Biomaterial Database

Effects of luminal hyperosmolality on cellular and paracellular ion transport pathways in necturus antrum. 1987

D I Soybel, and S W Ashley, and K DeSchryver-Kecskemeti, and L Y Cheung

Using microelectrode techniques, the electrical properties of the cell membranes and paracellular pathway of the surface epithelium in Necturus antrum were studied under control conditions and during exposure to mucosal solutions made hyperosmotic by addition of sucrose or urea. Sucrose (500 mmol/kg) significantly decreased apical membrane resistances (Ra, from 5501 +/- 841 to 3789 +/- 597 omega X cm2, p less than 0.01), and basolateral membrane resistances (Rb, from 3805 +/- 646 to 2594 +/- 429 omega X cm2, p less than 0.05). The paracellular pathway resistance (Rs) increased significantly from 720 +/- 57 to 822 +/- 71 omega X cm2 (p less than 0.001). Urea (500 mmol/kg) more markedly diminished the apical and basolateral resistances (Ra, from 4303 +/- 663 to 1914 +/- 286 omega X cm2, p less than 0.001; and Rb, from 2600 +/- 474 to 1034 +/- 213, p less than 0.001). In contrast to sucrose, urea-containing solutions significantly decreased Rs (from 682 +/- 78 to 398 +/- 57 omega X cm2, p less than 0.001). Electron micrographs revealed dilatation of lateral intercellular spaces and disruption of desmosomes in tissues exposed to urea, but no visible alterations in tissues exposed to solutions containing sucrose. The resistance of the cellular pathway to ion permeation was thus diminished during exposure to both solutes. In contrast, changes in resistance of the paracellular pathway appeared to depend on the effects of each solute on dimensions and structures of the intercellular pathways.

UI	MeSH Term	Description	Entries
D007552	Isotonic Solutions	Solutions having the same osmotic pressure as blood serum, or another solution with which they are compared. (From Grant & Hackh's Chemical Dictionary, 5th ed & Dorland, 28th ed)	Solutions, Isotonic
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
D008839	Microelectrodes	Electrodes with an extremely small tip, used in a voltage clamp or other apparatus to stimulate or record bioelectric potentials of single cells intracellularly or extracellularly. (Dorland, 28th ed)	Electrodes, Miniaturized,Electrode, Miniaturized,Microelectrode,Miniaturized Electrode,Miniaturized Electrodes
D009337	Necturus	A genus of the Proteidae family with five recognized species, which inhabit the Atlantic and Gulf drainages.	Mudpuppy,Mudpuppies
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
D011706	Pyloric Antrum	The region between the sharp indentation at the lower third of the STOMACH (incisura angularis) and the junction of the PYLORUS with the DUODENUM. Pyloric antral glands contain mucus-secreting cells and gastrin-secreting endocrine cells (G CELLS).	Antrum, Pyloric,Gastric Antrum,Antrum, Gastric,Antrums, Gastric,Antrums, Pyloric,Gastric Antrums,Pyloric Antrums
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D004553	Electric Conductivity	The ability of a substrate to allow the passage of ELECTRONS.	Electrical Conductivity,Conductivity, Electric,Conductivity, Electrical
D004848	Epithelium	The layers of EPITHELIAL CELLS which cover the inner and outer surfaces of the cutaneous, mucus, and serous tissues and glands of the body.	Mesothelium,Epithelial Tissue,Mesothelial Tissue,Epithelial Tissues,Mesothelial Tissues,Tissue, Epithelial,Tissue, Mesothelial,Tissues, Epithelial,Tissues, Mesothelial
D000077331	Ringer's Solution	An isotonic solution; the base contains SODIUM CHLORIDE; POTASSIUM CHLORIDE; and CALCIUM CHLORIDE. Other chemicals, such as SODIUM BICARBONATE or acetate salts may be added, as needed for pH buffering, or as an energy source.	Ringers Solution,Ringer Solution