Figure 1. Schematic representation of the ion transport system in the pancreatic duct cell. (For illustrative purposes, the Cl- and HCO3 - conductances on the apical membrane are represented as separate pathways. In reality, these ions probably move through the same channels (CFTR and CaCC) as determined by their permeability characteristics. The model is based on data derived from experiments on rat and guinea pig duct cells.)