Biomaterial Database

Electrical properties of the medullary collecting duct in the rat. 1980

J P Hayslett, and K A Backman, and D A Schon

Studies were performed in the rat to determine the transepithelial potential difference (PD) of the medullary collecting duct (MCD). With the microcatheter as an exploring electrode the PD from duct lumen to the reference electrode, placed in peritoneal fluid, was approximatley 1 mV, lumen positive, in the MCD. It was unlikely that the polarity and small magnitude of PD was due to an artifact created by the microcatheter, since essentially similar results were obtained by transmural puncture of the inner third of the duct using Ling-Gerard glass electrodes and glass microelectrodes, tip OD 3-5 micron. Moreover, a PD of a few millivolts, lumen positive, was observed in experimental states characterized by marked increases in potassium and hydrogen ion secretion and sodium absorption. Further studies showed that the diffusion potential existing within the interstitial fluid compartment, between papilla and reference electrode, was approximately +2 mV, owing to the higher NaCl concentration in the papillary area. These data demonstrate, therefore, that the transepithelial PD in MCD approaches zero in control animals, and is not substantially altered by marked changes in net electrolyte transport.

UI	MeSH Term	Description	Entries
D007684	Kidney Tubules	Long convoluted tubules in the nephrons. They collect filtrate from blood passing through the KIDNEY GLOMERULUS and process this filtrate into URINE. Each renal tubule consists of a BOWMAN CAPSULE; PROXIMAL KIDNEY TUBULE; LOOP OF HENLE; DISTAL KIDNEY TUBULE; and KIDNEY COLLECTING DUCT leading to the central cavity of the kidney (KIDNEY PELVIS) that connects to the URETER.	Kidney Tubule,Tubule, Kidney,Tubules, Kidney
D007685	Kidney Tubules, Collecting	Straight tubes commencing in the radiate part of the kidney cortex where they receive the curved ends of the distal convoluted tubules. In the medulla the collecting tubules of each pyramid converge to join a central tube (duct of Bellini) which opens on the summit of the papilla.	Kidney Collecting Ducts,Kidney Collecting Duct,Collecting Duct, Kidney,Collecting Ducts, Kidney
D008297	Male		Males
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
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D004039	Diet, Sodium-Restricted	A diet which contains very little sodium chloride. It is prescribed by some for hypertension and for edematous states. (Dorland, 27th ed)	Diet, Low-Salt,Diet, Low-Sodium,Diet, Salt-Free,Diet, Low Salt,Diet, Low Sodium,Diet, Salt Free,Diet, Sodium Restricted,Diets, Low-Salt,Diets, Low-Sodium,Diets, Salt-Free,Diets, Sodium-Restricted,Low-Salt Diet,Low-Salt Diets,Low-Sodium Diet,Low-Sodium Diets,Salt-Free Diet,Salt-Free Diets,Sodium-Restricted Diet,Sodium-Restricted Diets
D000138	Acidosis	A pathologic condition of acid accumulation or depletion of base in the body. The two main types are RESPIRATORY ACIDOSIS and metabolic acidosis, due to metabolic acid build up.	Metabolic Acidosis,Acidoses,Acidoses, Metabolic,Acidosis, Metabolic,Metabolic Acidoses
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
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