MIGRAINE PATIENTS SHOW INCREASED PLATELET VASOPRESSIN RECEPTORS

This study was designed to investigate vasopressin receptor status (B- max and K-d) on platelets, vasopressin plasma levels, and vasopressin- induced platelet aggregation in migraine patients (21 females and 6 ma les) during a headache-free interval and in a matched control group. I n the migraine group, B-max was significantly higher (P=0.02) at 53.9 +/- 20.6 fmol/mg than in the control group (36.8 + 21.0 fmol/mg). A co rrelation between B and high or low sensitivity to vasopressin as an a ggregator was evident in the control group, but not in the migraine gr oup. No differences in K-d or in plasma levels of vasopressin between the migraine and control group were apparent. Men in both groups were much less sensitive to vasopressin as a platelet aggregator than were women (P< 0.01). Whether the higher B-max in the migraine group is a r eflection of temporarily higher vasopressin levels during headache or reflects a primary increase in sensitivity to vasopressin, remains to be clarified. The higher sensitivity of platelets (as a model for vess el wall receptors) from women may indicate why many more women than me n suffer from migraine. Since the B-max of the vasopressin receptor on platelets from migraine patients is increased compared to controls, t reating migraine headache with vasopressin may deserve more attention.