title: Regulation of cholesterol and lipoprotein metabolism in guinea pigs mediated by dietary fat quality and quantity.
abstract: The effects of dietary fat quality and quantity on regulation of cholesterol and lipoprotein metabolism were measured in guinea pigs. The animals were fed 7.5 or 15% (wt/wt) fat diets containing either polyunsaturated corn oil (CO), monounsaturated olive oil (OL) or saturated lard as the fat source. Dietary fat quality had a number of significant effects: animals fed the CO-based diet had lower plasma LDL levels and LDL particles of higher density with decreased ratios of core-to-surface components. Apoprotein B/E receptor-mediated binding of LDL to hepatic membranes was twofold higher for animals fed the CO-based diet. Animals fed the OL-based diet had lower hepatic 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase activity and increased levels of hepatic cholesterol. Hepatic cholesteryl ester levels were lowest for animals fed the lard-based diet. Increasing dietary fat quantity resulted in increased plasma LDL levels and hepatic cholesterol, HMG-CoA reductase activity and receptor affinity for LDL. No changes were observed in LDL binding. These data demonstrate that, independent of dietary fat quantity, CO-based diets lower plasma LDL levels, modify LDL composition and increase hepatic apoprotein B/E receptor number.
authors.affiliation: Department of Nutrition and Food Science, University of Arizona, Tucson 85721.
authors.forename: M L
authors.initials: ML
authors.lastname: Fernandez
authors.forename: D J
authors.initials: DJ
authors.lastname: McNamara
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002784:Cholesterol / Q000097:blood / Q000378:metabolism*; D004041:Dietary Fats / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D006903:Hydroxymethylglutaryl CoA Reductases / Q000378:metabolism; D008074:Lipoproteins / Q000097:blood / Q000378:metabolism*; D008099:Liver / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D008297:Male; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000378:metabolism; D018110:Receptors, Lipoprotein
chemical_list: D004041:Dietary Fats; D008074:Lipoproteins; D011956:Receptors, Cell Surface; D018110:Receptors, Lipoprotein; C032531:apolipoprotein B,E receptor; D002784:Cholesterol; D006903:Hydroxymethylglutaryl CoA Reductases