Phα1β and its recombinant form (CTK 01512–2) selectively inhibit the calcium response evoked by stimulation of human TRPA1 channels. (A) Typical traces of the inhibitory effect of pre‐exposure (10 min) to Phα1β (3 μM) and CTK 01512–2 (3 μM) on the calcium response evoked by the TRPA1 channel agonist, AITC (30 μM), in HEK293 cells transfected with the cDNA for human TRPA1 channels (hTRPA1‐HEK293). Concentration–response curve of the inhibitory effect of Phα1β and CTK 01512–2 on the calcium response evoked by AITC (AITC concentrations are 30 μM). Phα1β (3 μM) and CTK 01512–2 (3 μM) and the selective TRPA1 channel antagonist HC‐030031 (HC03, 30 μM) inhibit calcium response evoked in hTRPA1‐HEK293 cells by AITC. (B) Phα1β (3 μM) and CTK 01512–2 (3 μM) do not affect responses evoked by capsaicin (CPS, 0.1 μM) in HEK293 cells transfected with the cDNA for human TRPV1 channels (hTRPV1‐HEK293) and by GSK1016790A (GSK, 50 nM) in HEK293 cells transfected with the cDNA for human TRPV4 channels (hTRPV4‐HEK293). Values are mean ± SEM of n > 25 cells from at least three different experiments for each condition. §
P < 0.05, significantly different from vehicle (Veh); *P < 0.05, significantly different from AITC.