Biomaterial Database

Ca2+ ions can affect intracellular pH in mammalian cardiac muscle. 1983

R D Vaughan-Jones, and W J Lederer, and D A Eisner

Although intracellular pH (pHi) has important effects on both the mechanical and electrical properties of cardiac muscle, the control of pHi in the heart is still poorly understood. One important determinant of pHi appears to be the transmembrane Na+ gradient. It has therefore been suggested that Na+-H+ exchange assists in the control of pHi in heart as has been proposed for other excitable cells. However, pHi and the intracellular Ca2+ concentration ([Ca2+]i) are interdependent in a variety of tissues and it has been shown recently that pHi can affect [Ca2+]i in cardiac muscle. As [Ca2+]i in cardiac muscle is also strongly influenced by the transmembrane Na+ gradient it is possible that the apparent Na+-dependence of pHi is secondary to changes in [Ca2+]i. Previous work in cardiac muscle has not been able to separate the effects of Na+-H+ exchange and [Ca2+]i on pHi (refs 4,5). Here we demonstrate in cardiac muscle that an increase in [Ca2+]i produces an intracellular acidification which cannot be ascribed to Na+-H+ exchange.

UI	MeSH Term	Description	Entries
D009200	Myocardial Contraction	Contractile activity of the MYOCARDIUM.	Heart Contractility,Inotropism, Cardiac,Cardiac Inotropism,Cardiac Inotropisms,Contractilities, Heart,Contractility, Heart,Contraction, Myocardial,Contractions, Myocardial,Heart Contractilities,Inotropisms, Cardiac,Myocardial Contractions
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D006321	Heart	The hollow, muscular organ that maintains the circulation of the blood.	Hearts
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
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
D012519	Sarcoplasmic Reticulum	A network of tubules and sacs in the cytoplasm of SKELETAL MUSCLE FIBERS that assist with muscle contraction and relaxation by releasing and storing calcium ions.	Reticulum, Sarcoplasmic,Reticulums, Sarcoplasmic,Sarcoplasmic Reticulums
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
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