Lipoproteins and lipid transport.

Continued advances in the delineation of pathways of lipid transport in lipoproteins now provide substantial information on all phases of plasma triglyceride transport. Analysis of certain genetic human disorders, together with studies in experimental animals, has begun to show how lipoproteins transport cholesterol as esters of long chain fatty acids. Both triglycerides and cholesterol are esters of long chain fatty acids. Both triglycerides and cholesteryl esters are transported in the "core" of lipoproteins, but the polar lipids and the apoproteins at the aqueous interface critically determine the interactions with enzymes and cellular receptors that control this complex transport system. Differences in pathways as well as in rates of lipid transport appear to underlie the large interspecies variations in lipoprotein concentrations.