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1.
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
2.
Cod (mean start weight of 26 g) were fed three diets for 15 months, each based on a dry pellet coated at a level of 9g/100
g with soybean oil, capelin oil or sardine oil. The fatty acid compositions of neutral lipids and four glycerophospholipids
of white muscle, liver, gills and heart were determined. The fatty acid composition of dietary lipids influenced the composition
of neutral lipids in all organs. Linoleic acid (18∶2n−6) from soybean oil was selectively incorporated into phosphatidylcholine
of the four tissues. Similar levels of 20∶5n−3 and 22∶6n−3 in phosphatidylcholine and phosphatidylethanolamine were found
in all organs from cod fed capelin oil and sardine oil in spite of highly differentiated feed fatty acid levels. The polyunsaturated
fatty acid (PUFA) composition of phosphatidylinositol was least influenced by dietary lipids. The preferred monoenic fatty
acid in phospholipids of cod was 18∶1n−9, independent of dietary intake, whereas the longer chain monoenoic acids seemed to
be preferentially catabolized. The results suggest that 20∶4n−6 as well as 20∶5n−3 and 22∶6n−3 fatty acids are essential for
cod. 相似文献
3.
L. Ulmann J. P. Blond C. Maniongui J. P. Poisson G. Durand J. Bézard G. Pascal 《Lipids》1991,26(2):127-133
The combined effects of age and dietary n−6 and n−3 fatty acids were studied in 3-, 6- and 9-month-old rats. At each age,
two groups were fed diets containing 5% (w/w) of vegetable oils rich in either 18∶3n−6 (borage group) or 18∶3n−6 plus 18∶4n−3
(black currant group), for a period increasing with age. A control group was fed the essential fatty acids 18∶2n−6 and 18∶3n−3
only. For each group, Δ6, Δ5 and δ9 desaturase activities were measured in liver microsomes, and fatty acid composition was
determined in microsomal phospholipids. Desaturase activity varied as a function of age and dietary lipids. Δ6 Desaturation
of 18∶3n−3 was more sensitive to these factors while Δ6 desaturation of 18∶2n−6 and Δ9 desaturation were more dependent on
season than the other two. Desaturase activity was influenced more by the black currant than by the borage diet, especially
at 6 and 9 months of age. A large proportion of arachidonic acid was maintained in the microsomes independent of the diet.
Changes in the fatty acid composition did not strictly reflect the differences in desaturase activities. The effects of the
two factors (age and diet) on the activities of the desaturases are complex, suggesting that the enzymes are susceptible to
other factors as well. 相似文献
4.
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
5.
The present study examined the effects of two atherogenic factors, animal protein and cholesterol, on the distribution of
fatty acids and the molecular species of major liver phospholipids in mice. Weanling mice were fed a semisynthetic diet supplemented
with either casein or soy protein (20%, w/w) in the presence or absence of 0.5% cholesterol for 4 wk. Results from mouse liver
showed that animal protein and, more so, dietary cholesterol modified the fatty acid profiles of the phospholipids. Animal
protein had no significant effect on the concentration of lipids, but it altered the relative distribution and fatty acid
profiles of the phospholipids, phosphatidylcholine and phosphatidylethanolamine. Dietary cholesterol, on the other hand, significantly
increased the concentration of liver lipids, but it did not alter the relative distribution of phosphatidylcholine and phosphatidylethanolamine.
In cholesterol-fed mice, the proportions of molecular species containing 18∶2n−6 were increased, whereas those containing
20∶4n−6 were decreased, indicating that dietary cholesterol suppressed linoleic acid metabolism. Since cholesterol feeding
selectively decreased the ratio of 18∶0/20∶4n−6 in phosphatidylcholine, whereas it increased the 18∶0/18∶2n−6 ratio in phosphatidylethanolamine,
this finding suggests that dietary cholesterol may affect the incorporation of fatty acids but not the rate of synthesis of
phosphatidylcholine and phosphatidylethanolamine. 相似文献
6.
