Figure 9.

Assessment of cross-talk between GPR55 and CB₂ receptors by impedance determinations. CellKey label-free assays were performed in HEK-GPR55 and HEK-CB₂R/GPR55 cells, treated with 1 nM of A-836339 (CB₂ receptor agonist), 5 μM of LPI or both. Results correspond to the maximal decrease in impedance with respect to basal levels. Representative traces for individual assays are shown for (A) HEK-GPR55 and (B) HEK-CB₂R/GPR55 cells (traces corresponding to 2 s interval recordings of impedance in four different wells). (C) The maximum decay in impedance that is, for each well, automatically provided by the equipment is depicted as bar graph (data for HEK-CB₂ receptor also shown). Data are mean ± SEM from 4–8 independent experiments performed in quadruplicates. Statistical significance was calculated by one-way anova followed by Bonferroni's post hoc multiple comparison test (^#P < 0.05 with respect to A-836339; *P < 0.05 with respect to LPI).