title: Stimulation of Cl/HCO3 exchange in rat duodenal brush border membrane vesicles by cAMP.
abstract: Brush border membrane vesicles have been used to study the regulation of rat duodenal HCO3 secretion. When vesicles were loaded with cAMP and ATP SITS-sensitive Cl/HCO3 exchange (unidirectional 36Cl influx in response to an outward-facing OH/HCO3 gradient) was stimulated by approximately 25%. In contrast, there was no effect of cAMP upon SITS-insensitive 36Cl uptake. The stimulation of Cl/HCO3 exchange caused by cAMP was abolished in the presence of a specific heat-stable cAMP-dependent protein kinase inhibitor. These results suggest that Cl/HCO3 exchange, and hence HCO3 secretion, is regulated by cAMP via phosphorylation of some component of the membrane associated with the transport protein.
authors.affiliation: Department of Medicine, Hope Hospital, University of Manchester School of Medicine, Salford, Great Britain.
authors.forename: C R
authors.initials: CR
authors.lastname: Dunk
authors.forename: C D
authors.initials: CD
authors.lastname: Brown
authors.forename: L A
authors.initials: LA
authors.lastname: Turnberg
mesh_terms: D000818:Animals; D001639:Bicarbonates / Q000378:metabolism*; D001692:Biological Transport; D002712:Chlorides / Q000378:metabolism*; D000242:Cyclic AMP / Q000502:physiology*; D004386:Duodenum / Q000378:metabolism*; D005615:Freezing; D005947:Glucose / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D008871:Microvilli / Q000378:metabolism; D047428:Protein Kinase Inhibitors; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D001639:Bicarbonates; D002712:Chlorides; D047428:Protein Kinase Inhibitors; D000242:Cyclic AMP; D005947:Glucose