Blood platelet 5-hydroxytryptamine accumulation and migraine.

The active uptake of 5-hydroxytryptamine (5-HT) by platelets from migraine patients was measured and the results compared with 5-HT uptake of platelets from normal subjects. No significant differences in platelet 5-HT uptake were found between migraine patients and control subjects. A significant correlation was found between the length of time since the patients last migraine attack and Vmax (maximal rate of 5-HT transport). Patients who had a headache within five days prior to the test had significantly lower values of Vmax than patients without recent headaches. The implications and possible causes of this reduction in platelet 5-HT transport are discussed.