Radioimmunoassay for 13, 14-dihydro-15-ketoprostaglandin F2 alpha and its application in normo- and anovulatory women.

Highly specific antibodies to 13, 14-dihydro-15-ketoprostaglandin F2 alpha (PGFM) were raised in rabbits. The animals were immunized with PGFM-bovine serum albumin (BSA)-conjugates. Prior to the incubation procedure PGFM was extracted by a rapid method with dichloromethane followed by column chromatography. The antisera dilution was 1:10 000 amd the cross-reactivity towards prostaglandin A2, E2, F2 alpha, 13, 14-dihydro-15-ketoprostaglandin E2 and the 15-ketoprostaglandin E2 and F2 alpha 2 was less than 1%. The limit of detection was 1.9 +/- 0.6 pg/ml plasma over the standard range 1.9--250 pg. The intra- and inter-assay variations were 3.9 and 15%, respectively. PGFM was measured throughout the menstrual cycle in female volunteers. In normal ovulatory women (n = 3) plasma levels of PGFM varied between 65.6 to 107.1 pg/ml. No significant variations of plasma PGFM were seen during the cycle. In anovulatory women (n = 4) no difference of PGFM was found during the cycle. PGFM levels in hyperprolactinaemic but ovulating women tend to be higher than in anovulatory, and normoprolactinaemic subjects. These data strongly indicate that PGFM is not correlated with other hormonal parameters tested here in the normal and anovulatory cycles.