Chloride-Bicarbonate Antiporters
Electroneutral chloride bicarbonate exchangers that allow the exchange of BICARBONATE IONS exchange for CHLORIDE IONS across the cellular membrane. The action of specific antiporters in this class serve important functions such as allowing the efficient exchange of bicarbonate across red blood cell membranes as they passage through capillaries and the reabsorption of bicarbonate ions by the kidney.
Bicarbonates
Inorganic salts that contain the -HCO3 radical. They are an important factor in determining the pH of the blood and the concentration of bicarbonate ions is regulated by the kidney. Levels in the blood are an index of the alkali reserve or buffering capacity.
Antiporters
SLC4A Proteins
Bicarbonate transporters that move BICARBONATE IONS in exchange of CHLORIDE IONS or SODIUM IONS across membranes. They regulate acid-base HOMEOSTASIS, cell volume and intracellular pH. Members include CHLORIDE-BICARBONATE ANTIPORTERS (SLC4A1, 2, 3, and 9); SODIUM-COUPLED BICARBONATE TRANSPORTERS (SLC4A4 and 5, 7, 8 and 10); and a sodium borate cotransporter (SLC4A11 protein).
Chlorides
Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.
Anion Exchange Protein 1, Erythrocyte
A major integral transmembrane protein of the ERYTHROCYTE MEMBRANE. It is the anion exchanger responsible for electroneutral transporting in CHLORIDE IONS in exchange of BICARBONATE IONS allowing CO2 uptake and transport from tissues to lungs by the red blood cells. Genetic mutations that result in a loss of the protein function have been associated with type 4 HEREDITARY SPHEROCYTOSIS.
Anion Transport Proteins
Membrane proteins whose primary function is to facilitate the transport of negatively charged molecules (anions) across a biological membrane.
Sodium Bicarbonate
Potassium-Hydrogen Antiporters
Membrane proteins that allow the exchange of hydrogen ions for potassium ions across the cellular membrane. The action of these antiporters influences intracellular pH and potassium ion homeostasis.
Hydrogen-Ion Concentration
Sodium-Hydrogen Antiporter
Chloride Channels
Sodium Chloride
A ubiquitous sodium salt that is commonly used to season food.
Zygosaccharomyces
Sodium
Metals, Alkali
Metals that constitute group 1(formerly group Ia) of the periodic table. They are the most strongly electropositive of the metals. Note that HYDROGEN is not considered an alkali metal even though it falls under the group 1 heading in the periodic table.
Lithium Chloride
A salt of lithium that has been used experimentally as an immunomodulator.
Acid-Base Equilibrium
The balance between acids and bases in the BODY FLUIDS. The pH (HYDROGEN-ION CONCENTRATION) of the arterial BLOOD provides an index for the total body acid-base balance.
Lithium
Acidosis
Vinyl Chloride
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.
Cations, Monovalent
Alkalies
Usually a hydroxide of lithium, sodium, potassium, rubidium or cesium, but also the carbonates of these metals, ammonia, and the amines. (Grant & Hackh's Chemical Dictionary, 5th ed)
Ion Transport
Biological Transport
Sodium-Bicarbonate Symporters
Proteins that cotransport sodium ions and bicarbonate ions across cellular membranes.
Proton Pumps
Integral membrane proteins that transport protons across a membrane. This transport can be linked to the hydrolysis of ADENOSINE TRIPHOSPHATE. What is referred to as proton pump inhibitors frequently is about POTASSIUM HYDROGEN ATPASE.
Salts
Molecular Sequence Data
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Hydrogen
The first chemical element in the periodic table. It has the atomic symbol H, atomic number 1, and atomic weight [1.00784; 1.00811]. It exists, under normal conditions, as a colorless, odorless, tasteless, diatomic gas. Hydrogen ions are PROTONS. Besides the common H1 isotope, hydrogen exists as the stable isotope DEUTERIUM and the unstable, radioactive isotope TRITIUM.
Cation Transport Proteins
Membrane proteins whose primary function is to facilitate the transport of positively charged molecules (cations) across a biological membrane.
Carbon Dioxide
Polyvinyl Chloride
Acetazolamide
One of the CARBONIC ANHYDRASE INHIBITORS that is sometimes effective against absence seizures. It is sometimes useful also as an adjunct in the treatment of tonic-clonic, myoclonic, and atonic seizures, particularly in women whose seizures occur or are exacerbated at specific times in the menstrual cycle. However, its usefulness is transient often because of rapid development of tolerance. Its antiepileptic effect may be due to its inhibitory effect on brain carbonic anhydrase, which leads to an increased transneuronal chloride gradient, increased chloride current, and increased inhibition. (From Smith and Reynard, Textbook of Pharmacology, 1991, p337)
Escherichia coli
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
Buffers
A chemical system that functions to control the levels of specific ions in solution. When the level of hydrogen ion in solution is controlled the system is called a pH buffer.
Escherichia coli Proteins
Proteins obtained from ESCHERICHIA COLI.
Cations
Ammonium Chloride
Amino Acid Sequence
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Protons
Vacuoles
Carbonic Anhydrases
A family of zinc-containing enzymes that catalyze the reversible hydration of carbon dioxide. They play an important role in the transport of CARBON DIOXIDE from the tissues to the LUNG. EC 4.2.1.1.
