Homocysteine, Paraoxonase-1 and Vascular Endothelial Dysfunction: Omnibus viis Romam Pervenitur

Increased oxidative stress, alterations of lipid metabolism and induction of thrombosis have been suggested to be pathogenic links which are present between hyperhomocysteinaemia and atherosclerosis. However, the mechanism by which homocysteine (Hcy) can promote atherogenesis is far from clear and it has been debated. In the presence of cardiovascular risk factors, endothelial dysfunction is the central commodity which converges a plenty of factors, which have been named as atherogenic. Now-a-days, there are only few studies which have presented the correlation between antioxidant enzyme HDL-associated-paraoxonase 1(PON1) and Hcy in atherosclerosis. Both PON 1 and Hcy have been implicated in human diseases which are related to endothelial dysfunction. Although paraoxonases have the ability to hydrolyze a variety of substrates, only one of them, Hcy-thiolactone, is known to occur naturally. It seems very likely that the involvement of Hcy in atherosclerotic disease is mediated through its interactions with PON1.