Effects of prostaglandin inhibition on vasopressin levels in women with primary dysmenorrhea.

Arginine vasopressin (AVP) concentrations in plasma were studied in women with primary dysmenorrhea before and after treatment with naproxen, and in healthy control women on the first day of menstruation. In the treated group the AVP concentration was about 4 times higher than that in the controls, and the AVP level remained unchanged after almost complete pain relief had been obtained by treatment with the prostaglandin synthesis inhibitor. No significant differences were found between the 2 groups in plasma osmolality and sodium concentration on the first day of menstruation, or in the concentrations of progesterone and estradiol at this time or in the midluteal phase of the preceding menstrual cycle. These results indicate that increased secretion of AVP may play an etiologic role in dysmenorrhea, activating the uterus via a final step of prostaglandin synthesis an release.