Figure 5.

In the absence of extracellular calcium, ouabain had no effect on the potassium currents of cells in MEMs. (A) Series of currents representative of the different experimental conditions. The pair of series on the left side were obtained from cells in a mature monolayer, which had been either untreated or treated with ouabain for 6 hours. The pair of series on the right side was obtained from cells in mature monolayers from which calcium had been removed from the extracellular medium before treatment with ouabain. (B) The graphs (B1–B4) show the relationship between the different parameters (current density, conductance density, g/gmax and tau_on) and the transmembrane voltage for the different experimental groups (with and without calcium, and with and without ouabain). The symbols for each group are shown in the box located below (B2,B3). (C) The bar charts (C1–C5) show the average values (±SE) obtained in each experimental group as well as the result of the statistical comparison between them. The numbers above the bars indicate the number of repetitions in each group. The asterisks above the horizontal lines denote a statistically significant difference between the means (±SE) of treated versus untreated cells; (*) indicates a p < 0.05.