Maher Anthony D, Chapman Bogdan E, Kuchel Philip W
School of Molecular and Microbial Biosciences, University of Sydney, 2006 Sydney, NSW, Australia.
Eur Biophys J. 2006 Apr;35(4):293-301. doi: 10.1007/s00249-005-0034-6. Epub 2005 Dec 10.
(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.
