PERIOVULATORY BETA-ENDORPHIN LEVELS IN PREMENSTRUAL-SYNDROME

Objective: To determine whether changes in peripheral beta-endorphin l evels during the periovulatory phase are associated with symptoms of p remenstrual syndrome (PMS). Methods: Twenty-one PMS patients and ten c ontrols were studied. All were in general good health and had no histo ry of psychiatric disorders. They were between 21-44 years of age, had had regular menses for at least six previous cycles, and were careful ly selected by charting the Visual Linear Analogue Scale and basal bod y temperature daily for 1 month. After an overnight fast, the subjects had blood drawn between 8:00 and 10:00 AM daily for 8 days, starting on the tenth day of the menstrual cycle, for one cycle. Beta-endorphin and LH were measured by radioimmunoassay. The day of the LH peak was defined as day LH 0. The beta-endorphin levels were expressed as the n umber of days before or after the LH surge. Results: Beta-endorphin le vels throughout the periovulatory phase were lower in PMS patients tha n in controls, and the differences were more remarkable on LH days 0 a nd 4. Conclusion: Our data suggest that an aberration of normal change s in beta-endorphin activity in PMS patients may occur around the time of ovulation.