A, traces of currents recorded during incremental 10 mV step depolarizations in control and in Kv1.5-transfected cardiomyocytes. B, effects of MCD on the outward current elicited by a test pulse from −80 to +60 mV in control, and after 350, 500 and 600 s MCD applications. Effect of 500 μm 4-AP on 650 s MCD-stimulated current is also shown. C, time course of the MCD and MCD–cholesterol complex effects on the outward current.