8-iso Prostaglandin F2α (8-iso PGF2α; 8-isoprostane) is a prostaglandin-like product of non-specific lipid peroxidation. 2,3-dinor-8-iso PGF2α is a metabolite of 8-iso PGF2α in humans and rats. In these species, exogenously infused 8-iso PGF2α is converted to 2,3-dinor-8-iso PGF1α and (2,3-dinor-8-iso PGF2α. Rat hepatocytes further metabolize 8-iso PGF2α to another β-oxidation product, 2,3,4,5-tetranor-8-iso PGF2α. 2,3-dinor-8-iso PGF2α is present in normal human urine at concentrations of 200-300 pg/ml. Its concentration is increased in conditions of oxidative injury (for example, smoking), and correlates well with that of the parent isoprostane, 8-iso PGF2α.