Related Experiment Video
Updated: Aug 9, 2026

Thermostabilization, Expression, Purification, and Crystallization of the Human Serotonin Transporter Bound to S-citalopram
Published on: November 27, 2016
Inhibition of serotonin transport by (+)McN5652 is noncompetitive
René Hummerich1, Oliver Schulze, Thomas Rädler
1Biochemical Laboratory, Central Institute of Mental Health, 68159 Mannheim, Germany.
Introduction:
Imaging of the serotonergic innervation of the brain using positron emission tomography (PET) with the serotonin transporter (SERT) ligand [11C] (+)McN5652 might be affected by serotonin in the synaptic cleft if there is relevant interaction between [11C] (+)McN5652 and serotonin at the SERT. The aim of the present study therefore was to pharmacologically characterize the interaction of [11C] (+)McN5652 and serotonin at the SERT.
Methods:
In vitro saturation analyses of [3H]serotonin uptake into HEK293 cells stably expressing the human SERT were performed in the absence and presence of unlabelled (+)McN5652. Data were evaluated assuming Michaelis-Menten kinetics.
Results:
Unlabelled (+)McN5652 significantly reduced the maximal rate of serotonin transport V(max) of SERT without affecting the Michaelis-Menten constant K(M).
Conclusions:
This finding indicates that (+)McN5652 inhibits serotonin transport through the SERT in a noncompetitive manner. This might suggest that [11C] (+)McN5652 PET is not significantly affected by endogenous serotonin.
Related Concept Videos
Drugs Affecting GI Tract Motility: Serotonin Receptor Agonists
Nonlinear Pharmacokinetics: Dependence of Elimination Half-Life and Dose Clearance
A study on guinea pigs examined the...
Nondepolarizing (Competitive) Neuromuscular Blockers: Mechanism of Action
Competitive antagonists prevent acetylcholine from binding to its receptor, inhibiting membrane depolarization. Without conformational changes or intrinsic...
Nonlinear Pharmacokinetics: Role of Transporters
Polymorphisms occurring in drug transporters can alter...
Antidepressant Drugs: MAOIs and Other Agents
G-protein Coupled Receptors
