ABSTRACT
OBJECTIVE: Using single photon emission computed tomography and the 5-HT2A receptor antagonist, 123I-5-I-R91150, we explored differences in 5-HT2A binding index in anorexia nervosa patients with and without bulimic features. We also searched for associations between temperament dimensions and cortical 5-HT2) binding. METHOD: About 9 restrictive and 7 bulimic anorexia nervosa patients were examined and cortical 123I-5-I-R91150 binding index values were compared between the two subgroups. Open explorative correlation analysis was used to examine any relationships between binding index values and temperament scores, as assessed with the Temperament and Character Inventory. RESULTS: 5-HT2A binding index was significantly reduced in the parietal cortex in bulimic anorexia nervosa patients in comparison with restrictive anorectics. Further, a positive correlation was documented between reward dependence and parietal 5-HT2A binding index across patients in the two subgroups. DISCUSSION: Restrictive anorexia nervosa patients differ from binging/purging anorexia nervosa patients on the basis of a reduced parietal 5-HT2A binding index in the latter. We speculate that the finding of a positive correlation between parietal 5-HT2A binding and reward dependence might reflect an association between these two variables, at least in anorexia nervosa patients.
Subject(s)
Anorexia Nervosa/diagnosis , Anorexia Nervosa/metabolism , Cerebral Cortex/metabolism , Receptor, Serotonin, 5-HT2A/metabolism , Tomography, Emission-Computed, Single-Photon , Adolescent , Adult , Anorexia Nervosa/psychology , Binding Sites , Character , Diagnostic and Statistical Manual of Mental Disorders , Female , Humans , Surveys and Questionnaires , TemperamentABSTRACT
OBJECTIVE: Bulimia nervosa has been associated with alterations in central serotonergic (5-HT) function. This study investigated iodine-labeled 4-amino-N-[1-[3-(4-fluorophenoxy) propyl]-4-methyl-4-piperidinyl]-5-iodo-2-methoxybenzamide ((123)I-5-I-R91150) binding to the 5-HT(2A) receptor in the brain by using single photon emission computed tomography in acutely ill bulimia nervosa patients. METHOD: Cortical (123)I-5-I-R91150 binding in 10 normal-weight patients with bulimia nervosa, purging type, was compared with that of 11 healthy volunteers. RESULTS: The 5-HT(2A) binding index of the bulimia nervosa patients, with and without correction for age, was not significantly different from that of the comparison group. CONCLUSIONS: As a group, acutely ill bulimia nervosa patients cannot be discriminated from healthy subjects on the basis of cortical (123)I-5-I-R91150 binding to the 5-HT(2A) receptor.
Subject(s)
Bulimia/metabolism , Cerebral Cortex/metabolism , Receptor, Serotonin, 5-HT2A/metabolism , Acute Disease , Adolescent , Adult , Body Mass Index , Body Weight , Bulimia/diagnostic imaging , Cerebral Cortex/diagnostic imaging , Female , Humans , Iodine Radioisotopes , Male , Piperidines , Protein Binding , Tomography, Emission-Computed, Single-PhotonABSTRACT
Acetylhomotaurine was labeled with (11)C via N-acetylation with [(11)C]acetyl chloride. The synthesis yielded 48.2+/-3.8%, decay corrected to end of bombardment. The specific activity of the (radio)chemically pure product was 20.8+/-2.0 GBq/micromol at EOS. In vivo studies revealed a very fast clearance of the tracer from the blood and a uniform distribution in the different brain regions. Unfortunately, the poor passage through the blood brain barrier makes the tracer not suitable for PET studies.
Subject(s)
Brain/diagnostic imaging , Brain/metabolism , Positron-Emission Tomography/methods , Taurine/analogs & derivatives , Taurine/pharmacology , Taurine/pharmacokinetics , Acamprosate , Alcohol Deterrents/pharmacology , Alcoholism/drug therapy , Animals , Brain/drug effects , Carbon Radioisotopes/chemistry , Carbon Radioisotopes/pharmacokinetics , Humans , Isotope Labeling/methods , Male , Metabolic Clearance Rate , Mice , Rabbits , Radiopharmaceuticals/chemical synthesis , Radiopharmaceuticals/pharmacokinetics , Taurine/chemical synthesis , Tissue Distribution , Treatment OutcomeABSTRACT
Serotonin (5-HT) and more specifically the 5-HT(2A) receptor is involved in cognitive and non-cognitive behavior and plays an important role in Alzheimer's disease (AD). The objective was to assess the 5-HT(2A) binding potential (BP) in healthy volunteers and AD with SPECT and 123I-5-I-R91150, a selective radio-iodinated 5-HT(2A) receptor antagonist. Twenty-six controls and nine AD patients were included. A semiquantitive analysis with normalization on cerebellar uptake provided estimates of BP for 26 cortical regions of interest. An age-related decline of neocortical BP was found (11.6% per decade). Compared to age-matched controls, a generally decreased neocortical BP in AD was found with a significant regional reduction in the orbitofrontal, prefrontal, lateral frontal, cingulate, sensorimotor, parietal inferior, and occipital region. These results are in line with previous postmortem, in vitro, and PET findings. The age-related decline highlights the necessity for matched advanced age study samples. The fact that the 5-HT(2A) receptor is differentially affected in AD patients has implications for both the etiological basis and therapeutic management of AD.
