Striatal dopamine transporter changes after glucose loading in humans.

ABSTRACT

AIMS: The dopamine transporter (DAT) actively translocates dopamine that is released from the presynaptic neurons across the membranes of nerve terminals into the extracellular space. We hypothesized that glucose loading-induced changes in striatal DAT levels could be associated with food intake in humans. MATERIALS AND METHODS: An intravenous bolus injection of 18 F-FP-CIT was administered after infusion of glucose or placebo (normal saline), and emission data were acquired over 90 minutes in 33 healthy males. For a volume-of-interest-based analysis, an atlas involving sub-striatal regions of ventral striatum (VST), caudate nucleus and putamen was applied. DAT availability and binding potential (BPND ) were measured using a simplified reference tissue method with cerebellum as the reference. RESULTS: The glucose-loaded BPND from the VST negatively correlated with body mass index (BMI), whereas the placebo-loaded BPND from the VST did not. After loading with glucose, there were substantial increases in BPND s 18.3%, 71.7% and 34.0% on average in the VST, caudate nucleus and putamen, respectively. CONCLUSION: Striatal DAT changes after glucose loading, and BMI is associated with glucose-loaded DAT availability, not with placebo-loaded DAT availability. DAT might have a role in the reward system of eating behavior.