Showing papers on "Docosahexaenoic acid published in 1974"

Studies on the lipid composition of the rat liver endoplasmic reticulum after induction with phenobarbitone and 20-methylcholanthrene.

Abstract: 1. The cholesterol content, proportions of different phospholipids and fatty acid components of phosphatidylcholine and phosphatidylethanolamine were studied in rat liver endoplasmic-reticulum membrane, after a single injection of 20-methylcholanthrene or injections of phenobarbitone for 5 days. 2. A marked decrease in the proportion of cholesterol occurred 5 days after injection of 20-methylcholanthrene or phenobarbitone. 3. The proportion of phosphatidylcholine was increased by injection of phenobarbitone and minor changes occurred in other phospholipids. 4. Phenobarbitone caused the proportion of linoleic acid in phosphatidylcholine and phosphatidylethanolamine to increase to 120–125% of the control and the proportion of oleic acid, arachidonic acid and docosahexaenoic acid to decrease. 5. 20-Methylcholanthrene caused an increase in the proportion of oleic acid in phosphatidylcholine and ethanolamine to 125–140% of the control, 1 day after injection. 6. The increased proportion of linoleic acid in phosphatidylcholine after phenobarbitone injection occurs simultaneously with the increase of cytochrome P-450 concentration, the rate of oxidative demethylation of aminopyrine and the rate of hydroxylation of biphenyl. It is therefore considered that distinct species of phosphatidylcholine or phosphatidylethanolamine containing linoleic acid in the β position are essential in the endoplasmic-reticulum membrane for optimal activity of oxidative demethylation.

Embryonic vs tumor lipids. II. Changes in phospholipids of developing chick brain, heart, and liver.

Abstract: Brain, heart, and liver tissues were excised from embryos and chicks 10, 13, 16, 19, 22, 27, and 53 days after incubation was initiated and the lipids extracted. The quantitative distribution of the phospholipids and the fatty acid composition of the individual phosphatides were determined for each time period. Each tissue exhibited a distinct phospholipid composition that differed from the composition of egg. Elevated concentrations of particular phosphoglycerides that characterize certain mature tissues were observed at the earliest time period. As development progressed, some phospholipid classes in all tissues showed dramatic change, while others remained relatively constant. Brain showed the most stable composition, while the phosphatides of liver were the most dynamic. Each phospholipid class exhibited a characteristic fatty acid profile that was unique for each tissue. All of the phospholipid classes showed a change in fatty acid composition as development progressed, and, in some tissue, the change was dramatic. The fatty acid composition of brain phosphoglycerides showed the least change, while liver showed the greatest fluctuation. Docosahexaenoic acid and, in most cases, arachidonic acid decreased in the phosphoglycerides with increased development. The decrease in docosahexaenoic acid correlated well with the decreasing mitotic indices of heart and liver cells as development progressed. Comparison of observed abnormal lipid patterns between mature and neoplastic tissue with embryonic tissue lipid profiles suggest that some of the observed abnormalities of neoplasms probably are due to changes in lipid metabolism associated with rapidly proliferating cells, whereas other abnormalities appear to be associated with neoplasia.

Total glycerophospholipid fatty acid and phospholipid class composition of nerve ending and related fractions from fetal and adult pig cerebellum and adult pig whole brain cortex.

Abstract: Membrane fractions derived from crude mitochondrial fractions of pig cerebellums were separated on a continuous CsCl-sucrose gradient. Fetal and adult brains were used as starting material. The major differences in total glycerophospholipid fatty acid composition between fetal and adult membranes were an increase with maturation in docosahexaenoic acid and a decrease in palmitic acid which occurred in all membranes, including nerve ending and smooth membrane fractions. Phosphatidylcholine levels decreased, and ethanolamine phosphatide levels increased with maturation in all adult membrane fractions. Phosphatidylserine levels increased primarily in nonmitochondrial fractions in adult tissues. The results indicate that both hydrophobic and hydrophylic characteristics of several membrane fractions, including nerve endings, change with development. The developmental changes in pig cerebellums are similar to those reported for whole brain or brain regions from other species. Mitochondrial enriched fractions derived from adult pig whole brain cortex had significantly reduced palmitate levels and significantly elevated oleate levels compared with nerve ending and smooth membrane fractions.