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1.
The effect of fish oil high in docosahexaenoic acid (22∶6n−3) and low in eicosapentaenoic acid (20∶5n−3) in formula on blood
lipids and growth of full-term infants was studied. Infants were fed formula with about 15% oleic acid (18∶1), 32% linoleic
acid (18∶2n−6), 4.9% linolenic acid (18∶3n−3) and 0, 0.10 or 0.22% 22∶6n−3, or 35% 18∶1, 20% 18∶2n−6, 2.1% 18∶3n−3 and 0,
0.11 or 0.24% 22∶6n−3 from 3 d to 16 wk of age (n=16, 18, 17, 21, 17, 16, respectively). The formulae had <0.1% 20∶5n−3 and no arachidonic acid (20∶4n−6). Breast-fed infants
(n=26) were also studied. Plasma phospholipid and red blood cell (RBC) phosphatidylcholine (PC) and phosphatidylethanolamine
(PE) fatty acids were determined at 3 d and 4, 8, and 16 wk of age. These longitudinal analyses showed differences in blood
lipid 22∶6n−3 between breast-fed and formula-fed infants depending on the feeding duration. At 16 wk, infants fed formula
with 0.10, 0.11% 22∶6n−3, or 0.22% 22∶6n−3 had similar 22∶6n−3 levels in the plasma phospholipid and RBC PC and PE compared
with breast-fed infants and higher 22∶6n−3 than infants fed formula without 22∶6n−3. Formula with 0.24% 22∶6n−3, however,
resulted in higher plasma phospholipid 22∶6n−3 than in breast-fed infants at 16, but not 4 or 8 wk of age. Plasma and RBC
phospholipid 20∶4n−6 was lower in formula-fed than breast-fed infants, but no differences in growth were found. Higher blood
lipid C20 and C22 n−6 and n−3 fatty acids in infants fed formula with 20% 18∶2n−6 and 2.4% 18∶3n−3 compared with 32% 18∶2n−6 and 4.9% 18∶3n−3
show the increase in blood lipid 22∶6n−3 in response to dietary 22∶6n−3 depending on other fatty acids in the formula. 相似文献
2.
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
3.
The esterification, desaturation, and elongation of [1-14C]18∶3n−3, [1-14C]18∶2n−6, and [1-14C]20∶5n−3 at 5 and at 12°C were studied using cultivated hepatocytes from Atlantic salmon. The salmon were fed diets, in which
0, 50, or 100% of the supplementary fish oil had been replaced by soybean oil, for 950 day-degrees at 5 and 12°C. The endogenous
percentage of 18∶2n−6 in hepatocyte lipids was 2% in cells from fish fed a diet with 100% of the supplemental lipid from fish
oil, and it was slightly less than 25% in cells from fish fed the diet with 100% of the supplemental lipid from soybean oil.
Furthermore, the percentages of 20∶3n−6 and 20∶4n−6 were significantly higher in hepatocytes from fish fed on soybean oil
than they were in those of fish fed on fish oil. The percentages of 20∶5n−3 and 22∶6n−3, on the other hand, were lower. The
endogenous levels of n−6 FA were not significantly correlated with the total amounts of radiolabeled FA esterified in hepatocyte
lipids. The main radiolabeled products formed from 18∶2n−6 were 20∶2n−6 and 20∶3n−6. The level of the important eicosanoid
precursor 20∶4n−6 was twice as high in hepatocyte phospholipids from fish fed the 100% soybean oil diet as it was in hepatocytes
from fish fed the diet with 100% of supplemental lipid from fish oil. The main products formed from 18∶3n−3 were 20∶4n−3,
20∶5n−3, and 22∶6n−3. High levels of dietary 18∶2n−6 do allow, or even seem to increase, the production of 22∶6n−3 from 18∶3n−3
in hepatocytes. The main products formed from 20∶5n−3 were 22∶5n−3 and 22∶6n−3. The production of 22∶6n−3 from 20∶5n−3 was
higher at 5°C than at 12°C. The percentage of 24∶5n−3 was higher at 5°C than it was at 12°C, as was the ratio of 24∶5 to 22∶5.
