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PubMed1979

Forebrain fatty acid composition during development in protein-calorie and essential fatty acid deficiencies in the rat.

Rats were fed three different dietary levels of essential fatty acids (EFA), 3.0, 0.75 and 0.1 cal%, representing normal, subnormal and severely deficient dietary intakes. From the animals kept on these diets, with a protein content of 16 cal%, 3-month-old females were randomly selected to be fed diets with only 6 cal% protein but with unchanged amounts of EFA. The rats were then mated, and the effects of the diets were studied in the forebrains of their offspring. The growth and the fatty acid patterns of the ethanolamine phosphoglyceride and total phosphoglyceride fractions were studied during the first 60 days of life. Addition of protein-calorie deficiency to rats severely undernourished in EFA mitigated the biochemical signs of EFA deficiency. In EPG the developmental pattern with a decrease of 20:4 (n-6) and an increase of 22:6 (n-3) was retarded between 11 and 21 days of age in the protein-calorie deficient groups suggesting a delay in the maturation of the forebrain.

Aging↗
PubMed1967

Rapid colorimetric micromethod for free fatty acids.

Free fatty acids (FFA), the uranyl ion, and the basic dye Rhodamine B form colored complexes, which are extractable into toluene or benzene. Fatty acids of different chain lengths above C(10) and different degrees of unsaturation gave constant molar yield. Complexes in toluene alone are unstable, especially in the light, but a small amount of aqueous uranyl acetate stabilizes them sufficiently for determination. At constant uranyl and Rhodamine B concentrations, a plot of optical density vs. FFA concentration yields two straight lines of different slope, i.e., a biphasic standard curve. Phospholipids interfere, and must be removed with zeolite during FFA extraction. Recovery of FFA added to rat plasma was very similar to that with titration. Assay of rat and dog plasma samples under fasting and fed conditions gave good agreement with the titration method. Values of human plasma samples tended to be higher by the colorimetric procedure; a few samples gave significant disagreement. The method compares well with previous methods in sensitivity and accuracy, and offers advantages in speed, simplicity, and possibly specificity.

Animals↗
PubMed1975

Quantitative effects of unsaturated fatty acids in microbial mutants. IV. Lipid composition of Saccharomyces cerevisiae when growth is limited by unsaturated fatty acid supply.

The Saccharomyces cerevisiae mutant KD46 (ole 2), which is unable to synthesize unsaturated fatty acids, was grown on limiting amounts of different added unsaturated fatty acids. The acyl chain composition of the cellular lipid classes was determined in these cultures at different stages or growth. During growth on added oleic acid, there was no marked change in the mole percentage of phosphatidylcholine, phosphatidylethanolamine. phosphatidylinositol, or phosphatidylserine among the total phospholipids. Cells grown on palmitoleic, oleic, or linoleic acid showed a steady decrease in their total phospholipid levels per cell concomitant with a decrease in growth rate approaching minimal levels at stationary phase. Furthermore, the mole percentage of the supplemented unsaturated fatty acid in the cellular phospholipids also decreased during growth and attained minimal values when growth ceased. At stationary phase the total phospholipid content per cell was similar for cells grown on a wide range of fatty acids or mixtures thereof, whereas the composition of the fatty acids in the cellular phospholipids were strikingly different. The differences in efficiencies for supporting growth of most of the unsaturated fatty acids tested did not seem due to the extent of their corporation into cellular phospholipids, but rather to differences in the ability of the derived membrane phospholipids to support cellular functions. Palmitoleate, oleate, linoleate, linolenate, arachidonate, eicosapentaenoate, and docosahexaenoate all appeared to contribute to the functionality of cellular membranes in an additive linear manner. Thus, the contribution of these acids to cellular growth can be characterized by a functionality factor that seems independent of the mixtures of acids supporting growth. Use of the functionality concept allows the cumulative influence of many different acids to be summarized quantitatively by a single number rather than resorting to qualitative decriptions of the degree of unsaturation or 'fitness' of the membrane phospholipids.

Cell Division↗
PubMed2006

Effect of temperature on the fatty acid composition and temporal trajectories of fatty acids in fasting Daphnia pulex (Crustacea, Cladocera).

Poikilothermic organisms accumulate highly unsaturated FA (HUFA) in their lipids at reduced temperatures to maintain cell membrane fluidity. In this study we investigated the effect of temperature on temporal trajectories of FA of fasting Daphnia pulex cultured on a HUFA-free diet. Daphnia pulex populations were maintained for 1 mon at 22 and 11 degrees C and were fed the chlorophyte Ankistrodesmus falcatus. We observed conversion of C18 FA precursors to EPA (20:5n3) and arachidonic acid (ARA; 20:4n6) in D. pulex. We showed that long-term exposure to cold temperature causes a significant increase in EPA. HUFA such as ARA and EPA are highly conserved during starvation. Therefore, D. pulex has the biosynthetic capacity to adjust and to maintain the content of HUFA required to survive at low temperatures.

