Plasma concentration of apolipoprotein E in intermediate-sized remnant-like lipoproteins in normolipidemic and hyperlipidemic subjects

Abstract

Triglyceride-rich lipoprotein (TRL) remnants have been strongly implicated in the pathogenesis of atherosclerosis. To further investigate plasma remnant lipoprotein metabolism, we have determined the plasma concentration of apolipoprotein (apo) E (by polyclonal enzyme-linked immunoassay) in remnant-like lipoproteins, isolated by automated gel filtration chromatography as a fraction intermediate in size between VLDL and HDL. In normolipidemic subjects (n = 12), 1.2±0.1 mg/dL (33±2%, mean±SE) of total plasma apoE was associated with this fraction (termed ISL apoE). In hypercholesterolemic (type III, n=12), hypertriglyceridemic (type IV, n=12), and mixed hyperlipidemic (type IIb, n=12) subjects, mean ISL apoE concentrations were 2.1±0.2, 2.5±0.2, and 3.8±0.4 mg/dL, respectively (P