Figure 6

GSH shifts the ADPR dose-response curve of TRPM2 channels by 3.5 fold. TRPM2 currents were generated in with or without 10 mM GSH included in the patch pipette. Intracellular concentrations of ADPR used to evoke the current ranged from 0.03 - 3 mM. Each point on the curve represents the mean +/- SE of 6 - 11 recordings. Significant inhibition by GSH was observed for TRPM2 currents evoked by ADPR concentrations of 0.1, 0.3, and 1 mM (p < 0.001), with no difference between groups at the highest (3 mM) and lowest (0.03 mM) ADPR concentration points (p > 0.05). The EC₅₀ value for ADPR was increased from 77 μM (control) to 269 μM (10 mM GSH) in the presence of 10 mM GSH, representing a ~3.5 fold change in sensitivity to ADPR. Dose-response curves were fit using a sigmoidal dose-response (variable slope), with a Hill slope of 2.2 in control, and 0.9 in the GSH data set.