Figure 5.

Effect of BHQ on activation and inactivation curves. Steady-state inactivation curves, obtained in the absence (CTRL) and presence of 50 μM BHQ, 250 u ml⁻¹ SOD or BHQ plus SOD, were fitted to the Boltzmann equation. Peak current values were used. The steady-state inactivation curve was obtained using the double-pulse protocol (see Methods section). The current measured during the test pulse is plotted against membrane potential and expressed as relative amplitude (a) and in per cent of control (b). Activation curves were obtained from the current–voltage relationships of Figure 1 and fitted to the Boltzmann equation (see Methods section). Relative amplitude is plotted against membrane potential. Each point represents the means±s.e.mean of four to seven cells (n=3).