ABSTRACT
The lipoproteins are macromolecular complexes of lipids and protein (Figure 2.1). Great diversity of composition and physical properties are possible, particularly in disease but also in health. As such, their classification and definition is particularly difficult. Each lipoprotein has a wide range of components, each with its own metabolic origin and fate. The components of lipoprotein undergo a complex metabolic interplay with receptors and with enzymes located on the lipoproteins, and on the capillary endothelium and between the circulating lipoproteins themselves, both in the vascular compartment and within the tissue fluid space. It is thus naive in the extreme to try to think of serum cholesterol or triglycerides in the same way as serum sodium or glucose, which are transported simply as solutes. The very existence of lipids within the circulation is dependent on lipoproteins.
