Glucose Metabolism in the Developing Cerebral Cortex as Detected by 1H{13C} Nuclear Magnetic Resonance Spectroscopy Ex Vivo

Autor: Tiina-R. M. Pirttilä, Risto A. Kauppinen, Seppo Auriola
Rok vydání: 2002
Předmět:
Zdroj: Journal of Neurochemistry. 64:417-423
ISSN: 1471-4159
0022-3042
Popis: Metabolism of [1- 13 C]glucose was monitored in superfused cerebral cortex slice preparations from 1-, 2-, and 5-week-old rats using 1 H-observed/ 13 C-edited ( 1 H{ 13 C}) NMR spectroscopy. The rate of label incorporation into glutamate C-4 did not differ among the three age groups: 0.52-0.67% of total 1 H NMR-detected glutamate/min. This was rather unexpected, as oxygen uptake proceeded at 1.1±0.1, 1.9±0.1, and 2.0±0.1 μmol/min/g wet weight in brain slices prepared from 1-, 2-, and 5-week-old animals, respectively. Steady-state glutamate C-4 fractional enrichments in the slice preparations were ∼23% in all age groups. In the acid extracts of slices glutamate C-4 enrichments were smaller, however, in 1- and 2-week-old (17.8±1.7 and 16.8±0.8%, respectively) than in 5-week-old rats (22.7±0.7%) after 75 min of incubation with 5 mM [1- 13 C]glucose. We add a new assignment to the 1 H{ 13 C} NMR spectroscopy, as acetate C-2 was detected in slice preparations from 5-week-old animals. In the acid extracts of slice prepara tions acetate C-2 was labeled by -30% in 5-week-old rats but by 15% in both 1- and 2-week-old animals, showing that the turnover rate was increased in 5-week-old animals. In the extracts 3-4% of the C-6 of N-acetyl-aspartate (NAA; CH 3 of the acetyl group) contained label as determined by both NMR and mass spectrometry, which indicated that there was no significant labeling to other carbons in NAA. NAA accumulated label from [1- 13 C]glucose but not from [2- 13 C]acetate, and the rate of label incorporation increased by threefold on cerebral maturation
Databáze: OpenAIRE
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