title: Development of central 5-HT2A receptor radioligands for PET: comparison of [3H]RP 62203 and [3H]SR 46349B kinetics in rat brain.
abstract: [3H]RP 62203 and [3H]SR 46349B binding were assessed in rat brain after intravenous (iv) injection. The distribution of specific binding of each radioligand corresponded to the known distribution of 5-HT2A receptor sites. The maximum signals (counts/g tissue over counts/g cerebellum) given by [3H]RP 62203 and [3H]SR 46349B were 9.0 +/- 0.9 at 60 min and 3.2 +/- 0.3 at 30 min, respectively, in frontopolar cortex. Specific binding was quantified using a reference-tissue compartment model. RP 62203 appears to be more suitable than SR 46349B for development as a PET radioligand on the basis of its higher receptor specific signal.
authors.affiliation: Cyclotron Unit, Royal Postgraduate Medical School, Hammersmith Hospital, London, UK.
authors.forename: S
authors.initials: S
authors.lastname: Ashworth
authors.forename: S P
authors.initials: SP
authors.lastname: Hume
authors.forename: A A
authors.initials: AA
authors.lastname: Lammertsma
authors.forename: J
authors.initials: J
authors.lastname: Opacka-Juffry
authors.forename: F
authors.initials: F
authors.lastname: Shah
authors.forename: V W
authors.initials: VW
authors.lastname: Pike
mesh_terms: D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism*; D003499:Cyclic S-Oxides / Q000493:pharmacokinetics; D005464:Fluorobenzenes / Q000493:pharmacokinetics; D007700:Kinetics; D008297:Male; D008962:Models, Theoretical; D009281:Naphthalenes / Q000493:pharmacokinetics; D010636:Phenols / Q000493:pharmacokinetics; D011869:Radioligand Assay / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin / Q000032:analysis / Q000378:metabolism*; D012702:Serotonin Antagonists / Q000493:pharmacokinetics; D013379:Substrate Specificity; D014018:Tissue Distribution; D014055:Tomography, Emission-Computed / Q000379:methods*; D014316:Tritium
chemical_list: D003499:Cyclic S-Oxides; D005464:Fluorobenzenes; D009281:Naphthalenes; D010636:Phenols; D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D014316:Tritium; C076033:SR 46349B; C070475:fananserin