title: [Role of membrane-bound calcium in changes in the ATPase activity, permeability and structural state of human erythrocyte membranes].
abstract: A study was conducted on the reconstituted erythrocytes obtained by the method of fast reversible hemolysis. The concentration of free Ca2+ ions in the reconstituted erythrocytes was supported by Ca-EGTA and Ca-nitrate buffers. Oubain-uninhibited ATPase component with a high affinity for Ca2+ (K0.5=4 micron) and alteration of passive and active K+-permeability in the region of free Ca2+ concentration up to 10 micron could be determined only when the content of membrane-bound Ca+ varied. Depletion of the inner side of the membrane of reconstituted erythrocyte is accompanied by alteration of hydrophobic character of the hydrocarbon region of the membrane. It is suggested that Ca+-induced alterations in the structure of the erythrocyte membrane may be a direct cause of the alterations in ATPase activity with a high Ca2+ affinity and permeability for univalent cations.
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D002021:Buffers / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology*; D002463:Cell Membrane Permeability / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004577:Electron Probe Microanalysis; D004910:Erythrocyte Membrane / Q000187:drug effects* / Q000201:enzymology; D004912:Erythrocytes / Q000187:drug effects*; D006801:Humans; D010042:Ouabain / Q000494:pharmacology; D013050:Spectrometry, Fluorescence
chemical_list: D002021:Buffers; D010042:Ouabain; D000251:Adenosine Triphosphatases; D002118:Calcium
vernacular_title: O roli membranosviazannogo kal'tsiia v izmenenii ATF-aznoĭ aktivnosti, pronitsaemosti i strukturnogo sostoianiia membrany éritrotsitov cheloveka.