A comparison of (13)C NMR measurements of the rates of glutamine synthesis and the tricarboxylic acid cycle during oral and intravenous administration of [1-(13)C]glucose.
13C-labeled glucose is increasingly used in conjunction with magnetic resonance spectroscopy to measure rates of metabolic pathways in the brain in vivo. Most studies of human subjects have used intravenous infusions to administer the labeled compounds, but the procedure is cumbersome and can be uncomfortable for patients with neurological or psychiatric disorders. It may be possible to improve the practicality of the method by administering the glucose orally instead of intravenously. This report describes the performance and comparison of the oral and intravenous protocols in the same subjects. The conclusion is that oral administration does yield the same result as intravenous administration but with lower precision. That sensitivity of the oral protocol may be improved by several ways that are available today.
Mason
Graeme F
GF
Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA. graeme.mason@yale.edu
Falk Petersen
Kitt
K
de Graaf
Robin A
RA
Kanamatsu
Tomoyuki
T
Otsuki
Taisuke
T
Shulman
Gerald I
GI
Rothman
Douglas L
DL
D000284:Administration, Oral; D000328:Adult; D000465:Algorithms; D002952:Citric Acid Cycle / Q000502:physiology*; D005260:Female; D005947:Glucose / Q000008:administration & dosage / Q000378:metabolism*; D005973:Glutamine / Q000096:biosynthesis*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007262:Infusions, Intravenous; D007700:Kinetics; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008954:Models, Biological
D005973:Glutamine; D005947:Glucose