Secretion of cholesteryl-ester-rich lipoproteins by the perfused livers of rabbits fed a wheat-starch-casein diet.
Rabbits fed a cholesterol-free semi-synthetic wheat-starch-casein diet had a high plasma cholesterol concentration; most of the cholesterol was associated with low-density lipoproteins (LDL). Chemical analyses of plasma lipoproteins revealed that very-low-density lipoproteins (VLDL), intermediate lipoproteins and LDL from casein-fed rabbits contained more cholesteryl ester than that of lipoproteins isolated from chow-fed animals. The fatty acid composition of cholesteryl esters of plasma lipoproteins showed that there were higher contents of oleic acid than linoleic acids in lipoproteins from casein-fed rabbits. Lipoproteins isolated from liver perfusates of casein-fed rabbits had higher cholesteryl oleate content than lipoproteins from chow-fed rabbit liver perfusates. There was a marked increase in secretion of apolipoproteins from perfused livers of casein-fed rabbits. We conclude that the high levels of plasma cholesterol in casein-fed rabbits are of hepatic origin and that one of the hypercholesterolemic actions of dietary casein in rabbits is the induction of hepatic synthesis and secretion of cholesteryl-ester-rich lipoproteins.
D000818:Animals; D001053:Apolipoproteins / Q000378:metabolism; D002364:Caseins; D002788:Cholesterol Esters / Q000378:metabolism*; D004040:Dietary Carbohydrates / Q000494:pharmacology*; D004044:Dietary Proteins / Q000494:pharmacology*; D005227:Fatty Acids / Q000097:blood; D008074:Lipoproteins / Q000097:blood; D053419:Lipoproteins, IDL; D008077:Lipoproteins, LDL / Q000097:blood; D008079:Lipoproteins, VLDL / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D008239:Lysine / Q000378:metabolism; D008297:Male; D010477:Perfusion; D011817:Rabbits; D013213:Starch; D014908:Triticum
D001053:Apolipoproteins; D002364:Caseins; D002788:Cholesterol Esters; D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D005227:Fatty Acids; D008074:Lipoproteins; D053419:Lipoproteins, IDL; D008077:Lipoproteins, LDL; D008079:Lipoproteins, VLDL; D013213:Starch; D008239:Lysine