scholarly journals Vitamin E and stress

1967 ◽  
Vol 21 (1) ◽  
pp. 69-101 ◽  
Author(s):  
J. Green ◽  
A. T. Diplock ◽  
J. Bunyan ◽  
D. Mchale ◽  
I. R. Muthy
Keyword(s):  
Fatty Acids ◽  
Ascorbic Acid ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Vitamin E ◽  
Dietary Fat ◽  
Methyl Esters ◽  
Cod Liver Oil ◽  
Deficient Diet

1. A critical analysis of the biological antioxidant theory of vitamin E function has been made and the implications of the theory have been tested.2. When small amounts of [5-Me-14C]α-tocopherol were present in lipid systems subject to autoxidation in vitro, it was found that, whether the tocopherol was the sole antioxidant or was in synergistic combination with a secondary antioxidant (ascorbic acid), peroxidation did not occur without concomitant destruction of the tocopherol. This was so, whether a simple fat substrate or a liver homogenate (subject to catalysis) was used. The decomposition of tocopherol took place even when the secondary antioxidant was in large excess, as would occur under physiological conditions in the vitamin E-deficient animal, and accelerated as the induction period neared its end.3. When [5-Me-14C,3H]α-tocopherol and ascorbic acid were used as a synergistic antioxidant couple in vitro, tocopherol recovered from the peroxidizing system always had the same isotopic ratio as the starting material. This means that regeneration of tocopherol by the secondary antioxidant cannot involve, as an intermediate, a tocopherol carbon radical formed by loss of hydrogen from the 5-methyl group. Such radicals probably dimerize before they can be regenerated. The same result was found when doubly labelled α-tocopherol was given to the rat and recovered later from its tissues.4. In a series of experiments, rats were rigorously depleted of vitamin E for periods up to 7 months and then given as little as 50 μg [14C]D-α-tocopherol. They were then given, either by stomach tube daily or by dietary addition, large amounts of methyl linoleate or vitamin E-free polyunsaturated fatty acid methyl esters prepared from cod-liver oil and compared with controls given methyl oleate for up to 31 days. When the possibility of interaction between the lipid and tocopherol in the gut was eliminated, analyses of liver, kidney, testis, adrenal, adipose tissue, whole carcass and faeces showed that there was no effect of the polyunsaturated fatty acids on either the metabolism or recovery of [14C]α-tocopherol in any of the animals.5. When interaction between the administered fatty acid esters and tocopherol in the gut was allowed to take place, a marked destruction of [14C]α-tocopherol in the tissues was observed in animals given the polyunsaturated esters. The importance of oxidative destruction of tocopherol in the gut before absorption was demonstrated in a nutritional trial, in which cod-liver oil and lard were compared and the degrees of resistance of rats' erythrocytes to dialuric acid-induced haemolysis was used as an index of vitamin E depletion.6. Similar experiments with [14Cα-tocopherol in weanling rats given large amounts of cod-liver oil methyl esters also showed little effect. Although there was a suggestion that prolonged feeding of partly peroxidized polyunsaturated esters could lead to a slight depression of tissue tocopherol concentrations, no significant differences were usually obtained.7. Fourteen-day-old rats were given a vitamin E-deficient diet and received three weekly doses of 0.5 mg α-tocophcryl acetate. The dosage was stopped, the rats were then given a deficient diet containing 4% of either vitamin E-free linseed oil fatty acids or oleic acid, and the rate of their tocopherol depletion was measured by the erythrocyte haemolysis test. No effect of the polyunsaturated fatty acids was found. Nor was there any effect on the concentrations of ‘secondary antioxidants’ (glutathione and ascorbic acid) in liver, kidney, testis, muscle or adipose tissue.8. The results of the experiments in vivo contrast strongly with those in vitro. They lead to the conclusion that lipid peroxidation, if it occurs in the living animal, is irrelevant to the problem of vitamin E function. This conclusion has been substantiated by a critical review of the literature on the quantitative aspects of the vitamin E-dietary fat relationship.9. The effects of dietary fat stress in vitamin E-deficient animals are, we believe, due to two causes: (1) destruction of tocopherol in the diet or in the gastro-intestinal tract of the animal, and (2) the existence of an increased requirement for vitamin E for the metabolism of certain long-chain fatty acids. The specific effects of certain of these substances in producing or accelerating some vitamin E deficiency diseases may be related to the toxic states known to be induced in vitamin E-deficient animals by other stress factors.

