- Pharmacology
- Electrophysiology
Background:
- Daurisoline (DS) has demonstrated antiarrhythmic effects in prior studies.
- Early afterdepolarizations (EADs) are a significant concern in cardiac hypertrophy.
- Investigating DS's impact on EADs and their underlying mechanisms is crucial.
Purpose of the Study:
- To investigate the effects of Daurisoline (DS) on early afterdepolarizations (EADs) in a rabbit model of cardiac hypertrophy.
- To elucidate the potential mechanisms by which DS influences EADs, particularly its effect on L-type calcium currents (I(Ca-L)).
Main Methods:
- Cardiac hypertrophy was induced in rabbits via abdominal aorta coarctation.
- Standard microelectrode technique was used to study action potential duration (APD) and EAD incidence in hypertrophied papillary muscles.
- Whole-cell patch clamp recorded L-type calcium current (I(Ca-L)) in isolated ventricular cells.
Main Results:
- In hypertrophied papillary muscles, dofetilide (dof) induced EADs (66.7%) and prolonged APD.
- Daurisoline (DS) (15 microM) completely inhibited EADs (0%) and shortened the prolonged APD.
- DS inhibited dofetilide-, low [K+], and low [Mg2+] induced EADs in single myocytes, decreasing triangulation and affecting I(Ca-L) parameters.
Conclusions:
- Daurisoline (DS) effectively inhibits early afterdepolarizations (EADs) in cardiac hypertrophy.
- DS's antiarrhythmic effect is likely mediated through the blockade of L-type calcium currents (I(Ca-L)).
- DS shows promise as a therapeutic agent for arrhythmias associated with cardiac hypertrophy.
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