[A new concept of atherogenesis: the role of oxygen radicals]

The author discusses a new concept of atherogenesis which is based on older hypotheses (lipid infiltration hypothesis), theory of impaired endothelial barrier, role of immunological and thrombocytic factors) and supplements it by new findings on the role of oxygen radicals in the development of atherosclerosis. The atherogenity of native low density lipoproteins (LDL) is enhanced substantially by their post-secretory changes caused by the action of free oxygen radicals on unsaturated fatty acids in the outer layer of LDL particles. The development of lipid peroxides on the surface of LDL leads to a changed orientation of the metabolism of LDL particles: oxidized LDL are not bound to classical LDL receptors in the liver but to so-called scavenger receptors in monocytes and macrophages. Lipid accumulation in monocytes, not controlled by feedback mechanisms, leads to formation of foam cells which are the basis of atheromatous plaques. This process can be influenced by antioxidants which block the formation of lipid peroxides. The new concept is particularly important for the population of Czechoslovakia and other formerly totalitarian countries where deterioration of the environment occurred and concurrently also adverse dietary changes (high fat, sucrose and spirit intake, low vegetable and fruit consumption). It is probable that an increased intake of antioxidants (ascorbic acid, carotenes, tocopherols, bioflavonoids, selenium etc.) would, along with other corrective provisions, suppress the steep increase of cardiovascular diseases.