Basolateral K conductance: role in regulation of NaCl absorption and secretion

In this review we explore the possible role of basolateral K conductance (gK) in the regulation of salt absorption and secretion. This inquiry is prompted by a growing body of evidence which, taken together, suggests that basolateral gK is very labile and that alterations in basolateral gK may be a key feature in both stimulatory and inhibitory regulatory mechanisms. We first consider the role of basolateral gK in relation to models for salt absorption and secretion, particularly in relation to the maintenance of cellular charge balance and the obligatory coupling between the apical and basolateral membranes that is produced by transcellular current flow. Next, we review some of the experimental evidence that suggests that changes in basolateral gK are associated with transport regulation. The cellular mechanisms that are known to impact on K channel regulation are considered in a general way, and finally, we consider the use of integrated models for understanding possible coordinate regulation of apical and basolateral cell membranes.