Fig. 4: Pharmacology of the human Na_X-QTT channel.

a Representative I–V curves from HEK293T cells expressing human Na_X-QTT with indicated extracellular monovalent cations with or without indicated amounts of CaCl₂ in the extracellular solution. Voltage ramp from −80 to +80 mV was applied. Right, percentage of block of outward Na⁺ by indicated concentrations of Ca²⁺ at 80 mV. Data are shown as mean ± SD of n = 5 cells over three independent experiments. b Representative currents from Xenopus laevis oocytes expressing human Na_X-QTT in standard extracellular solution with or without indicated divalent and trivalent cations (unit in mM), when stepping from 0 to +80 mV. c Representative currents from oocytes expressing human Na_X-QTT in standard extracellular solution with or without indicated blockers added, when stepping from 0 to +80 mV (left) or from 0 to −100 mV (right). Middle, summary of currents measured from two independent experiments. Data are shown as mean ± SD. Numbers of biological replicates (n) are indicated. See Methods for concentrations of compounds tested.