FIGURE 12.

Effect of the P2X7 antagonist A438079 on ATP-induced currents of hP2X4/hP2X7-coexpressing oocytes. Two-electrode voltage clamp measurements of ATP-induced current amplitudes (I_act,3s) at 3 s after the application of 0.1 mM ATP. Current amplitudes of the first and second ATP application are denoted (1) and (2), respectively. The theoretical current remaining after applying A438079 to P2X4/P2X7-expressing oocytes (rightmost column) was calculated as described in Section “Results.” The theoretical current amplitude was not significantly different from the measured value (next to rightmost column), indicating the lack of a P2X4/P2X7 phenotype related to A438079, which may be explained by A438079 affecting only homomeric P2X7 receptors. Data are means ± SD from 4–11 oocytes.