Kinetic modelling of [I-123]CNS 1261 – a potential SPET tracer for the NMDA receptor

N-(1-napthyl)-N’-(3-[I-123]-iodophenyl)-N-methylguanidine ([I-123]CNS 1261) is a novel SPET ligand developed for imaging the NMDA receptor intra-channel MK 801/PCP/ketamine site. Data was acquired in 7 healthy volunteers after bolus injection of [I-123]CNS 1261. Kinetic modeling showed reversible tracer binding. Arterial and venous time-activity curves overlapped after 90 min. The rank order of binding was: Thalamus > striatum > cortical regions > white matter. This distribution concurs with [C-11]-ketamine and [F-18]-memantine PET studies [14,1]. These data provide a methodological basis for further direct in vivo challenge studies. (C) 2003 Elsevier Inc. All rights reserved.