Biomaterial Database

Regulation of intracellular pH in cardiac muscle. 1988

R D Vaughan-Jones

University Laboratory of Physiology, Oxford, UK.

Intracellular pH (pHi) in sheep cardiac Purkinje fibres is controlled by sarcolemmal Na+/H+ and Cl-/HCO3- exchange. At normal pHo (7.4), Na+/H+ exchange mediates an acid efflux whenever pHi falls and Cl-/HCO3- exchange mediates an equivalent acid influx in response to a rise in pHi. Intracellular pH is also influenced by Ca2+i, which can activate force development leading to the anaerobic production of lactic acid. This is evident after an increase in stimulation rate which reversibly reduces both pHi and extracellular surface pH (pHs). Rate-dependent pHi changes are inhibited following inhibition of glycolysis, indicating that they are caused by accumulation of lactic acid. In some cases, the efflux of lactic acid may provide a faster method for recovery of pHi from a metabolic acidosis than that provided by Na+/H+ exchange. Finally, direct pHi measurement in isolated mammalian ventricular myocytes suggests that the intrinsic intracellular buffering power (beta) of ventricular tissue may be considerably lower than previously believed. An accurate knowledge of beta is essential for calculating net membrane fluxes of acid equivalents from changes in pHi.

UI	MeSH Term	Description	Entries
D007773	Lactates	Salts or esters of LACTIC ACID containing the general formula CH3CHOHCOOR.
D009206	Myocardium	The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.	Muscle, Cardiac,Muscle, Heart,Cardiac Muscle,Myocardia,Cardiac Muscles,Heart Muscle,Heart Muscles,Muscles, Cardiac,Muscles, Heart
D011522	Protons	Stable elementary particles having the smallest known positive charge, found in the nuclei of all elements. The proton mass is less than that of a neutron. A proton is the nucleus of the light hydrogen atom, i.e., the hydrogen ion.	Hydrogen Ions,Hydrogen Ion,Ion, Hydrogen,Ions, Hydrogen,Proton
D002352	Carrier Proteins	Proteins that bind or transport specific substances in the blood, within the cell, or across cell membranes.	Binding Proteins,Carrier Protein,Transport Protein,Transport Proteins,Binding Protein,Protein, Carrier,Proteins, Carrier
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
D006019	Glycolysis	A metabolic process that converts GLUCOSE into two molecules of PYRUVIC ACID through a series of enzymatic reactions. Energy generated by this process is conserved in two molecules of ATP. Glycolysis is the universal catabolic pathway for glucose, free glucose, or glucose derived from complex CARBOHYDRATES, such as GLYCOGEN and STARCH.	Embden-Meyerhof Pathway,Embden-Meyerhof-Parnas Pathway,Embden Meyerhof Parnas Pathway,Embden Meyerhof Pathway,Embden-Meyerhof Pathways,Pathway, Embden-Meyerhof,Pathway, Embden-Meyerhof-Parnas,Pathways, Embden-Meyerhof
D006168	Guinea Pigs	A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.	Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea
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
D000136	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.	Anion Gap,Acid-Base Balance,Acid Base Balance,Acid Base Equilibrium,Anion Gaps,Balance, Acid-Base,Equilibrium, Acid-Base,Gap, Anion,Gaps, Anion
D000584	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)	Amidal,Amiduret Trom,Amiloberag,Amiloride Hydrochloride,Amiloride Hydrochloride, Anhydrous,Kaluril,Midamor,Midoride,Modamide,Anhydrous Amiloride Hydrochloride,Hydrochloride, Amiloride,Hydrochloride, Anhydrous Amiloride,Trom, Amiduret