Enzyme immunoassays for ovarian steroid metabolites in the urine of Macaca fascicularis

In vivo studies using carbon 14 labeled estradiol (E₂) and progesterone (Po) were performed to characterize the time course and metabolic fate of circulating E₂ and Po. Co-chromatography of human, orangutan, and macaque luteal phase urine samples demonstrated the presence of a steroid conjugate peak in all three species that was identified as being androsterone and etiocholanolone glucuronides. An enzyme immunoassay for urinary metabolites of Po was developed subsequently for Macaca spp. using a monoclonal antibody that cross-reacted with both C-19 and C-21 metabolites.