Adenosine is a nucleoside that plays a role in both vascular and nociceptive systems, and it has been proposed that adenosine may cause headache in particularly sensitive subjects.

Thus, considerable evidence implied that adenosine plays a role in migraine pathophysiology, it is still unknown if intravenous adenosine infusion provokes migraine attacks in healthy subject or in migraine patients. Furthermore, adenosine's effects on the cerebral hemodynamic remains unknown.

This study aims to clarify a possible coherence between adenosine and headache/migraine. In general, the study will contribute to a greater understanding of migraine pathogenesis and possibly lead to development of specific migraine treatment.

Inclusion Criteria:

• Migraine patients without aura who fulfill criteria in the international classification of headaches. This does not apply to healthy volunteers.
• 18-60 years.
• 50-90 kg.
• Women of childbearing potential must use adequate contraception

Exclusion Criteria:

• Headache less than 48 hours before the tests start
• All primary headaches, except migraine without aura for migraine patients, according to international classification of headache
• Daily consumption of drugs of any kind other than oral contraceptives
• Pregnant or nursing women.
• Cardiovascular disease of any kind, including cerebrovascular diseases.