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1.
Skuladottir GV Olason PI Jonsson L Skarphedinsson JO Eriksdottir VH Atlason PT Franzson L Schiöth HB 《Lipids》2003,38(11):1127-1132
Hyperphagia was achieved by continuous intracerebroventricular infusion of a melanocortin receptor antagonist (HS024; Neosystem,
Strasbourg, France) in rats. The effects of hyperphagia on FA composition and concentration of plasma phospholipids (PL),
plasma FFA, and adipose tissue TAG were studied in rats for 8 d [short-term hyperphagia (STH); n=8], or 28 d [longterm hyperphagia (LTH); n=9]. The control rats were treated with artificial cerebrospinal fluid for 8 d (n=8) or 28 d (n=10). The rats were fed the same regular diet. In STH rats the plasma PL and fasting plasma FFA contained higher concentrations
of saturated FA (SFA) and monounsaturated FA (MUFA), and plasma FFA contained lower n−6 PUFA than in the control rats. In
LTH rats the plasma PL contained higher concentrations of SFA, MUFA, and n−3 PUFA and higher proportions of 16∶1n−7 and 18∶1n−9
at the expense of 18∶2n−6 than in the control rats. In LTH rats the abundant dietary intake of 18∶2n−6 did not enrich 18∶2n−6
of the plasma PL or adipose tissue TAG. In LTH rats the fasting plasma FFA contained more than twofold higher concentrations
of SFA and MUFA, and higher proportions of 16∶1n−7 and 18∶1n−9 at the expense of 18∶2n−6 than in the control rats. This animal
obesity model shows that LTH affects the FA composition and concentration of plasma PL, plasma FFA, and adipose tissue TAG,
a result consistent with changes associated with increased risk of various diseases in humans. These results also demonstrate
that LTH alters the FA composition of plasma PL and adipose tissue TAG in a way that does not reflect the FA composition of
dietary fat. 相似文献
2.
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
3.
The American marten (Martes americana) is a boreal forest marten with low body adiposity but high metabolic rate. The study describes the FA composition in white
adipose tissue depots of the species and the influence of food deprivation on them. American marten (n=8) were fasted for 2 d with 7 control animals. Fasting resulted in a 13.4% weight loss, while the relative fat mass was >25%
lower in the fasted animals. The FA composition of the fat depots of the trunk was quite similar to other previously studied
mustelids with 14∶0, 16∶0, 18∶0, 16∶1n−7, 18∶1n−9, and 18∶2n−6 as the most abundant FA. In the extremities, there were higher
proportions of monounsaturated FA (MUFA) and PUFA. Food deprivation decreased the proportions of 16∶0 and 16∶1n−7, while the
proportion of long-chain MUFA increased in the trunk. The mobilization of FA was selective, as 16∶1n−7, 18∶1n−9, and particular
n−3 PUFA were preferentially mobilized. Relative mobilization correlated negatively with the carbon chain length in saturated
FA (SFA) and n−9 MUFA. The Δ9 desaturation of SFA enhanced the mobilization of the corresponding MUFA, but the positional
isomerism of the first double bond did not correlate consistently with relative mobilization in MUFA or PUFA. In the marten,
the FA composition of the extremities was highly resistant to fasting, and the tail tip and the paws contained more long-chain
PUFA to prevent the solidification of lipids and to maintain cell membrane fluidity during cooling. 相似文献
4.