These results suggest that the elongation rate of 22∶5n−3 to 24∶5n−3 is higher at the lower temperature. 相似文献
4.
Docosahexaenoic acid (22∶6n−3) can be synthesized in the liver and/or brain from α-linolenic acid (18∶3n−3) and is required
in large amounts in structural membranes of developing brain and retina. The adequacy and efficacy of formulas containing
18∶3n−3 and/or fish oil in providing 22∶6n−3 for deposition was investigated in piglets fed formula from birth to 15 days.
The test formulas contained high (HL) or low (LL) 18∶3n−3 (3.9 or 0.7% of the total formula fatty acids, respectively), or
low 18∶3n−3 plus fish oil (LL+FO) to provide C20 and C22 n−3 polyunsaturated fatty acids (0.8% of total fatty acids). Fatty acid analyses of synaptic plasma membrane and retina ethanolamine
phospholipids (EPL), which are especially enriched in 22∶6n−3, were compared to those of 15-day-old piglets fed sow milk (SM).
Feeding LL resulted in lower 22∶6n−3 in synaptic plasma membrane. Fatty acid levels in HL and LL+FO piglets were equivalent
to SM, with the exception of lower 22∶5n−3 in the synaptic plasma membrane of LL+FO and in the retina of HL and LL+FO-fed
piglets. Levels of 22∶4n−6 were also lower in the retina of the LL+FO group. The results suggest formula 18∶3n−3 is at least
24% as effective as C20 and C22 n−3 fatty acids as a source of membrane 22∶6n−3. This study shows dietary 18∶3n−3, as the only n−3 fatty acid, can support
deposition of comparable percentage of 22∶6n−3 to natural milk. Fish oil also supported tissue levels of 22∶6n−3 similar to
natural milk; however, lower 22∶4n−6 may indicate possible inhibitory effects on n−6 metabolism.
Recipient of the 1967 Science and Engineering Scholarship, Natural Sciences & Engineering Research Council of Canada. 相似文献
5.
Sheila M. Innis Roger Dyer Louis Wadsworth Paul Quinlan Deborah Diersen-Schade 《Lipids》1993,28(7):645-650
Platelet lipid composition is important to normal platelet morphology and function, and is influenced by dietary fatty acids
and cholesterol. The fatty acid composition and cholesterol content of infant formulas differs from those of human milk, but
the possible effects on platelet lipids in young infants is not known. This was studied in piglets fed from birth to 18 d
of age with one of eight formulas differing in saturated fatty acid chain length, or content of 18∶1, 20∶5n−3 plus 22∶6n−3,
or cholesterol. A reference group of piglets fed sow milk was also studied. Sow milk has a fatty acid composition and cholesterol
content similar to that of human milk. Piglets fed formulas high in 18∶1 (34.9–40.8% wt fatty acids) and low in 16.0 (≤6.5%
wt fatty acids) had lower platelet counts and greater platelet size than piglets fed sow milk (40.4% 18∶1, 30.7% 16∶0). Piglets
fed formulas high in 16∶0 (27–29.6%) and 18∶1 (40–40.6%), or low in both 16∶0 (5.9–6.1%) and 18∶1 (10.8–11.2%), had similar
platelet counts and size to piglets fed sow milk. Platelet phospholipid % 20∶4n−6 was lower in all the groups of piglets fed
formula than in the group fed sow milk. Addition of fish oil with 20∶5n−3 plus 22∶6n−3 to the formula further decreased platelet
phospholipid 20∶4n−6. Addition of cholesterol to the formula increased the platelet phospholipid % 20∶4n−6 and platelet volume. 相似文献
6.
