Dopamine D-2 receptor imaging radiopharmaceuticals: synthesis, radiolabeling, and in vitro binding of (R)-(+)- and (S)-(-)-3-iodo-2-hydroxy-6-methoxy-N- ((1-ethyl-2-pyrrolidinyl)methyl)benzamide
In developing central nervous system (CNS) dopamine D-2 receptor imaging agents, enantiomers, R-(+) and S-(-) isomers, of 3-(/sup 125/I)iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2- pyrrolidinyl)methyl)benzamide, (/sup 125/I)IBZM, were synthesized, and their in vitro binding characteristics were evaluated in rat striatum tissue preparation. The (S)-(-)-(/sup 125/I)IBZM showed high specific dopamine D-2 receptor binding (Kd = 0.43 nM, Bmax = 0.48 pmol/mg of protein). Competition data of various ligands for IBZM binding displayed the following rank order of potency: spiperone greater than (S)-(-)-IBZM greater than (+)-butaclamol much greater than (R)-(+)-IBZM greater than (S)-(-)-BZM greater than dopamine greater than ketanserin greater than SCH23390 much greater than propanolol. The results indicate that (/sup 125/I)IBZM binds specifically to the dopamine D-2-receptor with stereospecificity. The (/sup 125/I)IBZM is potentially useful as an imaging agent for the investigation of dopamine D-2 receptors in humans.
- Research Organization:
- Univ. of Pennsylvania, Philadelphia (USA)
- OSTI ID:
- 6970273
- Journal Information:
- J. Med. Chem.; (United States), Journal Name: J. Med. Chem.; (United States) Vol. 31:5; ISSN JMCMA
- Country of Publication:
- United States
- Language:
- English
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62 RADIOLOGY AND NUCLEAR MEDICINE
AMINES
ANIMALS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
AZOLES
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CARDIOTONICS
CARDIOVASCULAR AGENTS
CHEMICAL PREPARATION
DAYS LIVING RADIOISOTOPES
DOPAMINE
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
IN VITRO
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPES
KINETICS
LABELLED COMPOUNDS
LIGANDS
MAMMALS
MEMBRANE PROTEINS
NEUROREGULATORS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHENOLS
POLYPHENOLS
PROTEINS
PYRROLES
PYRROLIDINES
RADIOISOTOPES
RADIOPHARMACEUTICALS
RATS
REACTION KINETICS
RECEPTORS
RODENTS
SPECIFICITY
STRUCTURE-ACTIVITY RELATIONSHIPS
SYMPATHOMIMETICS
SYNTHESIS
VERTEBRATES