Alterations in the Fatty Acid Composition of Rat Brain Cells (Neurons, Astrocytes, and Oligodendrocytes) and of Subcellular Fractions (Myelin and Synaptosomes) Induced by a Diet Devoid of n‐3 Fatty Acids

TLDR

The study aimed to characterize the fatty acid composition of isolated rat brain cells. Rats were fed a semisynthetic diet containing sunflower oil for four generations, while half of the animals received a soya‑oil replacement ten days before mating, and their offspring were analyzed for brain cell fatty acid profiles. In sunflower‑fed animals, total unsaturated fatty acids were largely unchanged except in 60‑day‑old neurons, but docosahexaenoic acid was markedly reduced and compensated by increased n‑6 fatty acids, leading to a 16‑fold drop in the n‑3/n‑6 ratio in oligodendrocytes, 12‑fold in myelin, and significant reductions in neurons, synaptosomes, and astrocytes, with saturated and monounsaturated fatty acids and trienes largely unaffected.

Abstract

Abstract: Rats were fed through four generations with a semisynthetic diet containing 1.0% sunflower oil (6.7 mg/ g n‐6 fatty acids, 0.04 mg/g n‐3 fatty acids). Ten days before mating, half of the animals received a diet in which sunflower was replaced by soya oil (6.6 mg/g n‐6 fatty acids, 0.8 mg/g n‐3 fatty acids) and analyses were performed on their pups. Fatty acid analysis in isolated cellular and subcellular material from sunflower‐fed animals showed that the total amount of unsaturated fatty acids was not reduced in any cellular or subcellular fraction (except in 60‐day‐old rat neurons). All material from animals fed with sunflower oil showed an important reduction in the docosahexaenoic acid content, compensated (except in 60‐day‐old rat neurons) by an increase in the n‐6 fatty acids (mainly C22:5 n‐6). When comparing 60‐day‐old animals fed with soya oil or sunflower oil, the n‐3/n‐6 fatty acid ratio was reduced 16‐fold in oligodendrocytes, 12‐fold in myelin, twofold in neurons, sixfold in synaptosomes, and threefold in astrocytes. No trienes were detected. Saturated and monounsaturated fatty acids were hardly affected. This study provides data on the fatty acid composition of isolated brain cells.