Rats adapted to a corn oil or a fish oil diet were fed a fat-free diet, and changes in phospholipid polyunsaturated fatty
acids (PUFA) in the inner and outer leaflets of liver microsomal membranes were followed for 18 wk. In rats previously adapted
to a corn oil diet, arachidonic acid in phosphatidylcholine and phosphatidylethanolamine in the inner and outer leaflets did
not decrease quickly; rather, linoleic acid decreased more than arachidonic acid for the first three weeks of feeding the
fat-free diet. Even at 18 wk, 40–50% of the beginning arachidonic acid levels were still retained. In contrast, in rats previously
adapted to a fish oil diet, the n−3 PUFA were quickly decreased by the fat-free diet to only 10–30% at 18 wk. Due to the appearance
and increase of n−9 eicosatrienoic acid in the replacement of the n−3 and n−6 PUFA, total PUFA did not decrease in the inner
and outer phosphatidylcholine in either group, but decreased somewhat in the phosphatidylethanolamine due to the insufficient
increase of the n−9. On the other hand, the overall degrees of unsaturation in phosphatidylcholine fatty acids were always
higher in the outer than in the inner leaflets and were not altered by feeding the fat-free diet even for 18 wk. Thus, the
results appear to reveal the physiological importance of unsaturation ratio of fatty acids and the necessity of arachidonic
acid in each membrane leaflet. 相似文献
7.
Sheila M. Innis Salim S. Akrabawi Deborah A. Diersen-Schade M. Velma Dobson David G. Guy 《Lipids》1997,32(1):63-72
This multicenter, parallel group study determined plasma phospholipid and red blood cell (RBC) phosphatidylcholine and phosphatidylethanolamine
fatty acids, plasma cholesterol, apo A-1 and B, growth and visual acuity (using the acuity card procedure) in term infants
fed from birth to 90 d of age with formula containing palm-olein, high oleic sunflower, coconut and soy oil (22.2% 16∶0, 36.2%
18∶1, 18% 18∶2n−6, 1.9% 18∶3n−3) (n=59) or coconut and soy oil (10.3% 16∶0 18∶6% 18∶1, 34.2% 18∶2n−6, 4.7% 18∶3n−3) (n=57) or breast-fed (n=56) with no formula supplementation. Different centers in North America were included to overcome potential bias due to differences
in n−6 or n−3 fatty acids at birth or in breast-fed infants that might occur in a single-site study. Plasma and RBC phospholipid
docosahexaenoic acid (DHA, 22∶6n−3) and arachidonic acid (AA, 20∶4n−6), cholesterol and apo B were significantly lower in
the formula- than breast-fed infants. There were no differences in looking acuity or growth among the breast-fed and formula-fed
infants. No significant relations were found between DHA and looking acuity, or AA and growth within or among any of the infant
groups. This study provides no evidence to suggest the formula provided inadequate n−6 or n−3 fatty acids for growth and looking
acuity for the first 3 mon after birth. 相似文献
8.
