DECREASED COLLAGEN-INDUCED PLATELET-AGGREGATION AND INCREASED PLATELET ARGININE LEVELS IN MIGRAINE - A POSSIBLE LINK WITH THE NO PATHWAY

We studied whole blood platelet aggregation induced by collagen, plate let activating factor (PAF) and measured basal platelet L-arginine (L- arg) levels, as an indirect index of the nitric oxide (NO) pathway in migraine. Migraine, both with and without aura groups, showed a reduce d aggregation to collagen, but not to PAF, compared with control subje cts. Platelet L-arg levels were significantly increased in migraine wi th aura sufferers, whereas the plasma levels were in the same range in migraineurs and controls. Platelet hyperesponsiveness to collagen sti mulation in migraine may be linked to an increased availability of the amino acid precursor and an abnormal NO synthesis.