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At least 19 recordsLinked to original sources

PubMed1976

Changes in (Na+ + K+)-ATPase activity of Ehrlich ascites tumor cells produced by alteration of membrane fatty acid composition.

The fatty acid composition of plasma membrane derived from Ehrlich ascites tumor cells was altered in vivo by changing the dietary lipid of the tumor-bearing mice. The activity of (sodium + potassium)-adenosinetriphosphatase ((Na+ + K+ATPase), in partially purified plasma membranes, was measured ass a function of temperature. Arrhenius plots of the data were biphasic. Striking differences, dependent on the membrane fatty acid composition, were observed in the transition temperature and in the energies of activation below the transition temperature. The transition temperatures for the (Na+ + K+)-ATPase of plasma membrane derived from tumor cells grown in mice fed a regular chow diet containing a mixture of fatty acids (PMC), a 16% sunflower oil diet (PMSU), or a 4% tristearin diet (PMTS) were 20, 21, and 13.5 degrees C, respectively...

Adenosine Triphosphatases↗

PubMed1976

[Fatty acid composition and phospholipid pattern in auxotrophs for unsaturated fatty acids (author's transl)].

The relationship between fatty acid composition and phospholipid pattern has been studied in Escherichia coli auxotrophs for unsaturated fatty acids. 1. The presence of a regulatory mechanism which enables the organism to maintain a given fluidity of the lipids has been corroborated using exogenous fatty acids which cause dramatic changes in fatty acid composition. 2. The fatty composition of phosphatidic acid is different from that of the other classes of phospholipids. 3. Changes in fatty acid composition are concomittant with the alteration of the phospholipid pattern. The ratio of phosphatidylglycerol to diphosphatidylglycerol is particularly sensitive to the physical characteristics of the exogenous unsaturated fatty acid. The relative increase in diphosphatidylglycerol is associated with membrane alterations.

Cell Membrane↗

PubMed1976

Fatty acid composition of margarines.

The fatty acid composition of 27 samples of bar margarines, 58 samples of tub margarines, and one sample of a liquid margarine spread, purchased at different centers in Canada and the United States over a 1-year period (1973-1974), has been determined. The values of total polyunsaturated fatty acids determined by gas-liquid chromatography were compared to the results obtained by an enzymatic method using lipoxidase. The margarines have also been compared on the basis of fatty acid composition and polyunsaturated to saturated fatty acid ratios. All of these parameters showed considerable variations among the different samples analyzed in this study. As a general rule, soft (tub) margarines tended to have a higher concentration of cis,cis-9,12-octadecadienoic (linoleic) acid than hard (bar) margarines. The labeling of the products as regards fatty acid composition was not always helpful in choosing a margarine of high linoleic acid composition.

Canada↗

PubMed1992

Tracking of serum fatty acid composition: a 6-year follow-up study in Finnish youths.

The composition of fatty acids in serum cholesteryl esters was analyzed with gas chromatography in 759 Finnish boys and girls aged 3-18 years in 1980 and again in the same subjects in 1983 and in 1986. The mean percentage of linoleate (18:2 n-6) increased from 50.85% in 1980 to 52.60% in 1986, while there was a decrease in myristate (14:0), palmitate (16:0), and eicosapentaenoate (20:5 n-3). The percentage of oleate (18:1) did not change. The stability (tracking) of cholesteryl ester fatty acid composition was examined by calculating linear correlation coefficients among the percentages of each fatty acid at the three study points. For linoleate, 3- and 6-year tracking correlations were 0.59-0.61 and 0.50, respectively; they were of about the same magnitude for arachidonate (20:4 n-6) and lower for the other fatty acids. Results indicate that the serum cholesteryl ester fatty acid composition has somewhat lower tracking than the total cholesterol concentration. The changes in the mean fatty acid composition of the study population obviously reflect a shift from saturated to unsaturated dietary fats.

Adolescent↗

PubMed1978

Fatty acid composition of submandibular salivary gland lipids in essential fatty acid deficient rats.

