hERG - "Temperature controlled hERG recordings on the Port-a-Patch"
The hERG gene encodes a potassium channel responsible for the repolarization of the IKr current in cardiac cells. This channel is important in the repolarization of the cardiac action potential. Abnormalities in this channel can cause long or short QT syndrome, leading to potentially fatal cardiac arrhythmia. Given the importance of this channel in maintaining cardiac function, and disturbances of channel activity by certain compounds such as anti-arrhythmias and anti-psychotics, it has become an important target in compound safety screening. It is a desirable option to study this channel at physiological temperature since compounds can display different actions or potencies at physiological temperature. Here, we present data collected on the Port-a-Patch using the External Perfusion System coupled with Nanion’s Temperature Control. Cells were captured and sealed at room temperature and control recordings made before raising the temperature to 35°C so that parameters such as current peak amplitude could be compared at the two different temperatures. Furthermore, the hERG active compound, quinidine, was used at physiological temperature and a full dose response curve was achieved. This demonstrates the stability of the recordings on the Port-a-Patch at this temperature. The concentration response curve generated an IC50 similar to that obtained at room temperature, and similar to that published in the literature.