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1.
Because alterations in the dietary content of fatty acids are an important method for modulating macrophage eicosanoid production,
we have quantitated the levels of n−6 and n−3 polyunsaturated fatty acids in peritoneal macrophage individual phospholipids
from mice fed diets (3 wk) with either safflower oil (SAF), predominantly containing 18∶2n−6, borage (BOR) containing 18∶2n−6
and 18∶3n−6, fish (MFO) containing 20∶5n−3 and 22∶6n−3, and borage/fish mixture (MIX) containing 18∶2n−6, 18∶3n−6, 20∶5n−3
and 22∶6n−3. Dietary n−3 fattya cids were readily incorporated into macrophage phosphatidylcholine (PC), phosphatidylethanolamine
(PE), phosphatidylserine (PS) and phosphatidylinositol (PI). The increase in n−3 fatty acid levels was accompanied by a decrease
in the absolute levels of 18∶2n−6, 20∶4n−6 and 22∶4n−6 in PC, PE and PS. Interestingly, PI 20∶4n−6 levels were not significantly
lowered (P>0.05) in MIX and MFO macrophages relative to SAF and BOR. These data demonstrate the unique ability of this phospholipid
to selectively maintain its 20∶4n−6 levels. In BOR and MIX animals, 20∶3n−6 levels were significantly increased (P<0.05) in
all phospholipids relative to SAF and MFO. The combination of borage and fish oils (MIX diet) produced the highest 20∶3n−6/20∶4n−6
ratio in all phospholipids. These data show that the macrophage eicosanoid precursor levels of 20∶3n−6, 20∶4n−6 and n−3 acids
can be selectively manipulated through the use of specific dietary regimens. This is noteworthy because an increase in phospholipid
levels of 20∶3n−6 and 20∶5n−3, while concomitantly reducing 20∶4n−6, may have therapeutic potential in treating inflammatory
disorders. 相似文献
2.
Three groups of rats were fed diets with either 10 weight percent (wt%) of evening primrose oil, safflower oil or soybean
oil for 11 weeks. Diets contained 7.1 wt% linoleic acid +0.8 wt% γ-linolenic acid, 7.6 wt% linoleic acid, or 5.3 wt% linoleic
acid +0.7 wt% α-linolenic acid, respectively. In liver mitochondria as well as in heart, dietary γ-linolenic acid did not
affect the fatty acid profiles of phosphatidylcholnes (PC), phosphatidylethanolamines (PE) or cardiolipins (CL), whereas dietary
α-linolenic acid caused an increased formation of (n−3) polyunsaturated fatty acids (PUFA). The liver Δ6− and Δ5-desaturase
activities determined in vitro were not affected by the dietary fats. In brain PE, which are rich in C22− and C20-(n−3) PUFA,
as well as in testes PC and PE, which are rich in (n−6) PUFA, no effects were found from a partial replacement of dietary
linoleic acid with γ-linolenic acid or α-linolenic acid. In kidney PC, PE, phosphatidylinositol (PI) and CL, 20∶3(n−6) was
moderately elevated to ca. 1% following intake of γ-linolenic acid, whereas partial replacement of linoleic acid with α-linolenic
acid was followed by increased deposition of 22∶6(n−3) in PC and PE of testes and kidney. Thus, no general effect of evening
primrose oil on the content of (n−6) PUFA in rat tissue phospholipids was observed, wheras a significant incorporation of
γ-linolenic acid into liver and adipose tissue triglycerides was found. 相似文献
3.
We have utilized transgenic technology to develop a new source of γ-linolenic acid (GLA) using the canola plant as a host.
