Animal and human arteries' "in vitro" response to serum of migraineurs.

"In vitro" experiments carried out by us and partially published have resulted in significant data concerning the contracting activity of migraineurs sera on extracranial animal arteries. In the present study, human and animal arteries (superficial temporal) were tested by means of blood samples taken under identical conditions. No contracting activity from sera taken both in the headache-free period and during the migraine crisis was observed in animal arteries. By contrast, sera obtained in the pre-attack and post-onset stages showed a synergistic effect not only on the action of serotonin and histamine but also on that of norepinephrine. This synergism increases with the worsening of the migraine attack while it decreases as soon as the attack wears off. Other experiments on human specimens provided data which cannot be evaluated yet. There is evidence that, on the occasion of the migraine attack, vasoactive substances which enable isolated organs to contract "in vitro" are released or activated. Moreover, an activity raises in sera which interferes with the other mediators on extracranial arteries.