Displacement of specific serotonin and lysergic acid diethylamide binding by Ergalgin, a new antiserotonin drug.
[3H]-serotonin and [3H]-lysergic acid diethylamide (LSD) bind with a high affinity, KD = 12 nM and 6 nM, respectively, to distinct receptors of rat caudate membranes in vitro. Displacement experiments with unlabeled serotonin and LSD support the hypothesis of serotonin receptors existing in an agonist and antagonist state. Methysergide and Ergalgin display quite similar potencies in displacing [3H]-serotonin and [3H]-LSD from their specific binding sites (Ki = 46,7 and 53,4 nM; 22,3 and 36,5 nM, respectively). Contrary to pharmacological findings these binding results are in favour of mixed agonist/antagonist properties of these compounds.
D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D002421:Caudate Nucleus / Q000187:drug effects / Q000378:metabolism; D004873:Ergolines / Q000494:pharmacology*; D066298:In Vitro Techniques; D008237:Lysergic Acid / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology*; D008238:Lysergic Acid Diethylamide / Q000378:metabolism*; D008297:Male; D008784:Methysergide / Q000378:metabolism / Q000494:pharmacology; D051381:Rats; D012701:Serotonin / Q000378:metabolism*; D012702:Serotonin Antagonists / Q000378:metabolism / Q000494:pharmacology*
D004873:Ergolines; D012702:Serotonin Antagonists; D012701:Serotonin; D008238:Lysergic Acid Diethylamide; D008237:Lysergic Acid; D008784:Methysergide