Figure 5.

Effects of mutation F656V on erythromycin modulation of I_hERG sensitivity to 30 nM BeKm‐1. (a) Bar charts showing the level of block by 30 nM BeKm‐1 of F656V I_hERG tail in the absence (white bar; n = 5) and presence of 3 µM erythromycin (gray bar; n = 5; p > .05 vs. in the absence of erythromycin 3 µM [unpaired t test]). (b) Bar charts comparing t_half values of inhibition of F656V I_hERG tails in the absence (white bar; n = 5) and presence of 3 µM erythromycin (gray bar; n = 5; p > .05 vs. in the absence of erythromycin 3 µM [unpaired t test]). BeKm‐1 effect on I_hERG tail recorded on repolarization to −40mV was calculated as the mean fractional block and plotted against time to derive the value for time to half inhibition t_half of I_hERG tail. The F656V mutation increased hERG sensitivity to BeKm‐1 in the two experimental conditions tested but did not affect the rate of block (cf. Figure 4b and 4c)