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1.
The effect oftrans fat on the activities of liver mitochondrial and peroxisomal fatty acid oxidation enzymes was examined in various strains
of rats. When Wistar and Sprague-Dawley rats were fed for 30 days diets containing either olive oil or partially hydrogenated
corn oil as a source ofcis-ortrans-octadecenoate, respectively, the activities of various enzymes of mitochondrial and peroxisomal β-oxidation measured withcis- andtrans-9-octadecenoic acid as substratese showed little dietary fatdependent change. In Fischer 344 rats, feedingtrans fat for 15 mo increased only moderately various enzymes of β-oxidation except for carnitine acyltransferase. The rate of
mitochondrial ketogenesis and the activity of carnitine acyltransferase measured withtrans-9-octadecenoic acid as a substrate were about half those with thecis-counterpart. Peroxisomes oxidizedtrans-9-octadecenoyl-CoA at a rate comparable to thecis-counterpart. It was concluded from this study and previous ones that the difference in the geometry of dietary fatty acid
had only a marginal effect in modulating the hepatic fatty acid oxidation system, in spite of marked differences in the metabolic
behavior ofcis-andtrans fatty acid in cell-free preparations and perfused liver. 相似文献
2.
The essential fatty acid requirement for the development of intestinal carcinogenesis was determined and compared to the overall
essential fatty acid status of the animals as measured by the triene/tetraene ratio in the plasma, liver and colon. To induce
tumors, male Sprague-Dawley rats were given two weekly injections (20 mg/kg body wt) of azoxymethane. Two weeks after the
last injection, the rats were divided into groups of 25 and given one of six diets containing various levels of essential
fatty acids (as linoleate). The diets contained 5% total fat and were prepared by mixing safflower oil (high essential fatty
acids, beef fat (low essential fatty acids), and medium chain triglyceride oil (no essential fatty acids). One group of rats
was fed a 20% beef fat diet. The range of essential fatty acids was from <0.03% to 1.28% (w/w). Twenty-six weeks after the
first azoxymethane injection, the animals were killed and intestinal tumor incidence and multiplicty were determined. Samples
of plasma, liver and colon were also taken for measurement of the triene/tetraene ratio by gas chromatography.
Large bowel tumor incidence showed a dependence on the essential fatty acid content of the diet. The results were as follows:
(percent essential fatty acids: percent tumor incidence) Group A (1.28∶ 72.4), Group B (0.60∶ 73.3), Group C (0.11∶ 55.2),
Group D (0.08∶ 39.3), Group E (<0.03∶ 37.9) and Group F, which was fed 20% beef fat, (0.34∶ 88.5). These data suggest the
essential fatty acid requirement for colon tumorigenesis is much lower than values previously reported for tumorigenesis in
the breast and pancreas. The plasma and liver triene/tetraene ratios showed clear-cut essential fatty acid deficiency (ratio
>0.4) in Groups D and E, although no clinical symptoms were evident. In all dietary groups, the triene/tetraene ratio in the
colon was lower than 0.3. In addition in the colon, the percentage of fatty acids present as 20 carbon polyunsaturated fatty
acids was lower than in the plasma and liver. These data suggest the colon possesses low levels of the fatty acid desaturase
and elongase needed for conversion of linoleate to 20 carbon fatty acids, and therefore, that the colonic requirement for
essential fatty acids may be low. Furthermore, in the absence of other clinical symptoms, the reduced tumorigenesis observed
in the groups fed low essential fatty acids suggests the essential fatty acid requirement of tumor tissue may be higher than
that of normal colon mucosa. 相似文献
3.
Cardiolipins (CL) have unique fatty acid profiles with generally high levels of polyunsaturated fatty acids, primarily 18∶2n−6,
and low levels of saturated fatty acids. In order to study the effect of dietary fatty acid isomers on the fatty acid composition
of cardiolipins, rats were fed partially hydrogenated marine oils (HMO), rich in 16∶1, 18∶1, 20∶1, and 22∶1 isomeric fatty
acids, supplemented with linoleic acid at levels ranging from 1.9% to 14.5% of total fat. Although the dietary fats contained
33%trans fatty acids, the levels oftrans fatty acids in CL were below 2.5% in all organs. The fatty acid profiles of cardiolipins of liver, heart, kidney and testes
showed different responses to dietary linoleic acid level. In liver, the contents of 18∶2 reflected the dietary levels. In
heart and kidney, the levels of 18∶2 also parallelled increasing dietary levels, but in all groups fed HMO, levels of 18∶2
were considerably higher than in the reference group fed palm oil. In testes, the 18∶2 levels were unaffected by the dietary
level of 18∶2 and HMO. 相似文献
4.
