Figure 5.

Evaluation of test compounds for any effect on icilin-evoked Ca²⁺ entry signals using fura-2 based Ca²⁺ imaging of HEK-293 cells stably expressing human TRPM8. The fura-2 loaded cells bathed in Ca²⁺-free extracellular solution were exposed to icilin (500 nM) with or without the synthesized compounds or the known TRPM8 antagonist RQ-00203078 at various concentrations (For this figure, all were at 3 nM. The corresponding histogram is provided in Figure S3). After ~4 min of compound addition, Ca²⁺ free bath solution was replaced by the one containing 2 mM Ca²⁺. Ca²⁺ influx was monitored as fura-2 fluorescence ratio (F₃₅₅/F₃₈₀). Each data point represents mean ± SEM (n ≥ 35 cells from three independent experiments done in three different days).