title: Migraine attack restores the response of vascular smooth muscle cells to nitric oxide but not to norepinephrine.
abstract: OBJECTIVE
  To clarify whether the vasoconstrictory response is impaired and to study vascular function in patients with migraine during the headache attack.
  
  
  METHODS
  We studied vascular reactivity in the resistance arteries by using the forearm perfusion technique associated with plethysmography. We measured forearm blood flow by strain-gauge plethysmography during intra-brachial infusion of acetylcholine, sodium nitroprusside or norepinephrine in 11 controls and 13 patients with migraine, 11 of them (M) in the interval between the migraine attacks and 4 during a headache attack (MH). Written informed consent was obtained from patients and healthy controls, and the study was approved by the Ethics Committee of the University Federico II.
  
  
  RESULTS
  Compared to healthy control subjects, in patients with migraine studied during the interictal period, the vasodilating effect of acetylcholine, that acts through the stimulation of endothelial cells and the release of nitric oxide, was markedly reduced, but became normal during the headache attack (P < 0.05 by analysis of variance). The response to nitroprusside, which directly relaxes vascular smooth muscle cells (VSMCs), was depressed in patients with migraine studied during the interictal period, but normal during the headache attack (P < 0.005). During norepinephrine infusion, forearm blood flow decreased in control subjects (-40% ± 5%, P < 0.001). In contrast, in patients with migraine, either when studied during or free of the headache attack forearm blood flow did not change compared to the baseline value (-3% ± 13% and -10.4% ± 15%, P > 0.05).
  
  
  CONCLUSIONS
  In migrainers, the impaired relaxation of VSMCs is restored during the headache attack. The vasoconstrictory response is impaired and remains unchanged during the migraine attack.
authors.affiliation: Raffaele Napoli, Vincenzo Guardasole, Emanuela Zarra, Antonietta De Sena, Antonio Ruvolo, Simona Grassi, Speranza Giugliano, Giovanna De Michele, Antonio Cittadini, Luigi Saccà, Department of Translational Medical Sciences, Federico II University School of Medicine, 80131 Naples, Italy.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Napoli
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Guardasole
authors.forename: Emanuela
authors.initials: E
authors.lastname: Zarra
authors.forename: Antonietta De
authors.initials: AD
authors.lastname: Sena
authors.forename: Francesco
authors.initials: F
authors.lastname: Saccà
authors.forename: Antonio
authors.initials: A
authors.lastname: Ruvolo
authors.forename: Simona
authors.initials: S
authors.lastname: Grassi
authors.forename: Speranza
authors.initials: S
authors.lastname: Giugliano
authors.forename: Giovanna De
authors.initials: GD
authors.lastname: Michele
authors.forename: Antonio
authors.initials: A
authors.lastname: Cittadini
authors.forename: Pietro Biagio
authors.initials: PB
authors.lastname: Carrieri
authors.forename: Luigi
authors.initials: L
authors.lastname: Saccà
keywords: Endothelium; Migraine; Nitric oxide; Vascular smooth muscle cells