Maternal fish oil supplementation in lactation: Effect on visual acuity and n−3 fatty acid content of infant erythrocytes 总被引:5,自引:0,他引:5
Lauritzen L Jørgensen MH Mikkelsen TB Skovgaard lM Straarup EM Olsen SF Høy CE Michaelsen KF 《Lipids》2004,39(3):195-206
Studies on formula-fed infants indicate a beneficial effect of dietary DHA on visual acuity. Cross-sectional studies have
shown an association between breast-milk DHA levels and visual acuity in breast-fed infants. The objective in this study was
to evaluate the biochemical and functional effects of fish oil (FO) supplements in lactating mothers. In this double-blinded
randomized trial, Danish mothers with habitual fish intake below the 50th percentile of the Danish National Birth Cohort were
randomized to microencapsulated FO [1.3 g/d long-chain n−3 FA (n−3 LCPUFA)] or olive oil (OO). The intervention started within
a week after delivery and lasted 4 mon. Mothers with habitual high fish intake and their infants were included as a reference
group. Ninety-seven infants completed the trial (44 OO-group, 53 FO-group) and 47 reference infants were followed up. The
primary outcome measures were: DHA content of milk samples (0, 2, and 4 mon postnatal) and of infant red blood cell (RBC)
membranes (4 mon postnatal), and infant visual acuity (measured by swept visual evoked potential at 2 and 4 mon of age). FO
supplementation gave rise to a threefold increase in the DHA content of the 4-mon milk samples (P<0.001). DHA in infant RBC reflected milk contents (r=0.564, P<0.001) and was increased by almost 50% (P<0.001). Infant visual acuity was not significantly different in the randomized groups but was positively associated at 4
mon with infant RBC-DHA (P=0.004, multiple regression). We concluded that maternal FO supplementation during lactation did not enhance visual acuity
of the infants who completed the intervention. However, the results showed that infants with higher RBC levels of n−3 LCPUFA
had a better visual acuity at 4 mon of age, suggesting that n−3 LCPUFA may influence visual maturation. 相似文献
7.
Cardiolipin (CL) is a unique mitochondrial phospholipid, containing up to 85 wt% 18∶2n−6 in mammals. The influence of maternal
dietary fatty acids on the acyl composition of offspring CL has not been examined previously. Adult female mice were thus
fed diets rich in 18∶1n−9 (olive oil), 18∶2n−6 (safflower oil), 18∶3n−3 (linseed oil) or 20∶5n−3 and 22∶6n−3 (fish oil/safflower,
9∶1, w/w), for a five month period, encompassing two breeding cycles. Offspring from the second breeding cycle were then fed
these diets. The acyl composition of CL, phosphatidylcholine and phosphatidylethanolamine from liver and heart was evaluated
from mice killed 3, 18 and 42 days after parturition. The primary nutrient sources at these three time points were transplacental
nutrients, breast milk and the diet, respectively. Maternal diet was found to influence the acyl composition of CLvia both placental transfer of fatty acids and breast milk. Fish oil feeding resulted in replacement of a substantial portion
of 18∶2n−6 with 22∶6n−3; after 42 days, the area% of 18∶2n−6 in heart CL was reduced from 62% in safflower oil fed mice to
12%. In comparison to fish oil feeding, linseed oil feeding resulted in a much lower accumulation of 22∶6n−3. Olive oil feeding
resulted in substantial replacement of 18∶2n−6 with 18∶1n−9 (18∶2n−6 was reduced from 62% to 31%). Physiologically, these
findings are relevant because changes in CL acyl composition may influence the activity of associated inner mitochondrial
membrane enzymes.
This work was presented in part as an Honored Student Award paper at the 82nd Annual AOCS Meeting, Chicago, IL, May 1991. 相似文献
8.
