[The significance of ixidized low density lipoprotein in atherosclerosis]

The "oxidation hypothesis" states that oxidised low-density lipoprotein (ox-LDL) plays a central role in atherogenesis. LDL oxidation is a chaotic process initiated by reactive oxygen species. Enhanced uptake of ox-LDL in macrophages leads to foam cell formation in vitro, and ox-LDL has a variety of other experimental proatherogenic effects, e.g., endothelial cell activation, immunogenicity, platelet aggregation, and inhibition of endothelium-dependent vaso-relaxation. There are methodological limitations in the current laboratory methods aimed at characterization of the oxidative state of LDL. However, considerable evidence indicates that ox-LDL is found in plasma, arteries, and atheromatous plaques of humans, although the significance of this phenomenon is unknown. Antioxidants may inhibit atherosclerosis in experimental animals, and epidemiological data suggest an inverse relation between the intake of antioxidant vitamins and the risk of coronary artery disease. Randomised prospective trials are in progress, and until their conclusion, the clinical effect of antioxidant therapy in man remains unknown.