UP-REGULATED EXPRESSION OF PERIPHERAL SEROTONERGIC RECEPTORS IN MIGRAINE AND CLUSTER HEADACHE BY SUMATRIPTAN

The double-label flow cytometric analysis of peripheral serotonergic p athways of migraine and cluster headache on a monocyte model has been used to evaluate the activity of drugs with a selective activity on ce ntral vascular 5-HT1D receptors, such as sumatriptan, ergotamine and o ndansetron. The results indicated that sumatriptan and ergotamine prog ressively increase the peripheral expression of 5-HT (5-hydroxytryptam ine, serotonin). The increase obtained in migraine after ergotamine is more evident than that obtained in cases of cluster headache. Ondanse tron produced a moderate increase in serotonergic expression only in c luster headache. The events that occur at intracranic neural and vascu lar level may cause the described changes of 5-HT expression on the mo nocyte model as an indirect, reflective, peripheral registration of ce ntral serotonergic variations during headache attack as well as during the drug-sustained recovery phase.