title: p-Aminohippurate transport in rat renal brush-border membranes: a potential-sensitive transport system and an anion exchanger.
abstract: Transport mechanisms of p-aminohippurate (PAH) were investigated in rat renal brush-border membrane vesicles. The uptake of PAH was stimulated by an inside-positive membrane potential created by K+ and valinomycin. This potential-stimulated uptake of PAH was inhibited by various anion transport inhibitors and was saturable. In addition, PAH uptake in the presence of valinomycin was linearly increased in proportion to log[K+]out/[K+]in. On one hand, PAH uptake was stimulated by [14C]PAH/PAH or [14C]PAH/Cl- exchange, and the [14C]PAH/PAH exchange was insensitive to the membrane potential. The uptake by the exchanger was also inhibited by anion transport inhibitors, but the potential-stimulated uptake of PAH was more sensitive to furosemide and 4,4'-diisothiocyano-2,2'-disulfonic stilbene. On the contrary, [14C]PAH/PAH exchange was more sensitive to urate than the potential-stimulated uptake of PAH. These findings indicate that PAH is transported by two distinct transport systems in rat renal brush-border membranes, a potential-sensitive transport system and an anion exchanger.
authors.affiliation: Department of Pharmacy, Kyoto University Hospital, Faculty of Medicine, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ohoka
authors.forename: M
authors.initials: M
authors.lastname: Takano
authors.forename: T
authors.initials: T
authors.lastname: Okano
authors.forename: S
authors.initials: S
authors.lastname: Maeda
authors.forename: K
authors.initials: K
authors.lastname: Inui
authors.forename: R
authors.initials: R
authors.lastname: Hori
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; D002712:Chlorides / Q000493:pharmacokinetics; D004058:Diffusion; D005665:Furosemide / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism; D066298:In Vitro Techniques; D007474:Ion Exchange; D007668:Kidney / Q000378:metabolism* / Q000648:ultrastructure; D008297:Male; D008564:Membrane Potentials / Q000502:physiology; D008871:Microvilli / Q000378:metabolism; D011188:Potassium / Q000493:pharmacokinetics; D011506:Proteins / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D014527:Uric Acid / Q000494:pharmacology; D014634:Valinomycin / Q000494:pharmacology; D010130:p-Aminohippuric Acid / Q000493:pharmacokinetics*
chemical_list: D002712:Chlorides; D011506:Proteins; D014634:Valinomycin; D014527:Uric Acid; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; D005665:Furosemide; D005947:Glucose; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D011188:Potassium; D010130:p-Aminohippuric Acid