Fig. 3

EPA-triggered Ca²⁺ influx was insensitive to tetrandrine. a and b: [Ca²⁺]_i in bEND.3 cells was monitored in Ca²⁺-free bath solution. The cells were treated with 30 μM EPA (a) or 30 μM CPA (b), followed by HCl (solvent) or tetrandrine (100 μM) addition and finally replenishment of 2 mM CaCl₂. The final concentration of HCl was 0.33 mM, which did not significantly affect the pH of the bath solution. There is a significant difference (P < 0.05) between the two groups beginning at 719 s and afterwards. c and d: [Ca²⁺]_i in bEND.3 cells was monitored in Ca²⁺-containing bath solution. The cells were treated with 30 μM EPA (c) or 30 μM CPA (d), followed by tetrandrine (100 μM) addition. Results are mean ± SEM of 26–44 cells from 4 to 6 separate experiments