Figure 2. Effect of methoxamine on INain the presence of alpha1-adrenergic blockade with prazosin. Prazosin (1 micro Meter) was added to the external bath solution throughout all phases of the experiment. Time course of changes in membrane current, recorded from a VHof -80 mV to a test potential of -20 mV (protocol shown in an inset), is shown in representative cells for either 10 (A) or 100 micro Meter (B) methoxamine. (C) Summary of the block of INaat methoxamine concentrations of 10 (n = 6) and 100 micro Meter (n = 8) is shown in the continued presence of prazosin. *Significantly different versus control.