Watkins SM Lin TY Davis RM Ching JR DePeters EJ Halpern GM Walzem RL German JB 《Lipids》2001,36(3):247-254
Diet and fatty acid metabolism interact in yet unknown ways to modulate membrane fatty acid composition and certain cellular
functions. For example, dietary precursors or metabolic products of n-3 fatty acid metabolism differ in their ability to modify
specific membrane components. In the present study, the effect of dietary 22∶6n−3 or its metabolic precursor, 18∶3n−3, on
the selective accumulation of 22∶6n−3 by heart was investigated. The mass and fatty acid compositions of individual phospholipids
(PL) in heart and liver were quantified in mice fed either 22∶6n−3 (from crocodile oil) or 18∶3n−3 (from soybean oil) for
13 wk. This study was conducted to determine if the selective accumulation of 22∶6n−3 in heart was due to the incorporation
of 22∶6n−3 into cardiolipin (CL), a PL most prevalent in heart and known to accumulate 22∶6n−3. Although heart was significantly
enriched with 22∶6n−3 relative to liver, the accumulation of 22∶6n−3 by CL in heart could not quantitatively account for this
difference. CL from heart did accumulate 22∶6n−3, but only in mice fed preformed 22∶6n−3. Diets rich in non-22∶6n−3 fatty
acids result in a fatty acid composition of phosphatidylcholine (PC) in heart that is unusually enriched with 22∶6n−3. In
this study, the mass of PC in heart was positively correlated with the enrichment of 22∶6n−3 into PC. The increased mass of
PC was coincident with a decrease in the mass of phosphatidylethanolamine, suggesting that 22∶6n−3 induced PC synthesis by
increasing phosphatidylethanolamine-N-methyltransferase activity in the heart. 相似文献
9.
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
10.
The effect of stearidonic acid (18∶4n−3) present in fish and some plant oils, such as black currant seed oil, was studied
on human platelets. When added to platelets simultaneously with collagen, arachidonic acid or endoperoxide mimetic U46619,
18∶4n−3 appeared as a weak inhibitor of platelet aggregation. In addition, 18∶4n−3 did not alter the metabolism of exogenous
arachidonic acid. In contrast, when preincubated with platelets after precoating onto albumin, 18∶4n−3 inhibited platelet
aggregation induced by thrombin, collagen, arachidonic acid or U46619, and was as potent as eicosapentaenoic acid (20∶5n−3)
tested under similar conditions. Stearidonic acid also altered the endogenous arachidonate oxygenation stimulated by low doses
of thrombin, but to a significantly lesser extent than did 20∶5n−3. It seems therefore that, in addition to competing with
endogenous arachidonate metabolism, 18∶4n−3 may affect platelet aggregation by another mechanism. 相似文献
11.
Y. -S. Huang P. E. Wainwright P. R. Redden D. E. Mills B. Bulman-Fleming D. F. Horrobin 《Lipids》1992,27(2):104-110
This report examines the distribution of n−3 and n−6 fatty acids in heart, kidney and liver phosphatidylcholine and phosphatidylethanolamine
of suckling mice from dams fed a fat-supplemented diet with variable n−3/n−6 ratios. After conception and throughout the pregnancy
and lactation period, dams were fed a fat-free liquid diet supplemented with 20% by energy of oil mixtures (fish oil concentrate,
rich in 20∶5n−3 and 22∶6n−3, and safflower oil concentrate, rich in 18∶2n−6). The diets contained similar amounts of combined
n−3 and n−6 fatty acids but variable ratios of n−3 to n−6 fatty acids (0,025, 0.5, 1, 2, and 4). In 12-day-old suckling mice,
as the n−3nn−6 ratio in the maternal diet increased (up to approx. 0.5), the tissue levels of 20∶5n−3, 22∶5n−3 and 22∶6n−3
increased, whereas those of 18∶2n−6 and 20∶4n−6 decreased. The responses were similar in both phospholipid subclasses, but
varied between different tissues. Generally, the n−3/n−6 ratios were significantly greater in pup tissues than in milk fat,
indicating preferential incorporation of n−3 over n−6 fatty acids into phospholipids during growth. However, the incorporation
of n−3 fatty acids in pups was significantly suppressed whereas that of n−6 fatty acids was increased when 18∶2n−6 was replaced
by its δ6-desaturation product, 18∶3n−6 (concentrated from evening primrose oil), as the source on n−6 fatty acid. This result
suggests that δ6 desaturase activity in neonate tissues is low, and consequently, the metabolism of 18∶2n−6 to longer chain
n−6 fatty acids is reduced. The preformed long-chain n−3 fatty acids, which bypass δ6-desaturation, were thus, preferentially
incorporated into tissue phospholipids. 相似文献
12.
