Platelet high affinity adrenoceptor binding sites labelled with the agonist [3H]UK-14,304, in depressed patients and...

Increased numbers of platelet high affinity alpha 2-adrenoceptors binding sites have been reported in depressed patients using the agonist radioligand [3H]clonidine, whereas no differences from controls have been found using antagonist radioligands. We have measured platelet high affinity alpha 2-adrenoceptors in 13 depressed patients and 14 well-matched controls using a new selective agonist radioligand, [3H]UK-14,304. Unlike previous studies using [3H]clonidine, we find no differences in Bmax or KD of the high affinity alpha 2-adrenoceptor binding sites between the 2 groups.