Related Experiment Video
Updated: May 21, 2026

Thermostabilization, Expression, Purification, and Crystallization of the Human Serotonin Transporter Bound to S-citalopram
Published on: November 27, 2016
No change in [¹¹C]CUMI-101 binding to 5-HT(1A) receptors after intravenous citalopram in human
Lars H Pinborg1, Ling Feng, Mette E Haahr
1Center for Integrated Molecular Brain Imaging, Rigshospitalet, Copenhagen University Hospital, Denmark. pinborg@nru.dk
Abstract:
The main objective of this study was to determine the sensitivity of [¹¹C]CUMI-101 to citalopram challenge aiming at increasing extracellular 5-HT. CUMI-101 has agonistic properties in human embryonic kidney 293 cells transfected with human recombinant 5-HT(1A) receptors (Hendry et al. [2011] Nucl Med Biol 38:273-277; Kumar et al. [2006] J Med Chem 49:125-134) and has previously been demonstrated to be sensitive to bolus citalopram in monkeys (Milak et al. [2011] J Cereb Blood Flow Metab 31:243-249). We studied six healthy individuals. Two PET-scans were performed on the same day in each individual before and after constant infusion of citalopram (0.15 mg/kg). The imaging data were analyzed using two tissue compartment kinetic modeling with metabolite corrected arterial input and Simplified Reference Tissue Modeling using cerebellum as a reference region. There was no significant difference in regional distribution volume or non-displaceable binding potential values before and after citalopram infusion. The mean receptor occupancy was 0.03 (range -0.14 to 0.17). Our data imply that [¹¹C]CUMI-101 binding is not sensitive to citalopram infusion in humans.
Related Concept Videos
Drugs Affecting GI Tract Motility: Serotonin Receptor Agonists
Antidepressant Drugs: Tricyclics, SSRIs, and SNRIs
Drugs Affecting Neurotransmitter Release or Uptake
G-protein Coupled Receptors
Chemotherapy-Induced Nausea and Vomiting: 5-HT3 Receptor Antagonists
Nonlinear Pharmacokinetics: Dependence of Elimination Half-Life and Dose Clearance
A study on guinea pigs examined the...

