The fatty acid composition of leech lipids

• 1.1. The constituent fatty acids of the neutral and phospholipids of Macrobdella ditetra, Nephelopsis obscura, Philobdella gracilis and Hirudo medicinalis have been determined.
• 2.2. Unsaturated fatty acids predominated in both neutral and phospholipid fractions of all leech species examined.
• 3.3. Arachidonic acid (20:4) was the most prevalent fatty acid in all species, accounting for as much as 36.7% of the total phospholipid fatty acids.

     

The fatty acid composition of fern lipids

Fatty acid compositions of the lipids isolated from the pinnae of four fern species show that they differ from those of the lipids in leaves of higher plants in having C-20 polyunsaturated acids, mainly arachidonic acid. As in higher plants, the ω-3 polyunsaturated acids are concentrated in the monogalactosyl diglycerides. Variations are found both in the fatty acid compositions and in the monogalactosyl/digalactosyl diglyceride ratio during the growing season.     

The effect of essential fatty acid deficiency upon fatty acid uptake by the brain.

Young adult rats, either control or essential fatty acid deficient, were administered either [3-H] oleic acid or [3-H] arachidonic acid by stomach tube. In addition, a group of control rats was given [3-H] palmitic acid. The rats were killed at various times therafter, and the radioactivity of the lipids of brain and plasma was examined. In confirmation of previous work, the blood lipid label was found to rise rapidly and then fall, wheras the activity of brain lipids increased slowly and did not show a decline through the 24-h period studied. Analysis of the brain uptake data according to first-order kinetics confirmed the impressions gained from visual inspection of the data. The initial rate of uptake of arachidonic acid was about 4.5 times that of oleic acid in control animals and in deficient animals. Essential fatty acid deficiency, however, did not induce an altered rate of uptake for either oleic acid or arachidonic acid. The rate of uptake of palmitic acid by control rats was not significantly different from that of oleic acid. Even though the initial rates of incorporation of oleic and arachidonic acids were not changed during essential fatty acid deficiency, the final levels of radioactivity obtained in brain lipids were higher in deficient rats with both fatty acids. The plateau value obtained with oleic acid was 1.5 times higher in deficient animals, while the plateau value for arachidonic acid was 1.7 times higher. An experiment in which deficient animals were allowed access to a control diet for 12 or 24 h prior to the labeling experiment suggested that the higher levels of radioactivity found in brain lipids of deficient animals was not due to an isotope dilution effect. Such animals still displayed the labeling pattern of deficient animals with arachidonic acid, while the results with oleic acid varied somewhat. Our results suggest that essential fatty acid deficiency does not alter the ability of the brain to take up the fatty acids studied. However, the fatty acids, especially arachidonic, are retained in the brain to a greater extent in the deficient animals.     

The fatty acid composition of Ulothrix aequalis lipids

Fatty acid composition of the total lipids isolated from the fresh-water green alga Ulothrix aequalis shows that they resemble marine green algal lipids in having a high proportion of 16:4 ω-3 but differ in having only trace amounts of 18:4 ω-3. The distribution of ω-3 acids in the MGDG and DGDG fractions resembles that in green seaweeds and higher plants with the 16:4 ω-3 distribution in the Ulothrix fractions resemblmg that of 18:4 ω-3 in the corresponding fractions of the seaweeds.     

The fatty acid composition of the total lipids in Vibrio cholerae]

The fatty acid composition of total cell lipids of V. albensis typing strains, serovars 01-012, isolated from patients and environmental objects, as well as V. eltor and NAG vibrios, has been studied. Fatty acids contain 14-18 carbon atoms and are mainly represented by unsaturated monoacids. Palmitoleic and oleic acids constitute the greater part of unsaturated acids (their total content is 55.2-71.0%). The level of saturated fatty acids in considerably lower (27.0-43.1%), and these acids are mainly represented by palmitic acid, its maximum level being 28.4%. The similarity of the fatty acid profiles of the lipids common to the strains under study may indicate that these strains are phylogenetically related.     

Membrane lipids and ethanol tolerance in the mouse. The influence of dietary fatty acid composition

Mice of the TO Swiss strain received diets containing different amounts of saturated or unsaturated fat throughout life. These diets produced characteristic changes in cardiac phospholipid fatty acid composition, but produced no significant differences in fatty acid composition of phospholipids from a crude membrane fraction of brain. When littermates of these animals were exposed to ethanol vapour in an inhalation chamber it was observed that mice which had received a diet high in saturated fat lost the righting reflex at an estimated concentration of ethanol in blood higher than that required for mice receiving a control diet, or a diet rich in polyunsaturated fat. Analysis of the brain membrane fraction from those animals which had received ethanol revealed that mice receiving the highly saturated fat diet now had a significantly greater proportion of saturated fatty acids in brain membrane phospholipids. These results are discussed in relation to the hypothesis that brain membrane lipid composition may influence the behavioural response to ethanol.     

