[Oxidated sterols--a contributing factor in atherogenesis?]

Sterols are not only important metabolic precursors, they are also indispensable structural components of cell membranes. There is some evidence that synthesis of cholesterol is regulated by oxidized derivatives of cholesterol. They are able to inhibit the key enzyme of cholesterol synthesis, i.e. 3-hydroxy-3-methylglutaryl-CoA-reductase. In addition, oxidized sterols are inserted into the lipid bilayer of the cell membrane as cholesterol analogues. This insertion results in serious disturbances of morphology and function of the membrane. In animal models oxidized sterols have angiotoxic effects; they are also found in atheromas of human arteries. Therefore they may be a causative factor in atherogenesis.