title: Determination of the intracellular sodium concentration in perfused mouse liver by 31P and 23Na magnetic resonance spectroscopy.
abstract: A combination of 31P and 23Na NMR spectroscopy has been used to quantify the concentration of intracellular sodium, [Na]IC in the isolated and perfused mouse liver. The 31P resonances of dimethyl methylphosphonate and LaDOTP5-, markers of total tissue space and extracellular space, respectively, were used to determine the intracellular liver volume. For a mean wet weight of 1.7 +/- 0.3 g, the intracellular liver volume as measured by 31P NMR averaged 1.2 +/- 0.2 ml. The amount of intracellular sodium was measured from the baseline-resolved intracellular 23Na resonance during perfusion of the shift reagent, TmDOTP5-. These two measurements resulted in an NMR-determined value for [Na]IC of 29.0 +/- 5.2 mM. Separate measurement of total tissue Tm and Na by atomic absorption spectroscopy on the same samples provided an AAS-determined value for [Na]IC of 32.1 +/- 7.4 mM. These results indicate that intracellular sodium in the isolated, perfused liver is 100% visible by 23Na NMR spectroscopy.
authors.affiliation: Department of Chemistry, University of Texas at Dallas, Richardson, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Colet
authors.forename: J D
authors.initials: JD
authors.lastname: Makos
authors.forename: C R
authors.initials: CR
authors.lastname: Malloy
authors.forename: A D
authors.initials: AD
authors.lastname: Sherry
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis; D004195:Disease Models, Animal; D005110:Extracellular Space / Q000378:metabolism; D007424:Intracellular Fluid / Q000737:chemistry*; D007811:Lanthanum / Q000032:analysis; D008099:Liver / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009943:Organophosphorus Compounds / Q000032:analysis; D010477:Perfusion; D010759:Phosphorus Isotopes; D012680:Sensitivity and Specificity; D012964:Sodium / Q000032:analysis*; D012975:Sodium Isotopes; D014018:Tissue Distribution
chemical_list: D015415:Biomarkers; D009943:Organophosphorus Compounds; D010759:Phosphorus Isotopes; D012975:Sodium Isotopes; C031116:dimethyl methylphosphonate; D007811:Lanthanum; D012964:Sodium