23Na-NMR measurements of intracellular sodium in intact perfused ferret hearts during ischemia and reperfusion.
23Na nuclear magnetic resonance (NMR) spectroscopy was utilized to measure intracellular Na+ in perfused ferret hearts exposed to the shift reagent dysprosium triethylenetramine-hexa-acetic acid [Dy(TTHA)3-]. The intracellular Na+ signal was small under normal perfusion conditions; resolution was enhanced by using a Jump-Return NMR pulse protocol. During 20 min of total global ischemia at 30 degrees C, intracellular Na+ concentration ([Na+]i) increased steadily to a peak value fivefold greater than control. [Na+]i declined monotonically back to control levels within 9 min of reperfusion. In contrast, the mean contractile pressure only recovered to 54% of control levels. Thus major alterations in Na+ homeostasis occur during severe ischemia. [Na+] recovers rapidly during reperfusion and is therefore dissociated from the lingering postischemic depression of contractile function known as "stunning."
Pike
M M
MM
Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
Kitakaze
M
M
Marban
E
E
D000818:Animals; D003327:Coronary Disease / Q000378:metabolism* / Q000503:physiopathology; D005110:Extracellular Space / Q000378:metabolism; D005289:Ferrets; D006321:Heart / Q000503:physiopathology; D066298:In Vitro Techniques; D007425:Intracellular Membranes / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009200:Myocardial Contraction; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000378:metabolism*; D009994:Osmolar Concentration; D010477:Perfusion; D012964:Sodium / Q000378:metabolism*
D012964:Sodium