LDL RECEPTOR-INDEPENDENT AND RECEPTOR-DEPENDENT UPTAKE OF LIPOPROTEINS

The liver plays a decisive role in the regulation of the plasma levels of atherogenic lipoproteins. The primary liver interaction site for c hylomicron-remnants and VLDL remnants (P-VLDL) is still unidentified, while the subsequent cellular uptake is likely to be mediated in conce rt by the LDL receptor related protein (LRP) and the LDL receptor. The nature of the primary interaction site of remnants (remnant-receptor) might be a liver-specific proteoglycan or a liver-specific protein. A therogenic modified LDL can be recognized by a family of scavenger-rec eptors. A newly identified 95-kDa protein forms the most likely candid ate for mediating the in vivo uptake of oxidized LDL from the circulat ion and might thus protect the body against the presence of oxidized L DL in the blood compartment.