title: Measurement of intracellular potassium ion concentrations by n.m.r.
abstract: 39K n.m.r. was used to detect and quantify K+ within human erythrocytes. A shift reagent consisting of an anionic complex of dysprosium(III) with sodium tripolyphosphate permitted a distinction to be made between K+ inside and outside erythrocytes. Intracellular K+ concentrations determined by this method were similar to values obtained by flame photometry.
mesh_terms: D004419:Dysprosium; D004912:Erythrocytes / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D007424:Intracellular Fluid / Q000378:metabolism; D007554:Isotopes; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D011122:Polyphosphates; D011188:Potassium / Q000097:blood*
chemical_list: D007554:Isotopes; D011122:Polyphosphates; D004419:Dysprosium; C005692:triphosphoric acid; D011188:Potassium