Brain kinetics of (R)- and (S)-[N-methyl-11C]ketamine in the rhesus monkey studied by positron emission tomography (PET).

The regional brain kinetics of the two enantiomers of the NMDA channel blocker ketamine radiolabelled with 11C was studied in the Rhesus monkey by means of positron emission tomography (PET). The uptake in brain areas which showed high radioactivities was blocked in a dose-dependent manner for both 11C-labelled enantiomers with simultaneous doses of the respective unlabelled (S)- or (R)-ketamine, indicating specific binding. The binding in the striatum and cortical areas of (S)-[N-methyl-11C]ketamine was selective and displaceable by the (R)-enantiomer and by MK-801.