Animals↗
PubMed1998

Effects of buffers on milk fatty acids and mammary arteriovenous differences in dairy cows fed Ca salts of fatty acids.

Ten Holstein cows in early lactation were used in a replicated 5 x 5 Latin square design to study the effects of MgO and three buffers added to diets containing Ca salts of canola oil fatty acids. Treatments were 1) control (basal diet; no buffer). 2) 1.1% NaHCO3 plus 1.1% KHCO3, 3) 1.9% NaHCO3, 4) 0.5% MgO, and 5) 2.0% Na sesquicarbonate (percentage of dry matter). The control diet contained 53% grass silage, 43% concentrate, and 4% Ca salts. Body weight, intake, milk yield, and percentages of milk fat, protein, and lactose were unaffected by treatments. Buffers and MgO tended to increase triacylglycerol extraction by the mammary gland and changed the proportions of some fatty acids in milk. Arterial concentrations of acetate and triacylglycerol were correlated with their respective arteriovenous differences. Extraction by the mammary gland was high for acetate (approximately equal to 58.2%), triacylglycerol (approximately equal to 47.3%) propionate (approximately equal to 34.6%), and glucose (approximately equal to 24.3%). Extraction of free fatty acids, phospholipids, or cholesterol was negligible. Mammary triacylglycerol arteriovenous difference tended to be higher than when MgO was fed than when NaHCO3 was fed. Sodium sesquicarbonate, NaHCO3, and the blend of bicarbonate buffers increased C18:2 in milk fat when compared with the control treatment. The concentration of C18:2 in milk fat decreased when MgO was fed, but the ratio of cis-C18:1 to trans-C18:1 increased compared with effects of dietary NaHCO3. Medium-chain fatty acids in milk fat tended to be higher than Na sesquicarbonate than with NaHCO3. Buffers and MgO modified the profiles of fatty acids in milk.

Acetates↗
PubMed2000

Variation among strains of Xanthomonas campestris pv. vasculorum from Mauritius and other countries based on fatty acid analysis.

Fatty acid profiling was used to study variation amongst strains of Xanthomonas campestris pv. vasculorum (Xcv). They could be divided into five groups using cellular fatty acid profiles. Group A strains represent a new and little known taxon and all came from plants of broom bamboo (Thysanolaena maxima) from Mauritius. Group B strains included the Xcv pathotype reference strain and were from palms, broom bamboo and sugarcane from Mauritius, Reunion and Australia. Group C contained southern African and Malagasy strains from sugarcane and maize, together with X. campestris pv. holcicola strain. No Mascarene strains fell into this group. Group D strains isolated from sugarcane, maize and royal palm (Roystonea regia) were from Mauritius and Reunion, the earliest known strains coming from Réunion. These groups represented in the Mascarene Islands possibly belong to three different Xanthomonas species. A further Group E comprised one Xcv strain (NCPPB 182) from Puerto Rico, one X. vasicola pv. holcicola strain plus 6 other unclassified Xanthomonas strains causing red stripe disease symptoms in sugarcane. Three of these groups occur on Mauritius and two occur on Réunion. Group B strains originally caused serious problems in noble canes. As resistant interspecific hybrids were introduced, group D strains appeared in Mauritius possibly being introduced from Reunion but having similar host ranges within the Gramineae and Palmae. The findings that 3 of these groups (A, B, D) can cause gumming disease in a grass species (T. maxima) and that 2 of them (B, D) also cause gumming disease in sugar cane (Gramineae) and palms (Palmae) is unusual.

Fatty Acids↗
PubMed1993

Effects of maternal dietary n-3 and n-6 fatty acids (pre- and post-delta 6 desaturation) on tissue glycerophospholipid fatty acid compositions in dams and suckling mice.

