Lipids

Even though atherosclerosis is primarily a chronic inflammatory process, lipids are involved in atherosclerotic plaque formation. Lipoproteins are components of the foam cells that eventually develop into the plaque, if inflammation in blood vessels continues. The body needs fat-soluble molecules. Yet the environment of the blood is aqueous. Lipoproteins therefore are designed to allow fat-soluble, hydrophobic molecules through the aqueous blood. Lipoproteins contain a phospholipid membrane with protein receptors but they are not cells. They are simple 'particles' that are filled with hydrophobic cargo (cholesterol and triglycerides). There are four major lipoproteins: