title: Sodium-coupled chloride transport by epithelial tissues.
abstract: There is compelling evidence that active Cl absorption by a variety of epithelia, widely distributed throughout the animal kingdom, is the result of an electrically neutral Na-coupled transport process at the luminal membrane and that the energy for transcellular Cl movement is derived from the Na gradient across that barrier. These co-transport processes are found predominantly in "leaky" or "moderately leaky" epithelia and permit these tissues to absorb Na and Cl with high degrees of efficacy. In addition, there is a growing body of evidence that cyclic AMP and Ca-induced electrogenic Cl secretion by a wide variety of epithelia may involve electrically neutral, Na-coupled Cl entry across the contraluminal membrane and that the energy for these secretory processes is derived from the Na-gradient across that barrier. A model for electrogenic Cl secretion that accounts for the available data is presented.
mesh_terms: D000042:Absorption; D000818:Animals; D001693:Biological Transport, Active; D002712:Chlorides / Q000378:metabolism*; D002794:Choline / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D004594:Electrophysiology; D004848:Epithelium / Q000378:metabolism*; D005665:Furosemide / Q000494:pharmacology; D005704:Gallbladder / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D008564:Membrane Potentials; D008954:Models, Biological; D012867:Skin / Q000378:metabolism; D012964:Sodium / Q000378:metabolism*; D001743:Urinary Bladder / Q000378:metabolism
chemical_list: D002712:Chlorides; D005665:Furosemide; D012964:Sodium; D000242:Cyclic AMP; D002794:Choline