CORN-OIL, PALM OIL AND BUTTERFAT FRACTIONS AFFECT POSTPRANDIAL LIPEMIA AND LIPOPROTEIN-LIPASE IN MEAL-FED RATS

Our objective was to investigate the time course of postprandial lipem ia and lipolytic activity in male Sprague-Dawley rats trained to eat m eals containing butterfat fractions, palm oil or corn oil. Baseline an d postprandial blood samples were obtained via a carotid cannula in ra ts fed the experimental diets for 4 wk. Rats fed saturated fats compar ed with corn oil showed a significantly greater peak increase in postp randial triacylglycerol concentrations. Corn oil ingestion resulted in significantly lower concentrations of cholesterol and triacylglycerol in plasma and significantly less triacylglycerol accumulation (millim oles per liter per 24 h) compared with ingestion of saturated fats. Po stheparin plasma lipoprotein lipase activity and plasma insulin concen tration were generally greater with ingestion of corn oil compared wit h palm oil or butterfat. Palm oil ingestion resulted in a biphasic pla sma triacylglycerol response curve and greater postheparin plasma lipo protein lipase activity compared with butterfat ingestion, suggesting differential effects of saturated fats on postprandial lipemia. Our re sults indicate that greater postprandial lipemia with ingestion of sat urated fats compared with corn oil may be due in part to slower plasma triacylglycerol clearance.