Biomaterial Database

Modulation of K-Cl cotransport in volume-clamped low-K sheep erythrocytes by pH, magnesium, and ATP. 1996

O Ortiz-Carranza, and N C Adragna, and P K Lauf

Department of Physiology and Biophysics, Wright State University, Dayton, Ohio 45401, USA.

Cellular pH, ionized Mg (Mgi2+), and MgATP concentration of red blood cells, concomitantly with cell volume, change transiently during circulation. The action of these three effectors on Cl-dependent K efflux was examined in low-K sheep red blood cells with constant cell volume. Activation of K-Cl efflux by Mgi2+ extraction required ATP, suggesting that phosphorylation of a putative component occurred before Mgi2+ extraction. Conversely, Mg and ATP were synergistic inhibitors of K-Cl cotransport, since maximal inhibition was observed only in cells containing both ATP and > 300 microM Mgi2+. Both findings suggest dual roles for Mg and ATP. At 300-600 microM Mgi2+, lowering the pH from approximately 7.4 to approximately 6.5 stimulated K-Cl efflux only in fed cells, suggesting that protons oppose or release the inhibition by Mgi2+ and ATP. A direct effect of both protons and Mgi2+ on the cotransporter is suggested by their inhibition of K-Cl efflux in ATP-depleted cells. These findings are discussed in light of the current phosphorylation/dephosphorylation hypothesis.

UI	MeSH Term	Description	Entries
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
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.
D002712	Chlorides	Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.	Chloride,Chloride Ion Level,Ion Level, Chloride,Level, Chloride Ion
D004911	Erythrocyte Volume	Volume of circulating ERYTHROCYTES . It is usually measured by RADIOISOTOPE DILUTION TECHNIQUE.	Red Cell Mass,Erythrocyte Volumes,Mass, Red Cell,Masses, Red Cell,Red Cell Masses,Volume, Erythrocyte,Volumes, Erythrocyte
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D000255	Adenosine Triphosphate	An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.	ATP,Adenosine Triphosphate, Calcium Salt,Adenosine Triphosphate, Chromium Salt,Adenosine Triphosphate, Magnesium Salt,Adenosine Triphosphate, Manganese Salt,Adenylpyrophosphate,CaATP,CrATP,Manganese Adenosine Triphosphate,MgATP,MnATP,ATP-MgCl2,Adenosine Triphosphate, Chromium Ammonium Salt,Adenosine Triphosphate, Magnesium Chloride,Atriphos,Chromium Adenosine Triphosphate,Cr(H2O)4 ATP,Magnesium Adenosine Triphosphate,Striadyne,ATP MgCl2
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
D012756	Sheep	Any of the ruminant mammals with curved horns in the genus Ovis, family Bovidae. They possess lachrymal grooves and interdigital glands, which are absent in GOATS.	Ovis,Sheep, Dall,Dall Sheep,Ovis dalli
D014882	Water-Electrolyte Balance	The balance of fluid in the BODY FLUID COMPARTMENTS; total BODY WATER; BLOOD VOLUME; EXTRACELLULAR SPACE; INTRACELLULAR SPACE, maintained by processes in the body that regulate the intake and excretion of WATER and ELECTROLYTES, particularly SODIUM and POTASSIUM.	Fluid Balance,Electrolyte Balance,Balance, Electrolyte,Balance, Fluid,Balance, Water-Electrolyte,Water Electrolyte Balance