P. E. Wainwright Y. S. Huang D. E. Mills G. R. Ward R. P. Ward D. McCutcheon 《Lipids》1989,24(12):989-997
This study assesses the combined effects on brain and behavioral development of ethanol administration and supplementation
of the maternal diet with long chain n−3 polyunsaturated fatty acids. From day 7 to 17 of gestation, pregnant mice were fed
equivalent daily amounts of isocaloric liquid diets; 20% of the energy was provided by either ethanol or maltose-dextrin,
and a further 20% by either safflower oil (rich in linoleic acid, 18∶2n−6), or a combination of safflower oil with a fish
oil concentrate (rich in eicosapentaenoic acid, 20∶5n−3, and docosahexaenoic acid, 22∶6n−3). On day 18 the liquid diets were
replaced by lab chow; a fifth group was maintained on lab chow throughout the experiment. Measures on the pups included brain
weight and the fatty acid composition of the brain phospholipids on days 22 and 32 post-conception (birth=day 19), as well
as behavioral development. Maternal weight gain during gestation was decreased by ethanol relative to maltose-dextrin, and
increased by fish relative to safflower oil. On day 32, the brain weight of ethanoltreated animals fed fish oil was greater
than their safflower oil controls, whereas the reverse was true in the two maltose-dextrin groups; a similar trend was apparent
on day 22. The brain phospholipid content of the longer chain fatty acids (20∶4n−6, 22∶4n−6, 22∶5n−6, 20∶5n−3, 22∶5n−3, 22∶6n−3)
on day 22 reflected that of the prenatal diet, with the proportion of n−3 compounds being higher and that of n−6 floer in
the fish oil than safflower oil groups. Prenatal dietary effects were absent by day 32, with the exception of lower 22∶5n−6
in fish oil groups. Dietary supplementation with n−3 fatty acids increased the ratio of 20∶3n−6 to 20∶4n−6, which is consistent
with a blockade of the activity of Δ-5 desaturase. On day 22 the incorporation of dietary long chain n−3 fatty acids into
the brain phosphatidylcholine fraction was enhanced in the ethanol-treated animals; by day 32 the animals treated prenatally
with ethanol also showed increased levels of long chain n−6 compounds. Behavioral development was retarded by ethanol, but
there was no effect of the dietary oils. These results support the hypothesis that effects of ethanol on the developing brain
may be modified by the availability of an exogenous supply of long chain fatty acids. 相似文献
9.
Fish oil-enriched diets increase n−3 FA in tissue phospholipids; however, a similar effect by plant-derived n−3 FA is poorly
defined. To address this question, we determined mass changes in phospholipid FA, individual phospholipid classes, and cholesterol
in the liver, heart, and brain of rats fed diets enriched in flax oil (rich in 18∶3n−3), fish oil (rich in 22∶6n−3 and 20∶5n−3),
or safflower oil (rich in 18∶2n−6) for 8 wk. In the heart and liver phospholipids, 22∶6n−3 levels increased only in the fish
oil group, although rats fed flax oil accumulated 20∶5n−3 and 22∶5n−3. However, in the brain, the flax and fish oil diets
increased the phospholipid 22∶6n−3 mass. In all tissues, these diets decreased the 20∶4n−6 mass, although the effect was more
marked in the fish oil than in the flax oil group. Although these data do not provide direct evidence for 18∶3n−3 elongation
and desaturation by the brain, they demonstrate that 18∶3n−3-enriched diets reduced tissue 20∶4n−6 levels and increased cellular
n−3 levels in a tissuedependent manner. We hypothesize, based on the lack of increased 22∶6n−3 but increased 18∶3n−3 in the
liver and heart, that the flax oil diet increased circulating 18∶3n−3, thereby presenting tissue with this EFA for further
elongation and desaturation. 相似文献
10.
Sheila M. Innis 《Lipids》1992,27(11):879-885
Whether docosahexaenoic acid (22∶6n−3) is an essential nutrient for term or preterm infants, or if not, the quantity of dietary
linolenic acid (18∶3n−3) needed to support sufficient synthesis of 22∶6n−3 for assimilation in the central nervous system
is unknown. Infants fed formulas have lower plasma and red blood cell (RBC) levels of 22∶6n−3 than breast fed infants. No
relationship between the intake of 18∶3n−3 in formula (0.8 or 4.5% of fatty acids, 18∶2n−6/18∶3n−3 ratio 35∶1 or 7∶1, respectively)
and the infant's RBC 22∶6n−3 was found. Premature infants (<33 wk gestation) also showed a decrease in RBC 22∶6n−3 during
feeding with formula containing 18∶3n−3 as the only n−3 fatty acid. However, a marked decrease in plasma and RBC 22∶6n−3 occurred
between premature birth and the start of full enteral feeding at 1–2 wk of age. This was not reversed by breast milk or formula
feeding. Piglets, which are appropriate for studies of infant lipid metabolism, had decreased brain synaptic plasma membrane,
retina and liver 22∶6n−3 and increased 22∶5n−6 when fed formula with 0.8% fatty acids (0.3% of kcal) as 18∶3n−3. Formula with
4.0% fatty acids (1.7% of kcal) as 18∶3n−3 resulted in similar accretion of 22∶6n−3 in the organs compared to milk fed animals.
