EFFECT OF DONOR AGE ON THE BINDING AND DEGRADATION OF LOW-DENSITY LIPOPROTEINS BY CULTURED HUMAN ARTERIAL SMOOTH-MUSCLE CELLS

The ability of human arterial smooth muscle cells growing in tissue culture to bind, incorporate and degrade low density lipoproteins (LDL) was studied as a function of cell donor age from 5 to 71 years. LDL binding to cell surface receptors did not change with donor age. However, LDL degradation was significantly decreased in cells from older donors. These results may be relevant to the enhanced accumulation of cellular cholesterol and LDL observed in the aging human artery. Thus, impaired LDL degradation by arterial smooth muscle cells may be one of several factors involved in the accelerated development of atherosclerosis with aging.