Dietary restriction amplifies the metabolic disturbances of very-low-density lipoproteins in cholesterol-fed rabbits.
The effect of dietary restriction (half of the control ration) on VLDL turnover was investigated in cholesterol-fed rabbits. Rabbits on standard, cholesterol and restricted cholesterol diets were injected with homologous 125I-labelled VLDL. Accompanying the amplification of hypercholesterolemia, additional disturbances of VLDL turnover were observed when cholesterol feeding was associated with dietary restriction. Cholesterol-fed rabbits with normal caloric ration exhibited delayed clearance of 125I-labelled apolipoprotein B component of VLDL compared to control rabbits. This was markedly accentuated in underfed rabbits, indicating further down-regulation of apolipoprotein B,E receptors in these animals. Furthermore, a reduced proportion of radiolabelled apolipoprotein B was converted from VLDL to intermediate-density lipoprotein (IDL) and LDL in both groups receiving cholesterol-rich diets. Thus, the combination of further impairment in plasma clearance of VLDL and the poor conversion into IDL and LDL could account for the massive increase of beta-VLDL in underfed animals on cholesterol-rich diets.
D000818:Animals; D001053:Apolipoproteins / Q000097:blood; D001835:Body Weight; D002791:Cholesterol, Dietary / Q000008:administration & dosage / Q000494:pharmacology*; D007700:Kinetics; D008055:Lipids / Q000097:blood; D008079:Lipoproteins, VLDL / Q000378:metabolism*; D008099:Liver / Q000378:metabolism; D008297:Male; D008657:Metabolic Clearance Rate; D011817:Rabbits
D001053:Apolipoproteins; D002791:Cholesterol, Dietary; D008055:Lipids; D008079:Lipoproteins, VLDL