Extraction and measurement of prostanoids and isoprostanes: Introduction to Part II

The assessment of prostanoids (TXB(2), 6-keto-PGF(1alpha), PGD(2) and PGE(2)) generated in isolated or cultured cells in vitro can be directly assessed in media without extraction mainly using immunoassays, i.e. radioimmunoassay (RIA), enzyme-linked immunosorbent assay (ELISA), or enzyme immunoassay (EIA). However, the immunoassays have to have some fundamental requisites, such as the use of highly specific and sensitive antibodies. Importantly, the results obtained with immunoassays should be validated by comparison with gas chromatography (GC), mass spectrometry (MS), or liquid chromatography (LC)-MS. The measurement of prostanoid generation in vivo can be performed by the evaluation of prostaglandin breakdown products in urine using LC-MS, GC-MS, or validated immunoassays after extraction and rigorous sample purification. The measurement of F(2)-isoprostanes (F(2)-iPs), containing F-type ring analogous to PGF(2alpha), provides a reliable tool for identifying populations with enhanced rates of lipid peroxidation. Levels of 8- iso-PGF(2alpha) (also referred as iPF(2alpha)-III) in plasma or urine are assessed by GC/MS or validated immunoassays.