The studies suggest the dietary requirement for 18∶3n−3 in term animals in energy balance exceeds 0.3% diet kcal. Studies
in the premature infants suggest 18∶3n−3 may be oxidized rather than desaturated to 22∶6n−3 if energy requirements are not
met, and that due to early lipid restriction and later rapid growth, premature infants may have higher dietary n−3 requirements
than term infants.
Based on a paper presented at the Symposium on Milk Lipids held at the AOCS Annual Meeting, Baltimore, MD, April 1990. 相似文献
11.
Rainbow trout (Oncorhynchus mykiss) weighing ca. 5 g and previously acclimated for 8 wk on a diet comprising vegetable oil (11%), fish meal (5%), and casein (48%) as the
major constituents were fed a pulse of diet containing deuterated (D5) (17,17,18,18,18)-18∶3n−3 ethyl ester. The synthesis and tissue distribution of D5-22∶6n−3 was determined 3,7,14, 24, and 35 d after the pulse. The whole-body accumulation of D5-22∶6n−3 was linear over the first 7 d, corresponding to a rate of 0.54±0.12 μg D5-22∶6n−3/g fish/mg D5-18∶3n−3 eaten/d. Maximal accretion of D5-22∶6n−3 was 4.3±1.2 μg/g fish/mg of D5-18∶3n−3 eaten after 14 d. The amount of D5-22∶6n−3 peaked in liver at day 7, in brain and eyes at day 24, and plateaued after day 14 in visceral and eye socket adipose
tissue and in the whole fish. The majority of D5-22∶6n−3 was found in the carcass (remaining tissues minus the above tissues analyzed separately) at all times. On a per milligram
lipid basis, liver and eyes had the highest concentration of D5-22∶6n−3. The experimental diet also contained 21∶4n−6 ethyl ester as a marker to estimate the amount of food eaten by individual
fish. From such estimates it was calculated that the great majority of the D5-tracer was catabolized, with the combined recovery of D5-18∶3n−3 plus D5-22∶6n−3 being 2.6%. The recovery of 21∶4n−6 was 57.6%. The concentration of 22∶6n−3 in the fish decreased during the 13-wk
period, and the amount of 22∶6n−3 synthesized from 18∶3n−3 was only about 5% of that obtained directly from the fish meal
in the diet. 相似文献
12.
P. E. Wainwright Y. S. Huang B. Bulman-Fleming D. Dalby D. E. Mills P. Redden D. McCutcheon 《Lipids》1992,27(2):98-103
This study examines the effects of the ratio of n−3/n−6 fatty acids (FA) on brain development in mice when longchain n−3 FA
are supplied in the diet. From conception until 12 days after birth, B6D2F1 mice were fed liquid diets, each providing 10% of energy from olive oil, and a further 10% from different combinations of
free FA concentrates derived from safflower oil (18∶2n−6), and fish oil (20∶5n−3 and 22∶6n−3). The range of dietary n−3/n−6
ratios was 0,025, 0.5, 1.0, 2.0, and 4.0, with an n−6 content of greater than 1.5% of energy in all diets, and similar levels
of total polyunsaturated fatty acids (PUFA). In an additional group of ratio 0.5, 18∶2n−6 was partially replaced by its δ6
desaturation product, 18∶3n−6. Biochemical analyses were conducted on 12-day-old pup brains, as well as on samples of maternal
milk. No obvious effects on overall pup growth and development were observed, apart from a smaller litter size at ratio 1.
