Fatty Acid Composition Of Plasma Phospholipids Research Articles

Response of tissue phospholipid fatty acid composition to dietary (n-6) and replacement with marine (n-3) and saturated fatty acids in the rat

Nine groups of weanling male rats were maintained for ten weeks on a fat-free semi-synthetic diet supplemented with 10% by weight of oil, composed wholly of gamma-linolenic acid-rich evening primrose oil, or replaced partly or completely (25%, 50%, 75%, and 100%) by marine or hydrogenated coconut oils. Plasma phospholipid content and phospholipid fatty acid composition of plasma, red blood cells, liver, kidney, and heart were determined. Replacement of marine oil as 2.5% of the diet caused a decrease of plasma phospholipid concentration to 60%, with no furthur decrease at higher proportions. Except in the heart, marine oil in combination with evening primrose oil caused an increase in 20:3(n-6) concentration, and a decrease in 20:4(n-6) levels in all tissues examined. The ratio 20:3(n-6)/20:4(n-6) increased with increasing marine oil supplementation to the diet, but not when marine oil was the sole source of dietary fatty acids (10%). Replacement of hydrogenated coconut oil did not affect 20:3(n-6) concentrations. A decrease in 20:4(n-6) was observed when hydrogenated coconut oil was supplemented to the diet at 10%, causing a state of EFA deficiency as shown by the elevation of 20:3(n-9). There was an increase in 20:5(n-3) and 22:6(n-3) with increased marine oil intake. The ratio 20:3(n-6)/20:4(n-6) correlated significantly with 20:5(n-3), but not with 22:6(n-3), in all tissues except the heart, suggesting an inhibitory effect of 20:5(n-3) on delta-5-desaturase enzyme.

Plasma phospholipid fatty acids and urinary excretion of prostaglandins PGE1 and PGE2 in infants during total parenteral nutrition, with continuous or sequential administration of fat emulsion.

During total parenteral nutrition, using an identical supply of fat emulsion (350 mg/kg/24 hr) to correct essential fatty acid deficiency in children, the efficacy of two methods of administration was studied: continuous over 24 hr, or discontinuous 3 hr/day. At the beginning of the study, all the infants (1-4 months old) had proven essential fatty acid deficiency. After at least 1 month of one of the two nutritional protocols (continuous or discontinuous), plasma phospholipid fatty acid composition and PGE1 and PGE2 urinary excretion were measured. The results obtained indicate better utilization of the fat emulsion when it is administered almost every day, in continuous infusion over 24 hr (1 g/kg/24 hr of Intralipid 20%).

Effects of high vitamin a intake on plasma and liver phospholipid and triglyceride fatty acid compositions in hamsters

The fatty acid compositions of plasma and liver phospholipids and triglycerides were studied in hamsters fed for 4 weeks diets containing 0, 40 or 200 mg per kg diet of retinyl palmitate (vitamin A). No major differences were found between animals fed 0 and 40 mg/kg diet of vitamin A. However, significant increases in the levels of 20:3 (n-6) and 18:1 (n-9), and a concomitant decrease in those of 16:0 were found in hamsters fed 200 mg/kg vitamin A. High vitamin A intake also decreased the levels of 22:6 (n-3) in plasma and liver phospholipids. The levels of 20:4 (n-6) in both plasma and liver phospholipids were not affected but were decreased in plasma and liver triglycerides in animals fed various levels of vitamin A.

Significance of plasma lysolecithin in patients with multiple sclerosis: a longitudinal study.

Five patients with multiple sclerosis and four normal subjects have been followed for over two years. Plasma phospholipid levels and phospholipid fatty acid composition have been assayed periodically. The increased amount of plasma lysolecithin already described by us has been confirmed in this longitudinal study. A significant increase in saturated fatty acids of lysolecithin has also been demonstrated. In contrast, the lecithin concentration and fatty acid composition do not show any significant variations. The lysolecithin saturated/unsaturated fatty acid ratio was different in the same patients at different times, but no correlation was established between these variations and the clinical symptoms measured using the Kurtzke scale. The possible significance of saturated fatty acid increase in lysolecithin in the pathogenetic mechanisms of multiple sclerosis is discussed.

EFFECT OF ESTRADIOL AND TESTOSTERONE ON THE FATTY ACIDS OF PLASMA CHOLESTERYL ESTERS AND PHOSPHOLIPIDS IN THE CASTRATED RAT.

The effects of physiological doses of estradiol and testosterone on plasma cholesteryl ester and phospholipid fatty acid composition were investigated in castrated male rats. The animals were killed after 3 weeks on experiment, and their plasma cholesteryl esters and phospholipids were analyzed and compared with those of intact female and male rats.Estradiol appeared to be responsible for the increased proportion of plasma cholesteryl arachidonate seen in the female or estrogen-injected rats since the proportion of cholesteryl arachidonate in castrated control rats was lower and similar to that of male or testosterone-treated rats. Plasma phospholipids of female and estradiol-injected rats had a higher percentage of stearic acid relative to palmitic acid. On the other hand, male, castrated control and testosterone-treated rats had higher proportions of palmitic acid. Fractionation of the plasma phospholipids into cephalins, lecithins, sphingomyelins, and lysolecithins, and analyses of their fatty acids, revealed that a principal effect of estradiol was to increase proportions and amounts of stearic and arachidonic acids in the lecithin fraction.The results suggest that estradiol may influence the synthesis of a lecithin rich in stearic and arachidonic acid. A possible relationship between the arachidonic-acid-rich lecithin and the higher percentage of cholesteryl arachidonate in estradiol-treated rats is discussed.