Plasma prostaglandins in the normal menstrual cycle.

Plasma prostaglandins were studied by radioimmunoassay on alternate days during the menstrual cycle in fourteen normal women. No cyclic patterns were found for A-like prostaglandins using an assay which measured 13,14-dihydro-PGA. Mean subject values of PGA-like prostaglandin ranged from 367 to 904 pg/ml and varied significantly among women. Prostaglandin E determinations showed an upward trend beginning 8 days before the LH peak. PGE subject means varied significantly and ranged from 182 to 362 pg/ml. Prostaglandin F did not exhibit a cyclic pattern. The average concentration of PGF for individual women ranged from 58 to 153 pg/ml, showing significant variance. The physiologic implications of the results are discussed as well as recommendations for the design of future studies.