Fig. 3.

Ginsenosides enhance Ca²⁺ influx responses in cells expressing hP2X4. Intracellular Ca²⁺ responses were measured in (A) Fura-2 acetoxymethyl ester–loaded HEK-hP2X4 cells or (C) Fura-2 acetoxymethyl ester–loaded 1321N1-hP2X4 cells. Baseline values were recorded for 15–20 seconds, and then ATP was automatically injected at 30 seconds (arrow indicates agonist addition). Representative ATP responses are shown in black; ATP plus CK (10 μM) are shown in red. Error bars are S.D. (B) Ca²⁺ responses in HEK-hP2X4 were calculated as average Fura-2 ratio over the final 150 seconds. CK and Rd (10 µM) significantly increase hP2X4-mediated Ca²⁺ influx. *P < 0.05, one-way ANOVA with Dunnett’s multiple comparison post hoc test. (D) Ca²⁺ responses in 1321N1-hP2X4 cells were measured as area under the curve of zero baseline; error bars are S.D.; data are from four independent experiments.