6533b857fe1ef96bd12b4312

RESEARCH PRODUCT

Synthesis, radiofluorination and first evaluation of (±)-[18F]MDL 100907 as serotonin 5-HT2Areceptor antagonist for PET

subject

description

In some psychiatric disorders 5-HT2A receptors play an important role. In order to investigate those in vivo there is an increasing interest in obtaining a metabolically stable, subtype selective and high affinity radioligand for receptor binding studies using positron emission tomography (PET). Combining the excellent in vivo properties of [11C]MDL 100907 for PET imaging of 5-HT2A receptors and the more suitable half-life of fluorine-18, MDL 100907 was radiofluorinated in four steps using 1-(2-bromoethyl)-4-[18F]fluorobenzene as a secondary labelling precursor. The complex reaction required an overall reaction time of 140 min and (±)-[18F]MDL 100907 was obtained with a specific activity of at least 30 GBq/µmol (EOS) and an overall radiochemical yield of 1–2%. In order to verify its binding to 5-HT2A receptors, in vitro rat brain autoradiography was conducted showing the typical distribution of 5-HT2A receptors and a very low non-specific binding of about 6% in frontal cortex, using ketanserin or spiperone for blocking. Thus, [18F]MDL 100907 appears to be a promising new 5-HT2A PET ligand. Copyright © 2008 John Wiley & Sons, Ltd.