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1.
Twelve-week-old Landes male geese were overfed with corn for 21 d in order to induce liver steatosis (fatty liver). Lipid
composition of hepatocyte plasma membranes from fatty livers was compared to that of lean livers obtained from geese fed a
normal diet. The ratio cholesterol/phospholipids was higher in fatty hepatocyte plasma membranes (0.63 vs. 0.47), whereas
the phospholipid/protein ratio was less than half. Overfeeding induced changes in fatty acid composition of hepatocyte plasma
membranes, including a greater than twofold increase in the percentage of oleic acid (29.7 vs. 13.8%) and a somewhat lesser
increase in lauric, palmitic, and palmitoleic acid contents of plasma membrane lipids of fatty livers. A concomitant reduction
in the proportion of stearic acid (18.4 vs. 25.1%) was also observed. In fatty livers, the increased ratio of saturated to
polyunsaturated fatty acids (PUFA) (1.5 vs. 1.0) was related to a significant decrease in PUFA content. Among all the PUFA,
only the eicosatrienoic acid (20∶3n−9) percentage was increased by liver steatosis. Overfeeding with corn appeared to induce
competition between de novo synthesized and dietary fatty acids incorporated in hepatocyte plasma membranes. This resulted in an accumulation of de novo synthesized monounsaturated and derived fatty acids in plasma membranes from overfed birds. A defect in the incorporation
of linoleic acid and linoleic- and linolenic-derived PUFA was observed despite the high proportion of these essential fatty
acids in the diet. It was conclued that in overfed palmipeds, de novo hepatic lipogenesis prevails over dietary lipid intake to modulate lipid composition of the fatty liver plasma membrane. 相似文献
2.
To examine whether dietary fat alters membrane lipid composition and peroxidation of polyunsaturated fatty acids in “non-proliferative”
and “proliferative” cells in the large intestine, Sprague-Dawley rats were fed diets providing a polyunsaturated-to-saturated
fatty acid ratio of 1.2 or 0.3 at a high or low level of fat intake for a 25-day period. Cell populations were isolated and
the effect of dietary fat on membrane polyunsaturated fatty acid content and peroxide levels was determined. Neither fat level
nor fatty acid composition of diet influenced total cholesterol, total phospholipids, and percentage of phospholipid classes
in membrane phospholipids. Feeding the high fat and/or high polyunsaturated-to-saturated fatty acid ratio diet increased polyunsaturated
fatty acid content of mucosal cell phospholipids. Increase in polyunsaturated fatty acid content was paralleled by a decrease
in the monounsaturated fatty acid content of mucosal cell phospholipids. Membrane content of total saturated fatty acids was
not significantly affected by diet. Variation in phospholipid fatty acid composition between “non-proliferative” and ”proliferative”
cells was observed. Lipid peroxide levels in mucosal cell lipid fractions were altered by dietary fat treatment. Animals fed
high fat diets, compared to groups fed low fat diets, exhibited higher membrane peroxide levels when results are expressed
as nmol/mg protein. Higher peroxide levels were observed in mucosal cells for rats fed high polyunsaturated-to-saturated fatty
acid ratio diets when results were expressed per nmol of phospholipid. It is concluded that changes in fat level and fatty
acid composition of the diet alters the mucosal cell membrane lipid composition in the rat large intestine and influences
susceptibility of mucosal cell lipid to peroxidation. Further research is required to delineate which dietary factors—fat
level, polyunsaturated-to-saturated fatty acid ratio, or both—have a primary influence on the degree of lipid peroxidation. 相似文献
3.
Diets supplemented with high levels of saturated fatty acids derived from sheep kidney (perirenal) fat or unsaturated fatty
acids derived from sunflowerseed oil were fed to marmoset monkeys for 22 wk. The effect of such diets on plasma, red blood
cell phospholipids, and liver, heart, kidney and brain mitochondrial phospholipid fatty acids was determined. Despite large
differences in the level and type of lipid present in the experimental diets, there was little effect on the proportion of
saturated to unsaturated fatty acids in the phospholipids of the membranes examined. The diets did, however, alter the proportion
of the various classes of polyunsaturated fatty acids in the membrane phospholipids, with the sunflower-seed oil diet elevating
and the sheep kidney fat diet reducing the n−6/n−3 unsaturated fatty acid ratio, relative to a low (mixed fat) reference diet.
