1. Measuring α4β2∗ Nicotinic Acetylcholine Receptor Density in Vivo with [18F]nifene PET in the Nonhuman Primate
- Author
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Hillmer, Ansel T, Wooten, Dustin W, Slesarev, Maxim S, Ahlers, Elizabeth O, Barnhart, Todd E, Schneider, Mary L, Mukherjee, Jogeshwar, and Christian, Bradley T
- Subjects
Neurosciences ,Animals ,Brain ,Female ,Fluorine Radioisotopes ,Kinetics ,Macaca mulatta ,Male ,Models ,Biological ,Positron-Emission Tomography ,Protein Binding ,Pyridines ,Pyrroles ,Receptors ,Nicotinic ,B-max ,K-D ,multiple injection ,nicotinic acetylcholine receptor ,[(18F)]nifene ,PET - Abstract
[(18)F]Nifene is an agonist PET radioligand developed to image α4β2* nicotinic acetylcholine receptors (nAChRs). This work aims to quantify the receptor density (Bmax) of α4β2* nAChRs and the in vivo (apparent) dissociation constant (KDapp) of [(18)F]nifene. Multiple-injection [(18)F]nifene experiments with varying cold nifene masses were conducted on four rhesus monkeys with a microPET P4 scanner. Compartment modeling techniques were used to estimate regional Bmax values and a global value of KDapp. The fast kinetic properties of [(18)F]nifene also permitted alternative estimates of Bmax and KDapp at transient equilibrium with the same experimental data using Scatchard-like methodologies. Averaged across subjects, the compartment modeling analysis yielded Bmax values of 4.8±1.4, 4.3±1.0, 1.2±0.4, and 1.2±0.3 pmol/mL in the regions of antereoventral thalamus, lateral geniculate, frontal cortex, and subiculum, respectively. The KDapp of nifene was 2.4±0.3 pmol/mL. The Scatchard analysis based on graphical evaluation of the data after transient equilibrium yielded Bmax estimations comparable to the modeling results with a positive bias of 28%. These findings show the utility of [(18)F]nifene for measuring α4β2* nAChR Bmax in vivo in the rhesus monkey with a single PET experiment.
- Published
- 2013