Metabolism of prostacyclin and 6-keto-prostaglandin F1 alpha in man.

The major metabolites of prostacyclin and 6-keto-prostaglandin F1 alpha in man were investigated. Healthy male volunteers were infused with the labeled and unlabeled prostanoids. The urine was chromatographed on different systems including high-pressure liquid chromatography (HPLC). The material under the major peak was derivatized to the methyl ester methoxime trimethyl silyl ether and analyzed by gas chromatography-mass spectrometry (GC-MS). Open bed reversed-phase chromatography of the urine obtained from PGI2 infusion resulted in two peaks. On further separation by two different HPLC systems one major peak containing 20.5 % of the radioactivity was obtained and was shown by GC-MS to be identical with dinor-6-keto-prostaglandin F1 alpha. Urine obtained from 6-keto-prostaglandin F1 alpha infusion was chromatographed similarly. Its major peak on HPLC appeared with a retention volume and mass spectrum identical with the major metabolite of PGI2. It is concluded that the major metabolite of PGI2 and 6-keto-prostaglandin F1 alpha in human urine is dinor-6-keto-prostaglandin F1 alpha.