Very-low-density lipoproteins (VLDLs) are large, complex particles containing both surface proteins (e.g., ApoB100) and core lipids, e.g., cholesterol and triglycerides (TG). Whereas ApoB100 kinetics have been thoroughly studied, accurate measurement of VLDL-TG kinetics have proven difficult due to either complex mathematics or laborious procedures. The present study was therefore designed to m...

The present investigations have examined the mechanism(s) whereby Sf 60-400 very low density lipoproteins (VLDL) from Type IV hypertriglyceridemic subjects cause cholesteryl ester and triglyceride accumulation in J774 macrophages. Both apolipoprotein (apo) E-poor and apoE-rich Type IV VLDL subfractions, isolated by heparin-Sepharose chromatography, were capable of enhancing cellular cholesterol...

The turnover and the catabolic fate of the B apoprotein of very low density lipoprotein (VLDL-B) was studied in 15 normal and hyperlipidemic subjects using reinjected autologous VLDL labeled with radioiodine. The specific radioactivity-time curve of the B apoprotein in total VLDL (S(f)20-400) was multiexponential but conformed to a two-pool model during the first 48 h of catabolism. The flux wa...

BACKGROUND The liver secretes very-low-density lipoproteins (VLDLs) and plays a key role in lipid metabolism. Plasma total triglyceride (TG) level variations have been studied in patients with hepatitis C virus (HCV)-related chronic hepatitis (CH-C). However, the results of these studies are variable. A homogenous assay protocol was recently proposed to directly measure the TG content in VLDL (...

The rat liver secretes very low density lipoproteins (VLDL) containing either apoB-100 or apoB-48. After oral fat intake, chylomicrons containing apoB-48 and endogenously synthesized VLDL are mixed in the blood and the triglyceride clearance from these triglyceride-rich lipoprotein species compete for the same lipolytic pathway, i.e., lipoprotein lipase. A situation mimicking alimentary lipemia...

The effects of efonidipine hydrochloride (efonidipine), a dihydropyridine calcium antagonist, on the cholesterol ester metabolism induced by beta-migrating very low density lipoprotein (beta-VLDL) in J774 macrophages were studied. The cholesteryl ester content in the macrophages was increased by incubation with beta-VLDL, and the increase was inhibited by efonidipine. Oleic acid incorporation i...

To investigate the regulation of lipid uptake into the eel oocyte in more detail, effects of 11-ketotestosterone (11-KT) and lipid transporters (lipoproteins) were determined in vitro. Ovarian explants from previtellogenic Japanese eels (Anguilla japonica) were incubated for 28 days with 11-KT and/or with very low density lipoproteins (Vldl), low density lipoproteins (Ldl), or high density lipo...

Dansyl phosphatidylethanolamine (DPE) (dansyl, 5dimethylaminonaphthalene-1-sulfonyl) was incorporated into human plasma very low density lipoproteins (VLDL). Concomitant with its lipolysis, DPE-VLDL undergoes a greater than %fold fluorescence enhancement, a large increase in fluorescence polarization, and a 20 nm blue shifl in the wavelength of its emission maxima. Based on fluorescence quenc...

To clarify the role of lipoprotein lipase (LPL) in the catabolism of nascent and circulating very low density lipoproteins (VLDL) and in the conversion of VLDL to low density lipoproteins (LDL), studies were performed in which LPL activity was inhibited in the cynomolgus monkey by intravenous infusion of inhibitory polyclonal or monoclonal antibodies. Inhibition of LPL activity resulted in a th...

The interrelationship between apolipoprotein B in very low density lipoprotein (VLDL-B) and in low density lipoprotein (LDL-B) was studied in seven normal and hyperlipidemic men and women, with purified radioiodinated VLDL. The time-course of the appearance of radioactivity in LDL was followed. As the specific activity curves intersected at the masimal height of the LDL-B curve, it was inferred...