Biomaterial Database

Operational modes of the organic anion exchanger in canine renal brush-border membrane vesicles. 1989

T G Steffens, and P D Holohan, and C R Ross

Department of Pharmacology, State University of New York Health Science Center, Syracuse 13210.

This study delineates the various operational modes catalyzed by the organic anion exchanger present in the canine renal brush-border membrane. The experiments examined the carrier-mediated effects of various organic and inorganic anions on the transport of either p-[3H]aminohippuric acid ([3H]PAH) or 36Cl-. [3H]PAH countertransport was significantly stimulated by PAH, urate, Cl-, Br-, HCO3-, and by a pH gradient. This pH stimulation remained in the absence of HCO3- (i.e., under N2), implying PAH-OH- exchange. Furosemide, bumetanide, penicillin, and probenecid inhibited countertransport of [3H]PAH. Likewise, the above anions produced cis inhibition of [3H]PAH transport. The cis and trans effects of SO4(-2) and formate were minimal. 36Cl- countertransport was stimulated by PAH, Cl-, Br-, HCO3-, formate, and by a pH gradient that was effective even in the absence of HCO3- (i.e., under N2), implying Cl- -OH- exchange. Cl- -OH- and Cl- -Cl- exchange was inhibited by PAH. In each instance, the trans-stimulation of 36Cl- efflux was insensitive to maneuvers that created an inside-positive membrane potential, demonstrating electroneutral mediated exchange. We conclude that the organic anion transporter can operate in three distinct exchange modes: organic-organic, organic-inorganic, and inorganic-inorganic.

UI	MeSH Term	Description	Entries
D007473	Ion Channels	Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.	Membrane Channels,Ion Channel,Ionic Channel,Ionic Channels,Membrane Channel,Channel, Ion,Channel, Ionic,Channel, Membrane,Channels, Ion,Channels, Ionic,Channels, Membrane
D007474	Ion Exchange	Reversible chemical reaction between a solid, often one of the ION EXCHANGE RESINS, and a fluid whereby ions may be exchanged from one substance to another. This technique is used in water purification, in research, and in industry.	Exchange, Ion
D007668	Kidney	Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.	Kidneys
D008565	Membrane Proteins	Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.	Cell Membrane Protein,Cell Membrane Proteins,Cell Surface Protein,Cell Surface Proteins,Integral Membrane Proteins,Membrane-Associated Protein,Surface Protein,Surface Proteins,Integral Membrane Protein,Membrane Protein,Membrane-Associated Proteins,Membrane Associated Protein,Membrane Associated Proteins,Membrane Protein, Cell,Membrane Protein, Integral,Membrane Proteins, Integral,Protein, Cell Membrane,Protein, Cell Surface,Protein, Integral Membrane,Protein, Membrane,Protein, Membrane-Associated,Protein, Surface,Proteins, Cell Membrane,Proteins, Cell Surface,Proteins, Integral Membrane,Proteins, Membrane,Proteins, Membrane-Associated,Proteins, Surface,Surface Protein, Cell
D008871	Microvilli	Minute projections of cell membranes which greatly increase the surface area of the cell.	Brush Border,Striated Border,Border, Brush,Border, Striated,Borders, Brush,Borders, Striated,Brush Borders,Microvillus,Striated Borders
D010130	p-Aminohippuric Acid	The glycine amide of 4-aminobenzoic acid. Its sodium salt is used as a diagnostic aid to measure effective renal plasma flow (ERPF) and excretory capacity.	4-Aminohippuric Acid,para-Aminohippuric Acid,Aminohippurate Sodium,Aminohippuric Acid,Nephrotest,Sodium Para-Aminohippurate,p-Aminohippurate,4 Aminohippuric Acid,Para-Aminohippurate, Sodium,Sodium Para Aminohippurate,Sodium, Aminohippurate,p Aminohippurate,p Aminohippuric Acid,para Aminohippuric Acid
D002352	Carrier Proteins	Proteins that bind or transport specific substances in the blood, within the cell, or across cell membranes.	Binding Proteins,Carrier Protein,Transport Protein,Transport Proteins,Binding Protein,Protein, Carrier,Proteins, Carrier
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001693	Biological Transport, Active	The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.	Active Transport,Uphill Transport,Active Biological Transport,Biologic Transport, Active,Transport, Active Biological,Active Biologic Transport,Transport, Active,Transport, Active Biologic,Transport, Uphill