title: In vitro and in vivo testing of the dopamine D1 ligand [123I]SCH 23982 with respect to its potential application in SPET investigations.
abstract: [123I]SCH 23982, a dopamine D1 ligand, was labelled in a large scale process and then tested in vitro for binding to rat brain sections and membranes. Because of the promising values of KD = 1.5 x 10(-10) M and Bmax = 0.7 x 10(-11) mol/g, in vivo evaluation was performed on rats and normal volunteers to test its possible usefulness for SPET imaging. In competition experiments, a higher binding in the presence of sulpiride was found while ketanserin displaced [123I]SCH 23982 only at a 10,000-fold excess. Differences between rats and men were seen with respect to their metabolism. SPET investigations failed because the washout of [123I]SCH 23982 was too rapid.
authors.affiliation: Division of Radiopharmacy, Paul Scherrer Institute, Villigen, Switzerland.
authors.forename: H F
authors.initials: HF
authors.lastname: Beer
authors.forename: S
authors.initials: S
authors.lastname: Lin
authors.forename: P
authors.initials: P
authors.lastname: Bläuenstein
authors.forename: P
authors.initials: P
authors.lastname: Hasler
authors.forename: P A
authors.initials: PA
authors.lastname: Schubiger
authors.forename: A
authors.initials: A
authors.lastname: Maier
authors.forename: W
authors.initials: W
authors.lastname: Lichtensteiger
authors.forename: R
authors.initials: R
authors.lastname: Oettli
authors.forename: A
authors.initials: A
authors.lastname: Bekier
authors.forename: B
authors.initials: B
authors.lastname: Weder
mesh_terms: D000368:Aged; D000818:Animals; D001552:Benzazepines / Q000031:analogs & derivatives* / Q000378:metabolism / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D051381:Rats; D017208:Rats, Wistar; D017447:Receptors, Dopamine D1 / Q000037:antagonists & inhibitors*; D014018:Tissue Distribution; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: C049558:8-iodo-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3-benzazepine-7-ol; D001552:Benzazepines; D007457:Iodine Radioisotopes; D017447:Receptors, Dopamine D1