FIBRINOGEN RECEPTORS IN BLOOD PLATELETS OF MIGRAINE PATIENTS

The augmentation of platelet aggregability in migraine patients was found in many studies, by the use of both in vivo and in vitro techniques. In order to evaluate the platelet characteristics responsible for the increased aggregability of migraine platelets we determined their binding capacities and the apparent dissociation constant (K_D ^app) of fibrinogen receptors. Twelve non-pregnant women in age ranged from 20 to 44 years with unequivocal history of common migraine and 10 control healthy age matched women were used in these studies. The patients were assessed in headache-free intervals. Blood was drawn into acid citrate dextrose containing apyrase (0.1 mg/ml) and platelets were isolated by differential centrifugation. The mean number of platelet fibrinogen receptors exposed by ADP in migraine patients ( 65197 ± 6276 ) was statistically ( p<0.05 ) higher than that obtained in healthy controls ( 40217 ± 7678 ). The apparent Kd for fibrinogen receptors in migraine platelets (6.01 ± 1.11 × 10⁻⁷ M ) was lower than that in control women about threefold < 2.17 ± 0.56 × 10⁻⁶ M). The difference was statistically significant ( p<0.02 ). With these results we conclude that the increased capacity and binding affinity of fibrinogen receptors may be responsible for the elevated number of circulating platelet aggregates in migraine patients and for the prevalance of various kinds of strokes during migraine attack.