title: Activation of calcium transport in skeletal muscle sarcoplasmic reticulum by monovalent cations.
abstract: The rates of calcium transport and Ca2+-dependent ATP hydrolysis by rabbit skeletal muscle sarcoplasmic reticulum were stimulated by monovalent cations. The rate of decomposition of phosphoprotein intermediate of the Ca2+-dependent ATPase of sarcoplasmic reticulum was also increased by these ions to an extent that is sufficient to account for the stimulation of calcium transport and Ca2+-dependent ATPase activity. The order of effectiveness of monovalent cations tested at saturating concentrations in increasing rate of phosphoprotein decomposition is: K+, Na+ greater than Rb+, NH4+ greater than Cs+ greater than Li+, choline+, Tris+.
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000641:Ammonia / Q000494:pharmacology; D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D002414:Cations, Monovalent; D002586:Cesium / Q000494:pharmacology; D002794:Choline / Q000494:pharmacology; D007700:Kinetics; D008094:Lithium / Q000494:pharmacology; D008861:Microsomes / Q000378:metabolism; D009132:Muscles / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism; D011188:Potassium / Q000494:pharmacology; D011817:Rabbits; D012413:Rubidium / Q000494:pharmacology; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism*; D012964:Sodium / Q000494:pharmacology; D014325:Tromethamine / Q000494:pharmacology
chemical_list: D002414:Cations, Monovalent; D010750:Phosphoproteins; D014325:Tromethamine; D002586:Cesium; D000641:Ammonia; D008094:Lithium; D012964:Sodium; D000251:Adenosine Triphosphatases; D012413:Rubidium; D002794:Choline; D011188:Potassium; D002118:Calcium