Feeding rats diets containing brominated corn oil or di- or tetrabromostearate as the monoglyceride produced changes in fatty
acid composition of liver lipids. Those changes associated with the feeding of brominated corn oil or tetrabromosterates could
be explained by the accumulation of triglyceride, and the changes associated with the feeding of dibromostearate could result
from the proliferation of a membrane system. A unique response to the feeding of diets containing brominated corn oil is an
increase in the level of γ-linolenic acid. 相似文献
5.
Jean Paul Blond Georges Durand Jean Bézard 《Journal of the American Oil Chemists' Society》1998,75(2):269-274
The effect of low levels of dietary arachidonic acid (20:4n-6) on Δ6 desaturation of linoleic acid (18:2n-6) and α-linolenic acid (18:3n-3), and on Δ5 desaturation of dihomo-γ-linolenic acid (20:3n-6) were studied in liver microsomes of obese Zucker rats, in comparison with their lean littermates. Fatty acid composition of serum total lipids and of phospholipids from liver microsomes and from total heart and kidney was determined to see whether modifications of desaturation rate, if any, were reflected in the tissue fatty acid profiles. Animals fed for 12 wk on a balanced diet, containing 20:4n-6 and 18:2n-6, were compared to those fed 18:2n-6 only. The low amount of dietary 20:4n-6 greatly inhibited Δ6 desaturation of 18:2n-6 and Δ5 desaturation of 20:3n-6, whereas Δ6 desaturation of 18:3n-3 was slightly increased in obese rats. Inhibition of the biosynthesis of long-chain n-6 fatty acids by dietary arachidonic acid was only slightly reflected in the 20:4n-6 content of liver microsome phospholipids. On the contrary, the enrichment of serum total lipids and heart and kidney phospholipids in this fatty acid was pronounced, more in obese than in lean animals. Our results show that, although the desaturation rate of the n-6 fatty acids in liver microsomes was greatly decreased by the presence of arachidonic acid in the diet, the tissue phospholipid content in arachidonic acid was not depressed. The potentiality of synthesis of eicosanoids of the 2 family from this fatty acid is consequently not lower, especially in obese rats, in which certain tissues are deficient in arachidonic acid, in comparison with their lean littermates. 相似文献
6.
Yung-Sheng Huang Dave E. Mills Ron P. Ward David F. Horrobin Valerie A. Simmons 《Lipids》1989,24(7):565-571
Weanling male spontaneously hypertensive (SHR) and normotensive (WKY) rats were maintained on a fat-free semisynthetic diet
and killed at various intervals. The effects of fat-depletion on the appearance of essential fatty acid (EFA) deficiency symptoms,
the progressive changes of major fatty acids in plasma, liver, heart, and kidney phospholipids (PL), and in skin total lipids
were compared between these two strains. After five weeks on the diet, the slower growth and the appearance of EFA deficiency
symptoms became evident in SHR. In general, fat-depletion reduced the levels of n−6 fatty acids, whereas it increased those
of 20∶3n−9. However, the fat-depletion induced reduction of 18∶2n−6 in heart PL and 20∶4n−6 in kidney, while the elevation
of 20∶3n−9 in plasma, heart, and kidney PL were greater in WKY than in SHR. As a result, the elevation of biochemical EFA
deficiency index—20∶3n−9/20∶4n−6 ratio—was greater in WKY than in SHR. In comparison with WKY, the concentrations of liver
triacylglycerols and the weights of adipose tissues in SHR were reduced to a greater extent, indicating an active catabolism
of triacylglycerols in SHR. This study suggests that the earlier appearance of morphological symptoms of EFA deficiency in
SHR was not associated with the reducing n−6 EFA levels or with an elevation of triene/tetraene ratio, but possibly to a reduced
supply of n−6 EFA for skin prostaglandin synthesis. 相似文献
7.
R. A. Eisenhauer R. E. Beal E. L. Griffin 《Journal of the American Oil Chemists' Society》1964,41(1):60-63
Linolenic acid of 95% purity was heated with excess alkali in ethylene glycol to produce cyclic fatty acids. Reaction variables,
which are associated with the cyclization reaction and which were investigated, included solvent-to-fatty-acid ratio, catalyst
concentration, and reaction temperature, headspace gas (N2 or C2H4), and head-space gas pressure.
