( sup 125 I)(+)FISCH: A new CNS D-1 dopamine receptor imaging ligand

Journal Article · Sat Dec 31 23:00:00 EST 1988 · Life Sciences; (USA)

DOI:https://doi.org/10.1016/0024-3205(89)90090-8· OSTI ID:6968640

Billings, J; Kung, M P; Chumpradit, S; Pan, S; Kung, H F ^[1]

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1. Univ. of Pennsylvania, Philadelphia (USA)

Radiolabeling and in vitro and in vivo evaluation of an iodinated benzazepine: ({sup 125}I)FISCH 7-Chloro-8-hydroxy-1-(4{prime}-iodophenyl)-3-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine, as a potential imaging agent for CNS D-1 dopamine receptors in animals, were investigated. After an iv injection, this benzazepine derivative showed good brain uptake in rats. The striatum/cerebellum ratio was 2.50 at 60 min after the injection. The regional distribution in rat brain, as measured by ex vivo autoradiography, displayed highest uptake in the regions of the striatal complex and the substantia nigra, regions known to have a high concentration of D-1 dopamine receptors. Furthermore, this localized regional cerebral distribution was blocked by pretreatment with SCH-23390, a selective D-1 dopamine receptor antagonist. The in vitro binding affinity of this agent in rat striatum tissue preparation displayed a Kd of 1.43 {plus minus} 0.15 nM. Competition data (in vitro) showed the following rank order of potency: SCH-23390 > ({plus minus})IBZP >> apomorphine > WB 4101 > ketanserin {approximately} spiperone. The preliminary data suggest that this analog of SCH-23390 shows similar selectivity for the CNS D-1 receptor.

• OSTI ID: 6968640
• Journal Information: Life Sciences; (USA), Journal Name: Life Sciences; (USA) Vol. 45:8; ISSN 0024-3205; ISSN LIFSA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
AMINES
ANIMALS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
AUTORADIOGRAPHY
BETA DECAY RADIOISOTOPES
BODY
BRAIN
CARDIOTONICS
CARDIOVASCULAR AGENTS
CENTRAL NERVOUS SYSTEM
DAYS LIVING RADIOISOTOPES
DISTRIBUTION
DOPAMINE
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
EVALUATION
HYDROXY COMPOUNDS
IMAGE PROCESSING
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LIGANDS
MAMMALS
MEMBRANE PROTEINS
NERVOUS SYSTEM
NEUROREGULATORS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PHENOLS
POLYPHENOLS
PROCESSING
PROTEINS
RADIOISOTOPES
RADIOPHARMACEUTICALS
RATS
RECEPTORS
RODENTS
SYMPATHOLYTICS
SYMPATHOMIMETICS
TISSUE DISTRIBUTION
TRACER TECHNIQUES
VERTEBRATES