Sur l'incorporation des chaînes stéariques dans les chylomicrons lymphatiques du rat

Abstract

Rats were fed either with triglycerides of known structure containing unsaturated and stearic chains or with mixtures of stearic (or palmitic) acid and oleic acid. Triglycerides from the chylomicrons of thoracic-duct lymph were then extracted and analyzed. 1. 1. When fatty acids were ingested in the free form, it was confirmed that palmitic acid is distributed at random among the internal and external positions of chylomicron triglycerides. On the contrary, stearic acid is attached principally on external positions. 2. 2. Stearic acid is much less incorporated than palmitic acid, when both are fed in the free state. An explanation is suggested, based on the difference of micellar solubilization of these acids by bile salts in the intestinal lumen. 3. 3. Stearic chains are better absorbed when fed as mixed triglycerides or even as ethyl stearate. This does not seem to be explained by any particular solubilizing properties of the monoglycerides liberated during intraluminar lipolysis, but rather by kinetic factors.