The metabolism of 125I-labelled apoprotein of low density lipoproteins was studied in rabbits fed either commercial or semi-purified, cholesterol-free, diet. The rise in apo-LDL intravascular pool size observed in the semi-purified group is accompanied by a marked decrease in the fractional catabolic rate and an increase in the total catabolic rate. The semi-purified diet induces an increase in the cholesterol ester/triglyceride ratio of the LDL which is normalized by cholestyramine therapy. The concomitant alterations in both LDL metabolism and lipid composition raise the possibility that enrichment of LDL in cholesterol esters is a consequence of the delayed LDL clearance from the plasma.
Animals Apoproteins