Conductance pathways involved in chloride secretion and their regulation.

Abstract

Cystic fibrosis impairs the secretory activities of a variety of exocrine glands and other secretory epithelia in the intestines and airways. The secretion of salt and water across epithelia of this type is driven by a secondary active Cl transport mechanism (Frizzell et al., 1979). Chloride enters secretory cells due to the combined activities of three basolateral membrane transport events: Na/K/Cl co-transporters, Na/K pumps, and K channels. Chloride leaves secretory cells across the apical membranes by diffusion, and alterations in apical Cl conductance represent a pivotal control point that determines Cl secretion rate. A variety of hormones and neurotransmitters stimulate salt secretion via their intracellular mediators, cAMP and Ca. The overall Cl secretory process is electrogenic so that the co-ion, Na, accompanies Cl to the lumen via paracellular pathways, driven by the lumen-negative voltage arising from Cl secretion.KeywordsCystic FibrosisCystic Fibrosis AirwayOutward RectificationSecretory Epithelial CellOutward RectifierThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.