Asymmetrical labeling of D-glucose generated from [3(-13)C]pyruvate in rat hepatocytes.
The generation of 13C-labeled D-glucose isotopomers by rat hepatocytes incubated for 30 or 120 min in the presence of 10 mM [3-(13)C]pyruvate was assessed by 13C NMR. The amount of C1-labeled D-glucose exceeded that of C2-labeled hexose, which was itself higher than that of C3-labeled D-glucose. A comparable hierarchy was observed in the C6-C5-C4 moiety of the hexose. The latter moiety of D-glucose was more efficiently labeled, however, than the C3-C2-C1 moiety. This finding is similar to that both previously reported and again observed in the present study when hepatocytes were exposed to [2(-13)C]pyruvate. These converging observations thus support the concept of enzyme-to-enzyme channeling of D-glyceraldehyde 3-phosphate between glyceraldehyde-3-phosphate dehydrogenase and phospho-fructoaldolase.
Verbruggen
I
I
High Resolution NMR Centre, Free University of Brussels (VUB), Belgium.
Ladrière
L
L
Willem
R
R
Malaisse
W J
WJ
D000818:Animals; D002247:Carbon Isotopes; D005260:Female; D005947:Glucose / Q000737:chemistry*; D006601:Hexoses / Q000737:chemistry; D066298:In Vitro Techniques; D008099:Liver / Q000737:chemistry* / Q000166:cytology; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D019289:Pyruvic Acid / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results
D002247:Carbon Isotopes; D006601:Hexoses; D019289:Pyruvic Acid; D005947:Glucose