Paraoxonases play important role in protection against various substrates, such as organophosphates, nerve gases or oxidized lipids in plasma LDL. Although it has long been recognized that serumPON1 plays an important role in organophosphatemetabolism, the role ofPON in lipid metabolism is a relatively new area of investigation. Oxidized LDL is believed to play a central role in initiation of atherosclerosis. HDL has been shown to prevent oxidative modification of LDL in vitro as well as in vivo. Recent studies indicate that PON and other HDL- -associated enzymes are responsible for its antioxidative and antiinflammatory properties. The paraoxonase gene cluster contains at least three members, including PON1, PON2 and PON3, located on chromosome 7. This article reviews the current evidence on the association between PON(s) polymorphisms and diseases other than only coronary heart disease, for example diabetes mellitus, vascular complications of diabetes (micro- and macroangiopathy),neurodegenerative diseases and some metabolic phenotypes such as plasma lipoproteins and glucose.

        Key words: paraoxonase, polymorphism, antioxidative activity, lipoperoxidation.