Ruud Bernardus van Heeswijk1, Florence D. Morgenthaler1, Lijing Xin1, Rolf Gruetter1,2
1Center for BioMedical Imaging (CIBM), Ecole Polytechnique Fdrale de Lausanne (EPFL), Lausanne, VD, Switzerland; 2Departments of Radiology, Universities of Lausanne and Geneva, Lausanne and Geneva, Switzerland
Brain glycogen concentration and turnover were determined in vivo in the rat by simultaneously monitoring both the C1 and C6 resonances with 13C NMR. These resonances lie 3.9 kHz apart at 9.4 T, so to prevent a chemical shift displacement artifact a sequence based on the Fourier series window was implemented. After bringing the C1 resonance in steady state through 'pre-labeling' with 1-13C1 glucose, an acute infusion of 1,6-13C2 glucose was used to label the C6 resonance of glycogen and so estimate its turnover time, while the C1 resonance was used to monitor for concentration changes.
Keywords