Age-related decline in central serotonin transporter availability with [(123)I]beta-CIT SPECT.
Postmortem studies have provided limited and conflicting data regarding aging effects on the central serotonin transporter (SERT). The present study investigated the effect of age on SERT availability in the human brainstem and diencephalon with single photon emission computed tomography (SPECT) using the ligand [(123)I]2 beta-carbomethoxy-3 beta-(4-iodophenyl)tropane ([(123)I]beta-CIT). Healthy control subjects (n = 126) who ranged in age from 18 to 88 were injected with 6.0 +/- 0.8 (mean +/- SD) mCi [(123)I]beta-CIT and imaged 23.1 +/- 1.9 h later under equilibrium conditions. A ratio of specific to nondisplaceable brain uptake (i.e. , V(3)" = [brainstem-diencephalon -occipital]/occipital), a measure proportional to the binding potential (B(max)/K(D)), was derived. SERT availability (V(3)") showed a significant inverse correlation with age (r = -0.40, P < 0.0001). Linear regression analysis revealed that V(3)" declined by 29.5% over the age range 18 to 88, or approximately 4.2% per decade. These results demonstrate reductions in the availability of central SERT binding sites with age in living human subjects.
Department of Psychiatry, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA. christopher.vandyck@yale.edu
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van Dyck
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Laruelle
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D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism*; D001923:Brain Chemistry / Q000502:physiology*; D001933:Brain Stem / Q000737:chemistry / Q000502:physiology; D002352:Carrier Proteins / Q000378:metabolism*; D003042:Cocaine / Q000031:analogs & derivatives; D004027:Diencephalon / Q000737:chemistry / Q000502:physiology; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism*; D026901:Membrane Transport Proteins; D008875:Middle Aged; D009419:Nerve Tissue Proteins; D012016:Reference Values; D050486:Serotonin Plasma Membrane Transport Proteins; D015899:Tomography, Emission-Computed, Single-Photon
D002352:Carrier Proteins; D007457:Iodine Radioisotopes; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; C493230:SLC6A4 protein, human; D050486:Serotonin Plasma Membrane Transport Proteins; C069723:2beta-carbomethoxy-3beta-(4-iodophenyl)tropane; D003042:Cocaine