Dietary fish oil modification of cynomolgus monkey low density lipoproteins results in decreased binding and cholesteryl ester accumulation by cultured fibroblasts

• Published in: Journal of lipid research 1993-05, Vol.34 (5), p.769-778
• Main Authors: Linga, V, Leight, M.A, St Clair, R.W, Parks, J.S
• Format: Article
• Language: English
• Subjects: ACEITES DE PESCADO; Animals; Apolipoproteins B - analysis; Apolipoproteins E - analysis; Binding, Competitive; Biological and medical sciences; Cells, Cultured; CHIMIORECEPTEUR; Cholesterol Esters - chemistry; Cholesterol Esters - metabolism; CORPS GRAS; CULTIVO DE CELULAS; CULTURE DE CELLULE; DIETA; Dietary Fats - pharmacology; Fatty Acids - analysis; Feeding. Feeding behavior; FIBROBLASTE; FIBROBLASTOS; Fibroblasts - metabolism; Fish Oils - pharmacology; Fundamental and applied biological sciences. Psychology; GRASAS; HUILE DE POISSON; LARD GRAS; LIPOPROTEINAS; LIPOPROTEINE; Lipoproteins, LDL - chemistry; Lipoproteins, LDL - drug effects; Lipoproteins, LDL - metabolism; Macaca fascicularis; Male; MENHADEN; MONO; Particle Size; Phospholipids - chemistry; QUIMIORECEPTORS; Receptors, LDL - metabolism; REGIME ALIMENTAIRE; SINGE; TOCINO DORSAL; Vertebrates: anatomy and physiology, studies on body, several organs or systems
• ISSN: 0022-2275; 1539-7262
• DOI: 10.1016/S0022-2275(20)39697-8

Dietary fish oil (FO) has been reported to increase low density lipoprotein (LDL) receptor function resulting in lower plasma LDL concentrations in the rat (Ventura et al. J. Clin. Invest. 84: 528-537, 1989). The purpose of this study was to determine whether dietary FO, as compared to lard, affected the receptor-mediated uptake of LDL by cultured skin fibroblasts. Plasma LDL was isolated by combined ultracentrifugation and column chromatography from cynomolgus monkeys fed diets enriched in FO or lard and the effect of these two dietary fats on the binding of LDL and esterified cholesterol (EC) accumulation by cultured fibroblasts was determined. There was no difference in total plasma or LDL cholesterol concentrations between diet groups. The monkeys fed FO had significantly smaller LDL which, on average, contained less protein, phospholipid (PL), and free and esterified cholesterol compared to the LDL from monkeys fed the lard diet. FO LDL were less effective than lard LDL in competing for binding, internalization, and degradation of a standard 125I-labeled LDL by fibroblasts (11.0 +/- 2.4 vs. 3.0 +/- 0.8 microgram LDL protein/ml for 50% displacement of binding, respectively; P = 0.013). FO versus lard LDL also resulted in less accumulation of cellular EC after a 24-h incubation with fibroblasts (7.7 +/- 0.2 vs. 13.0 +/- 0.4 microgram EC/mg protein, respectively; P = 0.0001). In general, cellular EC accumulation was proportional to LDL particle size and LDL apoE/B molar ratio; however, LDL from the lard group resulted in greater EC accumulation even when LDL particle size and apoE content were nearly equivalent between diet groups. When LDL were isolated from the same animals by sequential ultracentrifugation, the lard LDL apoE was reduced 22% compared to column isolated LDL and this resulted in a 32% decrease in cellular EC accumulation