Figure 9. 2-APB-induced increases of non-selective cation channel currents.

(A) Original traces of 2-APB activated TRPV channel responses to voltage ramps from −60 mV up to +130 mV (no leak current compensation) in the whole-cell configuration of the planar patch-clamp technique. Currents are shown before application (black), during application of 2-APB 100 µM, green), and after washout (blue). The currents were normalized to capacitance to obtain current density (pA/pF). (B) Comparison of inward and outward current densities with and without 2-APB at −60 mV and +130 mV (n = 5). Color bars show mean inward and outward current densities with 2-APB (green) and after washout (blue). Gray bars represent mean current densities without 2-APB (control). The asterisk (*) denote significant increase of outward currents by 2-APB (n = 5; p < 0.05; paired tested). (C) – (D) Similar experiments as shown in (A) and (B) (n = 6), but 20 µM ruthenium-red (RuR) was added in the presence of 2-APB instead of washout (n = 3; red-brown trace and bars). (E) – (F) Summary of the experiments with 2-APB and RuR. The asterisks (**) indicate statistically significant differences between controls and 2-APB at 130 mV (n = 6; p < 0.01; paired tested). Note that RuR suppressed 2-APB induced increases of outward currents (n = 3; p < 0.05; paired tested).