Title : Imaging of cholinergic terminals using the radiotracer [18F](+)-4-fluorobenzyltrozamicol: in vitro binding studies and positron emission tomography studies in nonhuman primates - Mach_1997_Synapse_25_368 |
Author(s) : Mach RH , Voytko ML , Ehrenkaufer RL , Nader MA , Tobin JR , Efange SM , Parsons SM , Gage HD , Smith CR , Morton TE |
Ref : Synapse , 25 :368 , 1997 |
Abstract :
The goal of the present set of studies was to characterize the in vitro binding properties and in vivo tissue kinetics for the vesicular acetylcholine transporter (VAcChT) radiotracer, [18F](+)-4-fluorobenzyltrozamicol ([18F](+)-FBT). In vitro binding studies were conducted in order to determine the affinity of the (+)- and (-)-stereoisomers of FBT for the VAcChT as well as sigma (sigma 1 and sigma 2) receptors. (+)-FBT was found to have a high affinity (Ki = 0.22 nM) for the VAcChT and lower affinities for sigma 1 (21.6 nM) and sigma 2 (35.9 nM) receptors, whereas (-)-FBT had similar affinities for the VAcChT and sigma 1 receptors (approximately 20 nM) and a lower affinity for sigma 2 (110 nM) receptors. PET imaging studies were conducted in rhesus monkeys (n = 3) with [18F](+)-FBT. [18F](+)-FBT was found to have a high accumulation and slow rate of washout from the basal ganglia, which is consistent with the labeling of cholinergic interneurons in this brain region. [18F](+)-FBT also displayed reversible binding kinetics during the 3 h time course of PET and produced radiolabeled metabolites that did not cross the blood-brain barrier. The results from the current in vitro and in vivo studies indicate that [18F](+)-FBT is a promising ligand for studying cholinergic terminal density, with PET, via the VAcChT. |
PubMedSearch : Mach_1997_Synapse_25_368 |
PubMedID: 9097396 |
Mach RH, Voytko ML, Ehrenkaufer RL, Nader MA, Tobin JR, Efange SM, Parsons SM, Gage HD, Smith CR, Morton TE (1997)
Imaging of cholinergic terminals using the radiotracer [18F](+)-4-fluorobenzyltrozamicol: in vitro binding studies and positron emission tomography studies in nonhuman primates
Synapse
25 :368
Mach RH, Voytko ML, Ehrenkaufer RL, Nader MA, Tobin JR, Efange SM, Parsons SM, Gage HD, Smith CR, Morton TE (1997)
Synapse
25 :368