This change occurred in all membranes except brain, in which only a small response to altered dietary lipid intake was observed.
Elevation of dietary linoleic acid led to an increase in membrane linoleic acid and a marked decrease in membrane arachidonic
acid, such that the membranes from animals fed the sunflowerseed oil diet exhibited the lowest proportion of arachidonic acid.
In this latter respect, the response of the marmoset monkey to dietary lipid supplementation differs markedly from the rat.
Our inability to alter significantly membrane lipid saturation/unsaturation supports the notion that a homeostatic mechanism
is in some way responsible for buffering membranes from the effects of significant changes in the nature of the dietary lipid
intake. 相似文献
4.
Existence of a dietary maximal level or threshold for incorporation of ω3 fatty acids into membrane phospholipids is of interest
as it may further define understanding of the dietary requirement for ω3 fatty acids. To test whether feeding increasing levels
of dietary ω3 fatty acids continues to increase membrane ω3 fatty acid content, weanling rats were fed a nutritionally adequate
semipurified diet which provided increasing amounts of C20 and C22 ω3 fatty acids, such as 20∶5ω3 and 22∶6ω3. Dietary 20∶5ω3 and 22∶6ω3 were provided by substituting a purified shark oil concentrate
of high 22∶6ω3 content for safflower oil high in 18∶2ω6. After four weeks of feeding, nuclear envelopes from four animals
in each diet group were prepared, lipid was extracted and phospholipids separated. Arachidonic acid content in membrane phosphatidylcholine,
phosphatidylethanolamine, phosphatidylinositol and phosphatidylserine was significantly reduced by feeding increased dietary
levels of ω3 fatty acids. Decline of 20∶4ω6 level in phospholipid tended to stabilize when the dietary content of total ω3
fatty acids reached 4–5% of total fatty acids. Above this level, dietary ω3 fatty acids did not result in a further decrease
in membrane content of 20∶4nω6. Increase in membrane phospholipid content of 20∶5ω3 occurred as the dietary intake of ω3 fatty
acids increased from 1.1% to 5% of total fatty acids. A dietary ω3 fatty acid level of 2.2–3% was sufficient to result in
maximum incorporation of 22∶6ω3 into membrane phosphatidylcholine and phosphatidylethanolamine, but not into phosphatidylinositol
or phosphatidylserine. 相似文献
5.
Daria V. Kuznetcova Michel Linder Carole Jeandel Cedric Paris Frederic Desor Denis A. Baranenko Liudmila A. Nadtochii Elmira Arab-Tehrany Frances T. Yen 《International journal of molecular sciences》2020,21(23)
Polyunsaturated fatty acids (PUFA) are important in reducing the risk for cardiovascular, metabolic and neurodegenerative diseases. Chia (Salvia hispanica L.) seeds contain high levels of omega-3 PUFA, α-linolenic acid (ALA) in particular, and are a potential source for development of omega-3 PUFA-based products. Our objective was to obtain and characterize chia seed lipids, focusing on phospholipid fraction, and to investigate their use in the formulation of nanoemulsions (NE) and nanoliposomes (NL). Solvent-based lipid extraction was performed on the ORURO variety of chia seeds, followed by lipid composition analysis using GC and LC-MS and physico-chemical characterization of chia NL and NE. Folch extraction led to a slightly higher yield of ALA as compared to Soxhlet extraction. Lipid, phospholipid, and fatty acid composition analysis of the oil and residue revealed that the residue was rich in phospholipids; these were used to prepare NE and NL. Physico-chemical characterization showed that NE and NL were generally spherical (transmission electron microscopy), with a size of <120 nm under hydrated conditions that remained stable over 5 days. In conclusion, chia oil and phospholipid-rich residue can be used to obtain stable NL or NE using a simple method that involves spontaneous emulsification during lipid hydration, which potentially may be useful in cosmetics, pharmaceutical, and other health applications. 相似文献
6.
