Figure 4
Differential effect of the Y745H mutation on the antagonism of TRPM8 by BCTC and SKF96365. A-B, Cold-evoked [Ca2+]i responses in HEK293 cells expressing TRPM8-wt or TRPM8-Y745H channels, showing the inhibition by A, 3 μM BCTC, and B, 3 μM SKF96365. C-D, Summary histograms of the [Ca2+]i responses of TRPM8-wt and TRPM8-Y745H channels to repeated cooling stimuli in the absence and presence of C, 3 μM BCTC (n = 9/11 wt/mut); and D, 3 μM SKF96365 (SKF; n = 33/47). Note the reversible nature of the inhibition. E, Comparison of block of TRPM8-wt vs. TRPM8-Y745H by BCTC and SKF96365. In panels C-E, intracellular calcium increases were normalized to the first cold application in control solution. In panel E, the block of each antagonist condition was compared between TRPM8-wt and -Y745H using Student's unpaired t-test: *** p < 0.001; ns. = not significant. The block by 20 μM SKF96365 over the Y745H mutant is included to show the complete lack of inhibition.