In vitro and in vivo evaluation of (/sup 123/I)IBZM: a potential CNS D-2 dopamine receptor imaging agent

Journal Article · Sun Jan 01 04:00:00 EST 1989 · J. Nucl. Med.; (United States)

OSTI ID:6406676

Kung, H F; Pan, S; Kung, M P; Billings, J; Kasliwal, R; Reilley, J; Alavi, A

In vitro binding characteristics of a CNS dopamine D-2 receptor imaging agent, (S)-N-((1-ethyl-2-pyrrolidinyl)) methyl-2-hydroxy-3-iodo-6-methoxybenzamide ((/sup 125/I)IBZM), was carried out in rats. Also brain images, as well as organ biodistribution were determined in a monkey following the administration of /sup 123/I-labeled compound. The S-(-)-I(/sup 125/I)IBZM showed high specific dopamine D-2 receptor binding in rat striatum (Kd = 0.426 +/- 0.082 nM, Bmax = 480 +/- 22 fmol/mg of protein). Competition of various ligands for the IBZM binding displayed the following rank order of potency: spiperone greater than S(-)IBZM much greater than R(+)IBZM greater than or equal to S(-)BZM greater than dopamine greater than ketanserin greater than SCH-23390 much greater than propranolol, norepinephrine, serotonin. In vivo planar images of a monkey injected with (/sup 123/I)IBZM demonstrated a high concentration in basal ganglia of brain. The ratios of activity in the basal ganglia to cerebellum and the cortex to cerebellum in monkey brain were 4.93 and 1.44, respectively, at 120 min postinjection. These preliminary results indicate that (/sup 123/I)IBZM is a potentially promising imaging agent for the investigation of dopamine D-2 receptors in humans.

• Research Organization: Univ. of Pennsylvania, Philadelphia (USA)
• OSTI ID: 6406676
• Journal Information: J. Nucl. Med.; (United States), Journal Name: J. Nucl. Med.; (United States) Vol. 30:1; ISSN JNMEA
• 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
AZOLES
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BODY
BRAIN
CARDIOTONICS
CARDIOVASCULAR AGENTS
CENTRAL NERVOUS SYSTEM
DAYS LIVING RADIOISOTOPES
DOPAMINE
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
EVALUATION
HETEROCYCLIC COMPOUNDS
HOURS LIVING RADIOISOTOPES
HYDROXY COMPOUNDS
IN VITRO
IN VIVO
INTERMEDIATE MASS NUCLEI
IODINE 123
IODINE 125
IODINE ISOTOPES
ISOTOPES
KINETICS
LABELLED COMPOUNDS
MAMMALS
MEMBRANE PROTEINS
MONKEYS
NERVOUS SYSTEM
NEUROREGULATORS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PHENOLS
POLYPHENOLS
PRIMATES
PROTEINS
PYRROLES
PYRROLIDINES
RADIOISOTOPES
RADIOPHARMACEUTICALS
RATS
REACTION KINETICS
RECEPTORS
RODENTS
SYMPATHOMIMETICS
VERTEBRATES