[Zn2+]i components in HEK-TRPA1 cells. (A) Comparative analysis of TPEN-sensitive basal [Zn2+]i components in control HEK and HEK-TRPA1 cells. [Zn2+]i levels in SBS was monitored using FluoZin-3 in the presence of 30 μM TPEN. (B) Peak changes in [Zn2+]i in the presence of TPEN (mean±SEM; n = 184 and n = 293, four and six independent experiments for control HEK and HEK-TRPA1 cells, respectively; ** p < 0.01). (C) Comparison of extracellular divalent cations and TPEN-sensitive basal [Zn2+]i components assayed with FluoZin-3 in control HEK and HEK-TRPA1 cells. The extracellular divalent cations were removed without EGTA (0DVC), followed by exposure to 30 μM TPEN. (D) Peak changes in [Zn2+]i in the presence of 0DVC and TPEN (mean ± SEM; n = 76 and n = 78 for HEK and HEK-TRPA1 cells, respectively; two independent experiments each, ** p < 0.01).