Diets in which both the lipid content and composition (polyunsaturated to saturated fatty acid ratio) were varied were fed
to rats for 20 weeks, and the effects on the tissue lipid profiles were determined. The fatty acid profile of the plasma lipids,
and the phospholipid fatty acids of the mitochondrial and microsomal fractions of liver, heart, kidney and brain, as well
as erythrocyte membranes were determined. Despite large differences in the level and type of lipid present in the experimental
diets and in the proportion of saturated fatty acids in the plasma lipids in response to the various diets, there was little
effect on the proportion of saturated to unsaturated fatty acids in the phospholipids of the various membranes examined. The
major effect of altering the dietary level of polyunsaturated to saturated fatty acids was on the ratio of the ω6/ω3 series
of unsaturated fatty acids in the membrane lipids. This change occurred in all tissues except the brain, in which only a small
response to altered dietary lipid intake was observed. The ω6/ω3 ratio was elevated upon feeding a diet rich in ω6 polyunsaturated
fatty acids, but decreased when a diet rich in saturated fatty acids was fed. The failure to significantly alter membrane
lipid saturation/unsaturation in the tissues examined would suggest that a homeostatic mechanism is operative in biological
membranes and may act to buffer membranes from the effects of changes in the nature of the dietary lipid intake. 相似文献
7.
Incorporation of alpha-linolenic acid and linoleic acid into human respiratory epithelial cell lines
Animal and human studies designed to examine the effects of α-linolenic acid (ALA) and linoleic acid (LA) supplementation
on the fatty acid composition of plasma and tissues have demonstrated a marked difference in incorporation into phospholipids
of these 18-carbon precursors of the long-chain polyunsaturates. Whereas tissue phospholipid levels are linearly related to
dietary ALA and LA, the levels of tissue LA can be 10-fold higher than tissue ALA even when dietary levels are equivalent.
There is some dispute whether this disparity is due to ALA being more rapidly metabolized to its products or substantially
oxidized by the liver, or whether LA but not ALA is readily incorporated into cellular phospholipids. We examined the level
of incorporation of polyunsaturated fatty acids into human respiratory epithelial cell lines (A549, 16HBE) by determining
the dose-dependent incorporation of ALA and LA as free fatty acid (5–150 μg FFA/mL). Cell membrane phospholipid ALA and LA
were both increased up to ∼20–30% total fatty acids, with a concomitant decrease predominantly in monounsaturated membrane
fatty acids, before significant toxicity was observed (50 μg/mL). Our data support the concept that rather than any inherent
inability by human cells to incorporate ALA into membrane phospholipids, the lack of ALA content in human and animal tissues
in vivo is due to the rapid metabolism or oxidation of this fatty acid in the liver. 相似文献
8.
Skeletal muscle membrane lipids and insulin resistance 总被引:4,自引:0,他引:4
L. H. Storlien D. A. Pan A. D. Kriketos J. O'Connor I. D. Caterson G. J. Cooney A. B. Jenkins L. A. Baur 《Lipids》1996,31(1):S261-S265
Skeletal muscle plays a major role in insulin-stimulated glucose disposal. This paper reviews the range of evidence in humans
and experimental animals demonstrating close associations between insulin action and two major aspects of muscle morphology:
fatty acid composition of the major structural lipid (phospholipid) in muscle cell membranes and relative proportions of major
muscle fiber types. Workin vitro andin vivo in both rats and humans has shown that incorporation of more unsaturated fatty acids into muscle membrane phospholipid is
associated with improved insulin action. As the corollary, a higher proportion of saturated fats is linked to impairment of
insulin action (insulin resistance). Studiesin vitro suggest a causal relationship. Among polyunsaturated fatty acids (PUFA) there is some, but not conclusive, evidence that
ω-3 (n−3) PUFA may play a particular role in improving insulin action; certainly a high n−6/n−3 ratio appears deleterious.