Uptake and incorporation of long-chain fatty acids were studied in a human colorectal cancer cell line (HT29/219) grown in
culture medium supplemented with either fetal calf serum (FSC) or horse serum (HS). The cells were grown for 120 h with no
change of medium; the two major cellular lipid classes, the phospholipids and the triacylglycerols, were analyzed at regular
time-points. We observed significant changes in the concentration of most fatty acids throughout culture, and differences
in their composition when different sera were used to supplement the medium. Minimal levels of free fatty acids were found
in the cells, indicating a very small “free fatty acid pool”. A major difference between the cells grown in media supplemented
with different sera was the changes observed in concentrations of cellular polyunsaturated fatty acids during growth. In cells
grown with FCS (in which 20∶4n−6 is present), the levels of this acid in the phsopholipid and triacylglycerol fractions declined
rapidly during cell growth, suggesting further metabolism. In cells grown in medium supplemented with HS, 18∶2n−6 was the
major polyunsaturated acid present. There was clear evidence that this acid accumulated in the cellular triacylglycerol and
phospholipid fractions. Furthermore, its concentration did not decline during growth in culture, suggesting minimal conversion
to other polyunsaturated n−6 acids. Our results suggest that fatty acids from additional sources in the medium, for example
triacylglycerols and phospholipids associated with the lipoproteins, are taken up by the cells. There is also indication of
cellular fatty acid synthesis, particularly of monounsaturated and saturated acids during the culture period. HT29/219 cells
were shown to take up and incorporate radioactivity when trace amounts of [1-14C]-labeled arachidonic, linoleic or oleic acids were added to the culture medium. Most (80%) of the label was detected in
cellular phospholipids and triacylglycerols, although the specific activities of these various fatty acids were different
in the two lipid fractions. 相似文献
5.
Gudrún V. Skúladóttir Sigrún Gudmundsdóttir Gunnlaugur B. Ólafsson Stefán B. Sigurdsson Nikulás Sigfússon Jóhann Axelsson 《Lipids》1995,30(7):649-655
Levels of serum lipids and lipoproteins, and the fatty acid composition of plasma phospholipids, were measured in two genetically
comparable, but widely separated, populations. The 1975 mortality rates for ischemic heart disease were significantly higher
in one of these populations, the Manitoban residents of pure Icelandic descent, than in the other, a rural population from
Northeastern Iceland. Two study populations, Icelanders and Icelandic-Canadians, were drawn from these larger populations.
The study populations were matched for age and sex and divided into three age groups, 20–39, 40–59, and 60–69 years. In comparison
to the Icelandic-Canadians, the Icelanders exhibited significantly higher levels of total cholesterol, low-density lipoprotein
cholesterol, and high-density lipoprotein cholesterol, but lower triglyceride levels. Their plasma phospholipids contained
significantly lower levels of saturated fatty acids (SFA), monounsaturated fatty acids, and n−6 polyunsaturated fatty acids
(PUFA); but their n−3 PUFA levels were three times as high. It was additionally found that fatty acid composition of plasma
phospholipids differed among Icelanders of different ages. SFA levels were significantly lower, and n−6 PUFA levels significantly
higher, in the 20–39 year group than in the 60–69 year group, possibly due to different dietary fat consumption patterns between
generations. No corresponding age-related difference in the fatty acid composition of plasma phospholipids was found in the
Icelandic-Canadian study population. As the Icelandic and Icelandic-Canadian groups are assumed to be genetically similar,
the biochemical differences between them are evidently due to environmental, probably dietary, differences. The findings indicate
that n−3 PUFA may be cardioprotective in the context of an otherwise atherogenic diet. 相似文献
6.
Gilles Nalbone Alain Grynberg Annick Chevalier Jeannie Leonardi Elise Termine Huguette Lafont 《Lipids》1990,25(6):301-306
Fatty acid composition of membrane phospholipids of cultured cardiomycotes can be modified by the type of polyunsaturated
fatty acids (n−3 or n−6 PUFA) constituting the culture medium. In this study, we investigated the effect of fatty acid modification
on the activities of the key enzymes involved in the deacylation-reacylation cycle of membrane phospholipids.
Results showed that cardiomyocytes grown in the presence of n−6 PUFA exhibited a higher specific alkaline phospholipase A
(mainly A2) activity (+34%) and a moderately lower lysophospholipase activity(−17%) than when incubated with n−3 PUFA. AcylCoA:lysophosphatidylcholine
acyltransferase, acid lysosomal phospholipase A1 and acylCoA synthetase activities were not significantly altered by changes in cellular PUFA composition. It was demonstrated
that the differences between phospholipase A activities of the two types of cultured cells were linked neither to a differential
leakage of enzyme nor to oxidative injury to the enzyme through blockage of essential sulfhydryl groups. One likely explanation
is that the PUFA-induced changes in membrane composition alter membrane physical properties which, in turn, affect membrane-bound
phospholipase A activity. Possible beneficial effects of the n−3 PUFA-induced changes on membrane stability are discussed. 相似文献
7.