The present study examined the effects of supplementation of either 18:3n-3 or a mixture of its post-delta 6-desaturation metabolites, 20:5n-3/22:6n-3, in combination with either 18:2n-6 or its immediate delta 6-desaturation product, 18:3n-6, in the maternal diet (n-3 to n-6 ratio at 0.25) on brain, liver, heart, and kidney glycerophospholipid fatty acid composition in dams (B6D2F1 mice) and their 12-day-old suckling pups. As expected, n-3 and n-6 fatty acids competed for incorporation into tissue glycerophospholipids in both dams and their suckling pups. Feeding a 20:5n-3/22:6n-3 as compared with an 18:3n-3 rich diet increased the tissue levels of 20:5n-3 and 22:5n-3, whereas it decreased those of 20:3n-6 and 20:4n-6. Replacing 18:2n-6 with 18:3n-6 in the maternal diet increased significantly the levels of 18:3n-6, 20:3n-6, and 20:4n-6, whereas it reduced those of 20:5n-3. However, the effects of maternal dietary fats on tissue fatty acid compositions in pups were qualitatively similar to but quantitatively smaller than those in dams. The discrepancy might be due to differences in the composition of fatty acids taken up and synthesized by the dams and that transferred to the pups.

Animals↗
PubMed1998

Expression and regulation of mRNA for putative fatty acid transport related proteins and fatty acyl CoA synthase in murine epidermis and cultured human keratinocytes.

The epidermis has a requirement for fatty acids in order to synthesize cellular membranes and the extracellular lipid lamellar membranes in the stratum corneum. Despite high endogenous production of fatty acids the transport of exogenous essential fatty acids into the epidermis is an absolute requirement. Fatty acid uptake by keratinocytes has been shown to be mediated by a transport system. In this study we determined in murine epidermis and human cultured keratinocytes the expression of three putative fatty acid transport related proteins and fatty acyl CoA synthase, an enzyme that facilitates the uptake of fatty acids by promoting their metabolism. In cultured human keratinocytes, mRNA for fatty acid transport protein (FATP), plasma membrane fatty acid binding protein (FABP-pm), and fatty acyl CoA synthase (FACS) were detectable. Differentiation, induced by high calcium, did not affect FATP mRNA levels, but resulted in an approximately 50% increase in FACS mRNA, while decreasing FABP-pm mRNA by 50%. Fatty acid translocase (FAT) mRNA was not detected in cultured human keratinocytes. In murine epidermis, FATP, FABP-pm, FACS, and FAT mRNA were all present. Barrier disruption by either tape stripping or acetone treatment increased FAT mRNA levels by approximately 2-fold without affecting FATP, FABP-pm, or FACS. Occlusion with an impermeable membrane immediately after barrier disruption completely blocked the increase in FAT mRNA levels, indicating that this increase is related to barrier disruption rather than a nonspecific injury effect. In summary, this study demonstrates that several putative fatty acid transport related proteins as well as fatty acyl CoA synthase are expressed in keratinocytes and epidermis, and that the expression of these proteins may be regulated by differentiation and/ or barrier disruption.

Animals↗
PubMed1997

Fatty acid composition, eicosanoid production and permeability in skin tissues of rainbow trout (Oncorhynchus mykiss) fed a control or an essential fatty acid deficient diet.

Rainbow trout (Oncorhynchus mykiss) were fed either a control diet containing fish oil or an essential fatty acid (EFA) deficient diet containing only hydrogenated coconut oil and palmitic acid as lipid source (93.4% saturated fatty acids) for 14 weeks and the fatty acid compositions of individual phospholipid classes from skin and opercular membrane (OM) determined. The permeability of skin and OM to water and the production of eicosanoids in skin and gills challenged with the Ca2+ ionophore A23187 were also measured. Phospholipid (PL) fatty acid compositions were substantially modified in EFA-deficient fish, with increased saturated fatty acids and decreased polyunsaturated fatty acids (PUFA), especially arachidonic acid (AA) and eicosapentaenoic acid (EPA), while docosahexaenoic acid (DHA) was largely retained. The onset of EFA deficiency was shown by the appearance of n-9 PUFA, particularly 20:3n-9. The main effects of EFA deficiency on phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were to increase saturated fatty acids and monoenes, especially 16:1 and 18:1, and to decrease EPA and DHA. The content of DHA in phosphatidylserine (PS) was high in control animals (40% in skin and 35% in opercular membrane) and was mostly retained in EFA deficient animals. Arachidonic acid (AA) was the most abundant PUFA esterified to phosphatidylinositol (PI) and was significantly reduced in EFA deficient animals (from 31% to 13% in skin), where a large amount of 20:3n-9 (9% in skin) was also present. Influxes and effluxes of water through skin and opercular membrane were measured in vitro. No differences were detected between rainbow trout fed the control or the EFA deficient diet. 12-Hydroxyeicosatetraenoic acid (12-HETE), 12-hydroxyeicosapentaenoic acid (12-HEPE) and 14-hydroxydocosahexaenoic acid (14-HDHE) could not be detected in skin from control or EFA deficient fish. There was no difference between control and EFA deficient trout in the levels of leukotriene C4 (LTC4) and leukotriene C5 (LTC5) in skin cells challenged with the calcium ionophore A23187, and of prostaglandin F2alpha (PGF2alpha), 12-HETE and 12-HEPE in gill cells challenged similarly. Prostaglandin F3alpha (PGF3alpha) production by ionophore stimulated gill cells was significantly reduced in fish fed the EFA-deficient diet. 14-HDHE produced by gill cells was 3.3 fold higher in EFA deficient fish compared to controls.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed2004

Enzymes for transgenic biosynthesis of long-chain polyunsaturated fatty acids.