In relation to fiber type, the more highly oxidative, insulin-sensitive type 1 and type 2a fibers have a higher percentage
of unsaturated fatty acids, particularly n−3, in their membrane phospholipid, compared to the insulin-resistant, glycolytic,
type 2b fibers. These variables, however, can be separated and may act in synergy to modulate insulin action. It remains to
establish whether lifestyle (e.g., dietary fatty acid profile and physical activity), genetic predisposition, or a combination
are the prime determinants of muscle morphology (particularly membrane lipid profile) and hence insulin action. 相似文献
9.
Changes in dietary lipid intake are known to alter the fatty acid composition of cardiac muscle of various animals. Because
changes in cardiac muscle membrane structure and function may be involved in the pathogenesis of arrythmia and ischemia, we
have examined the effects of dietary lipid supplements on the phospholipid distribution and fatty acid composition of rat
atria and ventricle following 20 weeks feeding of diets supplemented with either 12% sunflower-seed oil or sheep fat.
Neither lipid supplement produced significant changes in the proportions of cholesterol, total phospholipids or phosphatidylcholine,
phosphatidylethanolamine or diphosphatidylglycerol,—the phospholipid classes that together account for more than 90% of the
total phospholipids of rat cardiac muscle. Significant changes were found in the profiles of the unsaturated fatty acids of
all 3 phospholipid components of both atria and ventricle. Although similar, the changes between these tissues were not identical.
However, in general, feeding a linoleic acid-rich sunflower seed oil supplement resulted in an increase in the ω-6 family
of fatty acids, whereas feeding the relatively linoleic acid-poor sheep fat supplement decreased the level of ω-6 fatty acids
but increased the levels of the ω-3 family, resulting in major shifts in the proportions of these families of acids. In particular,
the ratio of arachidonic acid: docosahexaenoic acid (20∶4, ω-6/22∶6, ω-3), which is higher in all phospholipids of atria than
ventricle, is increased by feeding linoleic acid, primarily by increasing the level of arachidonic acid in the muscle membranes.
As dosahexaenoic acid does not occur in the diet, the increase in this acid which occurs after feeding animal fat, presumably
arises from increased conversion of the small amounts of linolenic acid in all diets when the amount of linoleic acid present
is reduced. 相似文献
10.
The amount of linoleic acid required to prevent undesirable effects of C18trans fatty acids was investigated. In a first experiment, six groups of rats were fed diets with a high content oftrans fatty acids (20% of energy [en%]), and increasing amounts of linoleic acid (0.4 to 7.1 en%). In a second experiment, four
groups of rats were fed diets designed to comparetrans fatty acids with saturated andcis-monounsaturated fatty acids of the same chain length at the 2 en% linoleic acid level. After 9–14 weeks, the oxygen uptake,
lipid composition and ATP synthesis of heart and liver mitochondria were determined.
The phospholipid composition of the mitochondria did not change, but the fatty acid compositions of the two main mitochondrial
phospholipids were influenced by the dietary fats.Trans fatty acids were incorporated in all phospholipids investigated. The linoleic acid level in the phospholipids, irrespective
of the dietary content of linoleic acid, increased on incorporation oftrans fatty acids. The arachidonic acid level had decreased in most phospholipids in animals fed diets containing 2 en% linoleic
acid. At higher linoleic acid intakes, the effect oftrans fatty acids on the phospholipid arachidonic acid level diminished. However, in heart mitochondrial phosphatidylethanolamine,trans fatty acids significantly increased the arachidonic acid level. Despite these changes in composition, neither the amount
of dietary linoleic acid nor the addition oftrans fatty acids influenced the mitochondrial function. For rats, a level of 2 en% of linoleic acid is sufficient to prevent undesirable
effects of high amounts of dietary C18trans fatty acids on the mitochondrial function. 相似文献
11.
