“ Intrathecal dihydroergotamine (10, 31 and 100μg) inhibited the vasodilatation to capsaicin , but not that to α-CGRP or acetylcholine.”
“Thus, intrathecal (C(1)-C(3)) dihydroergotamine seems to inhibit the external carotid vasodilatation to capsaicin by spinal activation of serotonin 5-HT(1B/1D) (probably 5-HT(1B)) receptors and α(2) (probably α(2A/2C))-adrenoceptors.”