The aim of the present study was to compare the growth and fatty acid metabolism in rats fed equal amounts of GLA obtained
from the transgenic canola plant relative to GLA from the borage plant. Young male Sprague-Dawley rats (n=10/group) were randomized and fed a purified AIN93G diet (10% lipid by weight) containing either a mixture of high GLA canola
oil (HGCO) and corn oil or a control diet containing borage oil (BO) for 6 wk. GLA accounted for 23% of the triglyceride fatty
acids in both diets. Growth and diet consumption were monitored every 2–3 d throughout the study. At study termination, the
fatty acid composition of the liver and plasma phospholipids was analyzed by gas chromatography. The growth and diet consumption
of the HGCO group were similar to the BO group. There were no adverse effects of either diet on the general health or appearance
of the rats, or on the morphology of the major organs. There was no significant difference between the diet groups for total
percentage of n−6 polyunsaturated fatty acids present in either the total or individual phospholipid fractions of liver or
plasma. The relative percentage of GLA and its main metabolite, arachidonic acid, in each phospholipid fraction of liver or
plasma were also similar between groups. The percentage of 18∶2n−6 in liver phosphatidylethanolamine and phosphatidylinositol/serine
was higher (P<0.05) and 22∶5n−6 was lower in the HGCO group than the BO group. This finding could be attributed to the higher 18∶3n−3 content
in the HGCO diet than the BO diet. Results from this long-term feeding study of rats show for the first time that a diet containing
transgenically modified canola oil was well-tolerated, and had similar biological effects, i.e., growth characteristics and
hepatic metabolism of n−6 fatty acids, as a diet containing borage oil. 相似文献
4.
This study examined the effects of n−3 and n−6 polyunsaturated fatty acid alimentation on murine peritoneal macrophage phospholipids.
Mice were fed complete diets supplemented with either corn oil predominantly containing 18∶2n−6, borage oil containing 18∶2n−6
and 18∶3n−6, fish/corn oil mixture containing 18∶2n−6, 20∶5n−3 and 22∶6n−3, or fish/borage oil mixture containing 18∶2n−6,
18∶3n−6, 20∶5n−3 and 22∶6n−3. After two weeks, the fatty acid levels of glycerophosphoserines (GPS), glycerophosphoinositols
(GPI), sphingomyelin (SPH), and of the glycerophosphocholine (GPC) and glycerophosphoethanolamine (GPE) phospholipid subclasses
were determined. We found that mouse peritoneal macrophage GPC contain primarily 1-0-alkyl-2-acyl (range for the dietary groups, 24.6–30.5 mol %) and 1,2-diacyl (63.2–67.2 mol %), and that GPE contains 1-O-alk-1-enyl-2-acyl (40.9–47.4 mol. %) and 1,2-diacyl (44.2–51.2 mol %) subclasses. In general, fish oil feeding increased
macrophage 20∶5n−3, 22∶5n−3 and 22∶6n−3 levels while simultaneously reducing 20∶4n−6 in GPS, GPI, GPE and GPC subclasses except
for 1-O-alk-1′-enyl-2-acyl GPC. Administration of 18∶3n−6 rich diets (borage and fish/borage mixture) resulted in the accumulation
of 20∶3n−6 (2-carbon elongation product of 18∶3n−6) in most phospholipids. In general, the novel combination of dietary 18∶3n−6
and n−3 PUFA produced the highest 20∶3n−6/20∶4n−6 phospholipid fatty acid ratios. This study demonstrates that marked differences
in the responses of macrophage phospholipid classes and subclasses exist following dietary manipulation. The reduction of
20∶4n−6, while simultaneously increasing 30∶3n−6 and n−3 PUFA levels, may be important in relation to the putative beneficial
effects of 20∶3n−6 and fish oil on macrophage eicosanoid and platelet activating factor (PAF) biosynthesis. 相似文献
5.
An essential fatty acid (EFA) deficiency-like profile of fatty acids has been observed in HF-1 human skin fibro-blasts cultured
at clonal densities in MCDB 110 and 0.4% fetal bovine serum (FBS). The profile was characterized by an accumulation of 16∶1n−7,
18∶1n−9, 20∶3n−9 and 22∶3n−9, a reduction of n−6 fatty acids and a reduction in total polyunsaturated fatty acids (PUFA).
The fatty acid composition of sphingomyelin (SPH), phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidylinositol
(PI) and phosphatidylethanolamine (PE) was determined and, except for SPH, each displayed an EFA deficiency-like profile.