Biosynthesis of fatty acids by the carp,Cyprinus carpio L., in relation to environmental temperature
Incorporation in vivo of sodium 1-14C-acetate into different lipid classes and fatty acids of total lipids and phospholipids of warm adapted and cold adapted
carp livers was studied at 5 C and 22 C, respectively. The fatty acid composition of total lipids and phospholipids was also
determined. The level of long chain polyunsaturated fatty acids in both total lipid and phospholipid fractions was higher
in cold adapted fish than in warm adapted ones. The distribution of radioactivity among different lipid classes depended only
on the actual incorporation temperature and was independent of the temperature history of the animals. Livers of fish incorporated
a higher percentage of radioactivity into long chain polyunsaturated fatty acids of total lipids and phospholipids in 5 C
than in 22 C. The distribution of radioactivity among different fatty acids was dependent on the experimental temperature
rather than on the temperature to which the fish were adapted. The results suggest that fish are able to adjust the pattern
of the biosynthesis of fatty acids very rapidly to the prevailing temperature and to assure by this way the proper physicochemical
properties of their membranes. The possible mechanisms involved in this rapid response are discussed. 相似文献
12.
Andrew J. Sinclair Kerin O'Dea Graeme Dunstan Paul D. Ireland Maggie Niall 《Lipids》1987,22(7):523-529
The effects of very low fat diets (<7% energy) enriched with different sources of long chain (C20 and C22) polyunsaturated
fatty acids (PUFA) on plasma lipid levels and plasma fatty acids (PUFA) on plasma lipid levels and plasma fatty acid composition
were studied in 13 healthy volunteers. Three diets provided 500 g/day of tropical Australian fish (rich in arachidonic acid
and docosahexaenoic acid), southern Australian fish (rich in docosahexaenoic acid) or kangaroo meat (rich in linoleic and
arachidonic acids). The fourth diet was vegetarian, similarly low in fat but containing no 20- and 22-carbon PUFA. Subjects
ate their normal or usual diets on weeks 1 and 4 and the very low fat diets in weeks 2 and 3. Weighed food intake records
were kept, and weeks 2, 3 and 4 were designed to be isoenergetic with week 1.
Plasma cholesterol levels fell significantly on all diets within one week. There were reductions in both low density (LDL)
and high density lipoprotein (HDL) cholesterol levels, with effects on HDL cholesterol being more consistent. There were no
consistent or significant effects on total triglyceride levels despite the high carbohydrate content of the diets. On all
diets the percentage of linoleic acid fell in the plasma phospholipid and cholesteryl ester fractions, while the percentage
of palmitic acid in the phospholipids and cholesteryl esters and palmitoleic acid in the cholesteryl ester fraction rose on
all diets. The percentage of arachidonic acid rose in the phospholipid and cholesteryl esters on the two diets that were good
sources of this fatty acid (tropical fish and kangaroo meat). The percentage of docosahexaenoic acid also rose on the two
diets that were the richest sources of this fatty acid (the fish diets), and the percentage of eicosapentaenoic acid rose
in the phospholipid and cholesteryl esters in proportion to the dietary level of this fatty acid (southern fish > kangaroo
> tropical fish). The changes in fatty acid composition were almost completely reversed within seven days of returning to
the usual higher fat diets. 相似文献
13.
Johannes M. B. Pöschl Karl Paul Michael Leichsenring Shan R. Han Matthias Pfisterer Hans J. Bremer Otwin Linderkamp 《Lipids》1999,34(5):467-473
The fatty acid composition of plasma cholesteryl esters, plasma phospholipids, red blood cell (RBC) membrane phosphatidylcholine
(corresponding to the outer membrane leaflet), and phosphatidylethanolamine (corresponding to the inner membrane leaflet)
was investigated in weanling guinea pigs fed with diets of cacao (saturated fatty acids), sunflower oil [n−6 polyunsaturated
fatty acids (PUFA)] or fish oil (n−3 PUFA) for 20 wk. RBC deformation was measured by means of a cell-transit analyzer (filtration)
and a cone-plate rheoscope. The contents of saturated fatty acids in plasma phospholipids and RBC membrane leaflets were similar
in all three groups. Diets with sunflower oil resulted in a high content of linoleic acid in plasma cholesteryl esters and
in the outer leaflet of RBC membranes. Fatty acids of fish oil were mainly incorporated in plasma phospholipids and in the
inner leaflet of RBC membranes. The arachidonic acid content was high in all groups in the plasma phospholipids and in the
inner leaflet. The n−6 and n−3 PUFA were mainly incorporated in the inner leaflet. In all groups the polyunsaturated/saturated
fatty acid ratio and the total PUFA content were similar in the inner RBC membrane. The RBC filtration times and the RBC deformation
indices were not affected by the dietary treatment. 相似文献
14.
