title: H+-gradient-dependent active transport of tetraethylammonium cation in apical-membrane vesicles isolated from kidney epithelial cell line LLC-PK1.
abstract: Transport of [3H]tetraethylammonium (NEt4+), an organic cation, has been studied by using apical-membrane vesicles isolated from cultured kidney epithelial cell line LLC-PK1. The uptake of NEt4+ by apical-membrane vesicles was osmotically sensitive, time-dependent and saturable. The presence of an H+ gradient ([H+]i greater than [H+]o) induced a marked stimulation of NEt4+ uptake against its concentration gradient (overshoot phenomenon), and this concentrative uptake was inhibited by HgCl2. These results suggest that apical membranes isolated from the LLC-PK1 cells retain the transport characteristics of NEt4+ similar to those observed in renal brush-border membranes.
authors.forename: K
authors.initials: K
authors.lastname: Inui
authors.forename: H
authors.initials: H
authors.lastname: Saito
authors.forename: R
authors.initials: R
authors.lastname: Hori
mesh_terms: D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D004848:Epithelium / Q000378:metabolism; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D008627:Mercuric Chloride / Q000494:pharmacology; D009994:Osmolar Concentration; D011522:Protons; D013552:Swine; D019789:Tetraethylammonium; D013757:Tetraethylammonium Compounds / Q000378:metabolism*
chemical_list: D011522:Protons; D013757:Tetraethylammonium Compounds; D008627:Mercuric Chloride; D019789:Tetraethylammonium