Comparison of lactate and glucose metabolism in cultured neocortical neurons and astrocytes using 13C-NMR spectroscopy.
Dev Neurosci
; 20(4-5): 310-20, 1998.
Article
en En
| MEDLINE
| ID: mdl-9778567
In cerebral cortical neurons, synthesis of the tricarboxylic acid (TCA) cycle-derived amino acids, glutamate and aspartate as well as the neurotransmitter of these neurons, gamma-aminobutyrate (GABA), was studied incubating the cells in media containing 0.5 mM [U-13C]glucose in the absence or presence of glutamine (0.5 mM). Lyophilized cell extracts were analyzed by 13C nuclear magnetic resonance (NMR) spectroscopy and HPLC. The present findings were compared to results previously obtained using 1.0 mM [U-13C]lactate as the labeled substrate for the neurons. Regardless of the amino acids studied, incubation periods of 1 and 4 h resulted in identical amounts of 13C incorporated. Furthermore, the metabolism of lactate was studied under analogous conditions in cultured cerebral cortical astrocytes. The incorporation of 13C from lactate into glutamate was much lower in the astrocytes than in the neurons. In cerebral cortical neurons the total amount of 13C in GABA, glutamate and aspartate was independent of the labeled substrate. The enrichment in glutamate and aspartate was, however, higher in neurons incubated with lactate. Thus, lactate appears to be equivalent to glucose with regard to its access to the TCA cycle and subsequent labeling of glutamate, aspartate and GABA. It should be noted, however, that incubation with lactate in place of glucose led to lower cellular contents of glutamate and aspartate. The presence of glutamine affected the metabolism of glucose and lactate differently, suggesting that the metabolism of these substrates may be compartmentalized.
Buscar en Google
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Corteza Cerebral
/
Astrocitos
/
Ácido Láctico
/
Glucosa
/
Neuronas
Límite:
Animals
Idioma:
En
Revista:
Dev Neurosci
Año:
1998
Tipo del documento:
Article
País de afiliación:
Dinamarca
Pais de publicación:
Suiza