Other Potassium channel assays (hK_VLQT1/MinK, hK_V4.3, hK_V1.5) for preclinical safety studies

The three main ion channels of the heart, i.e. hERG, Ca_v1.2 and Na_v1.5 do not completely cover the entire spectrum of electrical heart activity. An inhibition of the other remaining cardiac ion channels could also alter cardiac activity and modify the QT interval. PhysioStim provides a complete range of additional ion channel assays in order to quickly and accurately detect any potential undesirable cardiovascular effects.

The hK_VLQT1/MinK channel plays an important role in cardiac action potential repolarisation. A pharmacological reduction of the IKs current may delay the repolarisation process and lead to a prolongation of the QT interval. The hK_VLQT1/MinK potassium channel is therefore considered as a specific target for cardiac safety assessment.

Since the K_v4.3 potassium channel plays an important role in cardiac action potential repolarisation, a pharmacological reduction of the Ito current may delay the repolarisation process and may lead to a prolongation of the QT interval. Thus the K_v4.3 potassium channel represent a specific target for the cardiac safety assessment.

The human K_v1.5 potassium channel encodes for the ultrarapid component of the delayed rectifier potassium channel responsible of IKur current. In the cardiac tissue, K_v1.5 potassium channels are only expressed in atria in which they represent a major component of the cardiac repolarisation of atrial action potential. Thus K_v1.5 channel represents a major target for the treatment of atrial fibrillation, the most common sustained arrhythmia.