Fig. 2: Single channel analysis reveals menthol is a slow blocker of rbTRPV5 channels.

a Representative single-channel current traces of rbTRPV5 channels from an outside-out patch recorded at −100 mV in the presence of the indicated menthol concentration. The dashed and dotted lines indicate the closed and open amplitude, respectively. b All-points histograms of selected sections of records in (a), indicating the current amplitude of a single-channel opening. Histograms are fitted to the sums of three Gaussian functions. The main current amplitudes are as follows: no menthol, −9.46 ± 1.4 pA; 500 μM, −8.1 ± 1.47 pA; 1 mM, −7.66 ± 2.7 pA; 3 mM, -9.51 ± 0.99 pA. c Closed time distributions at increasing menthol concentrations. From top to bottom, no menthol, 500 μM, 1 mM and 3 mM menthol. Each histogram is fitted to the sum of three exponential components (orange), and each component is indicated by the dotted curves. d Open time histograms. Same order as in (c). Two exponential components are fitted to each histogram, indicated as in (c). e The dependance of the three closed time constants on the menthol concentration. Dotted lines are fits to linear equations and have no theoretical meaning. Blue, fast time constant, yellow, intermediate time constant, green, slow time constant (Table 1). Filled symbols are the mean value and error bars are ± SEM determined from n = 3 independent outside-out patches. f Dependance of the two open time constants on menthol concentration (Table 2). Filled symbols are the mean value and error bars are ± SEM determined from n = 3 independent outside-out patches. The slow open time constant data (black squares) is fitted to the empirical Eq. 3. The fast open time constant data (red circles) is fitted to a linear equation.