Metabolism of [1-13C]glucose in a synaptosomally enriched fraction of rat cerebrum studied by 1H/13C magnetic resonance spectroscopy.

This study explored the utility of 1H and 13C magnetic resonance spectroscopy to study a standard synaptosomally enriched fraction (P2 pellet) made from rat cerebrum. The preparations contained high concentrations of N-acetylaspartate and gamma-aminobutyric acid and low concentrations of glutamine, indicating that they were in fact rich in neuronal cytosol. The metabolic competence of the preparation was assessed by quantitative measurements of its ability to convert [1-13C]glucose into lactate, glutamate, aspartate, and other metabolites under well oxygenated conditions in 30 minutes. The minimum mean glycolytic rate was 0.8 mM glucose/min and the flow through the tricarboxylic acid cycle was equivalent to 0.2 mM glucose/min.