Pituitary adenylate cyclase-activating polypeptide expression in peripheral blood mononuclear cells of migraineurs

BACKGROUND: Pituitary adenylate cyclase-activating polypeptide (PACAP) plays several important roles in vasodilation, neurotransmission, neuromodulation and neurotrophy, as well as activation of the trigeminovascular system. The aim of the present study was to explore the relationship between altered PACAP levels in peripheral blood and different types of headache. METHODS: The present study enrolled 101 outpatients with headache and 35 healthy control volunteers. Blood samples were collected from the cubital vein and peripheral blood mononuclear cells (PBMCs) were separated. Total mRNA in the PBMCs was extracted and the expression of PACAP mRNA was analyzed by quantitative-polymerase chain reaction (Q-PCR). RESULTS: There was a significant decrease in PACAP mRNA expression in the PBMCs of the migraine (M) group relative to the healthy control group. However, there were no significant differences in PACAP mRNA expression between the control group and tension-type headache (TTH), cluster headache (CH), or medication overuse headache (MOH) groups. CONCLUSION: The PBMC levels of patients with migraine, but not other commonly seen headache types, exhibited a significant reduction in PACAP mRNA expression compared with healthy control subjects.