0000000001037390
AUTHOR
Nilufar Heydari
Occupancy of striatal D 2 -like dopamine receptors after treatment with the sigma ligand EMD 57445, a putative atypical antipsychotic
Rationale: EMD 57445 (panamesine) is a high affinity sigma ligand with the profile of an atypical antipsychotic in animal studies. It has been reported recently to have antipsychotic activity in schizophrenia. However, its metabolite, EMD 59983, binds also to D2 and D3 dopamine (DA) receptors. Objectives: The aim of this study was to test, using single photon emission computed tomography (SPECT) and [123I]iodobenzamide (IBZM) as the radiotracer, whether EMD 59983 would pass the blood-brain barrier and to what extent it would contribute to the effects of EMD 57445 in schizophrenia. Methods: Two IBZM SPECT-scans were performed in five neuroleptic-free schizophrenic patients (DSM IV), one befo…
Subchronic haloperidol downregulates dopamine synthesis capacity in the brain of schizophrenic patients in vivo
Udgivelsesdato: 2003-Apr The antipsychotic effect of neuroleptics cannot be attributed entirely to acute blockade of postsynaptic D(2)-like dopamine (DA) receptors, but may arise in conjunction with the delayed depolarization block of the presynaptic neurons and reduced DA synthesis capacity. Whereas the phenomenon of depolarization block is well established in animals, it is unknown if a similar phenomenon occurs in humans treated with neuroleptics. We hypothesized that haloperidol treatment should result in decreased DA synthesis capacity. We used 6-[(18)F]fluoro-L-dopa (FDOPA) and positron emission tomography (PET) in conjunction with compartmental modeling to measure the relative activi…