Metabolism of Lipid and Protein Components of Triglyceride-Rich Lipoproteins in Rats and Humans

Abstract

The pseudomicellar (apolar core, polar surface-shell) model for spherical lipoproteins occurring in normal blood plasma provides a useful framework for evaluating the metabolism of the various lipid and protein components of triglyceride-rich lipoproteins. Available evidence indicates that this basic structure is retained from the time that the synthesis of these particles is completed in the Golgi apparatus of the cells of origin until they are finally taken up by the liver or transformed to low-density lipoproteins. Available evidence indicates that this basic structure is retained from the time that the synthesis of these particles is completed in the Golgi apparatus of the cells of origin until they are finally taken up by the liver or transformed to low-density lipoprotein. If this is so, it follows that the fractions of particle volume occupied by core and surface-shell of individual particles are essentially fixed by their size (1). Much of the surface-shell is composed of phospholipids, particularly in particles in the upper size range; proteins and cholesterol comprise an increasing fraction as size decreases.