INCREASED DENSITY OF DOPAMINE D-5 RECEPTOR IN PERIPHERAL-BLOOD LYMPHOCYTES OF MIGRAINEURS - A MASKER FOR MIGRAINE

The expression of dopamine D-5 receptor was investigated in peripheral blood lymphocytes of 11 migraine patients and of ten healthy control subjects using a radioligand binding technique with [H-3]SCH 23390 as a ligand. [H-3]SCH 23390 is a benzazepine derivative with potent antag onist properties at the dopamine D-1-like receptors. [H-3]SCH 23390 wa s specifically bound to peripheral blood lymphocytes of migraineurs an d control subjects in a manner consistent with the labelling of a dopa mine D-5 receptor. In migraineurs a statistically significant higher d ensity of lymphocyte dopamine D-5 receptor compared with controls was noticeable, whereas the affinity of the radioligand was unchanged. The increased density of dopamine D-5 receptor in peripheral blood lympho cytes may reflect the dopaminergic hypersensitivity displayed by migra ineurs and may represent a relatively simple and reliable peripheral m arker of altered dopaminergic function.