Table 1.

Synergic effect of STEARDA and PALDA with low pH on the gating of human TRPV1 channels in HEK-293 cells

	pH=7.4	pH=6.7	pH=6.4	pH=6.0
Vehicle	0	−0.15±0.04	−0.27±0.06	−0.5±0.3
PALDA 1 μM	3.8±1.4	6.7±0.1a,b	11.5±3.0a,b	6.9±0.9a
PALDA 10 μM	17.3±4.8a	23.2±5.6a	24.4±0.9a,b	26.5±1.2a,b
STEARDA 1 μM	4.1±0.5	11.1±2.5a,c	10.6±2.0a,c	12.9±1.5a,c
Capsaicin 0.01 μM	12.7±1.8a	18.8±1.0a,d	35.3±3.7a,d	ND

Data are expressed as the % of the maximal obtainable effect on intracellular Ca²⁺ (i.e. effect of 4 μM ionomycin) and are means±s.e.m. of n=3 determinations. The synergic effect of low pH and a low concentration of capsaicin is shown for a comparison.

^aP<0.05 vs corresponding vehicle at the same pH.

^bP<0.05 vs PALDA at pH=7.4.

^cP<0.05 vs STEARDA at pH=7.4.

^dP<0.05 vs capsaicin at pH=7.4; statistically significant differences were assessed by ANOVA followed by Bonferroni's test. ND, not determined.