A study of the fatty acid composition of red cell phosphatidylcholine and phosphatidylethanolamine and serum cholesterol was
undertaken in 185 Canadian Inuit (age 2 months-82 years). Samples from 24 Canadian men and women (21–50 years) living in Vancouver
were also analyzed as a reference for the Inuit in this age range. Dietary survey of the Inuit community (325 Inuit) demonstrated
a diet based on traditional foods in which the principal source of n−3 fatty acid was marine mammal flesh (mean intake: 164
g/person/day) rather than fish (mean intake: 13 g/person/day). Compared to the Vancouver samples, the Inuit phosphatidylethanolamine
had higher 20∶5n−3 and 22∶6n−3 and lower 20∶4n−6, but similar 18∶2n−6 levels. The level of 20∶5n−3 was higher and 20∶4n−6
was lower in the Inuit than in the Vancouver red cell phosphatidylcholine. Despite these differences in percentage content
of C20 and C22 n−6 and n−3 fatty acids, the mean chain length and unsaturation index of the Inuit and Vancouver red cell phosphatidylcholine
and phosphatidylethanolamine were very similar. Serum cholesterol concentration showed no sex difference within the Inuit,
and no difference from Vancouver men and women of similar age. The analyses suggest that the fatty acid composition of the
Inuit red cell phospholipids are primarily a reflection of their diet-fat composition. 相似文献
13.
The effects of hypothyroidism and of daily treatment for up to 21 days with thyroxin (T4, 0.5 μg/100 g body weight) on the
fatty acid composition of total lipid, phosphatidylethanolamine, and phosphatidylcholine of rat liver mitochondria were studied.
The fatty acid compositions of hypothyroid and euthyroid (control) rats of similar age were compared. The n−6 and n−3 polyunsaturated
fatty acids (PUFA) were affected differently by the hypothyroid state. The levels of linoleic (18∶2n−6), γ-linolenic (18∶3n−6)
and dihomo-γ-linolenic acids (20∶3n−6) were higher in hypothyroid rats than in controls, while the level of arachidonic acid
(20∶4n−6) was lower, which suggests an impairment of the elongase and desaturase activities. The n−3 polyunsaturated fatty
acids, eicosapentaenoic (EPA, 20∶5n−3) and docosapentaenoic (22∶5n−3) acids, were higher in hypothyroid rats, whereas the
linolenic acid (18∶3n−3) content remained constant. The level of docosahexaenoic acid (DHA, 22∶6n−3) was dramatically decreased
in hypothyroid rats, while the levels of C22 n−6 fatty acids were unchanged. The differences were probably due to the competition between n−3 and n−6 PUFA for desaturases,
elongases and acyltransferases. When hypothyroid rats were treated with thyroxin, the changes induced by hypothyroidism in
the proportions of n−6 fatty acids were rapidly reversed, while the changes in the n−3 fatty acids were only partially reversed.
After 21 days of thyroxin treatments, the DHA content was only half as high in hypothyroid rats than in euthyroid rats. These
results suggest that the conversion of 18∶2n−6 to 20∶4n−6 is suppressed in the hypothyroid state which favors the transformation
of 18∶3n−3 to 20∶5n−3. The marked decrease in DHA content indicates an impairment of the enzymes involved in the DHA metabolism,
possibly the n−3 Δ4 desaturase or the acyltransferases. The increased levels of EPA and 22∶5n−3 is consistent with the inhibition
of the n−3 pathway at the Δ4 desaturase step. Observed modifications in the fatty acid composition may significantly alter
eicosanoid synthesis and membrane functions in hypothyroidism. 相似文献
14.
Claude Leger Lucie Fremont Didier Marion Ibrahim Nassour Marie-Françoise Desfarges 《Lipids》1981,16(8):593-600
This paper describes evidence of (n−3) and particularly of 22∶6 (n−3) fatty acid enrichment in trout lipoproteins as well
as in vitellogenin, egg lipovitellin and oil globule. Among the lipoproteins, HDL and LDL were the main forms of blood lipid
transport, whereas phospholipids and cholesteryl esters are the preferential chemical carriers for (n−3) fatty acid transport.
