title: High-resolution NMR studies of transmembrane cation transport in uremic patients.
abstract: Cation transport in erythrocytes of some uremic patients is impaired. Most studies have focused on the defect of the erythrocyte Na+/K+ pump in these diseased states. Herein, this cation transport defect was studied by using nuclear magnetic resonance spectroscopy (NMR) which is a non-invasive method permitting study on living erythrocytes. Firstly, we verified that the Na+ transport defect in uremic erythrocytes was not due to non-specific causes such as membrane alteration or a modification of the intracellular metabolism. The proton relaxation data, determined using a paramagnetic doping method, are consistent with a lack of erythrocytic membrane damage in uremic patients. Also, 31P-NMR results showed that in our experimental conditions, uremic and normal erythrocytes exhibit similar variations of ATP level over time. Lastly, the use of anionic paramagnetic shift reagent in 23Na-NMR revealed a defect in the Na+/K+ pump of erythrocytes from uremic patients with high Nain concentration. This defect seems to be due to a reduced number of pump units and to the presence of an endogenous inhibitor in uremic plasma.
authors.affiliation: Laboratoire de Biophysique, Faculté de Pharmacie, Université d'Aix-Marseille II.
authors.forename: J P
authors.initials: JP
authors.lastname: Monti
authors.forename: M
authors.initials: M
authors.lastname: Baz
authors.forename: R
authors.initials: R
authors.lastname: Elsen
authors.forename: Y F
authors.initials: YF
authors.lastname: Berland
authors.forename: A D
authors.initials: AD
authors.lastname: Crevat
mesh_terms: D002412:Cations; D004910:Erythrocyte Membrane / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D010042:Ouabain / Q000494:pharmacology; D010710:Phosphates / Q000097:blood; D011188:Potassium / Q000097:blood; D012964:Sodium / Q000097:blood* / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors / Q000378:metabolism; D014511:Uremia / Q000378:metabolism*
chemical_list: D002412:Cations; D010710:Phosphates; D010042:Ouabain; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium