Comparative effects of dietary fatty acids and triglycerides on lymph lipids in the rat

Abstract

The influence of fatty acids and corresponding triglycerides on the intestinal absorption of cholesterol has been studied in lymph-fistula rats. Butyric and lauric acids, given with bile salt and cholesterol as the free acids or the triglycerides, had little effect on total lymph lipids or on absorption of exogenous cholesterol. Palmitic acid gave a marked increase in lymph lipids which was due entirely to a rise in neutral fat, and a simultaneous depression of cholesterol absorption. The administration of stearic, oleic or linoleic acids produced large increases in the lymph levels of neutral fat and phospholipids. Oleic acid was most efficient, with linoleic and stearic acids somewhat less effective, in promoting cholesterol absorption. The increases in total lymph lipids after tristearin or triolein were less marked than with the free fatty acids, while in the case of trilinolein, total lipids, neutral fat, and phospholipid levels were comparable to the levels after linoleic acid. Of the triglycerides studied, only trilinolein caused a significant elevation of total lymph cholesterol.