High density lipoprotein metabolism is altered by dietary cholesterol but not fat saturation in guinea pigs

• Published in: Atherosclerosis Vol. 112; no. 2; pp. 161 - 175
• Main Authors: Lin, Emme C.K., Fernandez, Maria Luz, McNamara, Donald J.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Ireland Ltd 20-01-1995; Elsevier
• Subjects: Animals; Apolipoprotein A-I - blood; Apolipoprotein A-I - metabolism; apolipoproteins; binding proteins; Biological and medical sciences; blood plasma; cell membranes; Cholesterol; Cholesterol, Dietary - pharmacology; Cholesterol, HDL - blood; Cholesterol, HDL - metabolism; corn oil; diet; Dietary fat; Dietary Fats - pharmacology; Fundamental and applied biological sciences. Psychology; Guinea pig; Guinea Pigs; HDL binding protein; hepatocytes; High density lipoprotein; Kinetics; lard; lipid metabolism; Lipids. Glycolipids; Liver - metabolism; Male; metabolism; Metabolisms and neurohumoral controls; Protein Binding; Radioligand Assay; saturated fatty acids; Vertebrates: anatomy and physiology, studies on body, several organs or systems; apo; CETP; HDL binding protein; Dietary fat; E oHDL; P:S; High density lipoprotein; LCAT; Cholesterol; IDL; HDL; Guinea pig; FCR; LDL; Kinetics; CHD; Vertebrata; Mammalia; Diet; Saturated fatty acid; Animal; Rodentia; Lipids; Exploration; Lipoprotein HDL; Metabolism
• ISSN: 0021-9150; 1879-1484
• DOI: 10.1016/0021-9150(94)05410-K

To study dietary fat and cholesterol effects on plasma high density lipoprotein (HDL) metabolism and rates of apolipoprotein (apo) A-I catabolism, guinea pigs were fed 15% (
wt
wt
) lard- or corn oil-based diets with 0.01% (basal), 0.08%, 0.17% or 0.33% cholesterol. Absorbed dietary cholesterol provided 6%, 50%, 100% and 200%, respectively, of the daily endogenous cholesterol synthetic mass. While total plasma cholesterol concentrations increased significantly above basal levels at the 0.17% and 0.33% cholesterol intakes, plasma apo E-free HDL (E
oHDL) cholesterol concentrations did not increase significantly until the 0.33% cholesterol level (
P < 0.001). Fractional catabolic rates (FCR) of injected [
131I]-apo A-I were not altered by dietary treatment, either fat saturation or cholesterol, but were inversely correlated with plasma E
oHDL cholesterol levels (
r = −0.622), suggestive of a regulatory role of turnover rates on HDL cholesterol levels independent of dietary treatment. Analysis of the high affinity E
oHDL binding to isolated hepatic membranes suggested that hepatic binding was not a determinant of HDL catabolism, as dietary cholesterolinduced decreases in B
max (binding capacity) were not correlated with changes in apo A-I FCR. Even though dietary cholesterol was associated with increased plasma E
oHDL cholesterol and with decreased HDL binding protein B
max, these values did not correlate with each other nor with effects on apo A-I FCR.