Absorption
4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid
Mercuric Chloride
Homeostasis
Calcium Chloride
Carbonic Anhydrase Inhibitors
A class of compounds that reduces the secretion of H+ ions by the proximal kidney tubule through inhibition of CARBONIC ANHYDRASES.
Ethoxzolamide
Methylene Chloride
Dialysis Solutions
Potassium Chloride
A white crystal or crystalline powder used in BUFFERS; FERTILIZERS; and EXPLOSIVES. It can be used to replenish ELECTROLYTES and restore WATER-ELECTROLYTE BALANCE in treating HYPOKALEMIA.
Acidosis, Respiratory
Respiratory retention of carbon dioxide. It may be chronic or acute.
Carrier Proteins
Proteolipids
Protein-lipid combinations abundant in brain tissue, but also present in a wide variety of animal and plant tissues. In contrast to lipoproteins, they are insoluble in water, but soluble in a chloroform-methanol mixture. The protein moiety has a high content of hydrophobic amino acids. The associated lipids consist of a mixture of GLYCEROPHOSPHATES; CEREBROSIDES; and SULFOGLYCOSPHINGOLIPIDS; while lipoproteins contain PHOSPHOLIPIDS; CHOLESTEROL; and TRIGLYCERIDES.
Sequence Homology, Amino Acid
Electron Transport Complex I
A flavoprotein and iron sulfur-containing oxidoreductase complex that catalyzes the conversion of UBIQUINONE to ubiquinol. In MITOCHONDRIA the complex also couples its reaction to the transport of PROTONS across the internal mitochondrial membrane. The NADH DEHYDROGENASE component of the complex can be isolated and is listed as EC 1.6.99.3.
Kidney Tubules, Distal
Acid-Base Imbalance
Disturbances in the ACID-BASE EQUILIBRIUM of the body.
Saccharomyces cerevisiae
Cell Membrane
Secretin
Bacillus
Anions
Alkalosis, Respiratory
A state due to excess loss of carbon dioxide from the body. (Dorland, 27th ed)
Duodenum
Benzalkonium Compounds
Genetic Complementation Test
Pancreatic Juice
The fluid containing digestive enzymes secreted by the pancreas in response to food in the duodenum.
Carbonates
Salts or ions of the theoretical carbonic acid, containing the radical CO2(3-). Carbonates are readily decomposed by acids. The carbonates of the alkali metals are water-soluble; all others are insoluble. (From Grant & Hackh's Chemical Dictionary, 5th ed)
Acidosis, Renal Tubular
A group of genetic disorders of the KIDNEY TUBULES characterized by the accumulation of metabolically produced acids with elevated plasma chloride, hyperchloremic metabolic ACIDOSIS. Defective renal acidification of URINE (proximal tubules) or low renal acid excretion (distal tubules) can lead to complications such as HYPOKALEMIA, hypercalcinuria with NEPHROLITHIASIS and NEPHROCALCINOSIS, and RICKETS.
Electrolytes
Substances that dissociate into two or more ions, to some extent, in water. Solutions of electrolytes thus conduct an electric current and can be decomposed by it (ELECTROLYSIS). (Grant & Hackh's Chemical Dictionary, 5th ed)
Mutation
Potassium Compounds
Inorganic compounds that contain potassium as an integral part of the molecule.
Mutagenesis, Site-Directed
Membrane Transport Proteins
Membrane proteins whose primary function is to facilitate the transport of molecules across a biological membrane. Included in this broad category are proteins involved in active transport (BIOLOGICAL TRANSPORT, ACTIVE), facilitated transport and ION CHANNELS.
Cloning, Molecular
Kidney Tubules, Proximal
Cystic Fibrosis Transmembrane Conductance Regulator
Carbonic Anhydrase II
A cytosolic carbonic anhydrase isoenzyme found widely distributed in cells of almost all tissues. Deficiencies of carbonic anhydrase II produce a syndrome characterized by OSTEOPETROSIS, renal tubular acidosis (ACIDOSIS, RENAL TUBULAR) and cerebral calcification. EC 4.2.1.-
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.
Models, Molecular
Arabidopsis
A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.
Protein Structure, Secondary
The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.
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.
Cadmium Chloride
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.
Membrane Proteins
Biological Transport, Active
Hydrochloric Acid
A strong corrosive acid that is commonly used as a laboratory reagent. It is formed by dissolving hydrogen chloride in water. GASTRIC ACID is the hydrochloric acid component of GASTRIC JUICE.
4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid
Hemodialysis Solutions
Solutions prepared for hemodialysis. The composition of the pre-dialysis solution may be varied in order to determine the effect of solvated metabolites on anoxia, malnutrition, acid-base balance, etc. Of principal interest are the effect of the choice of buffers (e.g., acetate or carbonate), the addition of cations (Na+, K+, Ca2+), and addition of carbohydrates (glucose).
Protein Conformation
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
Models, Biological
Bromides
Osmolar Concentration
Substrate Specificity
Amiloride
A pyrazine compound inhibiting SODIUM reabsorption through SODIUM CHANNELS in renal EPITHELIAL CELLS. This inhibition creates a negative potential in the luminal membranes of principal cells, located in the distal convoluted tubule and collecting duct. Negative potential reduces secretion of potassium and hydrogen ions. Amiloride is used in conjunction with DIURETICS to spare POTASSIUM loss. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p705)
Base Sequence
Isotonic Solutions
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).