Essential fatty acid (EFA) deficiency was induced in young weanling rats by feeding a fat-free diet or a diet containing 7% Hydrogenated coconut oil (HCO). At intervals of 4, 8, and 16 weeks, rats from the deficient and the control groups were killed and their Submandibular Salivary Glands (SMSG) were dissected out and extracted for lipids. The fatty acid composition of total lipids, triglycerides (TG), free fatty acids (FFA), phosphatidyl choline (PC), and phosphatidyl ethanola-mine (PE) fractions was determined. The levels of 16:1 and 18:1 were increased whereas those of 18:2 and 20:4 were decreased in the EFA-deficient groups as compared to the controls. 5,8,11-eicosatrienoic acid (20:3 omega9) accumulated in the total lipids as well as other lipid fractions of the SMSG from the deficient rats. The levels of this fatty acid increased as the EFA-deficiency progressed. Changes in fatty acid composition of SMSG lipids of EFA-deficient rats were associated with a reduction in flow rate of whole saliva. Protein concentration and amylase activity of saliva was the same in the two groups.

Animals↗

PubMed1979

Modification of the fatty acid composition of cultured human fibroblasts.

The fatty acid composition of human skin fibroblasts grown in 10% dialyzed fetal calf serum can be modified considerably by adding supplemental fatty acids to the culture medium. The degree of modification was dependent on the concentration of added fatty acid over the range tested, 2.5 X 10(-5) to 1 X 10(-4) M. At the higher concentration, the extent of the modifications was as those which can be produced in nonhuman or malignant cell lines. Although the greatest changes were produced in the neutral lipid fraction, the cellular phospholipids also exhibited appreciable modifications. The phospholipids isolated from a microsomal fraction prepared from the cell homogenate exhibited similar changes in fatty acyl composition. These findings indicate that the human fibroblast can tolerate considerable variability in fatty acid composition, even in membrane phospholipids. The triglyceride content of the cells increased when they were grown in the presence of added fatty acids, but the phospholipid and cholesterol content remained unchanged. Growth was not affected by either oleic or linoleic acids, but it was reduced up to 50% when palmitic linolenic, or arachidonic acid was added in concentrations of 5 X 10(-5) M or above. Extensive modifications in phospholipid fatty acid composition also were produced in confluent monolayers of these fibroblasts. This suggest that some membrane lipid turnover occurs even when the cultures are not rapidly growing. Fatty acid modifications also were produced in the commercially available IMR-90 strain of human lung fibroblasts, suggesting that the ability to tolerate considerable differences in fatty acid composition is not a special property of the skin fibroblast line that was isolated locally.

Cell Line↗

PubMed1978

Fatty acid composition of prepared infant formulas.

The fatty acid composition of eight American, eight European, and four Japanese prepared infant formulas were determined and compared with fat sources listed on labels. Unsaturated fatty acids ranged from 20 to 83 per cent of the total. Generally, the fatty acid composition was consistent with the types of ingredients used; those with corn or soy oil had the highest levels of unsaturated fat, and those with milk fat the lowest; formulas of mixed composition fell in between. The formulas were compared with values for the fatty acid composition of human milk in the literature.

Dietary Fats↗

PubMed1976

Effects of essential fatty acid deficiency and carbon tetrachloride-induced liver cirrhosis on lipid and fatty acid compositions of oral palatal epithelium in rats.

Lipid pattern and fatty acid composition of oral palatal epithelium were investigated in three groups of Sprague-Dawley rats: essential fatty acid (EFA)-deficient rats, which were fed diets containing 0.07 calorie% EFA for more than two generations; liver cirrhotic rats repeatedly injected with carbon tetrachloride; control rats fed standard pellets. The fatty acid pattern was studied in choline phosphoglycerides, ethanolamine phosphoglycerides, total phosphoglycerides, triglycerides and free fatty acids. Disturbances in the farry acid composition were seen chiefly in the EFA-deficient group, where marked reductions of the polyunsaturated fatty acids 18:2 and 20:4 (n-6) of the linolecic acid series were observed. At the same time, a compensatory increase was registered in the amount of 18:1 and 20:3 (n-9) of the oleic acid series. Corresponding findings were also found for the liver cirrhotic rats, except for the reduction of 18:2, but the changes of the fatty acid pattern in this group were not as marked as was observed for the EFA-deficient rats. In the lipid pattern no differences were seen between the three experimental groups, except for a somewhat higher content of lipid phosphorus and cholesterol in the EFA-deficient rats and a higher amount of free fatty acids in the liver cirrhotic group compared with the control rats. Changed physiological condition of the oral mucosa was suggested to be a result of the observed disturbances in the fatty acid composition of the oral epithelium.