The health benefits of long-chain n−3 PUFA (20∶5n−3 and 22∶6n−3) depend on the extent of incorporation of these FA into plasma
and tissue lipids. This study aimed to investigate the effect of the background dietary fat (saturated, monounsaturated, or
n−6 polyunsaturated) on the quantitative incorporation of dietary 18∶3n−3 and its elongated and desaturated products into
the plasma and the liver lipids of rats. Female weanling Wistar rats (n=54) were randomly assigned to six diet groups (n=9). The fat added to the semipurified diets was tallow (SFA), tallow plus linseed oil (SFA-LNA), sunola oil (MUFA), sunola
oil plus linseed oil (MUFA-LNA), sunflower oil (PUFA), or sunflower oil plus linseed oil (PUFA-LNA). At the completion of
the 4-wk feeding period, quantitative FA analysis of the liver and plasma was undertaken by GC. The inclusion of linseed oil
in the rat diets increased the level of 18∶3n−3, 20∶5n−3, and, to a smaller degree, 22∶6n−3 in plasma and liver lipids regardless
of the background dietary fat. The extent of incorporation of 18∶3n−3, 20∶5n−3, and 22∶5n−3 followed the order SFA-LNA>MUFA-LNA>PUFA-LNA.
Levels of 22∶6n−3 were increased to a similar extent regardless of the type of major fat in the rat diets. This indicates
that the background diet affects the incorporation in liver and plasma FA pools of the n−3 PUFA with the exception of 22∶6n−3
and therefore the background diet has the potential to influence the already established health benefits of long-chain n−3
fatty acids. 相似文献
8.
Mechanisms for the antiarrhythmic effect of n−3 polyunsaturated fatty acids (PUFA) are currently being investigated using
isolated cardiac myocytes. It is still not known whether the incorporation of n−3 PUFA into membrane phospholipids is a prerequisite
for its protective action or if n−3 PUFA exert antiarrhythmic effects in their nonesterified form as demonstrated by recent
studies. Adult porcine cardiomyocytes were grown in media supplemented with arachidonic acid (AA), eicosapentaenoic acid (EPA),
and docosahexaenoic acid (DHA). After 24 h, analysis of total lipids showed that the myocytes were enriched with the respective
fatty acids compared to control cells. Large proportions of all three fatty acids supplemented (69% AA, 72% DHA, and 66% EPA)
remained unesterified. Fatty acid analysis of total phospholipids (PL) revealed that the incorporation of EPA and DHA, though
small, was significantly different (P<0.05) from that of the control cells. The PL fraction was further separated into phosphatidylinositol (Pl), phosphatidylethanolamine,
phosphatidylcholine, and phosphatidylserine to study the pattern of incorporation of the fatty acids in these fractions. It
became apparent that EPA and DHA were selectively incorporated into the Pl fraction. This study demonstrates that in adult
porcine cardiomyocytes, the n−3 PUFA supplementation selectively modulates two important lipid fractions, nonesterified fatty
acid and Pl, which were implicated in the mechanisms of prevention of cardiac arrhythmias. 相似文献
9.
In this investigation, we demonstrate that rat liver epithelial (WB-F344) cells grown in medium supplemented with n−3 fatty
acids (FA) results in the inhibition of gap junctional intercellular communication (GJIC). Cells incubated for 48 hr in medium
containing 50 μM α-linolenate (18∶3n−3) resulted in a 60% inhibition of GJIC, compared to control cells, while treatment with
γ-linolenate (18∶3n−6) had no effect. Supplementation with octadecatetraenoate (18∶4n−3), eicosapentaenoate (20∶5n−3), and
docosahexaenoate (22∶6n−3), inhibited GJIC by 42%, 28%, and 18%, respectively. Incubation with each of the n−3 FA markedly
increased the total n−3 FA content of cellular phospholipids (PL). Growing cells in medium containing 50 μM arachidonate (20∶4n−6)
plus 50 μM 18∶3n−3 partially attenuated the inhibition of GJIC induced by 18∶3n−3. The mechanism by which n−3 FA inhibit GJIC
remains to be determined. 相似文献
10.