Alteration of the fatty acid composition of Ehrlich ascites tumor cell lipids.

The fatty acid composition of Ehrlich ascites tumor lipids was altered markedly $\text{in vivo}$ by changing the type of fat fed to the tumor-bearing mice. As compared with regular chow, large differences were produced in polar and neutral lipid fatty acyl groups when the tumor cells were grown in mice fed coconut oil, sunflower oil or fat deficient diets. Subcellular membrane fractions obtained from these cells exhibited similar variations in fatty acyl composition. This experimental system provides large quantities of malignant cells for study of the relationships between membrane lipid structure and function.     

Dietary protein and fatty acid composition of liver lipids in the rat

In order to compare the effects of different sources of dietary protein on the fatty acid composition of phosphatidylcholines (PC), phosphatidylethanolamines (PE), phosphatidylinositols (PI), cholesteryl esters and triacylglycerols, male rats were fed for a 4-week period on cholesterol-free, or cholesterol-containing, diets based on casein, or soybean protein and olive oil. The most conspicuous difference observed was the occurrence of significantly higher levels of 5,8,11-eicosatrienoic acid, 20:3 (n - 9), in the different lipid classes of casein-fed, compared with soybean protein-fed, animals. In the PI fraction of livers from the groups of rats fed casein diet, this fatty acid amounted to between 9.9 and 13.3% by weight of the total fatty acids. Phospholipids from livers of casein-fed rats contained increased levels of oleic acid, 18:1 (n - 9) (in PC and PE) and reduced levels of stearic acid (18:0). Moreover, in this group of rats PI contained a reduced level of arachidonic acid, 20:4 (n - 6). A casein-related decrease in the linoleic acid, 18:2 (n - 6), content of PC and PE was observed only in the rats fed on cholesterol-free diet. Effects on the fatty acid composition were also observed in the triacyglycerol and cholesteryl ester fractions, in which the rats fed casein diet showed higher levels of palmitoleic acid, 16:1 (n - 7) (cholesterol-supplemented diet) and lower values for linoleic acid, than the soybean protein-fed rats.     

Maternal diet during pregnancy has tissue-specific effects upon fetal fatty acid composition and alters fetal immune parameters

Both animal and human studies demonstrate that the docosahexaenoic acid (DHA) content of plasma and/or tissue lipids is increased during pregnancy. We hypothesised that increasing the α-linolenic acid (ALA) or longer chain (n-3) PUFA content of the maternal diet during pregnancy influences fetal fatty acid composition and the fetal immune system. Pregnant rats were fed a low-fat (LF) soybean oil diet, or high-fat (HF) soybean, linseed, salmon or sunflower oil diets from conception to 20 d gestation. The ALA-rich Linseed-HF diet resulted in an equivalent eicosapentaenoic acid (EPA) status in fetal immune tissues and an equivalent DHA status in the fetal brain to that achieved with the Salmon-HF diet. An (n-3) rich maternal diet during pregnancy associated with the highest expression of CD3 (Salmon-HF) and CD8 (Linseed-HF and Salmon-HF) on fetal thymic CD3⁺CD8⁺ cells. The Linseed-HF diet resulted in the highest proportion of CD161⁺ cells within the fetal thymus, which correlated with the production of IL-4. These data indicate that dietary ALA supplementation may confer some of the benefits of LC (n-3) PUFA during pregnancy. This should be examined in suitably designed human studies.     

The effect of ethonium on the fatty acid composition of the lipids in the hepatic and muscular tissues of hypotrophic piglets

Relative content of unsaturated, in particular polyene fatty acids, being a part of total lipids and lipase activity in the liver tissue and muscular tissue in the hypotrophic pigs is much lower than those parameters in normotrophic ones. Ethonium induces an increase in the percentage of irreplaceable polyene acids in total lipids, activity of lipase and CME in tissues as well as average diurnal increments and preservation percent of youngs.     

Polar lipids and fatty acid composition ofThermus strains from New Zealand

The polar lipids and fatty acid composition ofThermus aquaticus YT-1 and YS 041,T. filiformis Wai33 A1 and eighteen isolates from New Zealand, several of which are attributed toT. filiformis, were compared to complement the taxonomy of these organisms. The polar lipid patterns were essentially similar in all strains and consisted of one major phospholipid and one major glycolipid. The fatty acid analysis produced three basic groups corresponding toT. filiformis Wai33 A1,T. aquaticus and the third to the other New Zealand strains. The presence of hydroxy fatty acids is reported inThermus spp. for the first time.