However, cholesteryl esters were less important as esterified fatty acid carriers than in man. Taken together with the data
obtained in mammals, our results suggest that there may be a relationship between EFA activity and the distribution of the
EFA among the lipoprotein lipid fractions in vertebrates, irrespective of the EFA series. Administration of an (n−3) fatty
acid deficient diet for three months prior to trout spawning produced a significant increase in egg lipid content, primarily
as a result of the increase of the oil globule composed almost exclusively of triacylglycerols. This diet decreased the 22∶6
(n−3), as well as the (n−3) fatty acid contents of lipoproteins, lipovitellin, vitellogenin and the oil globule. In contrast,
the (n−3) fatty acid level was always higher in lipoproteins and lipovitellin than in the vitellogenin and the oil globule.
Moreover, the relative levels of 22∶6 (n−3) and total (n−3) fatty acids were quite similar in lipoproteins and lipovitellin
on the one hand, and in vitellogenin and the oil globule on the other. These findings suggest a direct relationship between
the two forms of plasma lipid transport and the two egg compartments. During ovogenesis, dietary lipids seemed to be diverted
from the adipose tissue and essentially deposited in the egg. 相似文献
15.
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
16.
Three groups of male mice were fed a normal diet or a semisynthetic diet containing either 10% hydrogenated coconut oil (CO
group) or 10% menhaden oil (MO group) for two wk. The synthetic diet altered the fatty acid composition of lung microsomal
lipids. Mice ingesting menhaden oil contained greater amounts of eicosapentaenoic acid (20∶5 n−3), docosapentaenoic acid (22∶5
n−3) and docosahexaenoic acids (22∶6 n−3) and decreased amounts of n−6 fatty acids such as arachidonic and adrenic. Synthesis
of prostaglandin E2 and prostaglandin F2α from exogenous arachidonic acid was significantly depressed in n−3 fatty acid-enriched lung microsomes. These studies indicated
that dietary fish oil not only alters the fatty acid composition of lung microsomes but also lowers the capacity of lungs
to synthesize prostaglandins from arachidonic acid. 相似文献
17.
Effect of dietary n−3 and n−6 polyunsaturated fatty acids on lipid-metabolizing enzymes in obese rat liver 总被引:2,自引:0,他引:2
Isabelle Niot Joseph Gresti Jacqueline Boichot Georges Semporé Georges Durand Jean Bézard Pierre Clouet 《Lipids》1994,29(7):481-489
This study was designed to examine whether n−3 and n−6 polyunsaturated fatty acids at a very low dietary level (about 0.2%)
would alter liver activities in respect to fatty acid oxidation. Obese Zucker rats were used because of their low level of
fatty acid oxidation, which would make increases easier to detect. Zucker rats were fed diets containing different oil mixtures
(5%, w/w) with the same ratio of n−6/n−3 fatty acids supplied either as fish oil or arachidonic acid concentrate. Decreased
hepatic triacylglycerol levels were observed only with the diet containing fish oil. In mitochondrial outer membranes, which
support carnitine palmitoyltransferase I activity, cholesterol content was similar for all diets, while the percentage of
22∶6n−3 and 20∶4n−6 in phospholipids was enhanced about by 6 and 3% with the diets containing fish oil and arachidonic acid,
respectively. With the fish oil diet, the only difference found in activities related to fatty acid oxidation was the lower
sensitivity of carnitine palmitoyltransferase I to malonyl-CoA inhibition. With the diet containing arachidonic acid, peroxisomal
fatty acid oxidation and carnitine palmitoyltransferase I activity were markedly depressed. Compared with the control diet,
the diets enriched in fish oil and in arachidonic acid gave rise to a higher specific activity of aryl-ester hydrolase in
microsomal fractions. We suggest that slight changes in composition of n−3 or n−6 polyunsaturated fatty acids in mitochondrial
outer membranes may alter carnitine palmitoyltransferase I activity. 相似文献
18.