Animals↗

PubMed1975

Influence of low ambient temperature and dietary lipids on adipose tissue and plasma fatty acid composition of the Japanese quail.

Japanese quail were maintained on synthetic diets containing 15% corn oil, 15% tallow, and zero fat, and were later exposed at 3.5 degrees C for 21 days. A distinct influence of dietary fat composition upon the adipose tissue triglyceride fatty acid composition was detected, but no change in fatty acid composition was produced with cold exposure. The fatty acid composition of adipose tissue from quail acclimatized to winter temperatures showed no trend towards a greater degree of unsaturation. There was no evidence of a gross selective mobilization of certain fatty acids from the depot lipids. Regional variation in the fatty acid composition of avian fats is discussed with respect to the level of food intake and body temperature.

Acclimatization↗

PubMed1976

Total fatty acid composition of duck fatty tissues.

Total lipids extracted from duck fatty tissues were fractionated on thin layer plates into polar lipids and neutral lipids. Neutral lipids were similarly fractionated into their components. Fatty acid methyl esters from total lipids were fractionated by gas-liquid-chromatography. Results indicated that duck fatty tissues are mostly formed by neutral lipids and that triglycerides comprise the vast majority of neutral lipids. Results also indicated that the major fatty acids in duck lipids are: oleic greater than linoleic greater than stearic greater than palmitoleic. About 73% of all fatty acids present belong to the C-18 series. The unsaturation level for duck lipids is about 73%.

Adipose Tissue↗

PubMed1979

Effects of vitamin E and selenium deficiency on the fatty acid composition of rat retinal tissues.

The fatty acid composition of retinal tissues was measured in rats maintained for 26--32 weeks on each of the following diets: a purified basal diet deficient in alpha-tocopherol and selenium, an identical control diet supplemented with alpha-tocopherol and selenium, and a commerical laboratory rat chow. Dietary deficiencies of antioxidant nutrients were found to cause a large decrease in total polyunsaturated fatty acids in the retinal pigment epithelium, a small decrease in the retinal rod outer segments, but no change in the whole retina or liver when compared to tissues from animals fed the vitamin E- and selenium-supplemented control diet. The polyunsaturated fatty acid content which we have observed for the retinal pigment epithelium from rats fed commerical lab chow is similar to that which we observed for bovine retinal pigment epithelium. Our results indicate that changes in fatty acid composition are not generalized to all tissues in severely antioxidant-deficient animals, but that changes do occur in some tissues, such as the retinal pigment epithelium, which appears to be particularly sensitive to in vivo lipid peroxidation.

Animals↗

PubMed1979

Fatty acid composition of Rhizobium spp.

The fatty acid composition of 42 isolates belonging to the major plant affinity groups of Rhizobium has been determined and found to vary reproducible with culture age. Numerical taxonomic techniques applied to the 15 major fatty acid components of log-phase cultures of comparable physiological age showed that the rhizobia constitute a uniform group. However, two clusters comprising soybean-cowpea isolates and pea-bean isolates were evident. These observations, based on a simple analysis of only one group of chemical components, indicate relationships among rhizobia which differ from the conventional plant-affinity groupings but which are consistent with other proposed relationships established using a variety of biochemical and physiological criteria.

Fabaceae↗

PubMed1975

Alteration of fatty acid composition of LM cells by lipid supplementation and temperature.

