Nature of the dysfunctional changes. Evidence suggest that oxLDL is a key component in endothelial injury . Formation of NO can prevent platelet aggregation , on the other hand , can promote oxidation of LDL . In contrast to the LDL receptors , the scavenger receptors are not subject to down-regulation . Presence of scavenger receptors allows the cells to take up oxidatively modified LDL .
Macrophages are present in all stages of atherogenesis .
Macrophages internalize oxLDL through both scavenger receptors and a putative oxLDL receptor and can oxidize LDL through several pathways , including lipoxygenase enzymes . Importance of oxLDL in atherosclerosis first established through the use of the antixodant probucol . Vitamin E , vitamin C , b -carotene suggested as a means of preventing and reducing lesions of atherosclerosis . NO causes vasodilatation guanylate cyclase and cyclic GMP production . NO may also be protective against atherosclerosis , because it reduces monocyte adhesion and proliferation of the vascular smooth muscle cells .