Reduced (1)H-NMR visibility of creatine in isolated rat hearts.
The aim of this study was to measure the concentration of creatine in Langendorff perfused rat hearts, both by quantitative (1)H-MRS and by high-pressure liquid chromatography (HPLC). First, the relaxation times and other parameters affecting absolute quantification by MRS were determined. At 11.75 T, the relaxation times of myocardial creatine were T(1) = 1.1+/-0.29 sec (mean +/- SD, n = 5) and T(2) = 56.4+/-6.2 ms (n = 9). In phantom experiments the MRS measurements gave accurate values for the known relative concentrations of the detected substances. In glucose-perfused rat hearts, the creatine concentration measured by HPLC was 14.2+/-1.9 mmol/kg wet weight (n = 8), in good agreement with literature values. The (1)H-MRS measurements, however, resulted in creatine concentrations of only approximately 60% of this value. The application of CHESS-pulses for water suppression led to a further 30% reduction of the creatine MRS signal. These results indicate a reduced (1)H-NMR visibility of creatine in the myocardium, which suggests a compartmentation of myocardial creatine into various pools.
Schneider
J
J
Department of Biophysics, University of Würzburg, Würzburg, Germany.
Fekete
E
E
Weisser
A
A
Neubauer
S
S
von Kienlin
M
M
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003401:Creatine / Q000032:analysis* / Q000378:metabolism; D046508:Culture Techniques; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D009200:Myocardial Contraction / Q000502:physiology*; D009206:Myocardium / Q000737:chemistry* / Q000378:metabolism; D019047:Phantoms, Imaging; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D003401:Creatine