Regional brain distribution of 2-deoxy-2-[F-18]Fluoro-D-talose: A new PET tracer for measurement of galactokinase activity

Journal Article · Sun May 01 04:00:00 EDT 1994 · Journal of Nuclear Medicine

OSTI ID:198105

Haradahira, T ^[1]; Inoue, O; Suzuki, K ^[2]

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1. Research Development Corporation of Japan, Tokyo (Japan)
2. National Institute of Radiological Sciences, Chiba (Japan)

We have recently developed a 2-deoxy-2-[F-18]fluoro-D-talose (2-[F-18]FDTal) as a new PET tracer for measurements of galactokinase activities in tissues. The rational of 2-[F-18]FDTal as a PET tracer is based on the metabolic trapping by a formation of 2-[F-18]FDTal-1-phosphate by galactokinase. In this study, we have examined the regional brain distribution of 2-[F-18]FDTal in monkey by PET, and compared it with those of 2-deoxy-2-[F-18]fluoro-D-glucose (2-[F-18]FDG) and 2-deoxy-2-[F-18]fluoro-D-galactose (2-[F-18]FDTal), PET tracers for D-glucose and D-galactose metabolisms, respectively. The F-18 sugars used for the PET studies were prepared through nucleophilic fluorinations of the corresponding triflates with [F-18]fluoride. PET imaging obtained by i.v. injection of 2-[F-18]FDTal in rhesus monkey showed very high accumulation of the radioactivity into an occipital cortex region. This regional distribution was very similar to that of 2-[F-18]FDGal, but was quite different with that of 2-[F-18]FDG. In PET data analyses, washout of the radioactivity from the occipital cortex (30% loss of the initial activity) was observed in an early period ({<=}5 min) after injection of 2-[F-18]FDTal, in contrast with the continuous increase of the radioactivity in the same region after injection of 2-[F-18]FDGal. This data indicates a smaller phosphorylation rate constant (K3) of 2-[F-18]FDTal by brain galactokinase than that of 2-[F-18]FDGal. 2-[F-18]FDGal has been reported to be partly metabolized into an UDP-2-[F-18]FDGal via 2-CF-18]FDGal-l-phosphate in animal brains. Therefore 2-[F-18]FDTal offers an advantage over 2-[F-18]FDGal in undergoing its simple metabolism which enables us to make a simple kinetic model for PET imaging. We conclude that 2-[F-18]FDTal may be a new PET tracer to give a characteristic regional brain distribution which reflect the regional galactokinase activity.

• OSTI ID: 198105
• Report Number(s): CONF-940605--
• Journal Information: Journal of Nuclear Medicine, Journal Name: Journal of Nuclear Medicine Journal Issue: Suppl.5 Vol. 35; ISSN 0161-5505; ISSN JNMEAQ
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
BIOCHEMISTRY
BRAIN
ENZYME ACTIVITY
FLUORINE 18
FLUORODEOXYGLUCOSE
GALACTOSE
GLUCOSE
LABELLED COMPOUNDS
METABOLISM
PHOSPHOTRANSFERASES
POSITRON COMPUTED TOMOGRAPHY
SACCHARIDES
TISSUES
TRACER TECHNIQUES