The purpose of this study was to examine the effects of feeding n−3 polyunsaturated fatty acid (PUFA)-enriched chicken eggs
on plasma and liver cholesterol levels and fatty acid composition in rats. Eggs were collected from laying hens fed diets
containing 10% flax seed (Hn−3), 12% sunflower seed (Hn−6), or wheat and soybean meal control (CON). Yolk powders were prepared
and fed at the 15% level to weanling female Sprague-Dawley rats for 28 days. Consumption of n−3 PUFA-enriched yolks significantly
reduced both plasma and liver total cholesterol. Liver total lipids and phospholipids of rats fed Hn−3 diet were enriched
with linolenic, eicosapentaenoic, and docosahexaenoic acids with a concomitant reduction of arachidonic acid in liver phospholipids.
The plasma cholesterol of rats fed yolk powders enriched with n−6 PUFA (mainly linoleic acid) was reduced to the same extent
as in those fed the n−3 enriched, but the liver cholesterol was significantly increased, indicating differential effects of
dietary n−3 and n−6 PUFA. The results demonstrated that the cholesterolemic and tissue lipid modulating properties of chicken
eggs could be modified in a favorable way by altering the fatty acid composition of yolk lipids through manipulation of laying
hen diets. 相似文献
11.
The effects of dietary cis and trans α-linolenic acid (18∶3n−3) on the FA composition of plasma, red blood cell, and liver phospholipids were studied in newborn
piglets. Animals were fed for 14 d with one of three diets: a control diet (group A) containing cis 18∶3n−3 at a level of 2.0% of total FA, a diet (group B) in which a part of the 18∶3n−3 acid was isomerized (1.3% of cis 18∶3n−3 and 0.7% of trans 18∶3n−3), or a diet (group C) with 2.0% cis 18∶3n−3 and 0.7% trans 18∶3n−3. Feeding animals with diets containing trans 18∶3n−3 resulted in the presence of trans isomers of 18∶3n−3, trans isomers of EPA, and trans isomers of DHA in phospholipids; however, the level of total trans n−3 PUFA in tissues was less than 0.3% of total tissue FA. In group B, the reduction of dietary amounts of cis 18∶3n−3 was associated with a decrease in individual and total cis n−3 PUFA. In contrast, in group C there was no decrease in tissue n−3 PUFA despite the increased dietary level of trans 18∶3n−3. These results suggest that the isomerization of a part of dietary n−3 PUFA, leading to the reduction of their levels
in the diet, could induce a decrease in n−3 PUFA in phospholipids. The physiological effects of trans PUFA are not known and should be considered in future studies. 相似文献
12.
Effects of the ratio of polyunsaturated and monounsaturated fatty acid to saturated fatty acid on rat plasma and liver lipid concentrations 总被引:6,自引:0,他引:6
The effects of dietary monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid+MUFA/saturated fatty acid (PUFA+MUFA/SFA)
ratio on plasma and liver lipid concentrations were studied. In experiment I, when rats were fed with 40% fat (energy%, PUFA/SFA
ratio 1.0) and 1% (w/w) cholesterol (C) diets for 21 d, a large amount of MUFA (28.1 energy%, PUFA+MUFA/SFA=5.7) in the diet
was found to increase the plasma total C, triacylglycerol (TAG), and phospholipid (PL) as compared with the low-MUFA diet
(7.0 energy%, PUFA+MUFA/SFA=1.4). The plasma very low density lipoprotein (VLDL)-C, VLDL-TAG, VLDL-PL, and low density lipoprotein
(LDL)-C increased significantly in the high-MUFA diet group, but high density lipoprotein (HDL)-C did not change significantly.
The high-MUFA diet resulted in greater accumulation of liver C but lesser accumulation of TAG. In experiment II, when dietary
SFA was fixed at a certain level (13.2 energy%; PUFA+MUFA/SFA=2.0), rats given a larger amount of MUFA (23.1 energy%; PUFA/MUFA=0.2;
MUFA/SFA=1.8) showed higher plasma and liver C levels than did the low-MUFA diet (7.7 energy%; PUFA/MUFA=2.5; MUFA/SFA=0.6).
