Fig. 3. Effect of 1 and 2 on whole cell currents in hTRPM2 expressing HEK293 cells. Electrophysiological analysis of the impact of ADPR analogues on human TRPM2. (a) During whole cell patch clamp experiments using HEK293 cells with stable expression of the ion channel, the analogues were included in the pipette solution at 100 μmol L⁻¹ or 1000 μmol L⁻¹. The maximum outward current at +15 mV over a time of 450 s from individual cells is plotted at a logarithmic scale with a horizontal bar indicating the mean value. Neither compound did result in a significantly higher current than the buffer control. (b) To check for potential inhibition of TRPM2 currents from activation by ADPR, the compounds were added at 300 μmol L⁻¹ or 900 μmol L⁻¹ to a pipette solution already containing 100 μmol L⁻¹ ADPR. Neither compound reduced the TRPM2 current significantly when compared to the control (pipette solution containing only ADPR). The numbers at the bottom indicate the number of cells analysed.