Figure 10. Correlation between NPPB-sensitive conductance and ouabain-sensitive current.

The ouabain-sensitive current did not increase linearly against the NPPB-sensitive conductance. The relationship between the NPPB-sensitive conductance and the ouabain-sensitive current was fitted by a Michaelis-Menten equation. The estimated value of the maximum ouabain-sensitive current (I_m) was 9·8 μA cm⁻²; the conductance showing the half-maximum ouabain-sensitive current (K_m) was estimated to be 104·3 μS cm⁻². The continuous line is drawn by the equation with these values (I_m of 9·8 μA cm⁻², K_m of 104·3 μS cm⁻²). Correlation coefficient = 0·86. The data fitting was done with a non-linear least-squares method.