Polyunsaturated fatty acids (PUFAs) are important for the normal development and function of all organisms, and are essential in maintaining human health. Impaired PUFA metabolism is thought to be associated with pathogenesis of many chronic diseases. Dietary supplementation of PUFAs, such as gamma-linolenic acid, arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid, which bypass the defective or dysfunctional steps of the biosynthetic pathway has been found to significantly alleviate the symptoms of the disease. These findings have drawn a great deal of interest from general public and food manufacturers. As the demand of these beneficial PUFAs has drastically increased in recent years, there are also increasing efforts in finding the alternate sources of PUFAs that are more economical and sustainable. One option is to modify the oil-seed crops to produce PUFAs through genetic engineering technique. This review examines the isolation, identification and expression of genes encoding the enzymes required for the biosynthesis of the above mentioned PUFAs in plants.

Acetyltransferases↗
PubMed1998

Multiplication and death-type of leukemia cell lines exposed to very long-chain polyunsaturated fatty acids.

Polyunsaturated fatty acids (PUFA) may reduce cell multiplication in cultures of normal, as well as transformed, white blood cells. We assessed the sensitivity of 14 different leukemia cell lines to PUFA by measuring cell number after 3 days of incubation. Ten of the examined cell lines were sensitive to 30, 60 and/or 120 microM of arachidonic, eicosapentaenoic and docosahexaenoic acid, whereas four cell lines were resistant. The sensitivity to PUFA was not associated with any particular cell lineage, clinical origin or specific mRNA pattern of bcl-2 and c-myc. Effects on cell viability were assessed by studying cell membrane integrity, DNA fragmentation and cell morphology. The sensitive cell lines Raji and Ramos died by necrosis and apoptosis, respectively, during incubation with eicosapentaenoic acid, whereas the viability of the resistant U-698 cell line was unaffected. The effects of EPA on Raji cells, was counteracted by vitamin E, indicating that lipid peroxidation was involved. However, apoptosis induced by eicosapentaenoic acid in Ramos cells, was unaffected by vitamin E, as well as eicosanoid synthesis inhibitors. In conclusion, our results indicate that a majority of leukemia cell lines are sensitive to PUFA. This sensitivity may be caused by induction of apoptosis or necrosis by very long-chain polyunsaturated fatty acids.

Apoptosis↗
PubMed1997

Human kidney free fatty acid and glucose uptake: evidence for a renal glucose-fatty acid cycle.

To determine the relationship between free fatty acids (FFA) and glucose uptake by the human kidney, 12 postabsorptive normal volunteers underwent renal vein catheterization and were infused to isotopic steady state with [6-3H]glucose and [9,10-3H]palmitate. Arterial and renal vein palmitate specific activities were not significantly different (3,533 +/- 219 vs. 3,549 +/- 220 dpm/mumol, P = 0.64). Palmitate renal fractional extraction and uptake determined isotopically (7.2 +/- 1.1% and 9.1 +/- 1.4 mumol/min) were not significantly different from those calculated by net balance measurements (8.3 +/- 1.2% and 9.7 +/- 1.2 mumol/min, P > 0.07 and P > 0.7, respectively). Renal palmitate uptake accounted for 8.7 +/- 1.3% of its systemic turnover. Renal linoleate and oleate fractional extraction calculated by net balance measurements (8.0 +/- 0.9 and 7.7 +/- 1.2%, respectively) were not significantly different from each other and that of palmitate (all P > 0.7). Renal uptake of palmitate, linoleate (7.9 +/- 1.0 mumol/min), and oleate (10.9 +/- 2.0 mumol/min) were all directly proportional to their arterial concentrations (r = 0.70, 0.68, and 0.63, respectively, all P < 0.025). Renal glucose uptake (93 +/- 10 mumol/min) accounted for 12.6 +/- 1.5% of its systemic turnover and was inversely related to the sum of palmitate, linoleate, and oleate uptake (r = -0.74, P < 0.01). These data indicate that in postabsorptive humans: 1) the kidney is an important site of FFA and glucose disposal, 2) a renal glucose-fatty acid cycle may exist, and 3) there appears to be little or no release into the circulation of stored renal FFA.

Adult↗