The triene to tetraene ratio (20∶3n−9/20∶4n−6) ranged from 5.3 in PI to 0.9 in PE. In addition, the highest percentage of
20∶3n−9 was present in the PI and the highest percentage of 22∶3n−9, in PE. Other human fibroblasts (normal, transformed and
at different population doubling number levels [PDL] were grown under the same conditions and were found to display triene
to tetraene ratios (20∶3n−9/20∶4n−6) in total cellular lipids ranging from 0.7 to 4.5. The accumulation of 20∶3n−9 and 22∶3n−9
is due primarily to the existence of a basal nutrient medium (MCDB 110) that allows for the rapid clonal growth of human fibroblasts
at reduced serum levels (0.4%). This culture procedure can be exploited to further elucidate various aspects of lipid metabolism
in human fibroblasts.
Fatty acids are abbreviated as number of carbon atoms: number of double bonds, followed by an n-number to designate the position
of the first double bond with respect to the methyl carbon. Thus, Mead acid is 20∶3n−9 and its elongation product is 22∶3n−9. 相似文献
6.
(n−3) and (n−6) polyunsaturated fatty acids in the phosphoglycerides of salt-secreting epithelia from two marine fish species 总被引:3,自引:0,他引:3
Fatty acid analyses were carried out on phosphoglycerides isolated from microsomal fractions of the rectal gland of the dogfish,Scyliorthinus canicula, and gills of the cod,Gadus morhua. Ratios of (n−3)/(n−6) polyunsaturated fatty acids were ca. 10 for phosphatidylcholine, (PC), phosphatidylethanolamine (PE)
and phosphatidylserine (PS) from cod gills, reflecting high concentrations of 20∶5 (n−3) and 22∶6(n−3). The ratio for phosphatidylinositol
(PI) from cod gills was 1.3, reflecting high concentrations of 20∶4(n−6) as well as (n−3) polyunsaturates. PC, PE and PS from
rectal glands all had much lower (n−3)/(n−6) ratios than in cod gills, reflecting higher concentrations of 20∶4(n−6), but
the lowest ratio was again present in PI. The latter phospholipid had high concentrations of 18∶0 in both tissues. The relative
constancy of the fatty acid composition of PI in the two salt-secreting tissues and its similarity to mammalian phospholipids
is considered to reflect its specialized role in biomembranes. 相似文献
7.
The purpose of this study was to examine the influence of long-term feeding of dietary fat rich in either n−3 or n−6 fatty
acids on the availability of arachidonic acid (20∶4n−6) in major phospholipids of gastric mucosa in rats. Three groups of
male Wistar rats were fed either a standard diet, a cod liver oil-enriched diet (10% by weight), or a corn oil-enriched diet
(10% by weight) for 8 mon. Dietary cod liver oil significantly reduced the level of 20∶4n−6 in phosphatidylcholine (PC) and
in phosphatidylethanolamine (PE) of gastric mucosa. The loss of 20∶4n−6 was compensated for by eicosapentaenoic acid (20∶5n−3)
in PC, whereas the decrease in 20∶4n−6 in PE corresponded to the increase in three n−3 fatty acids: 20∶5n−3, docosapentaenoic
acid (22∶5n−3), and docosahexaenoic acid (22∶6n−3). The level of 20∶5n−3 was higher than the level of 22∶6n−3 both in PC and
PE of mucosa in rats fed cod liver oil. Diets supplemented with corn oil increased the level of 18∶2n−6 but decreased the
monoene fatty acids 16∶1 and 18∶1n−7 in PC but not in PE of gastric mucosa. The 20∶4n−6 levels of both PC and PE were markedly
reduced by dietary cod liver oil, to about one-third of control levels. Similar changes were also observed in the stomach
wall. Gastric erosions were observed in all rats exposed to restriction stress, but this form of stress induced twice the
number of erosions in rats fed fish oil compared to control rats or rats fed corn oil. We conclude that a diet rich in fish
oil altered the balance between n−6 and n−3 fatty acids in major gastric mucosal phospholipids, markedly reduced the availability
of 20∶4n−6, and increased the incidence of gastric erosions induced by restriction or emotional stress. 相似文献
8.
