Figure 2. Local anesthetics inhibit lysophosphatidate signaling. (A) The Ca2+-activated Cl sup - current (ICl(Ca)) induced by 10 sup -7 M lysophosphatidate in control oocyte (4.6 micro Coulomb). Below is an example of lysophosphatidate signaling inhibition by lidocaine mM 42.7 (1.5 micro Coulomb) and 15.5 mM bupivacaine (1.1 micro Coulomb). (B) Lidocaine depresses lysophosphatidate-induced ICl(Ca) signaling in a dose-dependent manner. The half maximal inhibitory concentration (IC50) is 29.6 +/- 8.2 mM. (C) Bupivacaine depresses lysophosphatidate-induced ICl(Ca) signaling in a dose-dependent manner. The IC50is 4.5 +/- 1.2 mM.