Figure 4. Desensitization of I_K(ACh) by low-level activation.

A, nonadditivity of current evoked by Ado (10 μmol l⁻¹) plus ACh (20 μmol l⁻¹) and removal of desensitizing component. B and C, two examples of nonadditivity and removal of the desensitizing component of I_K(ACh) evoked by 20 μmol l⁻¹ ACh by low-level activation of current using 0.2 μmol l⁻¹ (B) or 0.2 and 0.5 μmol l⁻¹ ACh (B). Agonists were applied as indicated by horizontal bars.