Localized proton NMR observation of [3-13C]lactate in stroke after [1-13C]glucose infusion.
To assess whether elevated lactate in stable stroke is being actively produced from blood glucose localized 1H NMR stimulated echo spectra were obtained from a patient in the region of a 32-day-old cortical infarct before and 60-100 min after infusion of [1-13C]glucose. Prior to the infusion the spectrum from the region of the infarct contained an elevated resonance from C3 lactate and a greatly reduced resonance from N-acetyl groups relative to an unaffected contralateral region. After the infusion two additional resonances were observed at 62 and -64 Hz relative to the unlabeled resonance of C3 lactate which were assigned on the basis of chemical shift and relative intensity to [3-13C]lactate. The [3-13C]lactate fractional enrichment in the infarct region was measured to be 32% which is within error one-half the average [1-13C]plasma glucose enrichment during the postinfusion NMR measurement. The result suggests that the stroke lactate pool was completely derived from infused glucose.
Rothman
D L
DL
Department of Internal Medicine, Yale School of Medicine.
Howseman
A M
AM
Graham
G D
GD
Petroff
O A
OA
Lantos
G
G
Fayad
P B
PB
Brass
L M
LM
Shulman
G I
GI
Shulman
R G
RG
Prichard
J W
JW
D001786:Blood Glucose / Q000378:metabolism*; D002247:Carbon Isotopes; D002561:Cerebrovascular Disorders / Q000097:blood / Q000378:metabolism*; D005240:Feasibility Studies; D005947:Glucose / Q000008:administration & dosage; D006801:Humans; D007262:Infusions, Intravenous; D007773:Lactates / Q000096:biosynthesis* / Q000097:blood; D019344:Lactic Acid; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged
D001786:Blood Glucose; D002247:Carbon Isotopes; D007773:Lactates; D019344:Lactic Acid; D005947:Glucose