1H-[13C] NMR spectroscopy of the rat brain during infusion of [2-13C] acetate at 14.1 T.
Full signal intensity (1)H-[(13)C] NMR spectroscopy, combining a preceding (13)C-editing block based on an inversion BISEP (B(1)-insensitive spectral editing pulse) with a spin-echo coherence-based localization, was developed and implemented at 14.1 T. (13)C editing of the proposed scheme was achieved by turning on and off the (13)C adiabatic full passage in the (13)C-editing block to prepare inverted and noninverted (13)C-coupled (1)H coherences along the longitudinal axis prior to localization. The novel (1)H-[(13)C] NMR approach was applied in vivo under infusion of the glia-specific substrate [2-(13)C] acetate. Besides a approximately 50% improvement in sensitivity, spectral dispersion was enhanced at 14.1 T, especially for J-coupled metabolites such as glutamate and glutamine. A more distinct spectral structure at 1.9-2.2 ppm(parts per million) was observed, e.g., glutamate C3 showed a doublet pattern in both simulated (1)H spectrum and in vivo (13)C-edited (1)H NMR spectra. Besides (13)C time courses of glutamate C4 and glutamine C4, the time courses of glutamate C3 and glutamine C3 obtained by (1)H-[(13)C] NMR spectroscopy were reported for the first time. Such capability should greatly improve the ability to study neuron-glial metabolism using (1)H-observed (13)C-edited NMR spectroscopy.
Laboratory of Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
Lijing
L
Xin
Vladimír
V
Mlynárik
Bernard
B
Lanz
Hanne
H
Frenkel
Rolf
R
Gruetter
D000085:Acetates / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002247:Carbon Isotopes / Q000008:administration & dosage / Q000493:pharmacokinetics; D005240:Feasibility Studies; D007553:Isotope Labeling / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D011522:Protons; D019275:Radiopharmaceuticals / Q000008:administration & dosage / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley
D000085:Acetates; D002247:Carbon Isotopes; D011522:Protons; D019275:Radiopharmaceuticals