The behaviour of the pulmonary metabolites of prostaglandins in several simple thin-layer chromatography and bioassay systems

Abstract

The behaviour of the pulmonary metabolites of prostaglanding E1, E2 and F2alpha were examined in several thin-layer chromatography (TLC) systems commonly used to differentiate parent prostaglandins. Although the systems chosen readily distinguished between a prostaglandin and its own metabolites, they often did not differentiate between a parent prostaglandin and the metabolites of another. In particular, 13, 14-dihydro-PGF2alpha was virtually indistinguishable from PGE2 and 13, 14-dihydro-PGE2 was similarly indistinguishable from PGE1, in all systems investigated. These pairs of prostaglandins could not be distinguished by bioassay on the rat stomach strip alone. Although distinction could be made by parallel assay on the rat stomach strip, chick rectum and rat colon, the differential assay obtained would not be enough to allow identification of these prostaglandins and metabolites in samples containing their mixtures. The 13, 14-dihydro-prostaglandin metabolites were also active in contracting the isolated rat uterus. The findings indicate that TLC and bioassay together may not permit identification of prostaglandins in biological fluids.