title: (39)K nuclear magnetic resonance and a mathematical model of K(+) transport in human erythrocytes.
abstract: (39)K nuclear magnetic resonance was used to measure the efflux of K(+) from suspensions of human erythrocytes [red blood cells (RBCs)], that occurred in response to the calcium ionophore, A23187 and calcium ions; the latter activate the Gárdos channel. Signals from the intra- and extracellular populations of (39)K(+) were selected on the basis of their longitudinal relaxation times, T (1), by using an inversion- recovery pulse sequence with the mixing time, tau(1), chosen to null one or other of the signals. Changes in RBC volume consequent upon efflux of the ions also changed the T (1) values so a new theory was implemented to obviate a potential artefact in the data analysis. The velocity of the K(+) efflux mediated by the Gárdos channel was 1.19+/-0.40 mmol (L RBC)(-1) min(-1) at 37 degrees C.
authors.affiliation: School of Molecular and Microbial Biosciences, University of Sydney, 2006 Sydney, NSW, Australia.
authors.forename: Anthony D
authors.initials: AD
authors.lastname: Maher
authors.forename: Bogdan E
authors.initials: BE
authors.lastname: Chapman
authors.forename: Philip W
authors.initials: PW
authors.lastname: Kuchel
mesh_terms: D002414:Cations, Monovalent; D004912:Erythrocytes / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D017136:Ion Transport; D009682:Magnetic Resonance Spectroscopy; D008954:Models, Biological; D011188:Potassium / Q000378:metabolism*; D011194:Potassium Isotopes; D013054:Spectrophotometry, Atomic
chemical_list: D002414:Cations, Monovalent; D011194:Potassium Isotopes; D011188:Potassium