Simultaneous measurement of neuronal and glial metabolism in rat brain in vivo using co-infusion of [1,6-13C2]glucose and [1,2-13C2]acetate.
In this work the feasibility of measuring neuronal-glial metabolism in rat brain in vivo using co-infusion of [1,6-(13)C(2)]glucose and [1,2-(13)C(2)]acetate was investigated. Time courses of (13)C spectra were measured in vivo while infusing both (13)C-labeled substrates simultaneously. Individual (13)C isotopomers (singlets and multiplets observed in (13)C spectra) were quantified automatically using LCModel. The distinct (13)C spectral pattern observed in glutamate and glutamine directly reflected the fact that glucose was metabolized primarily in the neuronal compartment and acetate in the glial compartment. Time courses of concentration of singly and multiply-labeled isotopomers of glutamate and glutamine were obtained with a temporal resolution of 11 min. Although dynamic metabolic modeling of these (13)C isotopomer data will require further work and is not reported here, we expect that these new data will allow more precise determination of metabolic rates as is currently possible when using either glucose or acetate as the sole (13)C-labeled substrate.
Deelchand
Dinesh K
DK
Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota Medical School, 2021 6th St SE, Minneapolis, MN 55455, USA. dinesh@cmrr.umn.edu
Nelson
Christopher
C
Shestov
Alexander A
AA
Uğurbil
Kâmil
K
Henry
Pierre-Gilles
PG
D000085:Acetates / Q000378:metabolism*; D000818:Animals; D001253:Astrocytes / Q000378:metabolism; D001692:Biological Transport; D001921:Brain / Q000201:enzymology / Q000378:metabolism*; D002247:Carbon Isotopes / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D018698:Glutamic Acid / Q000378:metabolism; D007700:Kinetics; D009457:Neuroglia / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D011768:Pyruvate Dehydrogenase Complex / Q000378:metabolism; D051381:Rats
D000085:Acetates; D002247:Carbon Isotopes; D011768:Pyruvate Dehydrogenase Complex; D018698:Glutamic Acid; D005947:Glucose