The effect of a long-term adaptation of rainbow trout to 8 and 18°C combined with a corn oil-or a fish oil-supplemented diet
on the characteristics of the spermatozoan plasma membrane was investigated. The experiment lasted up to 22 mon during which
spermatozoa were collected from the mature males. Spermatozoan plasma membranes were isolated by nitrogen cavitation, and
the cholesterol content, phospholipid composition and fatty acid pattern were investigated. Membrane viscosity was assessed
on whole cells by electron spin resonance using spin-labeled phospholipids. Neither diet nor rearing temperature influenced
the cholesterol content of the plasma membrane nor the phospholipid class distribution. The rearing temperature of the broodstock
only slightly affected the phospholipid fatty acids. A minor decrease in 18∶0 and increase in monounsaturated fatty acids
was observed for the cold-adapted fish. These modifications were not sufficient to affect membrane fluidity, and we conclude
that trout spermatozoa do not display any homeoviscous adaptations in these conditions. On the contrary, the dietary fatty
acid intake greatly modified the fatty acid profile of plasma membrane phospholipids. The fish oil-fed trout displayed a much
higher n−3/n−6 fatty acid ratio than did the corn oil-fed ones, but the 22∶6n−3 levels remained unchanged. Modifications in
plasma membrane composition by the diet were obtained although neither of the two diets was deficient in essential fatty acids.
The enrichment in n−3 fatty acids, however, did not affect plasma membrane fluidity which was unchanged by the diets. 相似文献
15.
Sarah A. Brigandi Hong Shao Steven Y. Qian Yiping Shen Bai-Lin Wu Jing X. Kang 《International journal of molecular sciences》2015,16(5):10061-10076
Omega-6 (n-6) and omega-3 (n-3) polyunsaturated fatty acids (PUFA) are essential nutrients for brain development and function. However, whether or not the levels of these fatty acids are altered in individuals with autism remains debatable. In this study, we compared the fatty acid contents between 121 autistic patients and 110 non-autistic, non-developmentally delayed controls, aged 3–17. Analysis of the fatty acid composition of red blood cell (RBC) membrane phospholipids showed that the percentage of total PUFA was lower in autistic patients than in controls; levels of n-6 arachidonic acid (AA) and n-3 docosahexaenoic acid (DHA) were particularly decreased (p < 0.001). In addition, plasma levels of the pro-inflammatory AA metabolite prostaglandin E2 (PGE2) were higher in a subset of the autistic participants (n = 20) compared to controls. Our study demonstrates an alteration in the PUFA profile and increased production of a PUFA-derived metabolite in autistic patients, supporting the hypothesis that abnormal lipid metabolism is implicated in autism. 相似文献
16.
