Increased concentrations of eicosanoids and platelet-activating factor in menstrual blood from women with primary dysmenorrhea.

Prostanoids, leukotrienes and platelet-activating factor were measured by radioimmunoassay in menstrual blood of seven women with primary dysmenorrhea and five healthy controls. The eicosanoids and PAF concentrations in dysmenorrheic patients were significantly higher than those found in healthy women (P less than 0.005 for PGF2 alpha, 11-dehydro-TXB2, 2,3-dinor-TXB2 and LTC4/D4; P less than 0.001 for PAE; P less than 0.05 for PGE2 and 2,3-dinor-6-keto-PGF1 alpha). Whereas no relationship could be found between the concentrations of PGF2 alpha, PGE2, 11-dehydro- and 2,3-dinor-TXB2 and severity of primary dysmenorrhea, a close correlation between LTC4/D4 and PAF and severity of the disease was observed, particularly in patients who responded poorly to therapy with prostaglandin synthetase inhibitors. We conclude that the hyperstimulation of myometrial activity is not caused by selective stimulation of one metabolic pathway of arachidonic acid, but rather by an overall stimulation of phospholipid metabolism. The assessment of prostanoids, leukotrienes and PAF in menstrual blood many be useful as a direct index of primary dysmenorrhea, and the development of their antagonists may have therapeutic implications in improved treatment of the disease.