hERG - "Pharmacology of hERG recorded on Nanion´s Port-a-Patch"
The hERG gene (KCNH2) encodes a potassium ion channel responsible for the repolarizing IKr current in the cardiac action potential (Sanguinetti et al., 1995). Abnormalities in this channel may lead to either Long QT syndrome (LQT2) (with loss-of-function mutations) or Short QT syndrome (with gain-of-function mutations), both potentially fatal cardiac arrhythmia, due to repolarization disturbances of the cardiac action potential. Given the importance of this channel in maintaining cardiac function, it has become an important target in compound safety screening. A large range of therapeutic agents with diverse chemical structures have been reported to induce long QT syndrome. These include antihistamines (e.g. Terfenadine), gastrointestinal prokinetic agents (e.g. Cisapride) and others. Here we present data collected on the Port-a-Patch. Astemizole, Terfenadine, Cisapride and Flunarizine dose-response curves on hERG expressed in CHO cells are shown. The mean current amplitude in these cells was 1076 ± 79 pA (n= 88) at -40 mV.