Yields of cyclic acids were improved by increasing solvent ratio (1.5–6 wt basis), reaction temperature (225–295C), and catalyst
concentration (10–100% excess). With nitrogen the optimum catalyst concentration was about 100% excess, but when ethylene
was used, no increase was obtained beyond 50% excess catalyst. Yields of polymeric acids produced in the reaction generally
decreased as cyclic acid yields increased, except in one instance.
Higher yields of cyclic fatty acids were obtained with ethylene than with nitrogen under all comparable conditions, and increasing
the ethylene pressure to as high as 500 psi improved the yield. Ethylene adds to the conjugated double bonds and is believed
to give C20 fatty acids having a 1,4-disubstituted monoene ring in the chain. The maximum yield of monomeric cyclic acids from 95% linolenic
acid was 84.6%, the balance being polymeric and unreacted monomeric acids. Monomeric acids from this test contained 95% cyclic
acids.
Presented at AOCS meeting, New Orleans, 1962.
No. Utiliz. Res. & Dev. Div., ARS, U.S.D.A. 相似文献
8.
The fatty acid composition of heart, kidney, and lung was studied in weanling rats fed three diets differing in their polyunsaturated
fatty acid content for 0, 2, and 4 wk. The first group had a 10% w/w fat semipurified diet which consisted of a mixture of
olive oil (62.5%), soybean oil (11.1%), and refined coconut oil (26.4%) and provided 18:1n-9, 18:2n-6, and 18:3n-3 in similar
amounts to a maternal human milk (diet HO). The second group received 7% of HO fat and 3% fish oil (0.4% 20:4n-6 and 5% 22:6n-3
of total fatty acids) (diet FO), and the third group was fed 7% HO fat, 1.5% of the same fish oil, and 1.5% of a purified
pig brain phospholipid concentrate (0.6% 20:4n-6 and 3.5% 22:6n-3 of total fatty acids) (diet FO+BPL). The experimental diets
increased tissue monounsaturated fatty acids in comparison with rats at weaning. Tissue lipid content of 20:4n-6 was increased
and 22:6n-3 decreased in Group HO compared with weanling rats, whereas opposite changes were observed in Group FO. Feeding
diet FO+BPL increased 22:6n:3 in tissue lipids compared with diet HO, and increased 20:4n-6 content in relation to diet FO.
Our results indicate that rat heart, kidney, and lung are highly responsive to dietary n-3 and n-6 long-chain polyunsaturated
fatty acids during postnatal life. 相似文献
9.
Synthesized oils containing a high proportion of oleic, eicosenoic or docosenoic acid were fed to weanling rats as 20% w/w
of the diet. After 1 week, a high intake of eicosenoate produced cardiac fat droplets detected histologically, whereas erucate
(22∶1 Δ 13) or cetoleate (22∶1 Δ 11) caused an appreciably greater accumulation of cardiac lipid characterized by the dietary
fatty acids. 相似文献
10.
Rats were fed diets containing either camellia oil or partially hydrogenated corn oil, as a source ofcis ortrans octadecenoate, respectively, in the presence of adequate linoleic acid. After 35 days of feeding the diets, activities of
several hepatic drug metabolizing enzymes as well as the content of hepatic microsomal cytochrome P-450 were determined. Geometrical
difference in the dietary fat did not affect the amount of microsomal protein nor the content of cytochrome P-450. Also, activities
of NADPH cytochrome C reductase, aminopyrine N-demethylase and biphenyl hydroxylase were approximately the same between two
groups of rats. Aniline hydroxylase was slightly elevated in the rats fedtrans fat. It was concluded that the difference in the geometry of dietary fatty acids had little effect in modulating the hepatic
mixed function oxidase system. 相似文献
11.
Elaidination of unsaturated fatty acids usingp-toluenesulfinic acid yielded 77–80% totaltrans unsaturation in the products. Results from reactions with monoene, diene, and triene isomers indicated that only geometric
isomerization takes place. Each double bond isomerized randomly and independently in the polyunsaturated fatty acids. Reactions
proceeded quickly, and the method proved convenient and reliable. 相似文献
12.
Fahim U. Ahmed 《Journal of the American Oil Chemists' Society》1990,67(1):8-14
An efficient high yield synthesis of fatty monoglyceride sulfates from fatty acids or fatty acid methyl esters, glycerine
and chlorosulfuric acid in chloroform using stoichiometric amounts of reagents was developed. Sodium coco monoglyceride sulfate
was prepared in 79% yield with 93% purity from coco fatty acids. Similarly, sodium palm kernel monoglyceride sulfate in 57%
yield and sodium palm monoglyceride sulfate in 71% yield were obtained from palm kernel fatty acid methyl esters and palm
fatty acids, respectively. This new synthetic method produced better quality products with higher active ingredients and improved
yields without having to use such cost prohibitive, high purity, fatty acid monoglycerides, and it reduced the undesirable
aqueous sodium sulfate by-product by 60% over a current commercial process. The product’s composition and purity were confirmed
by cationic titration, infrared and C-13 NMR spectroscopy. 相似文献
13.