Analyses of lipids and fatty acids in ripe roes of some Northwest European marine fish 总被引:7,自引:0,他引:7
Lipid class analyses and fatty acid analyses of neutral and polar lipids were carried out on ripe roes of herring, cod, haddock,
whiting, saithe, sand eel and capelin. Total lipid was 10–26% of roe dry weight. The species with the highest total lipid,
sand eel and capelin, also had the highest percentage of neutral lipid in total lipid, 77% and 49% respectively. In the other
species, phospholipids accounted for 62–77% of roe total lipid. Both the neutral lipids, and especially the phospholipids,
of all species were very unsaturated because of high concentrations of (n−3) polyunsaturated fatty acids (PUFA), frequently
amounting to 50% of the total egg lipid. Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) had similar fatty acid
compositions in all species, with an average ratio (n−3)/(n−6) of ca. 20∶1. Phosphatidylinositol (PI) consistently had high
concentrations of 18∶0 and 20∶4 (n−6) with an average ratio of (n−3)/(n−6) of 1.8∶1. Requirements for high levels of (n−3)
PUFA in the embryonic and early larval development stages of marine fish are suggested as is a special role for the 20∶4(n−6)
in PI. 相似文献
9.
The effects of oil-derived dietary essential fatty acids on the activities of mitchondrial Mn-SOD (manganese-superoxide dismutase)
and cytosolic cupric zinc-superoxide dismutase (Cu/Zn-SOD) were investigated in rat heart. A control group of rats was fed
a stock diet for 29 d, and a second group was fed on a fat-free diet. Three other groups were fed fat-free diets that were
supplemented with (i) borage oil, which is rich in linoleic (18∶2n−6) and γ-linolenic (18∶3n−6) acids, (ii) fungal oil, which
is rich in γ-linolenic, but low in linoleic acid, or (iii) evening primrose oil, which is rich in linoleic acid and low in
γ-linolenic acid. An increase in the percentage composition of arachidonic acid (20∶4n−6) in both the choline and ethanolamine
phospholipids, together with a decrease in linoleic acid in ethanolamine phospholipids, were found in heart membranes after
feeding the rats with diets containing borage oil or fungal oil as compared to those fed the stock diet. The respective activities
of Mn-SOD in rats fed the borage or fungal oil diets were also significantly higher than in rats fed the stock diet alone.
No change in cytosolic Cn/Zn-SOD activity was observed. Dietary supply of linoleic acid-rich evening primrose oil resulted
in an increased proportion of choline phospholipid linoleic acid without any changes in arachidonic acid content or in the
activity of Mn-SOD. By contrast, a reduction in the activity of Mn-SOD was detected in rats fed a fat-free diet. These results
show that the activity of heart mitochondrial Mn-SOD is influenced by dietary essential fatty acids, whereas the activity
of cytosolic Cu/Zn-SOD remained unaffected. 相似文献
10.
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
11.
Ward GR Huang YS Xing HC Bobik E Wauben I Auestad N Montalto M Wainwright PE 《Lipids》1999,34(10):1057-1063
This study evaluated the effects of dietary supple-mentation with ψ-linolenic acid (GLA, 18∶3n−6) and docosahexaenoic acid
(DHA, 22∶6n−3) on the fatty acid composition of the neonatal brain in gastrostomized rat pups reared artificially from days
5–18. These pups were fed rat milk substitutes containing fats that provided 10% linoleic acid and 1% α-linolenic acid (%
fatty acids) and, using a 2×3 factorial design, one of two levels of DHA (0.5 and 2.5%), and one of three levels of GLA (0.5,
1.0, and 3.0%). A seventh artificially reared groups served as a reference group and was fed 0.5% DHA and 0.5% arachidonic
acid (AA, 20∶4n−6); these levels are within the range of those found in rat milk. The eighth group, the suckled control group,
was reared by nursing dams fed a standard American Institute of Nutrition 93M chow. The fatty acid composition of the phosphatidylethanolamine,
phosphatidyl-choline, and phosphatidylserine/phosphatidylinositol membrane fractions of the forebrain on day 18 reflected
the dietary composition in that high levels of dietary DHA resulted in increases in DHA but decreases in 22∶4n−6 and 22∶5n−6
in brain. High levels of GLA increased 22∶4n−6 but, in contrast to previous findings with high levels of AA, did not decrease
levels of DHA. These results suggest that dietary GLA, during development, differs from high dietary levels of AA in that
it does not lead to reductions in brain DHA. 相似文献
12.
