Figure 8. Effect of arachidonic acid on mean macropatch currents, single-channel amplitude and open-channel probability.

Fractional macropatch and single-channel currents in inside-out patches in the presence of 10 μm arachidonic acid without (A) and with (B) a cocktail of three oxygenase inhibitors (indomethacin, NDGA and clotrimazole, each 20 μm). Data were normalized to the mean current measured before application of arachidonic acid (I_o) and plotted as mean ± s.e.m.C, voltage dependence of steady-state open-channel probability. The data represent the ensemble-averaged current of 11 consecutive current responses to ramp pulses (from −50 mV to +50 mV at 10 mV s⁻¹ rate) in the absence (control; continuous line) and presence of 5 μm arachidonic acid (○). The patch contained 5–6 channels. The P_o values were calculated as P_o / (I/V)/G_max, where I is the patch current, V is voltage and G_max is the maximal patch conductance at 0 mV.