Figure 7.

Inhibition of I_M in P2Y₁ receptor expressing cells. A, I_M was measured by the amphotericin B-perforated patch technique in a wild-type PC12 cell and in a PC12 cell stably expressing P2Y₁ receptors (PC12-P2Y₁). The current traces shown were obtained by clamping the cell at -30 mV and by applying 1 sec hyperpolarizing voltage steps to -55 mV; the recordings were performed before (control), during, and after (washout) the application of the indicated concentrations of ADP. B, Four to six PC12-P2Y₁ cells were exposed to the indicated concentrations of ADP, and the graph shows the concentration dependence of the inhibition of I_M relaxation amplitudes, determined as shown in A.