Platelet alpha-adrenergic receptor activity and pizotifen in migrainous children.

Adrenoceptors have been measured in the platelets from migrainous children, using (3H) yohimbine. Maximum binding (Bmax) was not significantly different in migrainous children and controls, 259 +/- 21 and 265 +/- 19 f moles per mg of protein respectively. Dissociation constants (KD) were significantly higher in the migraine group than in the controls 2.62 +/- 0.18 and 2.17 +/- 0.07 respectively (p less than 0.02). Bmax values were lower in 6 out of 9 cases following treatment with pizotifen. In 8 out of 9 cases KD values were lower following pizotifen treatment; in one case there was no change.