Mouse and human β-cells contain functional TASK-1 channels. A, Left panel, Inhibition of mouse β-cell TASK-1 currents with 200nM A1899 (the currents are normalized to cell capacitance; currents recorded in 14mM glucose, 100μM tolbutamide, and 20mM TEA; currents recorded in response to a voltage ramp from −120 to 60 mV over a 1-second interval). Right panel, Average mouse β-cell TASK-1 current amplitude at −120 mV and +60 mV potentials before or 5 minutes after A1899 treatment (±SEM; *, P < .05). B, Left panel, Inhibition of human β-cell TASK-1 currents with 200nM A1899; the currents were normalized to cell capacitance (currents recorded in 14mM glucose, 100μM tolbutamide. and 20mM TEA). Right panel, Average human β-cell TASK-1 current amplitude at −120 mV and +60 mV potentials before or 5 minutes after A1899 treatment (±SEM; *, P < .05).