The content and composition of neutral lipids and phosphoglycerides from full-grown prophase-arrestedBufo arenarum Hensel oocytes and from their ghost preparations were studied. The ghosts obtained are highly enriched in plasma membrane
as suggested by the activity of 5′-nucleotidase, a marker enzyme, and the level of typical membrane components such as sphingomyelin,
phosphatidylserine (PS), phosphatidylinositol (PI), and phosphatidic acid. In whole oocytes, triacylglyceride (TAG) comprises
about 60% of the total lipids followed by phosphatidylcholine (PC), cholesterol, and phosphatidylethanolamine (PE). TAG and
diacylglycerides have a similar unsaturation index. PC and PE account for about 80% of the phosphoglycerides in the whole
oocyte and in their plasma membrane-enriched fractions. Arachidonic acid (20∶4n−6), 18∶0, and 16∶0 make up about 80 mol% of
the total fatty acids in Pl in whole oocytes and ghost fractions. The unsaturation index in PS is higher in intact oocytes
than in ghost preparations, probably owing to the significant amount of 20∶4n−6 which comprises 23 mol% of the total fatty
acids in whole oocytes. The fatty acid profile in phosphatidic acid from whole oocytes is rather different from that in ghosts.
Sphingomyelin contains mainly saturated and monounsaturated fatty acids, 24∶1 being the principal very long chain unsaturated
fatty acid in both oocytes and ghosts. 相似文献
13.
Robert A. Gibson Mark A. Neumann Sharon L. Burnard Josephine A. Rinaldi Glen S. Patten Edward J. McMurchie 《Lipids》1992,27(3):169-176
Adult male marmoset monkeys were fed eicosapentaenoic acid (20∶5n−3) as the ethyl ester in diets containing either 32% (reference
diet, no added cholesterol) or 7% (atherogenic diet with 0.2% added cholesterol) linoleic acid (18∶2n−6) for 30 wk. No changes
were seen in the level of phosphatidylcholine (PC) or phosphatidylethanolamine (PE) but minor changes were observed in both
the sphingomyelin (SPM) and phosphatidylinositol plus phosphatidylserine (PI+PS) fractions of erythrocyte lipids. The extent
of total n−3 fatty acid incorporation into membrane lipids was higher in atherogenic diets (polyunsaturated/monounsaturated/saturated
(P/M/S) ratio 0.2∶0.6∶1.0) than reference diets (P/M/S ratio 1∶1∶1) and this was true for both PE (33.4±1.0%vs 24.3±1.1%) and PC (9.3±0.5%vs 4.9±0.3%). Although suitable controls for cholesterol effects were not included in the study, earlier results obtained with
marmosets lead us to believe such effects were probably small. Regardless of basic diet (atherogenic, reference), 20∶5n−3
was preferentially incorporated into PE (10.8±0.2%, 6.0±0.02%) while smaller amounts were incorporated into PC (6.9±0.4%,
3.2±0.2%). The major n−3 polyunsaturated fatty acid found in PE in response to dietary 20∶5n−3 was the elongation metabolite
22∶5n−3 in both the atherogenic (17.7±0.7%) and reference (14.3±1.0%) dietary groups; 22∶6n−3 levels were less affected by
diet (4.7±0.3% and 3.9±0.2%, respectively). The results can be interpreted to indicate an inverse relationship between the
amount of dietary 18∶2n−6 and incorporation of 20∶5n−3 into erythrocyte membrane phospholipids regardless of whether the major
dietary n−3 fatty acid was α-linolenate (18∶3n−3) or 20∶5n−3. This interpretation is supported by theoretical calculations. 相似文献
14.
