Prostaglandin E2 (PGE2), one of the most widely investigated PGs, can be used as a biomarker of inflammation, disease state, or therapeutic effectiveness. However due to its rapid metabolism, direct measurement of PGE2 in biological samples is difficult. The major urinary metabolite of PGE2, tetranor-PGEM, serves as an indirect marker of PGE2 biosynthesis. Though like PGE2, tetranor-PGEM is also chemically unstable. tetranor-PGAM is a dehydration product of tetranor-PGEM and can be measured as a surrogate for tetranor-PGEM levels in urine.