scholarly journals Effects of vitamin E deficiency on total polyunsaturated fatty acids in rats and chicks

1967 ◽  
Vol 21 (1) ◽  
pp. 217-224 ◽  
Author(s):  
J. Bunyan ◽  
A. T. Diplock ◽  
J. Green
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Vitamin E ◽  
Cod Liver Oil ◽  
Pufa Content ◽  
Specific Nature ◽  
Vitamin E Deficiency ◽  
Exudative Diathesis ◽  
Total Pufa

1. The total polyunsaturated fatty acid (PUFA) content of tissues of vitamin E-deficient rats and chicks has been measured by the lipoxidase method.2. Vitamin E deficiency did not depress total PUFA in rat liver, kidney, heart, spleen, brain, adrenal and adipose tissue during experimental periods up to 13 months.3. Liver PUFA was not depressed by deficiency of vitamin E and selenium in rats at 9 weeks or 8 months of age.4. Rats given a muscular dystrophy-producing diet (containing oxidized cod-liver oil) showed a severe depletion of PUFA in muscle, but not in kidney or adipose tissue.5. Exudative diathesis induced in chicks by a deficiency of vitamin E and Se did not depress liver PUFA.6. It is considered that in vitamin E deficiency there is no general decrease in PUFA due to peroxidative loss. Changes of a more specific nature occur, as found by other workers.

Isotope tracer measures of meal fatty acid metabolism: reproducibility and effects of the menstrual cycle

2005 ◽  
Vol 288 (3) ◽  
pp. E547-E555 ◽  
Author(s):  
Ana Paola Uranga ◽  
James Levine ◽  
Michael Jensen
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Menstrual Cycle ◽  
Dietary Fat ◽  
Fatty Acid Uptake ◽  
Upper Body ◽  
Acid Oxidation ◽  
Acid Uptake ◽  
Lower Body

Oxidation and adipose tissue uptake of dietary fat can be measured by adding fatty acid tracers to meals. These studies were conducted to measure between-study variability of these types of experiments and assess whether dietary fatty acids are handled differently in the follicular vs. luteal phase of the menstrual cycle. Healthy normal-weight men ( n = 12) and women ( n = 12) participated in these studies, which were block randomized to control for study order, isotope ([3H]triolein vs. [14C]triolein), and menstrual cycle. Energy expenditure (indirect calorimetry), meal fatty acid oxidation, and meal fatty acid uptake into upper body and lower body subcutaneous fat (biopsies) 24 h after the experimental meal were measured. A greater portion of meal fatty acids was stored in upper body subcutaneous adipose tissue (24 ± 2 vs. 16 ± 2%, P < 0.005) and lower body fat (12 ± 1 vs. 7 ± 1%, P < 0.005) in women than in men. Meal fatty acid oxidation (3H2O generation) was greater in men than in women (52 ± 3 vs. 45 ± 2%, P = 0.04). Leg adipose tissue uptake of meal fatty acids was 15 ± 2% in the follicular phase of the menstrual cycle and 10 ± 1% in the luteal phase ( P = NS). Variance in meal fatty acid uptake was somewhat ( P = NS) greater in women than in men, although menstrual cycle factors did not contribute significantly. We conclude that leg uptake of dietary fat is slightly more variable in women than in men, but that there are no major effects of menstrual cycle on meal fatty acid disposal.

scholarly journals Metabolism and secretory function of white adipose tissue: effect of dietary fat

2009 ◽  
Vol 81 (3) ◽  
pp. 453-466 ◽  
Author(s):  
Cláudia M. Oller do Nascimento ◽  
Eliane B. Ribeiro ◽  
Lila M. Oyama
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
White Adipose Tissue ◽  
Dietary Fat ◽  
Dietary Fatty Acids ◽  
Secretory Function ◽  
High Fat ◽  
Adipose Tissue Metabolism ◽  
Tissue Metabolism

