Selective distribution of lactate dehydrogenase isoenzymes in neurons and astrocytes of human brain.

Détails

ID Serval
serval:BIB_50B74175A45E
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Selective distribution of lactate dehydrogenase isoenzymes in neurons and astrocytes of human brain.
Périodique
Journal of Cerebral Blood Flow and Metabolism
Auteur(s)
Bittar P.G., Charnay Y., Pellerin L., Bouras C., Magistretti P.J.
ISSN
0271-678X
Statut éditorial
Publié
Date de publication
1996
Peer-reviewed
Oui
Volume
16
Numéro
6
Pages
1079-1089
Langue
anglais
Résumé
In vertebrates, the interconversion of lactate and pyruvate is catalyzed by the enzyme lactate dehydrogenase. Two distinct subunits combine to form the five tetrameric isoenzymes of lactate dehydrogenase. The LDH-5 subunit (muscle type) has higher maximal velocity (Vmax) and is present in glycolytic tissues, favoring the formation of lactate from pyruvate. The LDH-1 subunit (heart type) is inhibited by pyruvate and therefore preferentially drives the reaction toward the production of pyruvate. There is mounting evidence indicating that during activation the brain resorts to the transient glycolytic processing of glucose. Indeed, transient lactate formation during physiological stimulation has been shown by 1H-magnetic resonance spectroscopy. However, since whole-brain arteriovenous studies under basal conditions indicate a virtually complete oxidation of glucose, the vast proportion of the lactate transiently formed during activation is likely to be oxidized. These in vivo data suggest that lactate may be formed in certain cells and oxidized in others. We therefore set out to determine whether the two isoforms of lactate dehydrogenase are localized to selective cell types in the human brain. We report here the production and characterization of two rat antisera, specific for the LDH-5 and LDH-1 subunits of lactate dehydrogenase, respectively. Immunohistochemical, immunodot, and western-blot analyses show that these antisera specifically recognize their homologous antigens. Immunohistochemistry on 10 control cases demonstrated a differential cellular distribution between both subunits in the hippocampus and occipital cortex: neurons are exclusively stained with the anti-LDH1 subunit while astrocytes are stained by both antibodies. These observations support the notion of a regulated lactate flux between astrocytes and neurons.
Mots-clé
Adolescent, Aged, Aged, 80 and over, Animals, Astrocytes, Brain, Female, Humans, Immunoblotting, Immunohistochemistry, Isoenzymes, L-Lactate Dehydrogenase, Male, Middle Aged, Neurons, Rats
Pubmed
Web of science
Création de la notice
24/01/2008 14:17
Dernière modification de la notice
20/08/2019 15:06
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