A modified low-temperature solvent crystallization process was employed for the enrichment of polyunsaturated fatty acids
(PUFA) in borage and linseed oil fatty acids. The effects of solvent, operation temperature, and solvent to free fatty acid
(FFA) ratio on the concentration of PUFA were investigated. The best results were achieved when a mixture of 30% acetonitrile
and 70% acetone was used as the solvent. With an operation temperature of −80°C and a solvent to FFA ratio of 30 mL/g, γ-linolenic
acid (GLA) in FFA of saponified borage oil can be raised from 23.4 to 88.9% with a yield of 62.0%. At a yield of 24.9%, α-linolenic
acid in linseed oil can be increased from 55.0 to 85.7%. The results of this work are comparable to the best results available
in the literature. 相似文献
14.
Rats of an inbred Sprague-Dawley strain were fed purified diets with low (0.3% of total energy), normal (3%) or high (10%)
content of essential fatty acids (EFA) for at least three generations. Two 30-days-old rats with similar weights were chosen
from one litter. One was killed; weight increase and food consumption of the other rat was measured for 15 days. Total lipid
content and fatty acid composition in total lipid and lipid classes were determined in both rats. Seven pairs of rats from
each group were treated in the same way. Calculations based an amount of linoleic acid ingested and retained in the carcass
lipids showed that 50% of the ingested linoleic acid was retained in the low EFA rats compared to 10–15% in the normal and
high EFA rats. 相似文献
15.
Cardiac fatty acids were studied in young rats fed marine oils for 1 week. When the diet contained 0, 0.5, 1, 2, 4, 8 or 16%
by weight of partially hydrogenated oil from Norwegian capelin, the concentration of fatty acids in the cardiac tissue was
elevated only at the highest level. The amount of the lipid and the content of docosenoic acid in the heart were less than
those observed with 15% partially hydrogenated oil from Canadian herring. Nonhydrogenated Peruvian anchovy oil lacking docosenoic
acid produced no change in the amount of fat deposited. The extent of fatty acid accumulation in the heart was related to
the dietary C22 acids. 相似文献
16.
The effect of very low levels of dietary long-chain n−3 fatty acids on Δ6 desaturation of linoleic acid (18∶2n−6) and α-linolenic
acid (18∶3n−3), and on Δ5 desaturation of dihomo-γ-linolenic acid (20∶3n−6), in liver microsomes and its influence on tissue
fatty acids were examined in obese and lean Zucker rats and in Wistar rats. Animals fed for 12 wk a balanced diet containing
ca. 200 mg of long-chain polyunsaturated n−3 fatty acids per 100 g of diet were compared to those fed the same amount of α-linoleic
acid. Low amounts of long-chain n−3 fatty acids greatly inhibited Δ6 desaturation of 18∶2n−6 and Δ5 desaturation of 20∶3n−6,
while Δ6 desaturation of 18∶3n−3 was not inhibited in Zucker rats and was even stimulated in Wistar rats. Inhibition of the
biosynthesis of long-chain n−6 fatty acids was reflected in a decrease in arachidonic acid (20∶4n−6) content of serum lipids
when fasting, and also in the phospholipid fatty acids of liver microsomes. On the contrary, heart and kidney phospholipids
did not develop any decrease in 20∶4n−6 during fish oil ingestion. Docosahexaenoic acid (22∶6n−3), present in the dietary
fish oil, was increased in serum lipids and in liver microsome, heart, and kidney phospholipids. 相似文献
17.