Approximately 40% of the total energy consumed by western populations is represented by lipids, most of them being ingested as triacylglycerols and phospholipids. The focus of this review is to analyze the effect of the type of dietary fat on white adipose tissue metabolism and secretory function, particularly on haptoglobin, TNF-α, plasminogen activator inhibitor-1 and adiponectin secretion. Previous studies have demonstrated that the duration of the exposure to the high-fat feeding, amount of fatty acid present in the diet and the type of fatty acid may or may not have a significant effect on adipose tissue metabolism. However, the long-term or short-term high fat diets, especially rich in saturated fatty acids, probably by activation of toll-like receptors, stimulated the expression of proinflammatory adipokines and inhibited adiponectin expression. Further studies are needed to investigate the cellular mechanisms by which dietary fatty acids affect white adipose tissue metabolism and secretory functions.

The effects of fat source and breed on the fatty acid composition of lamb muscle and adipose tissue

1999 ◽  
Vol 1999 ◽  
pp. 115-115 ◽  
Author(s):  
A.M. Wachira ◽  
L.A. Sinclair ◽  
R.G. Wilkinson ◽  
G. Demirel ◽  
M. Enser ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Vitamin E ◽  
Fish Oil ◽  
Acid Composition ◽  
Previous Experiment ◽  
Dietary Pufa ◽  
Long Chain

The benefits of long chain polyunsaturated fatty acids (PUFA) to human health, especially those of the n-3 series are now widely recognised. In a previous experiment (Wachira et al. 1998) supplementing diets with whole linseed or fish oil increased n-3 fatty acid levels in lamb muscle. To raise these further the whole linseed can be treated with formaldehyde to increase protection in the rumen. Dietary antioxidants such as vitamin E can control lipid oxidation but information on their effects on lamb performance and fatty acid composition is limited. The current experiments investigated the effects of different dietary PUFA sources and vitamin E levels on growth and fatty acid composition in two sheep breeds. Detailed results of the effects of vitamin E are presented in the accompanying abstract by Enser et al.

The 1990 Borden Award Lecture Dietary regulation of fatty acid and triglyceride metabolism

1991 ◽  
Vol 69 (11) ◽  
pp. 1637-1647 ◽  
Author(s):  
Gene R. Herzberg
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Lipoprotein Lipase ◽  
Fatty Acid Synthesis ◽  
Dietary Fat ◽  
Acid Synthesis ◽  
Fish Oils ◽  
Dietary Fish

The level of circulating triacylglycerols is determined by the balance between their delivery into the plasma and their removal from it. Plasma triacylglycerols are derived either from dietary fat as chylomicrons or from endogenous hepatic synthesis as very low density lipoproteins. Their removal occurs through the action of lipoprotein lipase after which the fatty acids are either stored in adipose tissue or oxidized, primarily in skeletal muscle and heart. The composition of the diet has been shown to influence many of these processes. Hepatic fatty acid synthesis and triacylglycerol secretion are affected by the quantity and composition of dietary fat, carbohydrate, and protein. Polyunsaturated but not saturated fats reduce hepatic fatty acid synthesis by decreasing the amount of the lipogenic enzymes needed for de novo fatty acid synthesis. Dietary fish oils are particularly effective at reducing both fatty acid synthesis and triacylglycerol secretion and as a result are hypotriacylglycerolemic, particularly in hypertriacylglycerolemic individuals. In addition, dietary fish oils can increase the oxidation of fatty acids and lead to increased activity of lipoprotein lipase in skeletal muscle and heart. It appears that the hypotriacylglycerolemic effect of dietary fish oils is mediated by effects on both synthesis and removal of circulating triacylglycerols.Key words: lipid, fish oil, fructose, liver, adipose tissue, oxidation.

scholarly journals Effects of dietary n-3 polyunsaturated fatty acids, breed and dietary vitamin E on the fatty acids of lamb muscle, liver and adipose tissue

2004 ◽  
Vol 91 (4) ◽  
pp. 551-565 ◽  
Author(s):  
G. Demirel ◽  
A. M. Wachira ◽  
L. A. Sinclair ◽  
R. G. Wilkinson ◽  
J. D. Wood ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Vitamin E ◽  
Fish Oil ◽  
Live Weight ◽  
Dietary Fatty Acids ◽  
Polar Lipids ◽  
Dietary Vitamin ◽  
Lipid Fractions

