TY - JOUR T1 - Measurement of 5-HT<sub>1A</sub> receptor density and <em>in vivo</em> K<sub>D</sub> of [F-18]Mefway in the nonhuman primate JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1180 LP - 1180 VL - 52 IS - supplement 1 AU - Dustin Wooten AU - Jeff Moirano AU - Ansel Hillmer AU - Todd Barnhart AU - Dhanabalan Murali AU - Jogeshwar Mukherjee AU - Mary Schneider AU - Bradley Christian Y1 - 2011/05/01 UR - http://jnm.snmjournals.org/content/52/supplement_1/1180.abstract N2 - 1180 Objectives [F-18]Mefway (MEF) was developed to offer an F-18 labeled serotonin1A (5-HT1A) PET antagonist to aid in the in vivo assessment of this system. The goal of this work was to characterize the in vivo kinetics of MEF and measure the 5-HT1A receptor density in rhesus monkeys. Methods Five rhesus monkeys (4f, 1m) were given 3 sequential bolus injections of MEF each with varying concentrations of unlabeled mefway. Dynamic scans were acquired with a microPET P4 scanner for a total of 180 minutes. Arterial sampling was performed throughout the scan to assay parent compound in plasma. Injection times and specific activities were optimized to measure values of Bmax, koff, and KDapp(=koff/kon). Time activity curves were extracted in the brain regions of the mesial temporal (MTC), frontal (FC), and parietal (PC) cortices. The kinetics of [F-18]mefway were modeled using COMKAT software (Muzic et al) and the arterial input function to estimate parameters of K1, k2, koff, Bmax, kon, and KDapp. Results When averaged across brain regions, parameters were koff: 0.029 ± 0.005 min-1; kon: 0.0055 ± 0.0016 mL/(pmol min); KDapp: 5.8 ± 2.1 pmol/mL; K1: 0.55 ± 0.18 min-1; k2: 0.36 ± 0.06 min-1 for MEF. Highest binding was seen in the MTC with Bmax values of 53 ± 4.4 pmol/mL, and 32 ± 5.3 pmol/mL in the FC and 18 ± 0.3 pmol/mL in the PC. Conclusions These results suggest that MEF has similar in vivo binding characteristics to [C-11]WAY100635. The favorable imaging characteristics make MEF a suitable radiotracer for PET assay of the 5-HT1A system. Work is ongoing to closely examine the potential presence of specific binding in the cerebellum and its use as a reference region for BPND estimation in the rhesus monkey. Research Support AA017706, MH086014, AG030524, AA1227 ER -