No change in [¹¹C]CUMI-101 binding to 5-HT(1A) receptors after intravenous citalopram in human.
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.
Center for Integrated Molecular Brain Imaging, Rigshospitalet, Copenhagen University Hospital, Denmark. pinborg@nru.dk
Lars H
LH
Pinborg
Ling
L
Feng
Mette E
ME
Haahr
Nic
N
Gillings
Agnete
A
Dyssegaard
Jacob
J
Madsen
Claus
C
Svarer
Stig
S
Yndgaard
Troels W
TW
Kjaer
Ramin V
RV
Parsey
Hanne D
HD
Hansen
Anders
A
Ettrup
Olaf B
OB
Paulson
Gitte M
GM
Knudsen
D000328:Adult; D002531:Cerebellum / Q000000981:diagnostic imaging; D015283:Citalopram / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D010879:Piperazines / Q000008:administration & dosage / Q000378:metabolism*; D049268:Positron-Emission Tomography; D044282:Receptor, Serotonin, 5-HT1A / Q000378:metabolism*; D058825:Serotonin 5-HT1 Receptor Agonists / Q000008:administration & dosage / Q000378:metabolism*; D017367:Selective Serotonin Reuptake Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D014227:Triazines / Q000008:administration & dosage / Q000378:metabolism*
D015283:Citalopram; D010879:Piperazines; D044282:Receptor, Serotonin, 5-HT1A; D058825:Serotonin 5-HT1 Receptor Agonists; D017367:Selective Serotonin Reuptake Inhibitors; D014227:Triazines; C529131:2-(4-(4-(2-methoxyphenyl)piperazin-1-yl)butyl)-4-methyl-1,2,4-triazine-3,5-(2H,4H)-dione