Cholesteryl esters from oxidized low-density lipoproteins are in vivo rapidly hydrolyzed in rat Kupffer cells and transported to liver parenchymal cells and bile.

Human low-density lipoprotein was labeled in its cholesteryl ester moiety with [3H]cholesteryl oleate or [3H]cholesteryl oleoyl ether and oxidized by exposure to 10 mumol/L of cupric sulfate. The in vivo metabolism of cholesteryl esters of oxidized low-density lipoprotein was determined after injection into rats. When oxidized low-density lipoprotein was labeled with [3H]cholesteryl oleoyl ether, a nonhydrolyzable analog of cholesteryl oleate, Kupffer cells contributed to 55.

Morphological characterization of scavenger receptor-mediated processing of modified lipoproteins by rat liver endothelial cells.

Scavenger receptor-mediated processing by rat liver endothelial cells in vivo is studied by using acetylated and oxidized low-density lipoproteins (LDL) as ligands. The cellular localization of acetylated LDL (Ac-LDL) is visualized by both immunohistochemistry and silver enhancement of ultrasmall gold particles conjugated to Ac-LDL. Scavenger receptor-mediated internalization by the endothelial cells only involves coated vesicle formation.

Visualization of the uptake and processing of oxidized low-density lipoproteins in human and rat liver.

The interaction of oxidized human low-density lipoproteins with human and rat liver was analyzed by light and electron microscopy. At the light microscopic level oxidized low-density lipoprotein was visualized by the fluorescent dye 1,1' dioctadecyl 3,3,3',3' tetramethyl indocarbocyanine perchlorate, whereas at the electron microscopic level, an indirect immunolabeling procedure was used that detected the apoprotein B of the oxidized low-density lipoprotein. In rats, oxidized low-density lipoprotein was administered intravenously, and uptake by human liver was studied by perfusion of tissue blocks.