Role of the high density lipoprotein-receptor cycle in macrophage-cholesterol metabolism.

The intracellular catabolism of lipids and the blood cholesterol level are known to have an essential impact on the onset and progress of atherosclerosis. As lipoprotein receptors can influence the co-operation of macrophages, high density lipoproteins and enzymes of lipid metabolism, the contribution of these receptors to transport and intracellular processing of cholesterol are investigated by means of biochemical analysis and electron microscopy. Taking the effect of second messenger systems into consideration, a model for impaired lipoprotein receptor function affecting the cholesterol metabolism is developed.