Improvement of brain uptake for in vivo PET imaging of astrocytic oxidative metabolism using benzyl [1-11C]acetate

• The measurement of astrocytic oxidative metabolism by PET.
• The brain uptake of benzyl [1-11C]acetate was higher than that of [1-11C]acetate.
• The uptake of benzyl [1-11C]acetate was inhibited by fluorocitrate.
• Benzyl [1-11C]acetate is a useful PET probe for astrocytic oxidative metabolism.

Brain uptake of acetate is insufficient for obtaining a quantitative image of astrocytic oxidative metabolism. To improve the brain uptake of [1-11C]acetate, we synthesized benzyl [1-11C]acetate ([1-11C]BA) and conducted a positron emission tomography (PET) study assessing astrocytic oxidative metabolism. The brain uptake of [1-11C]BA was markedly higher compared with [1-11C]acetate, and disappeared with a half-life of 20 min in all regions studied. The brain uptake of [1-11C]BA was significantly decreased by fluorocitrate. The results indicate that [1-11C]BA could be a useful PET probe for assessing astrocytic oxidative metabolism.