[3H]Mesulergine, a selective ligand for serotonin-2 receptors

[3H]Mesulergine binds with high affinity to rat cerebral cortex membranes. (KD = 1.9 nM, Bmax = 11.3 pM/g tissue). The binding of this ligand is selective for serotonin-2 receptors: Its next highest affinity, which is for dopamine receptors labelled by neuroleptics, is about 50 times weaker than its affinity for serotonin-2 receptors. No significant affinity for serotonin-1, alpha 1-adrenergic or histamine H1 receptors was observed. Specific [3H]mesulergine binding was diminished in the presence of low concentrations of lithium ions.