Referenced in: none

Automatically associated channels: Kv11.1 , Slo1

Title: The action of the novel gastrointestinal prokinetic prucalopride on the HERG K+ channel and the common T897 polymorph.

Authors: Hugh Chapman, Michael Pasternack

Journal, date & volume: Eur. J. Pharmacol., 2007 Jan 12 , 554, 98-105

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/17109852

Abstract
The human ether-à-go-go related gene (HERG) encodes the alpha-subunit of a delayed rectifier potassium channel important in the repolarisation of the cardiac action potential. Excessive action potential prolongation through HERG channel inhibition is associated with a risk of torsade de pointes arrhythmias and is a major challenge for drug development. The acute effects of the novel prokinetic prucalopride were examined on heterologously expressed HERG channels in human embryonic kidney (HEK) 293 cells using the whole-cell patch-clamp technique. Prucalopride inhibited HERG channels in a concentration-dependent manner with an IC(50) of 4.1 microM. Prucalopride significantly slowed channel deactivation and recovery from inactivation, accelerated and altered the extent of inactivation. Similar concentration-dependency and kinetic changes were observed with the minor T897 polymorphic HERG variant. Prucalopride block was frequency-independent due to rapid state-dependent block, with binding occurring in the open and inactivated states. Though prucalopride blocks HERG channels this is unlikely to be significant at clinically relevant concentrations.