The present investigation addressed three questions: (i) Does the obese syndrome alter the fatty acid composition of cardiac tissue and membrane phospholipids in obese (fa/fa) rats? (ii) Are changes, if they occur, similar to those reported for tissues of the genetically obese (ob/ob) mouse? (iii) Can cardiac tissue phospholipids and their component fatty acids be modified by dietary lipids and if so does this occur to the same extent in both fa/fa and lean (Fa/?) rats? Proportions of polyunsaturated fatty acids (PUFA) in cardiac total phospholipids of fa/fa rats differed significantly from those of Fa/? rats and from those reported for ob/ob mice. Increased 18∶2n?6 and decreased 20∶4n?6 and 22∶6n?3 in fa/fa rats indicated impaired PUFA metabolism, possibly reduced Δ6 and/or Δ5 desaturase activity, compared with Fa/? rats. No differences in hepatic Δ6 and Δ5 desaturase activity between fa/fa and Fa/? were found but enhanced activity of Δ9 desaturase activity in fa/fa as compared to Fa/? was evident. Inclusion of sunflower oil (SO) or triolein (TO) at 5% and 20% by weight in the diet elicited marked changes in the fatty acyl composition of cardiac phospholipids in both fa/fa and Fa/? rats when compared with animals fed the control Oxoid diet alone. Supplementation with triolein was most effective, reducing 18∶2n?6 and increasing 20∶4n?6 proportions in fa/fa rats so that they resembled those in Fa/? rats fed the control Oxoid diet. The type of fat rather than the amount of its dietary intake appears to be the main determinant of the observed changes in phospholipid composition. Pair feeding hyperphagic fa/fa rats to the lower intakes of Fa/? rats did not abolish the characteristic differences in the proportions of PUFA in cardiac phospholipids between the two phenotypes. The effect of triolein on cardiac phospholipid fatty acid composition in the present studies is intriguing and may be relevant in understanding the beneficial role of dietary olive oil in ameliorating cardiovascular disease in man. 相似文献
17.
The fatty acid composition of diacyl- and alkylacylglycerophosphocholine (PC), phosphatidylinositol (PI), phosphatidylserine
(PS), alkenylacyl-glycerophosphoethanolamine (aPE), and diacyl- and alkylacyl-glycerophosphoethanolamine (dPE) was assessed
in isolated splenocytes from C3H/Hen mice fed one of four purified isocaloric diets for six weeks. Diets contained 20% by
weight of either a high-linoleate sunflower oil (Hi 18∶2), a high-oleate sunflower oil (Hi 18∶1), a mixture of 17% menhaden
fish oil and 3% high-linoleate sunflower oil (Hi n−3), or a mixture of 17% coconut oil and 3% high-linoleate sunflower oil
(Hi SFA). Spleen weight and immune cell yield were significantly higher (P<0.05) in mice fed the Hi 18∶1 or the Hi n−3 diets
compared with those fed the Hi 18∶2 and Hi SFA diets. Distinctive patterns of fatty acids were observed for each phospholipid
in response to dietary fatty acids. Dietary fat significantly affected (P<0.05) total polyunsaturated fatty acids (PUFA) in
PC and dPE, total saturated fatty acids (SFA) in PC, total monounsaturated fatty acids (MUFA), and n−3 PUFA in all phospholipid
classes examined. In mice fed the Hi n−3 diet, n−3 PUFA were significantly elevated, whereas n−6 PUFA decreased in all of
the phospholipids. In these mice, eicosapentaenoic acid (EPA) was the predominant n−3 PUFA in PC and PI, whereas docosahexaenoic
acid (DHA) was the major n−3 PUFA in aPE and PS. Interestingly, the ratios of n−3/n−6 PUFA in the phospholipids from these
mice were 3.2, 2.4, 1.8, 0.8 and 0.8 for aPE, PS, dPE, PC and PI, respectively. These data suggest a preferential incorporation
of n−3 PUFA into aPE, PS and dPE over PC and PI. 相似文献
18.
This study tests the hypothesis that the rat chylomicrons are assembled and released into lymph similarly regardless of the
site (rough or smooth endoplasmic reticulum) or pathway (phosphatidic acid or monoacylglycerol) of triacylglycerol biosynthesis.
For this purpose we determined the lipid class, fatty acid and molecular species composition of the choline, ethanolamine,
inositol and serine phospholipids of lymph chylomicrons during absorption of menhaden, mustard-seed and corn oil (monoacylglycerol
pathway) or the corresponding fatty acid methyl or ethyl esters (phosphatidic acid pathway). The dietary fatty acids were
found to be incorporated to various extents into different phospholipid classes, the proportions of which were not affected
by the nature of the dietary fat. The chylomicron phospholipids contained 80–82% choline, 8% ethanolamine and 2.5% inositol
glycerophospholipids, and much smaller amounts of serine and other minor phospholipids. Administration of a meal of each dietary
fat resulted in a retention of approximately 50% endogenous fatty acids in the major glycerophospholipids of the chylomicrons.
