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.
Bouzier-Sore
Anne-Karine
AK
Centre de Résonance Magnétique des Systèmes Biologiques, UMR 5536 CNRS/Université, Bordeaux, France. akb@rmsb.ubordeaux2.fr
Voisin
Pierre
P
Canioni
Paul
P
Magistretti
Pierre J
PJ
Pellerin
Luc
L
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