Levels of 13,14-dihydro-15-keto-PGF2α in biological fluids as measured by radioimmunoassay

Antibodies directed toward 13,14-dihydro-15-keto-PGF_2α were prepared in rabbits. The C-15 keto group of the metabolite is immunodominant. The antibodies recognize, although to a lesser extent, the reduced 13,14-double bond, the C-9 hydroxyl group and the C-11 hydroxyl group of the metabolite. With previously described antibodies to 15-keto-PGF_2α the C-15 keto group and the 13,14-double bond of the homologous metabolite were equally immunodominant. Therefore, assay of biological samples with both antisera permits identification and quantitation of either metabolite. The levels of 13,14-dihydro-15-keto-PGF_2α in human peripheral venous sera and the levels of cross reacting metabolites in urine have been determined.