In 1990 we discovered the formation of prostaglandin F-2-like compounds, F-
2-isoprostanes (F-2-IsoPs), in vivo by nonenzymatic free radical-induced pe
roxidation of arachidonic acid. F-2-IsoPs are initially formed esterified t
o phospholipids and then released in free form. There are several favorable
attributes that make measurement of F-2-IsoPs attractive as a reliable ind
icator of oxidative stress in vivo: (i) F-2-IsoPs are specific products of
Lipid peroxidation; (ii) they are stable compounds; (iii) levels are presen
t in detectable quantities in all normal biological fluids and tissues, all
owing the definition of a normal range; (iv) their formation increases dram
atically in vivo in a number of animal models of oxidant injury; (v) their
formation is modulated by antioxidant status; and (vi) their levels are not
effected by lipid content of the diet. Measurement of F-2-IsoPs in plasma
can be utilized to assess total endogenous production of F-2-IsoPs whereas
measurement of levels esterified in phospholipids can be used to determine
the extent of lipid peroxidation in target sites of interest. Recently, we
developed an assay for a urinary metabolite of F-2-IsoPs, which should prov
ide a valuable noninvasive integrated approach to assess total endogenous p
roduction of F-2-IsoPs in large clinical studies. (C) 2000 Elsevier Science
Inc.