Radioimmunoassay of PGE and an approach to the specific measurement of PGE1.

A specific radioimmunoassay for prostaglandins of the E series is presented. Several refinements of the conventional procedures used for unknown sample preparation prior to assay are described. Validation of the method through recovery of labeled and unlabeled prostaglandin E from plasma indicates: 74% extraction efficiency, 80% chromatographic separation efficiency, and a 67% overall recovery figure for the complete assay. The development of an "absorbed system" approach for measuring one E prostaglandin (PGE1) without interference from the other E prostaglandin (PGE2) is also described. A preliminary study of rat tissue and male plasma samples measured by these assay systems is included. Alternate approaches to the development of a specific PGE1 assay, although less feasible in these authors' hands, are discussed.