The Vasoconstrictor Action of Sumatriptan on Human Isolated Dura Mater

Sumatriptan is a selective agonist for a 5-HT1 -like receptor sub-type which mediates contraction of some cranial blood vessels in vitro. It has been shown to be a very effective novel agent for the acute treatment of migraine and this has stimulated much interest in its clinical mode of action. It has been suggested that the pain of migraine results from a sterile neurogenic inflammatory response of intracranial blood vessels innervated by the trigeminal nerve. Furthermore, sumatriptan has been shown to inhibit plasma protein extravasation from blood vessels of the dura mater, induced by antidromic stimulation of the trigeminal nerve in the anaesthetised rat and guinea-pig. This effect could be explained by a localised vasoconstriction of the meningeal vessels. We now provide evidence that sumatriptan will potently constrict the blood vessels within the human isolated perfused dura mater. Preliminary work on characterising the 5-HT receptor involved indicates that it is a 5-HT1- like receptor. These studies add weight to the view that the anti-migraine action of sumatriptan results from selective cranial vasoconstriction.