Origin in Plasma of Low Density and High Density Lipoproteins

A concept that the low density (LDL) and high density (HDL) lipoproteins of the blood plasma are products of triglyceride transport in chylomicrons and very low density lipoproteins (VLDL) and not primary secretory products of cells has been recently developed by us (Eisenberg et al. 1978a, 1978b; Eisenberg 1979a). The concept assumes that chylomicrons and VLDL are the primary lipoproteins synthesized and secreted by cells in normolipidemie states. It is further assumed that both LDL and HDL are by-products of the process of fat transport, the former being a final “core remnant”, and the latter a final “surface remnant” of the triglyceride-rich lipoproteins. This concept is presented schematically in Figure 1 and is described and discussed here.