Adequate accumulation of polyunsaturated essential fatty acids, in particular docosahexaenoic acid (22∶6n−3), into membrane
phospholipids is critical for optimal fetal brain development. This process is maximal during the period of rapid neurite
outgrowth, neuritogenesis, which precedes the major growth phase, myelination. There is no information about differential
changes during gestation to individual brain phospholipid molecular species which contain 22∶6n−3. Such details of brain development
would be concealed by total fatty acid analysis of isolated phospholipid classes. We have detailed phosphatidylcholine (PC)
and phosphatidylethanolamine (PE) molecular species compositions in developing fetal guinea pig brain. Total brain PC concentration
increased substantially between 40 and 68 (term) d of gestation, corresponding to myelination, while PE increased in a biphasic
manner between 25–35 d, which was coincident with onset of neuritogenesis, and 40–68 d. Fetal brain development was accompanied
by complex changes in the concentration of individual phospholipid molecular species. During early gestation (25–40 d) 22∶6n−3
was enriched in both PC and PEsn−1 16∶0 molecular species. However, between 40 d and term there was no further increase in brain PC 22∶6n−3 content, while
brain PE was significantly enriched in both PE 18∶1/22∶6 and PE18∶0/22∶6. We hypothesize that accumulation of 22∶6n−3 intosn−1 18∶1 and 18∶0 species represents establishment of a 22∶6n−3-containing membrane PE pool which may be turned over more slowly
thansn−1 16∶0 species. Identification of specific changes in membrane phospholipids which are associated with defined events in
brain development may provide a basis for assigning functional roles to individual molecular species. 相似文献
15.
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
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.
The lipid composition of the pineal organ from the rainbow trout (Oncorhynchus mykiss) was determined to establish whether the involvement of this organ in the control of circadian rhythms is reflected by specific
adaptations of lipid composition. Lipid comprised 4.9% of the tissue wet weight and triacylglycerols were the major lipid
class present (47% of total lipid). Phosphatidylcholine (PC) was the principal polar lipid, and smaller proportions of other
phospholipids and cholesterol were also present. Plasmalogens contributed 11% of the ethanolamine glycerophospholipids (EGP).
No cerebrosides were detected. The fatty acid composition of triacylglycerols was generally similar to that of total lipids
in which saturated, monounsaturated and polyunsaturated fatty acids (PUFA) were present in almost equal proportions. Each
of the polar lipid classes had a specific fatty acid composition. With the exception of phosphatidylinositol (PI), in which
20∶4n−6 comprised 27.4% of the total fatty acids, 22∶6n−3 was the principal PUFA in all lipid classes. The proportion of 20∶5n−3
never exceeded 6.0% of the fatty acids in any lipid class. The predominant molecular species of PC were 16∶0/22∶6n−3 and 16∶0/18∶1,
which accounted for 33.2 and 28.5%, respectively, of the total molecular species of this phospholipid. Phosphatidylethanolamine
(PE) contained the highest level of di-22∶6n−3 (13.0%) of any phospholipid. There was also 4.9% of this molecular species
in phosphatidylserine (PS) and 4.1% in PC. In PE, the species 16∶0/22∶6, 18∶1/22∶6 and 18∶0/22∶6 totalled 45.1%, while in
PS 18∶0/22∶6 accounted for 43.9% of the total molecular species. The most abundant molecular species of PI was 18∶0/20∶4n−6
(37.8%). The lipid composition of the pineal organ of trout, and particularly the molecular species composition of PI, is
more similar to the composition of the retina than that of the brain.
Molecular species are abbreviated as follows: e.g., 16∶0/22∶6 PC is 1-palmitoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine. 相似文献
18.