When PUFA was fixed at a certain level (24.4 energy%), there was not a significant difference in the plasma C level between
the high-and low-MUFA dietary groups (PUFA+MUFA/SFA=4.8 and 8.4), but the higher PUFA+MUFA/SFA diet, which was high in MUFA/SFA
ratio, significantly decreased the plasma HDL-C and TAG levels. However, when MUFA content was fixed at a certain level (16.4
energy%), no significant difference was observed between the two groups with different PUFA/SFA ratios of 0.2 and 4.1, but
liver C level was raised in the higher PUFA/SFA diet. It appears that the PUFA/SFA ratio alone is unsuitable to predict the
change of plasma C level, because a large amount of dietary MUFA may lead to an increase of plasma and liver lipids in rats.
It seems that the prerequisites for keeping low plasma and liver C are (i) low MUFA/SFA ratio, (ii) high PUFA/MUFA ratio,
and (iii) PUFA+MUFA/SFA ratio not to exceed 2. 相似文献
13.
Yolk and embryonic total lipids were extracted from spotted dogfish eggs at two developmental stages. Total lipids were fractionated
into neutral lipids (NL) and polar lipids (PL), and the fatty acid composition of each group was determined. Yolk lipid composition
was found to be quantitatively different (NL/PL≊1) from embryo lipid composition (NL/PL≊0.5), for both stages of development.
However, individual fatty acid composition did not differ from younger to older eggs for either yolk or embryo. There were
significant differences (p<0.05) in major fatty acid groups from yolk and embryonic PL for saturated fatty acids, monounsaturated
fatty acids (MUFA) and n−3 polyunsaturated fatty acids (PUFA) for younger eggs, and for MUFA and n−3 PUFA for older eggs.
For NL, only MUFA composition from the oldest eggs showed differences between yolk and embryo. Results are discussed in terms
of embryonic needs for highly unsaturated fatty acid (HUFA) biosynthesis, as well as to provide some explanations for the
unusually high levels of 20∶4n−6 in both yolk and embryonic neutral lipids and polar lipids. 相似文献
14.
Functional and ultrastructural effects of essential fatty acid deficiency in kidney epithelial cells
Madin-Darby canine kidney (MDCK) epithelial cells were grown in culture medium supplemented with 1% fetal bovine serum (FBS)
to provide a cell culture model of essential fatty acid deficiency (EFAD). 5,8,11-Eicosatrienoic acid (20∶3n−9) accumulated
in cellular phospholipids, and arachidonic acid (20∶4) decreased. A large increase in cellular cholesterol/phospholipid ratio
was observed. Hemicyst formation was greatly reduced from normal levels in the EFAD-MDCK cells. Scanning and transmission
electron microscopy revealed that EFAD-MDCK were much flatter than their normal counterparts. They had much less dense surface
microvilli, mitochondria and other organelles were very sparse, except in the perinuclear area, and much of the peripheral
cytoplasm was amorphous. The EFAD was rapidly reversed by the addition of as little as 10 μM linoleic or arachidonic acid
to the medium. Cells supplemented with 10% FBS, the usual culture condition, displayed borderline EFAD, with intermediate
levels of 20∶3n−9 and 20∶4 and hemicyst formation. These studies suggest that EFAD reduces water and electrolyte transport
in renal tubular epithelium. 相似文献
15.
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
16.