Co-variance analysis indicated that increasing the n−3/n−6 ratio was associated with slightly smaller brains, relative to
body weight. We found that 18∶2n−6 and 20∶5n−3 were the predominant n−6 and n−3 FA in the milk; in the brain these were 20∶4n−6
and 22∶6n−3, respectively. Increasing dietary n−3/n−6 ratios generally resulted in an increase in n−3 FA, with a corresponding
decrease in n−6 FA. The n−3/n−6 ratio of the milk lipids showed a strong linear relationship with the diet, but in the brain
the rate of increase tended to decrease beyond 0.5 (phosphatidylcholine, PC) and 0.25 (phosphatidylethanolamine, PE), such
that there was a significant quadratic contribution to the relationship. The partial replacement of dietary 18∶2n−6 with 18∶3n−6
raised levels of 20∶4n−6 in milk, brain PC, and brain PE. These results indicate that the n−3/n−6 ratio of the phospholipids
in the developing mouse brain responds maximally to maternal dietary long-chain n−3/n−6 ratios of between 0.25 and 0.5. 相似文献
13.
The emperor penguin (Aptenodytes forsteri) is an Antarctic seabird feeding mainly on fish and therefore has a high dietary intake of n-3 polyunsaturated fatty acids.
The yolk is accumulated in the developing oocyte while the females are fasting, and a large proportion of the fatty acid components
of the yolk lipids are derived by mobilization from the female's adipose tissue. The fatty acid composition of the total lipid
of the yolk was characterized by high levels of n-3 polyunsaturated fatty acids. However, it differed in several respects
from that of the maternal adipose tissue. For example, the proportions of 14∶0, 16∶1n−7, 20∶1n−9, 22∶1n−9, 20∶5n−3, and 22∶6n−3
were significantly greater in adipose tissue than in yolk. Thus adipose tissue lipids contained 7.6±0.3% and 8.0±0.3% (wt%
of total fatty acids; mean ±SE; n=5) of 20∶5n−3 and 22∶6n−3, respectively, whereas the yolk total lipid contained 1.6±0.1 and 5.5±0.3% of these respective
fatty acids. The proportions of 16∶0, 18∶0, 18∶1n−9, 18∶2n−6, and 20∶4n−6 were significantly lower in the adipose tissue than
in the yolk lipids. The proportions of triacylglycerol, phospholipid, free cholesterol, and cholesteryl ester in the yolk
lipid were, respectively, 67.0±0.2, 25.4±0.3, 5.3±0.2, and 1.8±0.2% (wt% of total yolk lipid). The proportions of 20∶4n−6,
20∶5n−3, 22∶5n−3, and 22∶6n−3 were, respectively, 5.7±0.3, 2.8±0.2, 1.4±0.1, and 11.7±0.5% in phospholipid and 0.4±0.0, 1.2±0.1,
0.8±0.1 and 3.6±0.3% in triacylglycerol. About 95% of the total vitamin E in the yolks was in the form of α-tocopherol with
γ-tocopherol forming the remainder. Two species of carotenoids, one identified as lutein, were present. 相似文献
14.
When rats were fed a diet containing chow or fish oil for six weeks, the platelet phospholipid content and percent distribution
were similar. In the fish oil fed animals there was a 54, 40, 41, and 24% reduction, respectively, in the levels of 20∶4(n−6)
in the choline-, ethanolamine-, inositol-and serine-containing glycerophospholipids. Dietary fish oil increased the total
(n−3) polyunsaturated fatty acid content in all lipids. This effect was most pronounced in the ethanolamine glycerophospholipids
which now contained 26, 11, and 4 nmols of 20∶5(n−3), 22∶5(n−3), and 22∶6(n−3) in 109 cells. Ionophore A23187 stimulation of platelets from the chow fed rats resulted in the synthesis of 7, 64, and 3.5 nmols
of 12-hydroxy-5,8,10-heptadecatrienoic acid, 12-hydroxy-5,8,10,14-eicosatetraenoic acid and 12-hydroxy-5,8,10,14,17-eicosapentaenoic
acid, respectively, from 1×109 cells. The values from animals fed fish oil were 4, 18, and 27 nmol/109 platelets. It was not possible to detect any lipoxygenase products from 22∶5(n−3) or 22∶6(n−3), even though both acids are
readily metabolized by lipoxygenase when added directly to platelets. These findings suggest that 22-carbon (n−3) fatty acids
are not liberated when phospholipases are activated by calcium mobilization. 相似文献
15.
