Lactate is a preferential oxidative energy substrate over glucose for neurons in culture.
The authors investigated concomitant lactate and glucose metabolism in primary neuronal cultures using 13C- and 1H-NMR spectroscopy. Neurons were incubated in a medium containing either [1-13C]glucose and different unlabeled lactate concentrations, or unlabeled glucose and different [3-13C]lactate concentrations. Overall, 13C-NMR spectra of cellular extracts showed that more 13C was incorporated into glutamate when lactate was the enriched substrate. Glutamate 13C-enrichment was also found to be much higher in lactate-labeled than in glucose-labeled conditions. When glucose and lactate concentrations were identical (5.5 mmol/L), relative contributions of glucose and lactate to neuronal oxidative metabolism amounted to 21% and 79%, respectively. Results clearly indicate that when neurons are in the presence of both glucose and lactate, they preferentially use lactate as their main oxidative substrate.
Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536 CNRS/Université, Bordeaux, France. akb@rmsb.ubordeaux2.fr
Anne-Karine
AK
Bouzier-Sore
Pierre
P
Voisin
Paul
P
Canioni
Pierre J
PJ
Magistretti
Luc
L
Pellerin
D000818:Animals; D000831:Animals, Newborn; D002247:Carbon Isotopes; D002478:Cells, Cultured; D002952:Citric Acid Cycle; D004734:Energy Metabolism; D005947:Glucose / Q000378:metabolism*; D018698:Glutamic Acid / Q000378:metabolism; D007773:Lactates / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010085:Oxidative Phosphorylation; D051381:Rats; D017208:Rats, Wistar
D002247:Carbon Isotopes; D007773:Lactates; D018698:Glutamic Acid; D005947:Glucose