1. Radiosynthesis and Evaluation of [ 11 C]3-Hydroxycyclopent-1-enecarboxylic Acid as Potential PET Ligand for the High-Affinity γ-Hydroxybutyric Acid Binding Sites.
- Author
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Jensen CH, Hansen HD, Bay T, Vogensen SB, Lehel S, Thiesen L, Bundgaard C, Clausen RP, Knudsen GM, Herth MM, Wellendorph P, and Frølund B
- Subjects
- Animals, Binding, Competitive, Carbon Isotopes chemistry, Carbon Isotopes pharmacokinetics, Carboxylic Acids chemical synthesis, Carboxylic Acids chemistry, Cyclopentanes chemical synthesis, Cyclopentanes chemistry, Dose-Response Relationship, Drug, Female, Protein Binding drug effects, Radioligand Assay, Swine, Binding Sites drug effects, Brain diagnostic imaging, Brain drug effects, Carboxylic Acids pharmacokinetics, Cyclopentanes pharmacokinetics, Positron-Emission Tomography
- Abstract
γ-Hydroxybutyric acid (GHB) is an endogenous neuroactive substance and proposed neurotransmitter with affinity for both low- and high-affinity binding sites. A radioligand with high and specific affinity toward the high-affinity GHB binding site would be a unique tool toward a more complete understanding of this population of binding sites. With its high specific affinity and monocarboxylate transporter (MCT1) mediated transport across the blood-brain barrier in pharmacological doses, 3-hydroxycyclopent-1-enecarboxylic acid (HOCPCA) seems like a suitable PET radiotracer candidate. Here, we report the
11 C-labeling and subsequent evaluation of [11 C]HOCPCA in a domestic pig, as a PET-radioligand for visualization of the high-affinity GHB binding sites in the live pig brain. To investigate the regional binding of HOCPCA in pig brain prior to in vivo PET studies, in vitro quantitative autoradiography on sections of pig brain was performed using [3 H]HOCPCA. In vivo evaluation of [11 C]HOCPCA showed no brain uptake, possibly due to a limited uptake of HOCPCA by the MCT1 transporter at tracer doses of [11 C]HOCPCA.- Published
- 2017
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