The lipid classes, fatty acids of total and individual lipids and sterols of Antarctic krill (Euphausia superba Dana) from two areas of the Antarctic Ocean were analyzed by thin layer chromatography (TLC), gas liquid chromatography (GLC)
and gas liquid chromatography/mass spectrometry (GLC/MS). Basic differences in the lipid composition of krill from the Scotia
Sea (caught in Dec. 1977) and krill from the Gerlache Strait (caught in Mar. 1981) were not observed. The main lipid classes
found were: phosphatidylcholine (PC) (33–36%), phosphatidylethanolamine (PE) (5–6%), triacylglycerol (TG) (33–40%), free fatty
acids (FFA) (8–16%) and sterols (1.4–1.7%). Wax esters and sterol esters were present only in traces. More than 50 fatty acids
could be identified using GLC/MS, the major ones being 14∶0, 16∶0, 16∶1(n−7), 18∶1(n−9), 18∶1(n−7), 20∶5(n−3) and 22∶6(n−3).
Phytanic acid was found in a concentration of 3% of total fatty acids. Short, medium-chain and hydroxy fatty acids (C≤10)
were not detectable. The sterol fraction consisted of cholesterol, desmosterol and 22-dehydrocholesterol. 相似文献
19.
The sciatic nerve of rats fed sunflower oil (6 mg 18∶3n−3/100 g of diet) presented dramatic alterations in the long chain
polyunsaturated fatty acids in comparison with those fed soy oil (130 mg 18∶3n−3/100 g of diet). In both 15-day-old and 60-day-old
animals fed sunflower oil, 22∶6n−3 (cervonic acid) was fourfold less, 22∶5n−6 was 10-fold greater; adrenic acid (22∶4n−6)
was slightly greater and arachidonic acid (20∶4n−6) was close to that in rats fed soy oil. The percentage distribution of
total polyunsaturated fatty acids as well as the individual saturated and monounsaturated fatty acids were the same in both
groups.
When the sunflower oil-fed animals were switched to a soy oil-containing diet for either 15 or 60 days, the percentage distribution
of 22∶6n−3 increased slowly to reach the control value 2.5 months later. Conversely 22∶5n−6 decreased slowly. The decay of
22∶5n−6 was more rapid than the increase of 22∶6n−3. 相似文献
20.
Male and female weanling rats that were born to dams fed a diet low in linolenic acid received diets of 15% lipids by weight
containing 45% elaidic acid (as trielaidin) and 8.5% or 0.1% linolenic acid for 10 weeks. Four other groups, in which palmitic
or oleic acid replaced elaidic acid in the diet, served as controls. The fatty acid profiles of several lipid classes were
determined in adipose tissue, adrenals, testes, heart and brain. Elaidic acid was incorporated into tissue lipids in varying
degrees, depending on the organ and on the lipid class. Feeding elaidic acid induced no changes in the polyunsaturated fatty
acid (PUFA) profiles of testes lipids but resulted in definite modifications of the PUFA patterns of heart phosphatidylcholine
(PC) and phosphatidylethanolamine (PE). In linolenic acid-deprived rats, arachidonic acid was decreased in PC and linoleic
acid was increased in both PC and PE; 22∶5n−6 was strongly depressed in both PC and PE. In linolenic acid-fed rats, 22∶6n−3
was decreased in PC and PE. These changes, on the whole, were more evident in females, and some also were observed in adrenal
cholesteryl esters but only slightly in brain phospholipids. the apparent inhibition of the biosynthesis of PUFA induced by
dietary elaidic acid appeared to be complex and of greater intensity in the n−6 fatty acid series than in their n−3 homologues. 相似文献