RT Journal Article SR Electronic T1 The in vivo kinetics of three 5-HT1A PET antagonists in the rhesus monkey JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 163 OP 163 VO 51 IS supplement 2 A1 Dustin Wooten A1 Jeffrey Moirano A1 Dhanabalan Murali A1 Ansel Hillmer A1 Onofre DeJesus A1 Todd Barnhart A1 Robert Nickles A1 Jogesh Mukherjee A1 Mary Schneider A1 Bradley Christian YR 2010 UL http://jnm.snmjournals.org/content/51/supplement_2/163.abstract AB 163 Objectives The serotonin 5-HT1A receptor system plays a central role in regulating mood and affect and is implicated in neuropsychiatric illness. [18F]MEFWAY was developed to provide a 18F labeled neuroligand with high affinity for the 5-HT1A site to improve in vivo assessment. The goal of this work is to compare the in vivo kinetics of [18F]MEFWAY, [18F]MPPF, and [11C]WAY100635 in the rhesus monkey. Methods Each of three monkeys was given bolus injections of MEF, WAY, and MPPF. Scans were acquired with a microPET P4 scanner and arterial blood draws were taken to assay unchanged compound. Time activity curves were extracted in the high 5-HT1A binding areas of the cingulate (CG) and mesial temporal cortex (MTC) and the cerebellum (CB). Results The time course of unchanged compound in the plasma was comparable for all tracers with 16%, 15%, 17% (x10-4) (MEF, MPPF, WAY) present at 40 minutes after injection. The kinetics in the CB were comparable for all tracers with concentrations at peak uptake being within 20% of each other, concentrations at 90 minutes post injection being 40%, 26%, and 28% (i.d. x 10-4), and clearance rates being 0.0014, 0.0012, and 0.0014 (min-1)(MEF,MPPF,WAY). Bound to free ratios were found to be 12, 2.8, and 13 (MEF, MPPF, WAY) in the CG and 14, 5.2, and 14 (MEF, MPPF, WAY) in the MTC. Conclusions The behavior of all the tracers was similar in the plasma and nonspecific space. The kinetics and specific binding profiles of MEF and WAY were in close agreement in the receptor rich regions, with MEF yielding more than 10x higher count rate at 90 minutes with the 18F label. Research Support AA017706, MH086014, AG03052