Metabolic fate of glucose in the brain of APP/PS1 transgenic mice at 10 months of age: a 13C NMR metabolomic study.

Alzheimer's disease (AD) has been associated with the disturbance of brain glucose metabolism. The present study investigates brain glucose metabolism using 13C NMR metabolomics in combination with intravenous [1-13C]-glucose infusion in APP/PS1 transgenic mouse model of amyloid pathology at 10 months of age. We found that brain glucose was significantly accumulated in APP/PS1 mice relative to wild-type (WT) mice. Reductions in 13C fluxes into the specific carbon sites of tricarboxylic acid (TCA) intermediate (succinate) as well as neurotransmitters (glutamate, glutamine, γ-aminobutyric acid and aspartate) from [1-13C]-glucose were also detected in the brain of APP/PS1 mice. In addition, our results reveal that the 13C-enrichments of the C3 of alanine were significantly lower and the C3 of lactate have a tendency to be lower in the brain of APP/PS1 mice than WT mice. Taken together, the development of amyloid pathology could cause a reduction in glucose utilization and further result in decreases in energy and neurotransmitter metabolism as well as the lactate-alanine shuttle in the brain.