Migraine Inducing Effects and Changes in Brain Haemodynamics of PGI2

Inclusion Criteria: * migraine without aura and healthy apart from that * age 18-55 years * 50-100 kg * Secure contraceptives Exclusion Criteria: * Tension Type Headache more than 3 time a month * Other primary headaches * Medication prior to the study (closer than 4 times plasma halflife) * Migraine or headache 5 days prior to study. * Hypertension (systolic BP \>150 mmHg and/or diastolic BP \>100 mmHg). * Hypotension (systolic BP \<90 mmHg and/or diastolic BP \<50 mmHg). * Heart-vessel disease of any kind incl cerebrovascular disease. * Anamnestic or clinical signs of psychiatric disease or abuse. * Anamnestic or clinical signs of disease of any kind relevant for participation in the study.