Fig. 9. Inhibition of the HA signaling cascade leading to increased membrane currents. Membrane current densities of mock- and GRC-injected COS-7 cells were recorded at a membrane potential of -80 mV in standard external NaCl solution. The cells were pretreated with the inhibitors as described in Fig. 8, except for PTX, which was preincubated for 30 minutes to 8 hours, and for SK&F 93625, which was added after induction of GRC currents by HA. Each symbol represents one measured cell.