Measurement of hERG Ion Channel Currents in Lipid Bilayer

Abstract

hERG channels (human ether-a -go-go related gene, Kv11.1) play an important role conducting potassium ions in the cardiac delayed rectifier current, IKr, during the repolarization phase of the cardiac action potential. We have measured hERG channels in droplet interface bilayers using membrane preparations made from eukaryotic cells expressing hERG. We find single channel conductance and reversal potentials consistent with previously published patch clamp studies as well as the sensitivity of the measured currents to astemizole, a potassium channel blocker, and E-4031, a hERG specific blocker. This sensitivity is dosage dependent, with IC50 values measured, 91 nM and 12.4 nM for astemizole and E-4031, respectively.