Radioiodinated D-(+)-N1-ethyl-2-iodolysergic acid diethylamide: a ligand for in vitro and in vivo studies of serotonin receptors.
John R. Lever, Ursula Scheffel, J L Musachio, M Stathis, H N Wagner
Life Sciences 1991 DOI: 10.1016/0024-3205(91)90189-i (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Preclinical radioligand binding study Peer reviewed |
|---|---|
| Population | Rat prefrontal cortex membranes and mouse brain in vivo |
| Interventions | [125I]-EIL Ketanserin |
| Duration | In vivo measurements up to 16 hr |
| Topics | Serotonin |
| Key points | [125I]-EIL bound with high affinity (KD = 209 pM) and 80-95% specific binding to 5-HT2 receptors in rat prefrontal cortex membranes, and its in vivo distribution across seven mouse brain regions correlated with known 5-HT2 densities (Rs = 0.93). Ketanserin fully inhibited binding dose-dependently in all regions except cerebellum, whereas dopamine D2 and adrenergic blockers did not, leading the authors to propose [123I]-EIL for SPECT studies in living brain. |
Abstract
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-HT2 receptors. [125I]-EIL exhibited high affinity (KD = 209 pM) for 5-HT2 receptors with a high degree of specific binding (80-95%) in membranes from rat prefrontal cortex. The regional distribution of [125I]-EIL binding in vivo to seven areas of mouse brain correlated significantly (Rs = 0.93) with known densities of 5-HT2 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-HT2 receptor antagonist, fully inhibited binding in a dose dependent fashion in all brain regions except cerebellum. By contrast, blockers for dopamine D2, alpha- or beta-adrenergic receptors did not significantly inhibit radioligand binding in any region. [125I]-EIL selectively labels 5-HT2 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.
Comparable studies
Other preclinical and animal studies on serotonin, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Psilocybin induces rapid and persistent growth of dendritic spines in frontal cortex in vivo Mice | 2021 | Observational cohort | |
| Neurotoxicity of the psychedelic amphetamine, methylenedioxymethamphetamine. Rats (implied by typical neurochemical study context) | 1987 | Experimental study | |
| Psychedelics promote neuroplasticity through the activation of intracellular 5-HT2A receptors In vitro and in vivo (rodent) models | 2023 | Experimental study | |
| 3,4-Methylenedioxymethamphetamine and 3,4-methylenedioxyamphetamine destroy serotonin terminals in rat brain: quantification of neurodegeneration by measurement of [3H]paroxetine-labeled serotonin uptake sites. Rat brain | 1987 | Animal experiment | |
| Comparison of the monoamine transporters from human and mouse in their sensitivities to psychostimulant drugs Human and mouse dopamine, norepinephrine, and serotonin transporters expressed in cells | 2006 | In vitro laboratory study |