Isoprostanes originate from the non-enzymatic oxidation of arachidonic acid. As to isoprostanes, 8-iso-PGF2a and 8-iso-PGE2 are biologically active. They produce vasoconstriction, bronchoconstriction and support the formation of other free radicals by ischaemia-reperfusion damage. Their quantitative estimation in biological material is the best marker of lipoperoxidation. Immunochemical estimation using the ELISA method seems to be most perspective. Isoprostanes are suitable for testing the activity of different antioxidants. Their estimation is important in renal, cardiovascular and lung diseases, in brain injuries, scleroderma and others.

        Key words: isoprostanes, cyclooxygenase, lipoperoxidation, antioxidants, vasoconstriction.