Meeting Banner
Abstract #0319

Improved Quantification of Mitochondrial Exchange, TCA Cycle Rate and Neurotransmission Flux Using 1H{13C} MRS Measurements of C4 and C3 of Glutamate and Glutamine

Bernard Lanz1, Lijing Xin1, Rolf Gruetter1,2

1Laboratory for functional and metabolic imaging, Ecole Polytechnique Fdrale de Lausanne, Lausanne, Switzerland; 2Departments of Radiology, Universities of Lausanne and Geneva, Lausanne and Geneva, Switzerland

[2-13C]acetate infusion coupled with 13C MRS enables the separated assessment of glial and neuronal Krebs cycle fluxes with higher accuracy than 13C labeled glucose, due to the asymetric metabolism of acetate in the brain. However, the faster neuronal Krebs cycle induces a strong dilution of the 13C labeled glutamate on the neuronal side, resulting in lower 13C MRS signal than with glucose. In this study, we analyzed with Monte-Carlo simulations the precision of the fitted metabolic fluxes with separated GluC3/GlnC3 curves obtained with 1H{13C} MRS as well as the impact of the neuroglial partition of glutamate on the fluxes.