The effect of feeding n-3 PUFA on the fatty acid composition of muscle, adipose tissue and liver of lambs was investigated. Groups of eight ram lambs per breed, Suffolk×Lleyn (24kg live weight) and Scottish Blackface (18kg live weight), were each fed one of six diets containing one of three fat sources (50g fatty acids/kg DM; Megalac® (calcium soap of palm fatty acid distillate; Volac Ltd, Royston, Herts., UK) and formaldehyde-treated whole linseed (Trouw Nutrition UK, Northwich, Ches., UK) either alone or with fish oil (1:1, w/w) and either 100 or 500mg α-tocopheryl acetate/kg DM. Feed was offered ad libitum until slaughter at approximately half breed mature live weight. The type of dietary fat had no effect on intake, growth rate or feed conversion ratio. The 3·0-fold higher concentration of 18:3n-3 in the linseed compared with the Megalac® diet approximately doubled (P<0·001) the concentration in the neutral and polar lipid fractions of musculus semimembranosus and liver, and in adipose tissue it increased 2·5-fold. Feeding protected linseed also increased (P<0·001) concentrations of 20:5n-3 and 22:5n-3 in muscle polar lipids and both lipid fractions of liver. The linseed–fish oil raised the 20:5n-3 concentrations above those for the linseed diet and also increased 22:6n-3. Scottish Blackface lambs had lower concentrations of 18:3n-3 in all lipids compared with Suffolk x Lleyn lambs, but more 20:5n-3 in the polar lipids of muscle and liver. High levels of dietary vitamin E were associated with small decreases in the concentration of monounsaturated fatty acids and increases in PUFA. Linseed raised the PUFA:saturated fatty acid ratios in liver and adipose tissue but not in muscle, and improved the n-6:n-3 fatty acid ratio, as did the linseed–fish oil. Different combinations of dietary fatty acids and better protection against rumen biohydrogenation are required to improve muscle PUFA:saturated fatty acids ratios.

scholarly journals On the relationship between vitamin A and vitamin E in the rat

1968 ◽  
Vol 22 (1) ◽  
pp. 133-143 ◽  
Author(s):  
M. A. Cawthorne ◽  
J. Bunyan ◽  
A. T. Diplock ◽  
Elspeth A. Murrell ◽  
J. Green
Keyword(s):  
Weight Gain ◽  
Vitamin E ◽  
Vitamin A ◽  
Methyl Esters ◽  
Tocopheryl Acetate ◽  
Cod Liver Oil ◽  
Deficient Diet ◽  
Weanling Rats ◽  
The Relationship

1. The effect of vitamin E on the metabolism, utilization and storage of vitamin A has been studied in the rat.2. Male weanling rats were given a vitamin A-deficient, vitamin E-deficient diet until growth had ceased for 3 days, and each rat was then given 50 i.u. vitamin A palmitate. The rats were divided into four groups and given the diet with the addition of 10% methyl oleate or 10% cod-liver oil methyl esters, or either of these diets supplemented with 100 ppm D-α-tocopheryl acetate. There was no increase in maximum weight-gain response in the two groups given vitamin E. There was a significantly lower weight-gain response in the groups given cod-liver oil methyl esters. This effect was not influenced by the presence of vitamin E in the diet.3. Weanling rats of both sexes were made deficient in vitamins A and E and then divided into two groups. One group received, every other day, 1·75 i.u. vitamin A palmitate and 0·6 mg D-α-tocopherol given together; the second group received the two vitamins, in the same amounts, on alternate days. After 28 days there was no difference in the growth of the two groups of rats, irrespective of sex.4. Vitamin A-depleted, vitamin E-deficient rats were given 17·51 μg ‘14C-carbinol’retinyl acetate and then a vitamin A-deficient, vitamin E-deficient diet or that diet supplemented with 100 ppm D-α-tocopheryl acetate. After 6 days, the total remaining ‘14C’retinol and its lipidsoluble metabolites were measured in the carcasses of the rats. Vitamin E administration did not affect the metabolism of the vitamin A dose or its effect on growth.5. Vitamin E-deficient rats were given vitamin A until their liver reserves exceeded 30000 i.u. and were then divided into two groups. One group received a diet deficient in vitamins A and E and the other received, in addition to this diet, a weekly oral supplement of 1 mg D-α-tocopheryl acetate. The vitamin E supplement significantly decreased the rate of vitamin A depletion from the liver during the next 6 weeks. This effect, which was not found to occur when the initial liver reserves were only 3000 i.u., suggests a role for vitamin E in connexion with the capacity of the liver to bind vitamin A.6. The relationship between vitamin A and vitamin E in vivo cannot, in the light of these results, be regarded as that between an antioxidant and a peroxidizable substrate.