Fatty acids,the immune response,and autoimmunity: A question of n−6 essentiality and the balance between n−6 and n−3 总被引:8,自引:0,他引:8
Harbige LS 《Lipids》2003,38(4):323-341
The essentiality of n−6 polyunsaturated fatty acids (PUFA) is described in relation to a thymus/thymocyte accretion of arachidonic
acid (20∶4n−6, AA) in early development, and the high requirement of lymphoid and other cells of the immune system for AA
and linoleic acid (18∶2n−6, LA) for membrane phospholipids. Low n−6 PUFA intakes enhance whereas high intakes decrease certain
immune functions. Evidence from in vitro and in vivo studies for a role of AA metabolites in immune cell development and functions shows that they can limit or regulate cellular
immune reactions and can induce deviation toward a T helper (Th)2-like immune response. In contrast to the effects of the
oxidative metabolites of AA, the longer-chain n−6 PUFA produced by γ-linolenic acid (18∶3n−6, GLA) feeding decreases the Th2
cytokine and immunoglobulin (Ig)G1 antibody response. The n−6 PUFA, GLA, dihomo-γ-linolenic acid (20∶3n−6, DHLA) and AA, and
certain oxidative metabolites of AA can also induce T-regulatory cell activity, e.g., transforming growth factor (IGF)-β-producing
T cells; GLA feeding studies also demonstrate reduced proinflammatory interleukin (IL)-1 and tumor necrosis factor (TNF)-α
production. Low intakes of long-chain n−3 fatty acids (fish oils) enhance certain immune functions, whereas high intakes are
inhibitory on a wide range of functions, e.g., antigen presentation, adhesion molecule expression, Th1 and th2 responses,
proinflammatory cytokine and eicosanoid production, and they induce lymphocyte apoptosis. Vitamin E has a demonstrable critical
role in long-chain n−3 PUFA interactions with immune functions, often reversing the effects of fish oil. The effect of dietary
fatty acids on animal autoimmune disease models depends on both the autoimmune model and the amount and type of fatty acids
fed. Diets low in fat, essential fatty acid deficient (EFAD), or high in long-chain n−3 PUFA from fish oils increase survival
and reduce disease severity in spontaneous autoantibody-mediated disease, whereas high-fat LA-rich diets increase disease
severity. In experimentally induced T cell-mediated autoimmune disease, EFAD diets or diets supplemented with long-chain n−3
PUFA augment disease, whereas n−6 PUFA prevent or reduce the severity. In contrast, in both T cell- and antibody-mediated
autoimmune disease, the desaturated/elongated metabolites of LA are protective. PUFA of both the n−6 and n−3 families are
clinically useful in human autoimmune-inflammatory disorders, but the precise mechanisms by which these fatty acids exert
their clinical effects are not well understood. Finally, the view that all n−6 PUFA are proinflammatory requires revision,
in part, and their essential regulatory and developmental role in the immune system warrants appreciation. 相似文献
17.
Jean François Pageaux Catherine Joulain Jean Michel Fayard Michel Lagarde Christian Laugier 《Lipids》1992,27(7):518-525
The fatty acid (FA) compositions of plasma and oviduct phospholipids (PL) and triglycerides (TG) were studied throughout the
natural sexual development of the Japanese quail. In the oviduct, PL concentration increased rapidly during the period of
active oviduct cell proliferation and then remained at a constant level during the phase of cellular hypertrophy. Oviduct
and plasma TG concentrations were 2- and 10-fold higher, respectively, in fully developed animals than in immature ones. During
natural sexual maturation of the quail, the FA compositions of PL and TG were markedly modified both in plasma and in oviduct.
These qualitative changes occurred predominantly during the period of intense cellular proliferation of oviduct cells, and
also were observed in immature animals injected with physiological doses of estradiol. In oviduct PL, the proportions of 20∶4n−6
and 22∶4n−6 decreased significantly (from 20 to 10% and 3.5 to 0.7%, respectively) whereas those of 18∶2n−6 increased (from
8.5 to 21%). In contrast, the plasma PL proportions of 20∶4n−6, 22∶4n−6 and 18∶2n−6 were decreased significantly and the percentage
of 18∶1n−9 doubled, suggesting that the oviduct is able to utilize certain plasma FA to a greater extent than others. Changes
in plasma and oviduct lipid composition occurring in the quail during sexual development may be attributed to estradiol, which
stimulates hepatic Δ9 desaturase and inhibits the oviduct Δ6 desaturase. The changes in FA composition observed in oviduct
phospholipids are discussed in relation to eicosanoid production and cellular proliferation. 相似文献
18.
The influence of age and cholesterol on polyunsaturated fatty acids (PUFa) levels was studied in young and old male Sprague-Dawley
rats. Animals were fed a fat-free diet supplemented with 10% (by wt) safflower oil with or without 1% cholesterol for 8 wk.
As a result of cholesterol feeding, proportions of linoleic acid (18∶2n−6) and dihomo-γ-linolenic acid (30∶3n−6) were increased
and and that of arachidonic acid (20∶4n−6) was decreased in the liver and platelet phospholipids in 64-wk-old rats, suggesting
inhibitory effects of cholesterol on 20∶4n−6 synthesis from 18∶2n−6. The prominent age-dependent effect on the levels of PUFA
was a retention of C−22 n−3 PUFA, accompanied by decreased C−22 n−6 PUFA and increased 20∶3n−6 in the liver and platelet phospholipids.
