Upregulated expression of peripheral serotonergic receptors in migraine and cluster headache by sumatriptan.

The double-label flow cytometric analysis of peripheral serotonergic pathways of migraine and cluster headache on a monocyte model has been used to evaluate the activity of drugs with a selective activity on central vascular 5-HT1D receptors, such as sumatriptan, ergotamine and ondansetron. The results indicated that sumatriptan and ergotamine progressively increase the peripheral expression of 5-HT (5-hydroxytryptamine, serotonin). The increase obtained in migraine after ergotamine is more evident than that obtained in cases of cluster headache. Ondansetron produced a moderate increase in serotonergic expression only in cluster headache. The events that occur at intracranic neural and vascular level may cause the described changes of 5-HT expression on the monocyte model as an indirect, reflective, peripheral registration of central serotonergic variations during headache attack as well as during the drug-sustained recovery phase.