Changes of intracellular sodium T2 relaxation times during ischemia and reperfusion in isolated rat hearts.
The effect of ischemia and reperfusion on transverse relaxation (T2) of intracellular Na+ (Na+i) was measured with 5-min time resolution in isolated rat hearts. Nai T2 relaxation was biexponential with 28+/-7% fast (T2f) and 72+/-7% slow (T2s) decay. This ratio was constant throughout the protocol. During 20 min of ischemia, Na(i) T(2s) increased from 18.9+/-2.7 ms to 26.4+/-1.1 ms (P < 0.001), whereas T2f did not change significantly (3.1+/-1.8 versus 2.3+/-1.6 ms during control), and Na+i increased from 9.0+/-1.0 to 19.5+/-1.0 mmol/liter (P < 0.001). T(2s) and Na(+)i declined again during reperfusion. Changes in T2s relaxation correlated significantly (r = 0.73, P < 0.001) with the time course of Na+i.
Van Emous
J G
JG
Interuniversity Cardiology Institute of The Netherlands and Department of Cardiology, Heart Lung Institute, University Hospital, Utrecht.
Van Echteld
C J
CJ
D000704:Analysis of Variance; D000818:Animals; D001692:Biological Transport / Q000502:physiology; D004195:Disease Models, Animal; D066298:In Vitro Techniques; D007425:Intracellular Membranes; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000378:metabolism; D015425:Myocardial Reperfusion / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar; D012016:Reference Values; D012039:Regional Blood Flow; D012044:Regression Analysis; D012680:Sensitivity and Specificity; D012964:Sodium / Q000378:metabolism*
D012964:Sodium