Ratio of 20∶3n−6/20∶4n−6 increased in 64-wk-old rats regardless of dietary cholesterol, suggesting depressed Δ5-desaturase
with age. In aorta phospholipids, 20∶3n−6 content and 20∶3n−6/20∶4n−6 ratio increased with cholesterol supplementation, but
not with age. These results suggest that changes of PUFA composition of platelet phospholipids with age are closely linked
with changes in liver phospholipids. The 20∶4n−6 content in both platelet and aorta phospholipids is kept constant, despite
other n−6 and n−3 PUFA being affected by age. 相似文献
19.
Blood phospholipid fatty acid analysis of adults with and without attention deficit/hyperactivity disorder 总被引:5,自引:0,他引:5
Several psychiatric disorders, including juvenile Attention Deficit/Hyperactivity Disorder (ADHD), have been associated with
abnormalities of certain long-chain PUFA (LCPUFA). Despite this reported association, the FA levels of patients with the adult
form of ADHD have not previously been evaluated. In this study we measured the total blood phospholipid FA concentrations
in 35 control subjects and 37 adults with ADHD symptoms to determine whether adults with ADHD symptoms would show abnormalities
of FA relative to control subjects. In the serum phospholipids, adults with ADHD symptoms had significantly lower levels of
total saturated, total polyunsaturated, and total omega-6 (n−6) FA, as well as the omega-3 (n−3) LCPUFA DHA (22∶6n−3), and
significantly higher levels of total monounsaturated FA and the n−3 LCPUFA docosapentaenoic acid (22∶5n−3). In the erythrocyte
membrane phospholipids, adults with ADHD symptoms had significantly lower levels of total PUFA, total n−3 FA, and DHA, and
significantly higher levels of total saturated FA. Neither serum nor erythrocyte membrane phospholipid DHA was related to
ADHD symptom severity (as assessed by the Amen questionnaire) in ADHD subjects. Although the exact cause of these variations
is unknown, both environmental and genetic factors may be involved. 相似文献
20.
Milkfat is a complex mixture of many diverse FA, some of which have demonstrated health benefits including anticancer properties.
Attempts are under way to enrich milkfats with long-chain n−3 PUFA and CLA. It has been recommended that the analysis of these
milkfats requires gas chromatography (GC) equipped with long, highly polar capillary columns. However, many analyses have
been reported using CARBOWAXTM type (polyethylene glycol) capillary columns, such as SUPELCOWAX 10, even though the separation characteristics of many of
the FA and their isomers present in milkfats have not been described in detail. This includes the isomers of CLA, cis- and trans-octadecenoic acid (18∶1), linoleic acid (18∶2n−6), and linolenic acid (18∶3n−3), and the long-chain PUFA. On the other hand,
the resolution of these FA and their isomers has been more fully described using the highly polar capillary columns, such
as CP Sil 88 and SP2560 because of the improved resolution obtained using these polar columns. The present study was undertaken
to characterize the separation of these FA present in milkfats using a 60-m SUPELCOWAX 10 column, to compare the results to
those from a 100-m CP Sil 88 column, and to determine if these two columns could possibly serve to complement each other for
the analysis of total milkfat. The advantages of the SUPELCOWAX 10 column were a better resolution of the short-chain saturated
from their monounsaturated FA (MUFA) analogs, and a complete separation of the α-linolenic (18∶3n−3) and eicosadecenoic acid
(20∶1) isomers. It also provided an alternative elution order of the linoleic (18∶2n−6), 18∶3n−3 and γ-linolenic (18∶3n−6)
acid isomers. On the other hand, the CP Sil 88 column provided a better resolution of the CLA isomers, MUFA, the isolated
cis and trans MUFA fractions, the PUFA, and many the 18∶2n−6 and 18∶3n−3 isomers. A complete analysis of milk lipids using the CP Sil 88
column required the prior separation of total FAME using silver ion-TLC. The results of the present study confirm that the
100-m highly polar capillary GC columns are mandatory for the analysis of milk lipids, and at best, the 60 m SUPELCOWAX 10
capillary column serves as a complementary GC column to provide different separations in certain regions based on its intermediate
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