Binding interactions of lysergic acid diethylamide and related agents with dopamine receptors in the brain
Burt, D.R.; Creese, I.; Snyder, S.H.
Molecular Pharmacology 12(4): 631-638
1976
ISSN/ISBN: 0026-895X PMID: 958211 Document Number: 17794
In most brain regions saturable binding of [3H]LSD appears to involve postsynaptic serotonin receptors. In calf caudate, however, a portion of [3H]LSD binding involves postsynaptic dopamine receptors. In the hippocampus of calf brain, dopamine competes for [3H]LSD binding sites with a single low-affinity component, while in the caudate dopamine competition for [3H]LSD binding displays both high- and low-affinity components. The high-affinity component, accounting for 15-20% of [3H]LSD binding, displays a Ki value for dopamine of about 30 nM, similar to the Kd for the binding [3H]dopamine itself to postsynaptic dopamine receptors in the calf caudate. Addition of serotonin to the incubations increases the proportion of [3H]LSD binding in the caudate competed for by dopamine with high affinity, presumably by occupying serotonin receptors. d-LSD competes stereospecifically for [3H]dopamine binding in the caudate, consistent with the conclusion that LSD binds to dopamine receptors. Of numerous serotonin agonists and antagonists examined, several ergot alkaloids have high affinity for [3H]dopamine receptor binding in calf caudate, with Ki values similar to that of d-LSD.
Document emailed within 1 workday