Eurasian perch, Perca fluviatilis, were fed a semipurified fat-free diet for 4 wk, followed by a 16% feeding supplementation of either olive oil (OO), safflower
oil (SO), linseed oil (LO), or cod liver oil (CLO) as the only lipid source in each diet for 10 wk. Significant reductions
in total lipid of tissues were observed (31.4% in viscera, 66.7% in muscle, and 74.1% in liver) after feeding the fat-free
diet. The SO-, LO-, and CLO-fed fish significantly increased lipid deposition in liver and viscera compared to fish fed the
OO diet; however, muscle lipid levels were not significantly affected. Large amounts of dietary 18∶1n−9 were incorporated
directly into tissue lipids when fish were fed the OO diet. The LO diet significantly elevated 18∶4n−3, 20∶5n−3, 22∶5n−3,
and 22∶6n−3 in the liver compared to fish fed OO or SO diets, and the n−3/n−6 ratio was 16 times that of the SO group, with
significantly high desaturation and elongation products of 18∶3n−3. These results suggest that Δ6 and Δ5 desaturases are highly
active in Eurasian perch, and that the enzymes at this dietary n−3/n−6 ratio favor 18∶3n−3 over 18∶2n−6 as substrate. The
SO diet significantly increased 18∶3n−6, 20∶3n−6, and 22∶5n−6 in the liver and significantly decreased EPA and DHA. This indicates
that desaturation enzymes were not specifically favoring n−3 over n−6 acids in perch lipid metabolism, and that these elongation
and desaturation enzymes were influenced by n−3 and n−6 FA content in the diet. The present study indicates that high tissue
content of DHA in the muscle of Eurasian perch was attributable to the greater ability for n−3 acid bioconversion. 相似文献
16.
Atlantic salmon post-smolts were fed diets rich in linoleic acid (sunflower oil, SO), α-linolenic acid (linseed oil, LO) or
long-chain polyunsaturated fatty acids (fish oil, FO) for a period of 12 wk. In the liver phospholipids of fish fed SO, the
levels of 18∶2n−6, 20∶2n−6, 20∶3n−6 and 20∶4n−6 were significantly elevated compared to both other treatment. In choline phospholipids
(CPL), ethanolamine phospholipids (EPL) and phosphatidylserine (PS) the levels of 22∶4n−6 and 22∶5n−6 were significantly elevated
in fish fed SO. In liver phospholipids from fish fed LO, 18∶2n−6, 20∶2n−6 and 20∶3n−6 were significantly elevated but 20∶4n−6,
22∶4n−6 and 22∶5n−6 were similar or significantly decreased compared to fish fed FO. Liver phospholipids from fish fed LO
had increased 18∶3n−3 and 20∶4n−3 compared to both other treatments while EPL and phosphatidylinositol (PI) also had increased
20∶5n−3. In fish fed LO, 22∶6n−3 was significantly reduced in CPL, PS and PI compared to fish fed FO. Broadly similar changes
occurred in gill phospholipids. Production of 12-lipoxygenase metabolites in isolated gill cells stimulated with the Ca2+-ionophore A23187 were significantly reduced in fish fed either SO or LO compared to those fed FO. However, the ratio 12-hydroxy-5,8,10,14-eicosatetraenoic
acid (12-HETE)/12-hydroxy-5,8,10,14,17-eicosapentaenoic acid (12-HEPE) was significantly elevated in stimulated gill cells
from SO-fed fish. Although mean values of thromboxane B2 (TXB2) and prostaglandin E2 (PGE2) were increased in fish fed SO, they were not significantly different from those of the other two treatments. 相似文献
17.
