High density lipoproteins of rat blood plasma were labeled in vitro with radioiodinated apolipoprotein E and biologically with [3H]cholesteryl esters. These two components, present in high density lipoproteins separated from serum of normal or cholesterol-fed rats by molecular sieve chromatography, were removed slowly from perfused livers and the labeled apolipoprotein E was also removed slowly...

We have determined the composition and distribution of plasma and lung lymph lipoproteins from unanesthetized ewes. Cholesterol, triglyceride, and phospholipid levels in lung lymph were 45%, 50%, and 50%, respectively, of those in plasma. Lipoproteins from both lymph and plasma were separated into two major fractions: d less than 1.063 g/ml or "LDL", and d 1.063-1.21 g/ml or HDL. HDL was the ma...

This study examined the relation of decreased high density lipoprotein (HDL) levels in probucol-fed rats and the transport of HDL cholesterol esters (CEs) to the liver. HDLs from both control rats and rats fed 1% probucol for 3 weeks were doubly labeled in their CE and apolipoprotein A-I moieties with intracellularly trapped tracers and then intravenously injected into probucol-fed or control r...

We have studied the influence of triglyceride-rich particles on the analytical bias of apolipoprotein B measurements by various immunoturbidimetric methods. Three commercially available methods grossly overestimate apolipoprotein B in samples with even moderately above-normal triglyceride concentrations. This effect is due to the increased relative reactivity of very-low-density lipoproteins in...