Impaired very low-density lipoprotein-triglyceride catabolism in acute and chronic fructose-fed rats

Very low-density lipoprotein (VLDL)-triglyceride (TG) catabolism was compared in rats given chow and either a 10% fructose (F) or 10% glucose (G) drinking solution for both acute (A) (16 h) and chronic (C) (14 days) periods. VLDL-TG were labeled in F and G donor rats using different isotopic forms of glycerol. A mixture of the VLDLs was injected into F and G recipients and the decline in plasma TG radioactivities used as a measure of clearance. VLDL-TG from F donors was cleared more slowly than VLDL-TG from G donors. In F recipients, the half-life of VLDL-TG from either F or G donors was longer than that in G fed recipients. VLDL from the AF group, had a lower apoprotein E-to-C apoprotein ratio (E/C) than VLDL from the AG group. VLDL from both F groups had a lower E/C than did that from control rats. The E/C negatively correlated with plasma VLDL-TG. CF and CG VLDL had elevated CIII0 and lower CIII3 levels compared with their respective A groups and controls. The ratio of VLDL apoprotein B100, B95, and B48 did not differ between treatments. AF and AG VLDL were larger and enriched in TG compared with control or the CF and CG groups. The saturated fatty acid-to-unsaturated fatty acid ratio in VLDL-TG was higher in the G groups and AF group compared with controls. The present study suggests that the E/C may be lowered as a result of F consumption, thereby contributing to the impairment in VLDL-TG removal.