title: Time course of myocardial sodium accumulation after burn trauma: a (31)P- and (23)Na-NMR study.
abstract: In this study, (23)Na- and (31)P- nuclear magnetic resonance (NMR) spectra were examined in perfused rat hearts harvested 1, 2, 4, and 24 h after 40% total body surface area burn trauma and lactated Ringer resuscitation, 4 ml. kg(-1). %(-1) burn. (23)Na-NMR spectroscopy monitored myocardial intracellular Na+ using the paramagnetic shift reagent thulium 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetra(methylenephosphonic acid). Left ventricular function, cardiac high-energy phosphates (ATP/PCr), and myocyte intracellular pH were studied by using (31)P NMR spectroscopy to examine the hypothesis that burn-mediated acidification of cardiomyocytes contributes to subsequent Na+ accumulation by this cell population. Intracellular Na+ accumulation was confirmed by sodium-binding benzofuran isophthalate loading and fluorescence spectroscopy in cardiomyocytes isolated 1, 2, 4, 8, 12, 18, and 24 h postburn. This myocyte Na+ accumulation as early as 2 h postburn occurred despite no changes in cardiac ATP/PCr and intracellular pH. Left ventricular function progressively decreased after burn trauma. Cardiomyocyte Na+ accumulation paralleled cardiac contractile dysfunction, suggesting that myocardial Na+ overload contributes, in part, to the progressive postburn decrease in ventricular performance.
authors.affiliation: Department of Surgery, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9160, USA.
authors.forename: P J
authors.initials: PJ
authors.lastname: Sikes
authors.forename: P
authors.initials: P
authors.lastname: Zhao
authors.forename: D L
authors.initials: DL
authors.lastname: Maass
authors.forename: J W
authors.initials: JW
authors.lastname: Horton
mesh_terms: D000138:Acidosis / Q000503:physiopathology; D000818:Animals; D002056:Burns / Q000378:metabolism* / Q000503:physiopathology; D004734:Energy Metabolism; D006863:Hydrogen-Ion Concentration; D007425:Intracellular Membranes / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009200:Myocardial Contraction; D009206:Myocardium / Q000378:metabolism*; D010758:Phosphorus; D051381:Rats; D017207:Rats, Sprague-Dawley; D012964:Sodium / Q000378:metabolism*; D012975:Sodium Isotopes; D013050:Spectrometry, Fluorescence; D013997:Time Factors; D016277:Ventricular Function, Left
chemical_list: D012975:Sodium Isotopes; D010758:Phosphorus; D012964:Sodium