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 F-18-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 BP(ND)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.