Calcitonin gene-related peptide (CGRP): Responsible for the increased blood flow induced by the stimulation of sensory nerves

Calcitonin gene-related peptide (CGRP) is a potent vasodilator neuropeptide contained in sensory nerves. We have examined the relative contribution of CGRP and substance P-like peptides (with which CGRP is commonly colocalized) to the increase in blood flow induced by the stimulation of sensory nerves. The sensory nerve stimulant capsaicin increased blood flow in rabbit and rat skin and this effect was substantially inhibited by the CGRP antagonist CGRP_8–37. Further, electrical stimulation of the rat saphenous nerve led to an increase in blood flow which was significantly inhibited by CGRP_8–37. CGRP_8–37 also had a partial inhibitory effect on oedema formation, an effect which is suggested to be a consequence of the inhibition of blood flow.