We investigated the effect of oral supplementation with evening primrose oil, containing 72% linoleic acid (18∶2n−6) and 10%
γ-linolenic acid (18∶3n−6), on the epidermal and neutrophil phospholipid fatty acid composition in 15 patients with atopic
dermatitis (AD). Three different dose levels, 4, 8 and 12 capsules per day containing 0.5 g oil, were given to three groups
of patients. The only n−6 fatty acid showing a significant (p<0.05) dose-related increase was dihomo-γ-linolenic acid (20∶3n−6)
in neutrophil phospholipids. The highest dose increased dihomo-γ-linolenic acid by 45% in neutrophil phospholipids, by 46%
in lesion-free epidermal phosphatidylcholine, and by 15% in lesion-free epidermal phosphatidylethanolamine. In both lesional
and lesion-free epidermis, supplementation resulted in a rise in the ratio between n−6 and monounsaturated fatty acids, reaching
significance (p<0.05) in lesional epidermis. This study shows that moderate and favorable fatty acid changes can be obtained
in the epidermis of AD patients, when given 6 g per day of oil rich in n−6 fatty acids. The abnormal lipid and fatty acid
pattern of the atopic epidermis may be involved in the pathogenesis of the disease, and should therefore be the target for
future therapeutic approaches with fatty acid supplements. 相似文献
19.
The effect of supplementation with cod-liver oil containing eicosapentaenoic acid (EPA), 20∶5ω3, on bleeding times, thrombin-induced
platelet aggregation, platelet protein, platelet cholesterol, and the level and fatty acid composition of individual phospholipids
in the platelets of human subjects was determined. Measurement of these parameters was conducted before the subjects received
the supplement (day 0), after they received the supplement for 14 days (day 14), and 14 days after the supplement was terminated
(day 28) so as to monitor recovery. The mean bleeding times exhibited a marked increase (by 81%) with supplementation and
returned to near basal (day 0) values within 14 days after the supplement was terminated. Cod-liver oil supplementation significantly
reduced thrombin-induced platelet aggregation with a partial recovery being exhibited by day 28. The content of phospholipid,
cholesterol and protein (μg/109 platelets) was not significantly different (P>0.05) when isolated from the subjects at day 0, 14 and 28, as neither were
the composition of individual phospholipids [phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS),
phosphatidylinositol (PI) and sphingomyelin (SPH)] given as % of total phospholipid. However, the fatty acid compositions
of all platelet phospholipids were altered significantly by the fish oil supplement. In PC, EPA rose from 0.3 to 2.9% of total
fatty acids and docosahexaenoate from 0.7 to 1.8% concomitant with a drop in arachidonate (from 14.1 to 9.6%) and linoleate
(from 10.2 to 7.9%); these levels approached basal levels 14 days after supplementation was terminated. The highest percentage
of EPA with supplementation was found in PE (4.3%), while the arachidonate fell from 38.8 to 30.5%, with low percentages of
EPA occurring in PS (0.7%) and PI (0.5%). The level of 24∶1 in SPH increased significantly (from 17.8 to 24.8) with supplementation
and reverted to basal values by day 28. These results suggest a close relationship of the observed fatty acid changes in individual
platelet phospholipids to the altered hematological parameters and platelet-vessel wall interactions produced by cod-liver
oil supplementation. 相似文献
20.
M. S. K. Syed Rahmatullah V. K. S. Shukla K. D. Mukherjee 《Journal of the American Oil Chemists' Society》1994,71(6):569-573
Lipase-catalyzed selective partial hydrolysis of evening primrose (Oenothera biennis L.) seed oil and borage (Borago officinalis L.) seed oil led to an increase in the level of γ-linolenic acid (GLA; 18∶3n−6) in the unhydrolyzed acylglycerols. Thus,
in evening primrose oil, the GLA level could be raised from 9.4% in the starting material to 46.5% in the unhydrolyzed acylglycerols
by means of a lipase fromCandida cylindracea. Selective hydrolysis of borage oil with Pancreatin led to an increase in the GLA content from 20.4% in the oil to 33.5%
in the unhydrolyzed acylglycerols. Partial hydrolysis of borage oil with lipase fromC. cylindracea raised the GLA content of the acylglycerols to 47.8%. 相似文献