» Articles » PMID: 10510456

Inhibition of the Human Ether-a-go-go-related Gene (HERG) Potassium Channel by Cisapride: Affinity for Open and Inactivated States

Overview
Journal Br J Pharmacol
Publisher Wiley
Specialty Pharmacology
Date 1999 Oct 8
PMID 10510456
Citations 28
Authors
Affiliations
Soon will be listed here.
Abstract

1 Cisapride is a prokinetic agent which has been associated with QT prolongation, torsades de pointes and cardiac arrest. The cellular mechanism for these observations is high affinity blockade of IKr (encoded by HERG). 2 In a chronic transfection model using CHO-K1 cells, cisapride inhibited HERG tail currents after a step to +25 mV with similar potency at room and physiological temperatures (IC50 16. 4 nM at 20-22 degrees C and 23.6 nM at 37 degrees C). 3 Channel inhibition exhibited time-, voltage- and frequency-dependence. In an envelope of tails test, channel blockade increased from 27+/-8% after a 120 ms depolarizing step to 50+/-4% after a 1.0 s step. These findings suggested affinity for open and/or inactivated channel states. 4 Inactivation was significantly accelerated by cisapride in a concentration-dependent manner and there was a small (-7 mV) shift in the voltage dependence of steady state inactivation. 5 Channel blockade by cisapride was modulated by [K+]o, with a 26% reduction in the potency of channel blockade when [K+]o was increased from 1 to 10 mM. 6 In conclusion, HERG channel inhibition by cisapride exhibits features consistent with open and inactivated state binding and is sensitive to external potassium concentration. These features may have significant clinical implications with regard to the mechanism and treatment of cisapride-induced proarrhythmia.

Citing Articles

An LQT2-related mutation in the voltage-sensing domain is involved in switching the gating polarity of hERG.

Liu Z, Wang F, Yuan H, Tian F, Yang C, Hu F BMC Biol. 2024; 22(1):29.

PMID: 38317233 PMC: 11380439. DOI: 10.1186/s12915-024-01833-0.


Systematical Evaluation of the Structure-Cardiotoxicity Relationship of 7-Azaindazole-based PI3K Inhibitors Designed by Bioisosteric Approach.

Wu T, Chen Y, Yang C, Lu M, Geng F, Guo J Cardiovasc Toxicol. 2023; 23(11-12):364-376.

PMID: 37787964 DOI: 10.1007/s12012-023-09809-2.


Inhibition of the hERG Potassium Channel by a Methanesulphonate-Free E-4031 Analogue.

Helliwell M, Zhang Y, El Harchi A, Dempsey C, Hancox J Pharmaceuticals (Basel). 2023; 16(9).

PMID: 37765012 PMC: 10536391. DOI: 10.3390/ph16091204.


GCMS fingerprints and phenolic extracts of inhibit key enzymes associated with type 2 diabetes.

Adelusi T, Boyenle I, Tolulope A, Adebisi J, Fatoki J, Ukachi C J Taibah Univ Med Sci. 2023; 18(2):337-347.

PMID: 36817213 PMC: 9926220. DOI: 10.1016/j.jtumed.2022.09.011.


Ligand-based prediction of hERG-mediated cardiotoxicity based on the integration of different machine learning techniques.

Delre P, Lavado G, Lamanna G, Saviano M, Roncaglioni A, Benfenati E Front Pharmacol. 2022; 13:951083.

PMID: 36133824 PMC: 9483173. DOI: 10.3389/fphar.2022.951083.


References
1.
Kiehn J, Lacerda A, Wible B, Brown A . Molecular physiology and pharmacology of HERG. Single-channel currents and block by dofetilide. Circulation. 1996; 94(10):2572-9. DOI: 10.1161/01.cir.94.10.2572. View

2.
Suessbrich H, Waldegger S, Lang F, Busch A . Blockade of HERG channels expressed in Xenopus oocytes by the histamine receptor antagonists terfenadine and astemizole. FEBS Lett. 1996; 385(1-2):77-80. DOI: 10.1016/0014-5793(96)00355-9. View

3.
Spector P, Curran M, Zou A, Keating M, Sanguinetti M . Fast inactivation causes rectification of the IKr channel. J Gen Physiol. 1996; 107(5):611-9. PMC: 2217012. DOI: 10.1085/jgp.107.5.611. View

4.
Wysowski D, BACSANYI J . Cisapride and fatal arrhythmia. N Engl J Med. 1996; 335(4):290-1. DOI: 10.1056/NEJM199607253350416. View

5.
Snyders D, Chaudhary A . High affinity open channel block by dofetilide of HERG expressed in a human cell line. Mol Pharmacol. 1996; 49(6):949-55. View