Intake of 13C-4 creatine enables simultaneous assessment of creatine and phosphocreatine pools in human skeletal muscle by 13C MR spectroscopy

• Published in: Magnetic resonance in medicine Vol. 56; no. 5; pp. 953 - 957
• Main Authors: Kan, H.E., van der Graaf, M., Klomp, D.W.J., Vlak, M.H.M., Padberg, G.W., Heerschap, A.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.11.2006
• Subjects: Carbon Radioisotopes - pharmacokinetics; Creatine - metabolism; creatine supplementation; creatine turnover; Humans; in vivo; magnetic resonance spectroscopy; Magnetic Resonance Spectroscopy - methods; Male; Metabolic Clearance Rate; Middle Aged; Muscle, Skeletal - metabolism; PCr/TCr; Phosphocreatine - metabolism; Physical Exertion - physiology
• ISSN: 0740-3194; 1522-2594
• DOI: 10.1002/mrm.21068

The feasibility of a novel method for the noninvasive and local assessment of creatine (Cr) and phosphocreatine (PCr) dynamics in human skeletal muscle based on 13C magnetic resonance (MR) spectroscopy is presented. A high dose of Cr, labeled at the guanidino C‐4 position with 13C 11% enrichment, was administered orally to a human subject for 5 days. Using a surface coil, 13C MR spectra of the lower leg were acquired on a 1.5T MR system at regular time intervals during and after Cr supplementation. An almost twofold increase in the intensities of the resolved PCr and Cr 13C‐4 signals was observed during this period. The slow decrease in these signals to normal values after supplementation reflects the slow daily turnover of Cr. The PCr/Cr ratio did not appear to change over the whole measurement period. During exercise of the leg, reversible changes in PCr and Cr signals were observed, reflecting conversion by the Cr kinase reaction. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.