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Evaluation of Possible Proarrhythmic Potency: Comparison of the Effect of Dofetilide, Cisapride, Sotalol, Terfenadine, and Verapamil on hERG and Native IKr Currents and on Cardiac Action Potential.
- Source :
-
Toxicological sciences : an official journal of the Society of Toxicology [Toxicol Sci] 2019 Apr 01; Vol. 168 (2), pp. 365-380. - Publication Year :
- 2019
-
Abstract
- The proarrhythmic potency of drugs is usually attributed to the IKr current block. During safety pharmacology testing analysis of IKr in cardiomyocytes was replaced by human ether-a-go-go-related gene (hERG) test using automated patch-clamp systems in stable transfected cell lines. Aim of this study was to compare the effect of proarrhythmic compounds on hERG and IKr currents and on cardiac action potential. The hERG current was measured by using both automated and manual patch-clamp methods on HEK293 cells. The native ion currents (IKr, INaL, ICaL) were recorded from rabbit ventricular myocytes by manual patch-clamp technique. Action potentials in rabbit ventricular muscle and undiseased human donor hearts were studied by conventional microelectrode technique. Dofetilide, cisapride, sotalol, terfenadine, and verapamil blocked hERG channels at 37°C with an IC50 of 7 nM, 18 nM, 343 μM, 165 nM, and 214 nM, respectively. Using manual patch-clamp, the IC50 values of sotalol and terfenadine were 78 µM and 31 nM, respectively. The IC50 values calculated from IKr measurements at 37°C were 13 nM, 26 nM, 52 μM, 54 nM, and 268 nM, respectively. Cisapride, dofetilide, and sotalol excessively lengthened, terfenadine, and verapamil did not influence the action potential duration. Terfenadine significantly inhibited INaL and moderately ICaL, verapamil blocked only ICaL. Automated hERG assays may over/underestimate proarrhythmic risk. Manual patch-clamp has substantially higher sensitivity to certain drugs. Action potential studies are also required to analyze complex multichannel effects. Therefore, manual patch-clamp and action potential experiments should be a part of preclinical safety tests.<br /> (© The Author(s) 2018. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Subjects :
- Animals
Drug Evaluation, Preclinical
ERG1 Potassium Channel metabolism
Female
Heart Ventricles metabolism
Heart Ventricles physiopathology
Humans
Male
Myocytes, Cardiac metabolism
Patch-Clamp Techniques
Phenethylamines toxicity
Rabbits
Sotalol toxicity
Sulfonamides toxicity
Terfenadine toxicity
Tissue Donors
Verapamil toxicity
Action Potentials drug effects
Anti-Arrhythmia Agents toxicity
Heart Ventricles drug effects
Ion Channels metabolism
Myocytes, Cardiac drug effects
Potassium Channel Blockers toxicity
Subjects
Details
- Language :
- English
- ISSN :
- 1096-0929
- Volume :
- 168
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Toxicological sciences : an official journal of the Society of Toxicology
- Publication Type :
- Academic Journal
- Accession number :
- 30561737
- Full Text :
- https://doi.org/10.1093/toxsci/kfy299