DEVELOPMENT AND VALIDATION OF A RADIOIMMUNOASSAY FOR PROSTAGLANDIN-E2 METABOLITE LEVELS IN PLASMA

Abstract

Measurements of primary prostaglandins (PGs) in plasma are unreliable, and determinations of their metabolite levels are to be preferred. The principal circulating metabolite of PGE2 [13,14-dihydro-15-keto-PGE2 (PGEM)] is itself unstable however, and this has hindered development of PGE2 metabolite assays. Alkalinization of plasma uniformly converts PGEM and its degradation products to a stable bicyclo compound 11-deoxy-13,14-dihydro-15-keto-11 beta, 16 epsilon-cyclo PGE2 (bicyclo-PGEM). Measurement of bicyclo-PGEM, therefore, enables the PGEM instability problem to be circumvented. This paper describes a specific and sensitive RIA for bicyclo-PGEM in plasma. The assay uses a rabbit antiseru..