Figure 6.

Diazoxide enhances whole-cell K⁺ current in cardiomyocytes after treatment with DNFB, a creatine kinase inhibitor. (A) Time course of the diazoxide (300 μM) response of steady state whole-cell outward currents before and after application of DNFB (100 μM). Under conditions of physiological ionic concentration gradients with internal 2 mM ATP, steady state currents were measured at the end of 1-s pulses to +10 mV from a holding potential of −50 mV (●). In addition, the baseline current measured at −50 mV is shown (○). Original current traces corresponding to numbered circles are shown as Insets. Cardiomyocytes were pretreated with oligomycin (1 mg/ml) for 5 min to disrupt mitochondrial function and prevent effects of diazoxide through mitochondria. (B) Average currents measured at +10 mV from eight cardiomyocytes.