Functional expression of Brassica juncea oleate desaturase gene (Bjfad2) in Escherichia coli

Biologia ◽  
2013 ◽  
Vol 68 (4) ◽  
Author(s):  
Giriyapura Suresha ◽  
Sanjeev Kumar ◽  
Ittiamparambath Santha
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Brassica Juncea ◽  
Methyl Esters ◽  
Reaction Products ◽  
Activity Assay ◽  
Control Activity ◽  
Oleate Desaturase

AbstractThe synthesis of polyunsaturated fatty acids, the most abundant fatty acids in plants, begins with a reaction catalyzed by fatty acid desaturase-2 (FAD2; EC 1.3.1.35), also called as microsomal Δ12 oleate desaturase. The gene (Bjfad2; GenBank accession No. EF639848) coding for this enzyme from Brassica juncea was previously isolated and characterized. However, functional identity of Bjfad2 was not established. Utilizing the known Bjfad2 cDNA sequence, the ORF of Bjfad2 gene was cloned into the pMAL C2X Escherichia coli expression vector and produced recombinant plasmid by insertion of isolated ORF downstream to the maltose-binding protein coding sequence. The pMALC2X-Bjfad2 vector was used to transform the TB1 strain of E. coli. Induced expression of pMAL-BJFAD2 fused product resulted in the synthesis of a polypeptide with an apparent molecular mass of 80 kDa, which was 8 kDa less than calculated mass as determined by SDS-PAGE, since the fused MalE-Bjfad2 gene contains eight additional codons located between the MalE and Bjfad2 gene. In vitro activity assay of oleate desaturase using the corresponding bacterial crude extracts confirmed that the polypeptide was the product of the Bjfad2 gene. The reaction products analysis of the fatty acid methyl esters by gas chromatography showed the presence of a new peak with a similar retention time to linoleic acid, which was absent in the control activity assay without electron donors. Thus, B. juncea gene has been functionally identified since it encodes the enzyme that catalyzed the desaturation of oleate to linoleate.

THE STIMULATING EFFECTS OF ADRENALINE AND ANTERIOR PITUITARY HORMONES ON THE RELEASE OF FREE FATTY ACIDS FROM ADIPOSE TISSUE

1962 ◽  
Vol 25 (2) ◽  
pp. 189-198 ◽  
Author(s):  
R. M. BUCKLE
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Pituitary Hormones ◽  
Thyroid Stimulating Hormone ◽  
Adrenocorticotrophic Hormone ◽  
Fat Pads

SUMMARY The quantity of free fatty acids (FFA) released from rat epididymal fat pads in vitro and their concentration within the tissue were determined. The addition of adrenaline, adrenocorticotrophic hormone (ACTH), thyroid stimulating hormone (TSH) and growth hormone (GH) each increased the release of FFA, and their respective minimum effective concentrations were 0·125, 0·004, 0·5 and 1·25 μg./ml. of medium. In every case, the increased release of FFA was associated with a rise in the quantity present within the pads, and the amount released closely paralleled their concentration within the tissue. It is suggested that the stimulatory effect of all four hormones on the release of FFA from adipose tissue is largely a manifestation of their activity of increasing the concentration of FFA within the cells, and this they do by facilitating the net conversion of storage triglyceride to fatty acid. The significance of the relative activities of the hormones in vitro is discussed and compared with their fatty acid mobilizing effects in vivo.

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