title: Cl/HCO3 exchange in the basolateral membrane domain of rat jejunal enterocyte.
abstract: Basolateral membrane vesicles isolated from rat jejunal enterocyte and well purified from brush border contamination were tested to examine Cl and HCO3 movements. Uptake experiments provided no evidence for a coupling between Na and HCO3 fluxes; K-HCO3 and K-Cl cotransports also could be excluded. Transport studies revealed the presence of a Cl/HCO3 exchanger accepting other anions and inhibitable by the disulfonic stilbenes SITS and DIDS. We can exclude that the evidenced HCO3-dependent Cl uptake is due to brush border contamination, since in jejunal brush border membranes this mechanism, if present, has a very low transport rate. Besides the Cl/HCO3 antiporter, a Cl-conductive pathway seems to exist in jejunal basolateral membranes.
authors.affiliation: Dipartimento di Fisiologia e Biochimica Generali, Università di Milano, Italy.
authors.forename: M N
authors.initials: MN
authors.lastname: Orsenigo
authors.forename: M
authors.initials: M
authors.lastname: Tosco
authors.forename: A
authors.initials: A
authors.lastname: Faelli
mesh_terms: D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D001639:Bicarbonates / Q000493:pharmacokinetics; D002352:Carrier Proteins / Q000502:physiology*; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D002463:Cell Membrane Permeability / Q000187:drug effects / Q000502:physiology; D027963:Chloride-Bicarbonate Antiporters; D002712:Chlorides / Q000493:pharmacokinetics; D007408:Intestinal Absorption / Q000187:drug effects / Q000502:physiology; D007583:Jejunum / Q000166:cytology* / Q000502:physiology / Q000648:ultrastructure; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D001639:Bicarbonates; D002352:Carrier Proteins; D027963:Chloride-Bicarbonate Antiporters; D002712:Chlorides; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid