Radioimmunological measurement of F-2-isoprostanes after hydrolysis of lipids in tissues

8-Iso-prostaglandin F-2 alpha (8-iso-PGF(2 alpha)) is a major isoprostane f ormed in vivo mainly by non-enzymatic peroxidation of arachidonic acid and a potential biomarker of oxidative injury. We have recently reported develo pment of a specific radioimmunoassay for the measurement of free 8-iso-PGF( 2 alpha) in plasma and urine. The aim of this study was to employ this radi oimmunoassay to analyze the total amount of 8-iso-PGF(2 alpha) (sum of free and esterified) in liver tissues by using alkaline hydrolysis, and to appl y it in an experimental model of carbon tetrachloride-induced lipid peroxid ation in rats. Basal levels of total 8-iso-PGF(2 alpha) in hydrolyzed liver tissues of control rats were 6.5 times higher than the levels of free 8-is o-PGF(2 alpha). At maximum formation of total 8-iso-PGF(2 alpha) in the liv ers of carbon tetrachloride-treated rats, total levels of 8-iso-PGF(2 alpha ) were almost 13 times higher than the levels of free 8-iso-PGF(2 alpha). I n conclusion, high levels of 8-iso-PGF(2 alpha) in tissues can be quantifie d after hydrolysis both at basal conditions and in a model of increased lip id peroxidation. The methodology for measurement of total levels of 8-iso-P GF(2 alpha) in tissues may be suitable for future investigations of the loc ation of oxidative injury in the body. (C) 2000 Harcourt Publishers Ltd.