title: Simultaneous separation of intracellular and extracellular lactate NMR signals of human erythrocytes.
abstract: Intracellular/extracellular lactate (Lac) distribution has been determined before in human and animal erythrocytes (red blood cells [RBCs]) with various methods. However, all previous methods determine intra- and extracellular Lac separately or indirectly. Now, (13)C-NMR spectroscopy has been used to monitor intra- and extracellular Lac simultaneously in intact RBCs. Isolated human RBCs were incubated with [3-(13)C]-Lac, [3-(13)C]-pyruvate (Pyr), and [1-(13)C]-glucose (Gluc). A distortionless enhancement by polarization transfer (DEPT) sequence was used (TR = 3.3 s, N = 128) to monitor the (13)C-NMR resonances in both compartments. The intra- and extracellular methyl group resonances of Lac and Pyr were clearly separated by 9.6 Hz and 7.0 Hz, respectively, under normoxic conditions due to the RBC chemical-shift effect. The results show that the chemical-shift effect of RBCs is convenient to monitor intra- and extracellular Lac simultaneously in intact RBCs under normoxic conditions.
authors.affiliation: Biozentrum, Department of Biophysical Chemistry, University of Basel, Basel, Switzerland. goetz.kohler@unibas.ch
authors.forename: Götz
authors.initials: G
authors.lastname: Kohler
authors.forename: Florian
authors.initials: F
authors.lastname: Rost
authors.forename: Joachim
authors.initials: J
authors.lastname: Seelig
mesh_terms: D001786:Blood Glucose / Q000378:metabolism; D002247:Carbon Isotopes; D004912:Erythrocytes / Q000737:chemistry* / Q000378:metabolism; D005110:Extracellular Space / Q000378:metabolism; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D007773:Lactates / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D019289:Pyruvic Acid / Q000378:metabolism
chemical_list: D001786:Blood Glucose; D002247:Carbon Isotopes; D007773:Lactates; D019289:Pyruvic Acid