Biomaterial Database

Mechanism of Cl- transport in eel intestinal brush-border membrane vesicles. 1992

A De Giorgi, and L Carnimeo, and A Corcelli

Istituto di Fisiologia Generale, Università degli Studi, Bari, Italy.

Cl- transport was studied in a preparation of brush-border membrane vesicles (BBMV) from seawater eel intestine. 36Cl- uptake appeared to be stimulated by a positive inside membrane diffusion potential generated (a) by a concentration gradient of salts, the cations of which are more permeable than the anions, (b) by a K+ diffusion potential obtained by imposing a K+ concentration gradient (Cout greater than Cin) in the presence of valinomycin, (c) an inwardly directed H+ ion concentration gradient. The membrane-potential-driven Cl- transport was inhibited by 1 mM 5-nitro-2-(4-phenylpropyl-amino)-benzoic acid. Arachidonic acid also inhibited Cl- uptake in eel intestinal BBMV, but the effect appeared to be unspecific, as the unsaturated fatty acid also affected the Na+ dependent D-glucose uptake. The effect of arachidonic acid was reversed in the presence of bovine serum albumin. Cl- influx was the same in the presence of inwardly directed gradients of Li+, Na+ or K+, arguing against the presence of Na(+)-Cl-, as well as K(+)-Cl- cotransport. The absence of a significant contribution of the Na(+)-K(+)-2Cl- cotransport mechanism to the Cl- uptake in seawater eel intestinal BBMV was indicated from the observations that Cl- uptake was not stimulated by the simultaneous presence of inwardly directed Na+ and K+ gradients, and that it was nearly insensitive to 1 mM bumetanide in the presence of extravesicular Na+ and K+. Furthermore, no evidence for the dependence of Cl- uptake on the Na+ gradient was obtained under a short-circuited membrane diffusion potential, i.e. in the presence of equilibrated K+ and valinomycin.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
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
D009994	Osmolar Concentration	The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.	Ionic Strength,Osmolality,Osmolarity,Concentration, Osmolar,Concentrations, Osmolar,Ionic Strengths,Osmolalities,Osmolar Concentrations,Osmolarities,Strength, Ionic,Strengths, Ionic
D002712	Chlorides	Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.	Chloride,Chloride Ion Level,Ion Level, Chloride,Level, Chloride Ion
D004524	Eels	Common name for an order (Anguilliformes) of voracious, elongate, snakelike teleost fishes.	Anguilliformes,Eel
D006859	Hydrogen	The first chemical element in the periodic table with atomic symbol H, and atomic number 1. Protium (atomic weight 1) is by far the most common hydrogen isotope. Hydrogen also exists as the stable isotope DEUTERIUM (atomic weight 2) and the radioactive isotope TRITIUM (atomic weight 3). Hydrogen forms into a diatomic molecule at room temperature and appears as a highly flammable colorless and odorless gas.	Protium,Hydrogen-1
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
D001692	Biological Transport	The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.	Transport, Biological,Biologic Transport,Transport, Biologic
D012964	Sodium	A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.	Sodium Ion Level,Sodium-23,Ion Level, Sodium,Level, Sodium Ion,Sodium 23
D014634	Valinomycin	A cyclododecadepsipeptide ionophore antibiotic produced by Streptomyces fulvissimus and related to the enniatins. It is composed of 3 moles each of L-valine, D-alpha-hydroxyisovaleric acid, D-valine, and L-lactic acid linked alternately to form a 36-membered ring. (From Merck Index, 11th ed) Valinomycin is a potassium selective ionophore and is commonly used as a tool in biochemical studies.