In vivo binding of /sup 125/I-LSD to serotonin 5-HT/sub 2/ receptors in mouse brain
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), Vol. 37:7
- Country of Publication:
- United States
- Language:
- English
Similar Records
Development of a high specific activity radioligand, /sup 125/I-LSD, and its application to the study of serotonin receptors
Characterization, solubilization and partial purification of serotonin 5-HT1C receptors
Related Subjects
AMIDES
BIOCHEMICAL REACTION KINETICS
LYSERGIC ACID
RECEPTORS
LABELLING
TISSUE DISTRIBUTION
SEROTONIN
BRAIN
CEREBELLUM
CEREBRAL CORTEX
CHEMICAL BONDS
COMPUTERIZED TOMOGRAPHY
HYPOTHALAMUS
IN VIVO
INTRAVENOUS INJECTION
IODINE 125
LABELLED COMPOUNDS
LIGANDS
MICE
NEUROREGULATORS
OLFACTORY BULBS
TRACER TECHNIQUES
ALKALOIDS
AMINES
ANIMALS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
AZAARENES
AZOLES
BETA DECAY RADIOISOTOPES
BODY
CARBOXYLIC ACIDS
CENTRAL NERVOUS SYSTEM
CEREBRUM
DAYS LIVING RADIOISOTOPES
DIAGNOSTIC TECHNIQUES
DISTRIBUTION
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
INDOLES
INJECTION
INTAKE
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
NERVOUS SYSTEM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PYRROLES
RADIOISOTOPES
RADIOPROTECTIVE SUBSTANCES
REACTION KINETICS
RODENTS
SYMPATHOMIMETICS
TOMOGRAPHY
TRYPTAMINES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques
550801 - Morphology- Tracer Techniques