In vivo binding of /sup 125/I-LSD to serotonin 5-HT/sub 2/ receptors in mouse brain

Journal Article · Mon Aug 19 00:00:00 EDT 1985 · Life Sci.; (United States)

DOI:https://doi.org/10.1016/0024-3205(85)90433-3· OSTI ID:5438697

Hartig, P R; Wagner, Jr, H N

The binding of /sup 125/I-LSD (2-(/sup 125/I)-lysergic acid diethylamide) was studied in various mouse brain regions following intravenous injection of the radioligand. The high specific activity of /sup 125/I-LSD enabled the injection of low mass doses (14ng/kg), which are well below the threshold for induction of any known physiological effect of the probe. The highest levels of /sup 125/I-LSD binding were found in the frontal cortex, olfactory tubercles, extra-frontal cortex and striatum while the lowest level was found in the cerebellum. Binding was saturable in the frontal cortex but increased linearly in the cerebellum with increasing doses of /sup 125/I-LSD. Serotonergic compounds potently inhibited /sup 125/I-LSD binding in cortical regions, olfactory tubercles, and hypothalamus but had no effect in the cerebellum. Dopaminergic compounds caused partial inhibition of binding in the striatum while adrenergic compounds were inactive. From these studies the authors conclude that /sup 125/I-LSD labels serotonin 5-HT/sub 2/ receptor sites in cortical regions with no indication that other receptor sites are labeled. In the olfactory tubercles and hypothalamus, /sup 125/I-LSD labeling occurs predominantly or entirely at serotonic 5-HT/sub 2/ sites. In the striatum, /sup 125/I-LSD labels approximately equal proportions of serotonergic and dopaminergic sites. These data indicate that /sup 125/I-LSD labels serotonin receptors in vivo and suggests that appropriate derivatives of 2I-LSD may prove useful for tomographic imaging of serotonin 5-HT/sub 2/ receptors in the mammalian cortex.

• Research Organization: Johns Hopkins Univ., Baltimore, MD
• OSTI ID: 5438697
• Journal Information: Life Sci.; (United States), Journal Name: Life Sci.; (United States) Vol. 37:7; ISSN LIFSA
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
ALKALOIDS
AMIDES
AMINES
ANIMALS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
AZAARENES
AZOLES
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BODY
BRAIN
CARBOXYLIC ACIDS
CENTRAL NERVOUS SYSTEM
CEREBELLUM
CEREBRAL CORTEX
CEREBRUM
CHEMICAL BONDS
COMPUTERIZED TOMOGRAPHY
DAYS LIVING RADIOISOTOPES
DIAGNOSTIC TECHNIQUES
DISTRIBUTION
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
HYPOTHALAMUS
IN VIVO
INDOLES
INJECTION
INTAKE
INTERMEDIATE MASS NUCLEI
INTRAVENOUS INJECTION
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LABELLED COMPOUNDS
LABELLING
LIGANDS
LYSERGIC ACID
MAMMALS
MICE
NERVOUS SYSTEM
NEUROREGULATORS
NUCLEI
ODD-EVEN NUCLEI
OLFACTORY BULBS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PYRROLES
RADIOISOTOPES
RADIOPROTECTIVE SUBSTANCES
REACTION KINETICS
RECEPTORS
RODENTS
SEROTONIN
SYMPATHOMIMETICS
TISSUE DISTRIBUTION
TOMOGRAPHY
TRACER TECHNIQUES
TRYPTAMINES
VERTEBRATES