Figure 4. Inhibition of TRPV1-mediated proton-evoked Ca²⁺-influx by LA.

(A) Average effects of 10 mM LA on Ca²⁺-influx induced by pH 6.4 in cells expressing hTRPV1 as determined by ratiometric imaging. Cells were challenged with 3 subsequent 20s long applications of pH 6.4 within intervals of 5 min. 10 mM LA was co-applied with pH 6.4 during the second application. Capsaicin (0.3 μM) was applied to confirm expression of TRPV1. Dashed lines represent standard error of the mean. (B) Average effects of 10 mM LA on Ca²⁺-influx induced by pH 5.0 in DRG neurons from TRPA1^−/− knockout mice; same protocol as in (A). (C,D) Average responses to the 3 applications of pH 6.4 on hTRPV1 (C) and pH 5.0 on DRG neurons (D) expressed as area under the curve for increase in intracellular calcium calculated for all capsaicin-responsive cells. Data are presented as mean ± S.E.M. Statistical differences are indicated by ***p < 0.001.