Alteration of the fatty acid composition of monolayer cultures of LM cells grown in chemically defined medium was achieved by supplementation with fatty acids complexed to bovine serum albumin. Phospholipids containing up to 40% linoleate were found in cells grown in medium containing 20 mu g of linoleate/ml. Incorporation of linoleate into phospholipids reached a plateau after 12-24 hr, and cells remained viable for at least 3-4 days. Although linoleic, linolenic, and arachidonic acids were incorporated into LM cells equally well, only the latter was elongated by these cells under these experimental conditions. Nonadecanoic acid was incorporated to a lesser extent than the polyunsaturated fatty acids. Phosphatidylcholine and phosphatidylethanolamine of LM cells had different fatty acid compositions; phosphatidylethanolamine contained more longer chain and unsaturated fatty acids. Cells were also grown in the absence of choline and presence of choline analogs such as N,N-dimethylethanolamine, N-methylethanolamine, 3-amino-1-propanol, and 1-2-amino-1-butanol. The analog phospholipids in these cells had fatty acid compositions which were intermediate between those of phosphatidylethanolamine and phosphatidylcholine of control cells grown in the presence of choline. Linoleate was found in both phosphatidylcholine and phosphatidylethanolamine of cells supplemented with linoleate. The sphingolipid fraction of these cells, however, did not contain significant amounts of linoleate. When linoleate was present in the phospholipids, compensatory decreases in the oleate and palmitoleate content of phospholipids were observed. Lowering of the growth temperature to 28 degrees produced an increase in unsaturate fatty acid content of the phospholipids. When linoleate was supplied to cells grown at 28 degrees, there was no further increase in the unsaturated fatty acid composition of the phospholipids. Using both fatty acid supplementation and lowered growth temperature, LM cell membranes can be produced which have phospholipids with vastly different fatty acid compositions.

Animals↗

PubMed1978

The role of lipid components of the diet in the regulation of the fatty acid composition of the rat liver endoplasmic reticulum and lipid peroxidation.

The fatty acid compositions of the lipids and the lipid peroxide concentrations and rates of lipid peroxidation were determined in suspensions of liver endoplasmic reticulum isolated from rats fed on synthetic diets in which the fatty acid composition had been varied but the remaining constituents (protein, carbohydrate, vitamins and minerals) kept constant. Stock diet and synthetic diets containing no fat, 10% corn oil, herring oil, coconut oil or lard were used. The fatty acid composition of the liver endoplasmic reticulum lipid was markedly dependent on the fatty acid composition of the dietary lipid. Feeding a herring-oil diet caused incorporation of 8.7% eicosapentaenoic acid (C(20:5)) and 17% docosahexaenoic acid (C(22:6)), but only 5.1% linoleic acid (C(18:2)) and 6.4% arachidonic acid (C(20:4)), feeding a corn-oil diet caused incorporation of 25.1% C(18:2), 17.8% C(20:4) and 2.5% C(22:6) fatty acids, and feeding a lard diet caused incorporation of 10.3% C(18:2), 13.5% C(20:4) and 4.3% C(22:6) fatty acids into the liver endoplasmic-reticulum lipids. Phenobarbitone injection (100mg/kg) decreased the incorporation of C(20:4) and C(22:6) fatty acids into the liver endoplasmic reticulum of rats fed on a lard, corn-oil or herring-oil diet. Microsomal lipid peroxide concentrations and rates of peroxidation in the presence of ascorbate depended on the nature and quantity of the polyunsaturated fatty acids in the diet. The lipid peroxide content was 1.82+/-0.30nmol of malonaldehyde/mg of protein and the rate of peroxidation was 0.60+/-0.08nmol of malonaldehyde/min per mg of protein after feeding a fat-free diet, and the values were increased to 20.80nmol of malonaldehyde/mg of protein and 3.73nmol of malonaldehyde/min per mg of protein after feeding a 10% herring-oil diet in which polyunsaturated fatty acids formed 24% of the total fatty acids. Addition of alpha-tocopherol to the diets (120mg/kg of diet) caused a very large decrease in the lipid peroxide concentration and rate of lipid peroxidation in the endoplasmic reticulum, but addition of the synthetic anti-oxidant 2,6-di-t-butyl-4-methylphenol to the diet (100mg/kg of diet) was ineffective. Treatment of the animals with phenobarbitone (1mg/ml of drinking water) caused a sharp fall in the rate of lipid peroxidation. It is concluded that the polyunsaturated fatty acid composition of the diet regulates the fatty acid composition of the liver endoplasmic reticulum, and this in turn is an important factor controlling the rate and extent of lipid peroxidation in vitro and possibly in vivo.

Animals↗

PubMed1979

Restriction of patching of bound concanavalin A after incorporation of arachidonic acid into the plasma membrane of virally transformed fibroblasts.

