Figure 2.
Effects of the extracellular K+ concentration on the slope and reversal potential of IKir
A, voltage dependence of the peak IKir recorded in fibres bathed with external solutions containing 96 mm (filled circles), 48 mm (open circles), 24 mm (filled squares) and 12 mm (open squares) [K+]o. The symbols are connec-ted with lines of the same colour, and the bars represent SEM. B, enlarged section of the plot in A to show the leftward shift of reversal potential of the currents in response to reduced [K+]o. The reversal potentials for 96, 48, 24 and 12 mm were −4.5, −26, −43 and −64 mV, respectively. The corresponding theoretical EK values were (in mV): −11 (filled circles), −24 (open circles), −46 (filled squares) and −64 (open squares).