[Lower level of endothelin-1 in migraine with aura]

Endothelin-1 (ET-1) exerts powerful vasoconstrictive and blood pressure elevating properties through endothelial cells. However, no systematic examination of ET-1 in migraine has ever been attempted. The present investigation was focused on evaluating the level of ET-1 in patients with migraine with aura. Studies on ET-1 were made in 17 patients with migraine with aura (age, 23.4 +/- 9.1 years old, mean +/- SD) according to the Classification of Headache of the Ad Hoc Committee. All patients had been free of migraine attacks for at least 7 days prior to the examination. Twenty-eight age-matched healthy volunteers (age, 23.0 +/- 12.3 years old) were similarly used as a control group. None of them revealed evidence of any other disease, such as hypertension, obesity, or heart disease. Informed consent was obtained from each subject. We measured the immunoreactive ET-1 in plasma by radioimmunoassay. The plasma level of ET-1 in migraine was 2.53 +/- 1.06 pg/ml. On the other hand, the level of ET-1 in the controls was 4.24 +/- 0.80 pg/ml. The ET-1 level in migraine was significantly lower than that in the controls (p < 0.002). We also measured the level of ET-1 in the cerebrospinal fluid (CSF). There was no significant difference between migraine (23.2 +/- 3.10 pg/ml) and the control group (20.85 +/- 3.20 pg/ml). In conclusion, the lower plasma level of ET-1 observed in the patients with migraine is consistent with the pathogenesis of migraine, further supporting the hypothesis that a lower ET-1 may be closely related to marked vasodilatation following constriction partly due to a deficiency of ET-1 for maintaining vasoconstriction.