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The Metabolism of [3-13C]Lactate in the Rat Brain Is Specific of a Pyruvate Carboxylase-Deprived Compartment.

Authors :
Bouzier, Anne-Karine
Thiaudiere, Eric
Biran, Marc
Rouland, Richard
Canioni, Paul
Merle, Michel
Source :
Journal of Neurochemistry. Aug2000, Vol. 75 Issue 2, p480-486. 7p. 2 Charts, 5 Graphs.
Publication Year :
2000

Abstract

Lactate metabolism in the adult rat brain was investigated in relation with the concept of lactate trafficking between astrocytes and neurons. Wistar rats were infused intravenously with a solution containing either [3-13C]lactate (534 mM) or both glucose (750 mM) and [3-13C]lactate (534 mM). The time courses of both the concentration and 13C enrichment of blood glucose and lactate were determined. The data indicated the occurrence of [3-13C]lactate recycling through liver gluconeogenesis. The yield of glucose labeling was, however, reduced when using the glucose-containing infusate. After a 20-min or 1-h infusion, perchloric acid extracts of the brain tissue were prepared and subsequently analyzed by 13C- and 1H-observed/13C-edited NMR spectroscopy. The 13C labeling of amino acids indicated that [3-13C]lactate was metabolized in the brain. Based on the alanine C3 enrichment, lactate contribution to brain metabolism amounted to 35% under the most favorable conditions used. By contrast with what happens with [1-13C]glucose metabolism, no difference in glutamine C2 and C3 labeling was evidenced, indicating that lactate was metabolized in a compartment deprived of pyruvate carboxylase activity. This result confirms, for the first time from an in vivo study, that lactate is more specifically a neuronal substrate. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00223042
Volume :
75
Issue :
2
Database :
Academic Search Index
Journal :
Journal of Neurochemistry
Publication Type :
Academic Journal
Accession number :
5508333
Full Text :
https://doi.org/10.1046/j.1471-4159.2000.0750480.x