Topographical distribution of concanavalin A binding sites (CABS) was studied in two lines of virally transformed fibroblasts as a function of fatty acid composition. Fatty acid composition was manipulated by incubating cells in fatty acid, ATP, CoA, and delipidated fetal calf serum (FCS). VLM cells grown in medium containing 5% FCS have a clustered CABS distribution. Plasma membrane vesicles (PMVs) derived from these cells have an arachidonate content of 1.7%. Elevation of PMV arachidonate to 15.8% results in a marked restriction of CABS patching, while elevation to 6.8% is associated with intermediate restriction of patching. Restriction of patching is associated with increased microviscosity. CABS of Rous sarcoma virus-transformed chicken embryo fibroblasts (RSV-CEF) are also responsive to arachidonate enrichment medium. Whereas untreated cells have a clustered CABS distribution, cells incubated for 24 h in arachidonate enrichment medium have predominantly a dispersed CABS distribution. In both VLM cells and RSV-CEF, ATP, CoA, and delipidated FCS alone have no effect upon CABS mobility. Inhibition of CABS patching is also observed when aspirin is included in the arachidonate enrichment medium but not when the cells are incubated in prostaglandins, thus suggesting that the restriction of CABS mobility is not mediated by prostaglandins. Other fatty acids (palmitate, oleate, nonadecanoate) failed to restrict CABS movement. The inhibition of CABS mobility is independent of cell shape change.

Animals↗

PubMedDate not supplied

[Comparative study of the fatty acid composition of glycerophosphatides from whole vertebrate brain and portions of it].

Fatty acids of phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and monophosphoinositide were studied in the whole brain, in the forebrain and the brain stem in the frog Rana temporaria, tortoise Emys orbicularis, hen and cat. Every family of phospholipids (PL) possesses a characteristic fatty acid pattern irrespectively of the brain part. There are regular topologic differences in the fatty acid composition of PL, namely the relative amount of saturated and polyenoic acids is higher and that of monoenoic acids lower in the forebrain as compared to the brain stem. The increase in the relative size of the forebrain, occurring in the evolution of vertebrate brain, exerts a definite influence on the fatty acid composition of the total brain. Nevertheless this increase in the size of the forebrain does not solely determine the fatty acid composition of the total brain. Similar changes are occurring in all brain parts: the relative amount of saturated fatty acids of PL is increasing and that of unsaturated acids decreasing. The evolutionary deductions derived from the biochemical study of the total brain find confirmation in the investigation of the brain parts.

Animals↗

PubMed1975

The effect of salt on phospholipid fatty acid composition in Escherichia coli K-12.

The fatty acid compositions of the three major phospholipids of Escherichia coli K-12; phosphatidylethanolamine, phosphatidylglycerol and cardiolipin; were determined during growth in media differing in NaCl concentration. Significant differences in fatty acid composition of the phospholipids were observed in the stationary phase cultures, but no appreciable differences were found in early exponential cultures.

Cardiolipins↗

PubMed1978

Lipid compositional manipulation in Acholeplasma laidlawii B. Effect of exogenous fatty acids on fatty acid composition and cell growth when endogenous fatty acid production is inhibited.

A variety of potential inhibitors of de novo fatty acid biosynthesis have been tested for activity in Acholeplasma laidlawii B. Two compounds, avidin and N,N-dimethyl-4-oxo-2trans-dodecenamide (CM-55), an antimicrobial fatty amide, strongly inhibit de novo biosynthesis without nonspecific toxic effects at moderate dosages. Avidin is the more potent inhibitor, abolishing de novo fatty acid synthesis and greatly reducing the chain elongation of exogenous fatty acids at level of 25 U/l. CM-55 gives complete inhibition of de novo biosynthesis only at low temperatures and inhibits exogenous fatty acid elongation to a variable extent. However, CM-55 is still a more potent antilipogenic agent in this organism than is the fungal antibiotic cerulenin. Cells cultured with avidin grow only when one or more exogenous medium- or long-chain fatty acids are added to the growth medium. The extent of cell growth under these conditions depends primarily on the physical properties of the exogenous fatty acid(s). In general, fatty acids giving diacylglycerolipids of very high or very low fluidity are unsuitable growth substrates, while those whose diacylglycerol derivatives are of intermediate fluidity support fair to good cell growth.

Acholeplasma laidlawii↗