[Structural analysis of the interaction of low density lipoproteins with arterial intima cells in atherosclerosis]

Abstract

Structural characteristics of low density lipoprotein (LDL)-intimal cellular element interaction were studied in atherosclerotic lesions in the aortas obtained from rabbit with experimentally induced hypercholesterolemia and in human coronary arteries. An electron microscopic autoradiographic examination using 125I to study the in vivo interaction between LDL and rabbit aortic intimal cells indicated that the formation of foam cells was associated with activated endocyte activity and uncontrolled capture of atherogenic lipoproteins. The structural analysis of the interaction of native and modified LDL labelled with colloid gold, on the one hand, and human coronary intimal cells, on the other, was made by using ultrathin sections. This enabled the localization of the receptors to lipoproteins to be established. This also demonstrated that transformation of the cells to foam ones was due to the functional insufficiency of lysosomal activity and to the filling of the cytoplasm with membranelles and membrane-surrounded lipid vacuoles.