CGRP has been postulated as an essential mediator in migraine.
However, in the study briefly summarized below, CGRP was found to have no effect in the absence of nitric oxide (NO).
This strongly suggests that NO is of greater importance in migraine pathogenesis than is CGRP.
Nitroglycerin facilitates calcitonin gene-related peptide-induced behavior.
Summary of the abstract
Nitric oxide and calcitonin gene-related peptide (CGRP) have been implicated in craniofacial pain including migraine headache.
The aim of this study was to test whether systemic administration of nitroglycerin (NTG) influences the CGRP-induced behavior in awake rats and whether sumatriptan, a 5-HT1B/1D receptor agonist, can block the effects of NTG.
CGRP was not significantly different from normal saline in inducing face-grooming behavior but NTG facilitated the effect of CGRP. Furthermore, sumatriptan was found to block the effect of NTG.
These data suggest that facilitatory processes involving nitric oxide may be necessary for CGRP to play a role in some craniofacial pain conditions including possibly migraine headache.