Figure 5. Effect of halothane (1.2 mM) and methoxamine (10 micro Meter) on steady-state inactivation. The shifts shown are corrected for spontaneous background shift. Peak Na sup + currents were recorded during test potential to -20 mV after preconditioning pulse potentials from -130 mV to +20 mV in 10-mV increments. The holding potential was -110 mV. Peak currents normalized to control conditions are shown for control (open circles), halothane (filled circles), and halothane plus methoxamine (open triangles) and washout (filled triangles). Steady-state inactivation curves were fitted to a Boltzmann distribution. The potentials for half-maximal inactivation (V1/2) for this example were -69.5 mV (control), -72.9 mV (halothane), -74.2 mV (halothane plus methoxamine), and -71.4 mV (washout).