A minimum of 50% of the molecular species of the choline and ethanolamine glycerophospholipids contained at least one exogenous
fatty acid. No significant discrepancies were found in the fatty acid and molecular species composition of the glycerophospholipids
between chylomicrons from the oil and corresponding ester feeding. It is concluded that the chylomicrons arising from the
monoacylglycerol (oil feeding) and the phosphatidic acid (ester feeding) pathways of triacylglycerol biosynthesis become enveloped
in surfactant monolayers containing qualitatively and quantitatively identical classes and molecular species of phospholipids.
Part of this work was presented at the Annual Meeting of the American Oil Chemists' Society, Baltimore, MD, April, 1990. 相似文献
19.
Martin R. L. Scheeder Didier Gumy Ruth Messikommer Caspar Wenka Pierre Lambelet 《European Journal of Lipid Science and Technology》2003,105(2):74-82
The influence of the distribution of polyunsaturated fatty acids on the glycerol backbone of dietary triacylglycerols on the fatty acid profile of adipose tissue and muscle phospholipids was investigated in growing‐finishing pigs (48) and broiler chicken (84). The animals were fattened on barley/soybean meal diets supplemented with a blend of soybean oil and beef tallow, either in the ratio 3:1 w/w (high‐PUFA) or 1:3 w/w (low‐ PUFA). Part of the high‐ and low‐PUFA blends was chemically interesterified to randomly distribute all fatty acids over the three positions of the glycerol. Thus, two sets of diets of identical overall fatty acid composition, but differing in the distribution of fatty acids in the triacylglycerols, were fed. Growth performance and carcass composition were neither affected by fatty acid composition nor by randomisation of dietary fats in either animal species. Apparent digestibility of energy was slightly lower in pigs fed the low‐PUFA blends. Fatty acid profile of subcutaneous fat of pigs and broilers as well as of internal body fat (lamina subserosa) and muscle phospholipids of pigs varied according to the dietary fatty acid composition but was not affected by randomisation of dietary fats. These findings are explained in terms of the hydrolysis of TAG during transport of lipids from enterocytes to adipose tissue cells and the continuous lipolysis and re‐esterification of fatty acids that take place in adipose tissue cells. 相似文献
20.
Paul B. McCay J. Lee Poyer Peter M. Pfeifer Hubert E. May James M. Gilliam 《Lipids》1971,6(5):297-306
Events accompanying electron transport in the membrane fraction of liver and other tissues have led us to propose a specific
function for α-tocopherol based on a sequence of biochemical changes we observed to occur in these membranes and on pertinent
information from other laboratories. The activity of a membrane-bound enzyme system (TPNH oxidase) which involves transport
of electrons from substrate to oxygen, has been shown to promote simultaneous formation of peroxide functions on the β position
polyunsaturated fatty acids (PUFA) of phospholipids in the membrane. The phospholipid peroxides then undergo a chain cleavage
reaction producing phospholipids containing a variety of carbonyl moieties in the β position. The process results in marked
alteration of the membrane structure. During the overall reaction α-tocopherol present in the membrane is converted to a compound
more polar than tocopheryl quinone and the conversion is dependent on the same enzymic factors promoting the phospholipid
alterations. The membrane alteration process is enhanced in microsomes from animals fed diets containing relatively high levels
of PUFA or diets low in α-tocopherol, and is diminished by low levels of dietary PUFA or relatively high levels of α-tocopherol.
The experimental data indicate that enzymic electron transport associated with TPNH oxidation by the microsomal membrane involves
free radical functions. The latter apparently can promote extensive peroxidative alterations of phospholipids that result
in structural changes in the membrane unless adequate α-tocopherol is present in this organelle. This system appears to be
part of the microsomal drug metabolizing system. 相似文献