Table 1 Binding affinity constants (pK_i) for the α₂-adrenergic, dopamine D₂-like or serotonin 5-HT₁ receptor families and their respective receptor subtypes for dihydroergotamine (DHE), rauwolscine, GR127935 and haloperidol for cloned human receptors (unless otherwise stated)

From: Dihydroergotamine inhibits the vasodepressor sensory CGRPergic outflow by prejunctional activation of α₂-adrenoceptors and 5-HT₁ receptors