Fig. 2. (A ) Example trace of LPA (at EC50290 nm)-induced ICl(Ca), under control conditions (top , 1.05 μA) and 10 min after intracellular injection of QX314 (100 μm;bottom , 0.34 μA). (B ) Intracellular injection of QX314 inhibits LPA (EC50)-induced ICl(Ca)in a concentration-dependent manner. Curve fitting using the Hill equation revealed a half-maximal inhibitory concentration (IC50) of 209 ± 164 μm. (C ) Example trace of LPA (at EC50290 nm)-induced control response (top , 1.61 μA) and ICl(Ca)after 10 min intracellular treatment with lidocaine on LPA response elicited by EC50of LPA (bottom , 0.78 μA). (D ) Intracellular lidocaine inhibited LPA responses with an IC50of 148 ± 105 μm.