Simplified PET measurement for evaluating histamine H1 receptors in human brains using [11C]doxepin

The aim of this study was to develop simplified positron emission tomography measurement using [(11)C]doxepin ([(11)C]DOX) to evaluate histamine H(1) receptors (H1Rs) in human brains. We evaluated the correlation between the distribution volume (DV) of [(11)C]DOX, estimated quantitatively with a two-compartment model, and the [(11)C]DOX uptake obtained at various time intervals and normalized using the metabolite-corrected plasma radioactivity. We found that the static 70- to 90-min images normalized using the plasma radioactivity at 10 min postinjection reflected the DV of [(11)C]DOX-H1R binding.