The type of dietary fat alters the hepatic uptake and biliary excretion of cholesterol from chylomicron remnants

• Published in: British journal of nutrition 2000-04, Vol.83 (4), p.431-438
• Main Authors: Lambert, Marc S., Avella, Michael A., Botham, Kathleen M., Mayes, Peter A.
• Format: Article
• Language: English
• Subjects: Animals; Biliary steroids; Biological and medical sciences; Butter - adverse effects; Cholesterol - metabolism; Chylomicron remnants; Chylomicrons - metabolism; Deuterium; Diet, Fat-Restricted; Dietary fat; Dietary Fats - administration & dosage; Dietary Fats - metabolism; Fats, Unsaturated - metabolism; Fish Oils - metabolism; Fundamental and applied biological sciences. Psychology; Liver - metabolism; Liver. Bile. Biliary tracts; Male; Perfusion; Plant Oils - metabolism; Rats; Rats, Wistar; Vertebrates: digestive system
• ISSN: 0007-1145; 1475-2662
• DOI: 10.1017/S0007114500000532

The consumption of fat-enriched diets may alter the uptake and metabolism of chylomicron remnant cholesterol by the liver. To test this hypothesis, [3H]cholesterol-labelled chylomicron remnants derived from different dietary fats were studied in perfused livers both from rats fed on diets enriched in the corresponding fats and from rats fed on a low-fat diet. Livers from rats fed on each of the fat-enriched diets removed similar amounts (34–40 %) of the [3H]cholesterol-labelled remnants added, whereas livers from rats fed on the low-fat diet removed significantly more labelled fish-oil and butter-fat remnants than olive-, maize- or palm-oil remnants. Significantly more remnant [3H]cholesterol was secreted into the perfusate HDL by livers from rats fed on the olive-oil, fish-oil and butter-fat diets when compared with those from rats fed on the low-fat diet or the maize-oil diet. Furthermore, the excretion of remnant [3H]cholesterol via the bile acid was increased by the olive-, maize-, palm- or fish-oil diets, and decreased by the butter-fat diet when compared with the low-fat diet, although the [3H]bile acid excreted remained less on saturated fat diets. This investigation shows that the hepatic uptake and subsequent metabolism of cholesterol from chylomicron remnants is influenced by the type of fat in the diet as well as the fatty acid composition of the particles themselves, and may help to explain some of the hyper- and hypocholesterolaemic effects of saturated and unsaturated fatty acids.