ADRENERGIC-RECEPTORS IN PREMENSTRUAL DYSPHORIC DISORDER - I - PLATELET ALPHA(2) RECEPTORS - G(I) PROTEIN COUPLING, PHASE OF MENSTRUAL-CYCLE, AND PREDICTION OF LUTEAL-PHASE SYMPTOM SEVERITY

Background: Abnormal alpha(2)-adrenergic receptor (AR) function is imp licated in anxiety and depressive disorders. Premenstrual dysphoric di sorder (PMDD) is characterized by anxiety and depressive symptoms, whi ch may be associated with changes in alpha(2)AR function. Previous stu dies on alpha(2)AR function during phases of the menstrual cycle in co ntrols and PMDD patients are inconsistent, Methods: alpha(2)AR functio n was examined in 16 PMDD patients and 15 controls during the follicul ar phase, and in 10 PMDD patients during late luteal phase, Antagonist -measured maximum binding capacity, agonist-measured receptor density in high- and low-conformational states, and agonist affinity to both s tates were measured. Coupling efficiency to G(i) protein was estimated . Results: There were no significant differences in coupling efficienc y PMDD patients had significantly low antagonist affinity; there were no differences in other binding parameters. There were no changes in a lpha(2)AR binding parameters between phases of menstrual cycle in PMDD women. alpha(2)AR density and symptom severity were inversely related during the follicular phase in controls and patients, During luteal p hase, alpha(2)AR density correlated positively,vith symptom severity i n patients. High follicular alpha(2)AR density predicted more severe l uteal symptoms in PMDD patients. Conclusions: These findings are discu ssed in view of the molecular biology of alpha(2)AR, and their role in PMDD, anxiety, and depressive disorders. Published 1998 Society Biolo gical Psychiatry.