Figure 2.

BmK I increased Nav1.8 transient current in small DRG neurons. (A) Representative Nav1.8 currents were recorded from a small-sized DRG neuron in the absence (left) and presence of 1 μmol/L BmK I. (B) I(V) relationship of Nav1.8 was determined before and after application of 100 nmol/L, 500 nmol/L or 1 μmol/L BmK I. Nav1.8 currents were normalized by respective maximum current under control condition. (C) Nav1.8 peak current densities were significantly enhanced in the presence of BmK I. (100 nmol/L: n = 7; 500 nmol/L: n = 6; 1 μmol/L: n = 10; control: n = 16; *P < 0.05, **P < 0.005, compared with control, respectively; ^## P < 0.005, compared with 100 nmol/L). (D) The EC₅₀ for BmK I effect determined by the increase of transient current in the presence of a series of BmK I concentration (30 nmol/L: 39 ± 21%, n = 5; 100 nmol/L: 40 ± 9%, n = 6; 200 nmol/L: 65 ± 18%, n = 5; 500 nmol/L: 146 ± 35%, n = 6; 1 μmol/L: 156 ± 35%, n = 7)