Structure glycéridique du tissu adipeux périrénai de rats soumis à un régime à base d'huile d'arachide

Abstract

Weanling male rats were fed a balanced diet containing 15 p. 100 peanut oil by weight. The digestibility and fecal excretion of oil fatty acids were studied for 8 days at the beginning of the diet, which was then continued up to 4 months. At the end of the experiment, perirenal adipose tissues were removed and their triacylglycerols isolated and studied. They were fractionated into 8 fractions according to unsaturation and then analyzed by gas-liquid chromatography (GLC) for fatty acids and triacylglycerols. Each fraction was submitted to pancreatic lipolysis; the mono- and diacylglycerols formed were isolated and their fatty acids analyzed by GLC. The diacylglycerols were further fractionated according to unsaturation and their fatty acid composition analyzed. The triacylglycerol structure of the adipose tissue was determined using mathematical methods previously described. The long-chain saturated fatty acids (from stearic to lignoceric) were poorly absorbed and not incorporated into the fat tissue, whereas oleic acid, the major fatty acid of the oil (54 p. 100), was highly incorporated (57 p. 100) into triacylglycerols. As in the diet oil, unsaturated fatty acids were mainly esterified at the 2-position. Trioleoylglycerol was the major (21 p. 100) triacylglycerol, as in the oil (25 p. 100). Only 14 isomers accounted for more than 1 p. 100 and together represented more than 80 p. 100 of the total. Of the 14 isomers, the first four (10 p. 100 or more) accounted for more than one-half of oil triacylglycerols, namely 56 p. 100. The triacylglycerol structure of studied adipose tissue was very similar to that of the diet peanut oil.