Radioiodinated D-(+)-N1-ethyl-2-iodolysergic acid diethylamide: A ligand for in vitro and in vivo studies of serotonin receptors

Journal Article · Tue Jan 01 04:00:00 EST 1991 · Life Sciences; (USA)

DOI:https://doi.org/10.1016/0024-3205(91)90189-I· OSTI ID:5858926

Lever, J R; Scheffel, U A; Musachio, J L; Stathis, M; Wagner, Jr, H N ^[1]

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1. Johns Hopkins Univ., Baltimore, MD (USA)

Radioiodinated D-(+)-N1-ethyl-2-iodolysergic acid diethylamide ((125I)-EIL) has been evaluated as a ligand for in vitro and in vivo studies of cerebral serotonin 5-HT{sub 2} receptors. (125I)-EIL exhibited high affinity for 5-HT{sub 2} receptors with a high degree of specific binding in membranes from rat prefrontal cortex. The regional distribution of (125I)-EIL binding in vivo to seven areas of mouse brain correlated significantly with known densities of 5-HT{sub 2} receptors. In vivo specificity, defined by tissue to cerebellum radioactivity ratios, reached a maximum for frontal cortex at 6 hr (21.2) and persisted through 16 hr (8.8). Ketanserin, a 5-HT{sub 2} receptor antagonist, fully inhibited binding in a dose dependent fashion in all brain regions except cerebellum. By contrast, blockers for dopamine D{sub 2}, {alpha}- or {beta}-adrenergic receptors did not significantly inhibit radioligand binding in any region. (125I)-EIL selectively labels 5-HT{sub 2} receptors in vivo with the highest specificity of any serotonergic ligand reported to date, indicating that (123I)-EIL should prove applicable to single photon emission computed tomography studies in living brain.

• OSTI ID: 5858926
• Journal Information: Life Sciences; (USA), Journal Name: Life Sciences; (USA) Vol. 48:15; ISSN 0024-3205; ISSN LIFSA
• Country of Publication: United States
• Language: English

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550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AFFINITY
AMINES
ANIMALS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
AZAARENES
AZOLES
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BODY
BRAIN
CELL CONSTITUENTS
CELL MEMBRANES
CENTRAL NERVOUS SYSTEM
COMPUTERIZED TOMOGRAPHY
DAYS LIVING RADIOISOTOPES
DIAGNOSTIC TECHNIQUES
DOSE-RESPONSE RELATIONSHIPS
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
EMISSION COMPUTED TOMOGRAPHY
ENZYME INHIBITORS
EVALUATION
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
IN VITRO
IN VIVO
INDOLES
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LABELLED COMPOUNDS
LIGANDS
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
MICE
NERVOUS SYSTEM
NEUROREGULATORS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PROTEINS
PYRROLES
RADIOISOTOPES
RADIOPHARMACEUTICALS
RADIOPROTECTIVE SUBSTANCES
RATS
REACTION KINETICS
RECEPTORS
RODENTS
SEROTONIN
SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY
SYMPATHOMIMETICS
TOMOGRAPHY
TRACER TECHNIQUES
TRYPTAMINES
VERTEBRATES