Background: Calcitonin gene-related peptide release in trigeminovascular system is a pivotal component of neurogenic
inflammation underlying migraine pathophysiology. Transient receptor potential channels and voltage-gated KCNQ/Kv7
potassium channels expressed throughout trigeminovascular system are important targets for modulation of calcitonin
gene-related peptide release. We investigated the effects of certain transient receptor potential (TRP) channels the
vanilloid 1 and 4 (TRPV1 and TRPV4), the ankyrin 1 (TRPA1), and metastatin type 8 (TRPM8), and voltage-gated
potassium channel (Kv7) opener retigabine on calcitonin gene-related peptide release from peripheral (dura mater
and trigeminal ganglion) and central (trigeminal nucleus caudalis) trigeminal components of rats.
Methods: The experiments were carried out using well-established in-vitro preparations (hemiskull, trigeminal ganglion and trigeminal nucleus caudalis) from male Wistar rats. Agonists and antagonists of TRPV1, TRPV4, TRPA1 and TRPM8 channels, and also retigabine were tested on the in-vitro release of calcitonin gene-related peptide. Calcitonin generelated peptide concentrations were measured using enzyme-linked immunosorbent assay.
Results: Agonists of these transient receptor potential channels induced calcitonin gene-related peptide release from hemiskull, trigeminal ganglion and trigeminal nucleus caudalis, respectively. The transient receptor potential channelsinduced calcitonin gene-related peptide releases were blocked by their specific antagonists and reduced by retigabine. Retigabine also decreased basal calcitonin gene-related peptide releases in all preparations.
Conclusion: Our findings suggest that favorable antagonists of these transient receptor potential channels, or Kv7
channel opener retigabine may be effective in migraine therapy by inhibiting neurogenic inflammation that requires
calcitonin gene-related peptide release.