Mouse peritoneal macrophages accumulate large amounts of cholesteryl ester when incubated with human low-density lipoprotein that has been modified by chemical acetylation (acetyl-LDL). This accumulation is related to a high-affinity cell surface binding site that mediates the uptake of acetyl-LDL by adsorptive endocytosis and its delivery to lysosomes. The current studies demonstrate that the ...

Twenty-four adult male African green grivet monkeys were fed diets containing 42% of calories as lard or menhaden oil and 0.76 mg of cholesterol/kcal for a period of 8 months. Plasma samples from fasting animals were then taken and low density lipoproteins (LDL) were isolated by ultracentrifugation and agarose column chromatography. The LDL were analyzed chemically, and physical properties of t...

The effect of lipid transfer proteins on the exchange and transfer of cholesteryl esters from rat plasma HDL2 to human very low (VLDL) and low density (LDL) lipoprotein populations was studied. The use of a combination of radiochemical and chemical methods allowed separate assessment of [3H]cholesteryl ester exchange and of cholesteryl ester transfer. VLDL-I was the preferred acceptor for trans...

Cholesteryl ester-rich particles extracted from human atherosclerotic plaques were shown to increase the rate of incorporation of [14C]oleate into cholesteryl [14C]oleate and to cause massive accumulation of cholesteryl esters in monolayers of mouse peritoneal macrophages. This stimulation showed saturation kinetics and susceptibility to competition by polyanions (polyinosinic acid, fucoidin, d...

p-Nitrophenyl N-butyl, N-octyl, and N-dodecyl carbamates and a newly synthesized diethyl phosphate compound were studied as potential inhibitors of the cholesteryl ester hydrolases of Fu5AH rat hepatoma cells. Whole homogenates of Fu5AH cells were used as an enzyme source for the assay of cholesteryl ester hydrolase activity. All four compounds led to marked inhibition (70-80%) of neutral chole...

Although some previous studies have suggested that triglyceride, a major core lipid, plays a key role in the assembly and secretion of apolipoprotein B-containing lipoproteins from HepG2 cells, other reports have indicated the importance of cholesteryl ester, another core lipid. We attempted to better define the roles of triglyceride and cholesteryl ester in the assembly and secretion of apolip...

Recent studies from our laboratory (Yancey, P.G., and R. W. St. Clair. 1992. Arterioscler. Thromb. 12: 1291-1304) have shown that cultured peritoneal macrophages from White Carneau (WC) pigeons clear cholesteryl esters at a slower rate than do macrophages from Show Racer (SR) pigeons (9% per 24 h vs. 42% per 24 h, respectively) when incubated in the presence of a cholesterol acceptor apo high d...

These studies were undertaken to examine the effects of lipoprotein lipase (LPL) and cholesteryl ester transfer protein (CETP) on the transfer of cholesteryl esters from high density lipoproteins (HDL) to very low density lipoproteins (VLDL). Human or rat VLDL was incubated with human HDL in the presence of either partially purified CETP, bovine milk LPL or CETP plus LPL. CETP stimulated both i...

The ability of mouse peritoneal macrophages to hydrolyze and excrete cytoplasmic cholesteryl ester droplets was studied. The macrophages were loaded with cholesteryl esters by incubation with acetylated low density lipoprotein (acetyl-LDL), which is internalized by adsorptive endocytosis. The cholesteryl esters of acetyl-LDL are hydrolyzed within lysosomes and the liberated cholesterol is re-es...

Hepatic lipase-deficient subjects in the Ontario kindred are compound heterozygotes for hepatic lipase mutations (Ser^-^Phe and Thr^^Met). Cholesteryl ester-rich 0-very-low-density lipoprotein (/3VLDL) accumulates in plasma and such subjects have premature atherosclerosis. To determine a possible mechanism, we hypothesized that hepatic lipase-deficient 0-VLDL, homozygous for apolipoprotein (apo...