Figure 11. Effect of varying the distribution of K⁺ permeability between apical and basolateral membranes on key variables in the secreting duct model.

Steady‐state values in the stimulated condition of apical membrane potential (E _ap) (A), secretory volume flow (J _v) (B) and secreted HCO₃ ⁻ concentration ([HCO₃ ⁻]_l) (C) for a range of apical K⁺ permeability values expressed as a fraction of the whole‐cell K⁺ permeability, which was maintained at a constant value. The red data points show the value (0.01) used for optimization. The vertical dotted lines show the maximum value (0.1) estimated for rat pancreatic duct cells (Novak & Greger, 1991). The Cl⁻:HCO₃ ⁻ stoichiometry of the SLC26A6 exchanger was assumed to be 1:2. [Color figure can be viewed at wileyonlinelibrary.com]