A. Representative acid-evoked current traces evoked by a first application of pH 6.5 and a following application of pH 5.5 in HEK293 cells transfected by TRPV1 WT (top), S502A (middle), or S800A (bottom). Cells were pretreated with PMA (1 µM) or vehicle (ethanol) as indicated. Current amplitudes were evaluated at −60 mV. Scale bar, 0.2 nA/pF-30 sec.
B. Current density evoked by a first application of pH 6.5 (left panel) and a following application of pH 5.5 (right panel). Numbers in parenthesis represent numbers of observations. ***p<0.001; *p<0.05; unpaired Student’s t-test.
C. Relative current quantified by the current density at pH 6.5 normalized to the average current density evoked by pH 5.5 in each group. NS, not significant.
D. Representative acid-evoked current traces evoked by a first application of pH 6 and a following application of pH 5 in HEK293 cells transfected by TRPV1 T704A (bottom). Cells were pretreated with PMA (1 µM) or vehicle (ethanol) as indicated. Current amplitudes were evaluated at −60 mV. Scale bar, 0.2 nA/pF-30 sec.
E. Representative current traces evoked by 30 µM capsaicin following pretreatment with vehicle or PMA in TRPV1 T704A. Scale bar, 2 nA-1 min.
F. Current density evoked by the consecutive application of pH 6 and pH 5 (left panel) or 30 µM capsaicin (right panel) in HEK293 cells transfected by TRPV1 T704A following pretreatment with vehicle or PMA.
G. Relative current quantified by the current density at pH 6 or pH 5 normalized to the average current density evoked by capsaicin in each group.