title: Molecular and functional identification of organic anion transporter isoforms in cultured bovine mammary epithelial cells (BME-UV).
abstract: Mammary epithelial cells express a diversity of membrane transporters including members of organic cation and organic anion (OAT) transporter subfamilies. Four mammal OAT isoforms have been identified: OAT-1, OAT-2, OAT-3, and OAT-4. The pharmacological significance of OAT isoforms has been emphasized because of their role in the movement of a wide variety of substrates across epithelial barriers. The present study identified (molecularly and functionally) bovine OAT isoforms in bovine mammary epithelial (BME-UV) cells. mRNA expression levels of all tested transporters in BME-UV cells were less than expression levels of the corresponding transporters in bovine kidney. Directionality in the flux of P-aminohippuric acid and acetylsalicylate, compounds known to interact with OAT-1 and OAT-2, respectively, across BME-UV monolayers was not observed at the concentrations used in this study. Directionality was, however, observed in the flux of estrone sulfate (EsS). Adding probenecid, penicillin G or nonradiolabeled EsS to the apical donor compartment significantly increased the apical-to-basolateral flux of EsS across the BME-UV monolayer. These results suggest that BME-UV cells express an organic anion transport system, making it a potentially useful model to study the role of this transport system in the mammary epithelial barrier.
authors.affiliation: Department of Clinical Sciences, Kansas State University, Manhattan, KS 66506, USA.
authors.forename: M M
authors.initials: MM
authors.lastname: Al-Bataineh
authors.forename: D
authors.initials: D
authors.lastname: Van Der Merwe
authors.forename: B D
authors.initials: BD
authors.lastname: Schultz
authors.forename: R
authors.initials: R
authors.lastname: Gehring
mesh_terms: D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D004848:Epithelium / Q000378:metabolism; D005260:Female; D008321:Mammary Glands, Animal / Q000166:cytology* / Q000378:metabolism / Q000502:physiology; D027362:Organic Anion Transport Protein 1 / Q000235:genetics / Q000502:physiology; D027361:Organic Anion Transporters / Q000235:genetics / Q000502:physiology*; D029363:Organic Anion Transporters, Sodium-Dependent / Q000235:genetics / Q000502:physiology; D020033:Protein Isoforms / Q000235:genetics / Q000502:physiology; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D027362:Organic Anion Transport Protein 1; D027361:Organic Anion Transporters; D029363:Organic Anion Transporters, Sodium-Dependent; D020033:Protein Isoforms