biostudies-literatureNaganawa MNCATS NIH HHSNCRR NIH HHSNIMH NIH HHS1818-25https://www.ebi.ac.uk/biostudies/studies/S-EPMC4269759biostudies-literatureUnknown34(11)(11)C-LY2795050 is a novel kappa opioid receptor (KOR) antagonist tracer for positron emission tomography (PET) imaging. The purpose of this first-in-human study was to determine the optimal kinetic model for analysis of (11)C-LY2795050 imaging data. Sixteen subjects underwent baseline scans and blocking scans after oral naltrexone. Compartmental modeling and multilinear analysis-1 (MA1) were applied using the arterial input functions. Two-tissue compartment model and MA1 were found to be the best models to provide reliable measures of binding parameters. The rank order of (11)C-LY2795050 distribution volume (VT) matched the known regional KOR densities in the human brain. Blocking scans with naltrexone indicated no ideal reference region for (11)C-LY2795050. Three methods for calculation of the nondisplaceable distribution volume (VND) were assessed: (1) individual VND estimated from naltrexone occupancy plots, (2) mean VND across subjects, and (3) a fixed fraction of cerebellum VT. Approach (3) produced the lowest intersubject variability in the calculation of binding potentials (BPND, BPF, and BPP). Therefore, binding potentials of (11)C-LY2795050 can be determined if the specific binding fraction in the cerebellum is presumed to be unchanged by diseases and experimental conditions. In conclusion, results from the present study show the suitability of (11)C-LY2795050 to image and quantify KOR in humans.Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and MetabolismKinetic modeling of (11)C-LY2795050, a novel antagonist radiotracer for PET imaging of the kappa opioid receptor in humans.PMC4269759UL1 TR000142UL1 RR024139R01 MH091537Naganawa MRopchan JTauscher JNeumeister ALabaree DHuang YHenry SNabulsi NLin SFCarson REZheng MQTomasi GfalseKinetic modeling of (11)C-LY2795050, a novel antagonist radiotracer for PET imaging of the kappa opioid receptor in humans.(11)C-LY2795050 is a novel kappa opioid receptor (KOR) antagonist tracer for positron emission tomography (PET) imaging. The purpose of this first-in-human study was to determine the optimal kinetic model for analysis of (11)C-LY2795050 imaging data. Sixteen subjects underwent baseline scans and blocking scans after oral naltrexone. Compartmental modeling and multilinear analysis-1 (MA1) were applied using the arterial input functions. Two-tissue compartment model and MA1 were found to be the best models to provide reliable measures of binding parameters. The rank order of (11)C-LY2795050 distribution volume (VT) matched the known regional KOR densities in the human brain. Blocking scans with naltrexone indicated no ideal reference region for (11)C-LY2795050. Three methods for calculation of the nondisplaceable distribution volume (VND) were assessed: (1) individual VND estimated from naltrexone occupancy plots, (2) mean VND across subjects, and (3) a fixed fraction of cerebellum VT. Approach (3) produced the lowest intersubject variability in the calculation of binding potentials (BPND, BPF, and BPP). Therefore, binding potentials of (11)C-LY2795050 can be determined if the specific binding fraction in the cerebellum is presumed to be unchanged by diseases and experimental conditions. In conclusion, results from the present study show the suitability of (11)C-LY2795050 to image and quantify KOR in humans.2014-01-01T00:00:00Z2014 Nov2024-11-20T21:27:53.507Z2019-03-27T01:41:57ZS-EPMC42697592518266410.1038/jcbfm.2014.150