Dopamine D(2) receptor quantification in extrastriatal brain regions using [(123)I]epidepride with bolus/infusion
Research output: Contribution to journal › Journal article › Research › peer-review
The iodinated benzamide epidepride, which shows a picomolar affinity binding to dopamine D(2) receptors, has been designed for in vivo studies using SPECT. The aim of the present study was to apply a steady-state condition by the bolus/infusion approach with [(123)I]epidepride for the quantification of striatal and extrastriatal dopamine D(2) receptors in humans. In this way the distribution volume of the tracer can be determined from a single SPECT image and one blood sample. Based on bolus experiments, an algorithm using conventional convolution arguments for prediction of the outcome of a bolus/infusion (B/I) experiment was applied. It was predicted that a B/I protocol with infusion of one-third of the initial bolus per hour would be appropriate. Steady-state conditions were attained in extrastriatal regions within 3-4 h but the infusion continued up to 7 h in order to minimize the significance of individual differences in plasma clearance and binding parameters. A steady-state condition, however, could not be attained in striatal brain regions using a B/I protocol of 20 h, even after 11 h. Under near steady-state conditions a striatal:cerebellar ratio of 23 was demonstrated. Epidepride has a unique signal-to-noise ratio compared to [(123)I]IBZM but present difficulties for steady-state measurements of striatal regions. The bolus/infusion approach is particularly feasible for quantification of the binding potential in extrastriatal regions.
Original language | English |
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Journal | Synapse (New York, N.Y.) |
Volume | 36 |
Issue number | 4 |
Pages (from-to) | 322-9 |
Number of pages | 8 |
ISSN | 0887-4476 |
DOIs | |
Publication status | Published - 15 Jun 2000 |
Bibliographical note
Copyright 2000 Wiley-Liss, Inc.
- Adult, Aged, Benzamides/administration & dosage, Brain/diagnostic imaging, Contrast Media/administration & dosage, Homeostasis, Humans, Iodine Radioisotopes, Male, Middle Aged, Pyrrolidines/administration & dosage, Receptors, Dopamine D2/metabolism, Tissue Distribution, Tomography, Emission-Computed, Single-Photon
Research areas
ID: 260897134