Effect of sucrose on intestinal very low-density lipoprotein production.

The effect of 2 to 3 weeks of 73% sucrose feeding and intestinal sucrose infusion upon intestinal lipoprotein formation was studied in mesenteric lymph cannulated female rats. Lymph lipoprotein fractions were analyzed for lipid and apoprotein content and were compared to chow-fed control rats. The sucrose regimen increased mesenteric lymph triglyceride output by 54%, the increase being confined to the very low-density lipoprotein fraction. Sucrose infusion in chow-fed control rats did not increase lymph triglyceride transport when compared to infusion of a glucose polymer. Unesterified cholesterol output in whole lymph was stimulated by sucrose by 76%. Both the d greater than 1.006 and d less than 1.006 g/ml fractions of lymph were found to have an increase in unesterified cholesterol output. Since no difference in the chemical composition of very low-density lipoproteins in the two groups of animals was detected, sucrose appeared to increase the number of very low-density lipoprotein particles secreted by the intestine. Sucrose did not alter the relative proportions of apo A1, apo A4, apo ARP, and total C peptides present in very low-density lipoproteins. However, differences in the proportion of apo C subunits after sucrose were detected by isoelectric focusing with a pronounced increase in the apo CIII0 peak. The present studies demonstrate that the intestine participates in changes in lipoprotein formation and metabolism that accompany experimental sucrose induced hyperlipidemia.