R. S. Farag S. A. Osman S. A. S. Hallabo A. A. Nasr 《Journal of the American Oil Chemists' Society》1978,55(10):703-707
Model systems were designed to study linoleic acid oxidation in the presence and absence of various amino acids with or without
cupric ions. The tested amino acids exhibited a potential prooxidant effect in linoleic acid dispersed in aqueous media. The
effectiveness of various amino acids on linoleic acid oxidation decreased in the following order: cysteine > serine > tryptophan
> phenylalanine > histidine > alanine. The addition of alanine, serine, phenylalanine, histidine, or tryptophan to linoleic
acid showed an autocatalytic chain reaction. With cysteine, there was a linear relation between concentration of hydroperoxides
and time during the early stages of oxidation. The prooxidative activity of the tested amino acids in general could be attributed
to the presence of the a-amino group in the form H3-N-R. The apparent difference in the prooxidative activity is mainly due to the functional groups attached in the β-carbon
atom in the amino acid molecules. The addition of cupric ions at a concentration of 10-5M to linoleic acid catalyzed with various a-amino acids showed that these amino acids had no significant effect. Increasing
the copper concentration from 10-5M to 10-3M had the following effects: a shortening of the induction period of linoleic acid catalyzed by amino acids having an aromatic
side chain, no effect on the induction period but an increase in the oxidation rate during the propagation step in the model
systems catalyzed by alanine and serine, and in the model system containing cysteine a linear increase in the linoleic acid
oxidation from the start of the reaction. 相似文献
18.
G. Lakshminarayana R. Subbarao Y. Sita Rama Sastry T. Chandrasekhara Rao Vijay Kale P. Vijayalakshmi 《Journal of the American Oil Chemists' Society》1982,59(5):238-240
The composition (wt %) of the fatty acids obtained by decomposition of castor oil fatty acid estolides and distillation was
determined by a combination of spectroscopic (ultraviolet, nuclear magnetic resonance, infrared), chromatographic (thin layer
on Silica Gel G modified with silver nitrate and ammonium hydroxide, gas liquid) and chemical (partial reduction and periodate/permanganate
oxidation) techniques and found to be 16:0, 2.7; 18:0, 2.6; 18:1, 5.2; conjugatedcis,trans (trans,cis)-18:2, 34.4; conjugatedcis,cis-18:2, 9.7; conjugatedtrans,trans-18:2, 3.9; 9-cis,12-trans-18:2, 20.8; 9-trans,12-cis-18:2, 2.3; and 9-cis,-18:2, 18.4. 相似文献
19.
In the starved state and during metabolic stress, free fatty acids (FFA) are the principal hepatic energy supply, undergoing
β-oxidation. Accordingly, it appears paradoxical that H-A have been reported to increase the liver's esterification capacity
by translocating the rate-limiting enzyme phosphatidic acid phosphohydrolase (PAP-1) from the cytosol to the endoplasmic reticulum.
We have therefore investigated the regulation of rat liver PAP-1. Oleic acid inhibited PAP activity in all subcellular fractions,
with PAP-1 activity in cytosol being the most sensitive. Inhibition was also observed with oleoyl-CoA, linoleate, and palmitate.
Fatty acids and their derivatives show detergent effects at high concentrations, and such effects can lead to enzyme inhibition.
Inhibition by oleate, however, was reversed by phosphatidic acid and albumin and exhibited sigmoidal kinetics. These results
demonstrate that PAP-1 is reversibly inhibited by FFA and their CoA esters, which may play a role in directing hepatic FFA
to β-oxidation during times of increased energy demand. 相似文献
20.
This study evaluated the effects of conjugated linoleic acids (CLA) on tissue fatty acid composition and ex vivo prostaglandin E2 (PGE2) production in rats given diets varying in n-6 and n-3 fatty acids. Four groups of rats were given a basal semipurified diet
(AIN-93G) containing 70 g/kg of added fat for 42 d. The fat treatments were formulated to contain CLA (0 vs. 10 g/kg of diet)
and n-6 (soybean oil having an n-6/n-3 ratio of 7.3) and n-3 fatty acids (menhaden oil+safflower oil having an n-6/n-3 ratio
of 1.8) in different ratios in a 2×2 factorial design. Fatty acids in liver, serum, muscle, heart, brain, spleen, and bone
(cortical, marrow, and periosteum) were analyzed by capillary gas-liquid chromatography. The various dietary lipid treatments
did not affect growth; however, CLA improved feed efficiency. The CLA isomers were found in all rat tissues analyzed although
their concentrations varied. Dietary CLA decreased the concentrations of 16∶1n−7, 18∶1, total monounsaturates and n−6 fatty
acids, but increased the concentrations of n−3 fatty acids (22∶5n−3 and 22∶6n−3), and saturates in the tissues analyzed. Ex vivo PGE2 production in bone organ culture was decreased by n−3 fatty acids and CLA. We speculate that CLA reduced the concentration
of 18∶1 fatty acids by inhibiting liver Δ9-desaturase activity. The fact that CLA lowered ex vivo PGE2 production in bone organ culture suggests that these conjugated fatty acids have the potential to influence bone formation
and resorption. 相似文献