DELAYED RECTIFIER CURRENT ASSAYS

hERG CHANNEL TAIL CURRENT

EFFECTS OF E-4031 ON THE hERG CHANNEL TAIL CURRENT

Figure 1  Effects of E-4031 on the hERG channel tail current.

Figure 1 shows an example of typical hERG channel tail currents recorded by scientists at OCP, under our standard whole-cell patch-clamp conditions for the measurement of hERG channel tail currents in a stably transfected cell line.

Figure 1 shows superimposed hERG channel tail current records in the absence (black) and presence (red) of E-4031 (3 µM).

Figure 2   Time course for the effect of E-4031 on the amplitude hERG channel tail current.

Figure 2  shows hERG channel tail current amplitude (denoted by black symbols) is stable over the 4 minute control recording period. Application of E-4031  (3 µM) caused a time dependent decrease in the outward tail current consistent with block of I_Kr.

Figure 3   Determination of the IC₅₀ of E-4031 on hERG channel tail current measured in a stably transfected cell line.

Figure 3   shows the percentage decrease in the peak amplitude of hERG channel tail current plotted as a function of concentration of dofetilide.

The left hand panel shows the data points taken from individual experiments.

The right hand panel shoes mean±sem data for these experiment.  These data points can be fit by a sigmoid curve (logistic function) which produces and IC₅₀ value of 6.8±nM.