The endothelium, which is only a single cell thick, comprises the lining of that innermost layer and acts as an interface between blood and arterial wall. The second breakthrough was that atherosclerosis appears to be a healing response by the body that goes haywire. When any part of the body is damagedwhether by infection with bacteria, sports injury, a burn, etc.the body increases the flow of blood to the injured area and puts white blood cells to work there. White blood cells surround the bacteria or the damaged tissue. Then, together with other cells in the damaged tissue, the white blood cells neutralize and remove whatever is causing the injury and repair the damage.
Researchers now believe that a similar process occurs in atherosclerosis.
But the process of inflammation and healing the injury may be slow and excessive, and the result can be increased risk of stroke and heart attack. From LDL to Oxidized LDL to Adhesion Molecules. Now it appears that the endothelium does much more. When high levels of LDL are in the blood, a small amount of the LDL that builds up in the artery wall becomes oxidized. This occurs through chemical reactions in the endothelium that change the LDL by adding extra oxygen atoms to it.