Handling of 5-hydroxytryptamine by platelets in migraine

There is little dispute that a link exists between 5-hydroxytryptamine (5HT) and migraine but the exact mechanism of an attack has yet to be established. The handling of 5HT by the platelet is regarded as a simple model of the handling of 5HT by nerve terminals. If differences are seen in how the platelets from migraineurs handle 5HT compared to those from a control population, it is possible that a similar difference exists in the nerve terminal. The Haemostatometer allows the rapid and simultaneous in vitro assessment of platelet function (shear-induced haemostasis), coagulation and thrombolysis from non anticoagulated blood samples. In this study, a baseline comparison of haemostasis was made on 20 migraineurs between attacks and 20 controls. No differences were found in the results from each of the two groups. 5 microM of 5HT was then added to blood taken from 10 migraineurs and 10 controls and the recordings were repeated. Again, no differences were found between the results from the two groups. In blood taken from both migraineurs and controls, the effect of 5HT was to significantly enhance clotting time and clot lysis. No effect was seen on primary aggregation. The possible reasons for and significance of these findings is discussed.