The present study was designed to investigate the metabolism of the n−3 olyunsaturated fatty acids (PUFA) in adipose tissue
and its dependence upon dietary factors. Changes in the positional distribution of the fatty acids in triacylglycerols from
retroperitoneal adipose tissue were studied as a function of time on rats fed for 4 wk a diet enriched with fish oil. The
stereospecific analysis of triacylglycerols was based on random formation ofrac-1,2-diacylglycerols by Grignard degradation. This was followed by synthesis ofrac-phosphatidic acids and treatment with phospholipase A2. In the triacylglycerols of the fish oil diet, 57% of the total n−3 fatty acids were in position 3,i.e., two-thirds of 22∶5n−3 and 22∶5n−3 were esterified insn-3 position, whereas 22∶6n−3 was equally distributed in positions 2 and 3. After 4 wk of feeding fish oil, the fatty acid
composition of adipose tissue triacylglycerols reached a steady state. Half of the n−3 fatty acids were found in position
3, namely 75% of 22∶5n−3, 50% of 20∶5n−3 and 18∶4n−3 and 45% of 22∶6n−3, the latter being equally distributed in positions
2 and 3. This pattern of distribution resembled that found in triacylglycerols of the fish oil diet, except for a higher proportion
of 20∶5n−3 in adipose tissue in position 1 at the expense of position 3. Throughout the 4-wk period of fish oil feeding, the
distribution pattern of minor n−3 fatty acids (18∶4n−3 and 22∶5n−3) in adipose tissue triacylglycerols remained unchanged.
On the other hand, at the onset of fish oil feeding, 20∶5n−3 and 22∶6n−3 became concentrated in position 3, but thereafter
20∶5n−3 was progressively incorporated into position 1 and 22∶6n−3 into position 2. We thus conclude that n−3 fatty acids
are differentially esterified in triacylglycerols of white adipose tissue. Despite the complex sequence of hydrolysis and
acylation steps involved, the positional distribution of n−3 fatty acids was found to be similar in both the fish oil diet
and the stored fat, in contrast to what was observed for nonessential fatty acids. 相似文献
18.
This study examined effects of dietary n−3 fatty acids on age-related changes in erythrocyte anion transport and susceptibility
to oxidation. Blood was drawn from healthy adult volunteers before and after six weeks' supplementation (nine/group) with
4.0 g/day of safflower oil (containing 2.9 g n−6 fatty acids) or fish oil (containing 1.2 g long-chain n−3 fatty acids). Following
density separation of young and old erythrocytes, membrane anion transport and cell membrane lipid composition were measured.
Oxidative damage was measured in erythrocyte ghosts exposed to a free radical generator. Fish oil significantly increased
16∶0 and 20∶5n−3 in ghosts of both young and old cells, and 22∶5n−3 and 22∶6n−3 in old cells alone. Safflower oil increased
16∶0, 18∶0, 18∶1n−9, and 22∶5n−6 in ghosts of young cells only. The age-dependent increase in membrane anion transport (P<0.01) was decreased by dietary fish oil supplementation, but not by safflower oil supplementation. Safflower oil and fish
oil increased the susceptibility of both young and old erythrocytes to oxidative damage by free radical generation (P<0.001). 相似文献
19.
Recent studies have demonstrated that long-chain n−3 PUFA (LCn-3PUFA) are beneficial in reducing the risk of cardiac arrhythmias.
This study was conducted to determine the extent of incorporation of LCn-3PUFA into human atrium following supplementation
with a fish oil concentrate high in LCn-3PUFA. Volunteers preparing for coronary bypass surgery were randomized either to
the treatment group (n=8), receiving 6 g/d of fish oil concentrate (4.4 g of LCn-3PUFA), or the placebo group (n=9), receiving 6 g/d of olive oil for a minimum period of 6 wk. Blood samples were collected prior to commencement of treatment,
and preoperatively before bypass surgery. Atrial biopsies were obtained during surgery. The plasma and atrium samples were
analyzed by GC following trans-methylation to determine FA profile. Post-supplementation, the treatment group had significantly
higher plasma levels of 20∶5n−3, 22∶5n−3, and 22∶6n−3 than the placebo group. Analysis of the atrium total lipids revealed
a significant increase in the proportion of 20∶5n−3 following fish oil supplementation. There was no significant difference
in the concentration of 22∶5n−3 and 22∶6n−3 in the atrium total lipids; however, an upward trend was observed in subjects
receiving fish oil supplementation. In the phospholipid fraction of the atrium, both 20∶5n−3 and 22∶6n−3 increased, whereas
20∶4n−6 levels decreased. This study demonstrates for the first time that short-term supplementation with fish oil concentrate
results in significant incorporation of LNc-3PUFA with a concomitant depletion of the eicosanoid substrate (20∶4n−6) in the
human atrium. 相似文献
20.
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