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1.
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
2.
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
3.
Docosahexaenoic acid (DHA, 22∶6n−3) is an n−3 polyunsaturated fatty acid which attenuates the development of hypertension
in spontaneously hypertensive rats (SHR). The effects of DHA on delta-9-desaturase activity in hepatic microsomes and fatty
acid composition were examined in young SHR. Two groups of SHR were fed either a DHA-enriched diet or a control diet for 6
wk. Desaturase activity and fatty acid composition were determined in hepatic microsomes following the dietary treatments.
Delta-9-desaturase activity was decreased by 53% in DHA-fed SHR and was accompanied by an increase in 16∶0 and a reduction
in 16∶1n−7 content in hepatic microsomes. The DHA diet also increased the levels of eicosapentaenoic acid (20∶5n−3) and DHA.
The n−6 fatty acid content was also affected in DHA-fed SHR as reflected by a decrease in gamma-linolenic acid (18∶3n−6),
arachidonic acid (20∶5n−6), adrenic acid (22∶4n−6), and docosapentaenoic acid (22∶5n−6). A higher proportion of dihomo-gamma-linolenic
acid (20∶3n−6) and a lower proportion of 20∶4n−6 is indicative of impaired delta-5-desaturase activity. The alterations in
fatty acid composition and metabolism may contribute to the antihypertensive effect of DHA previously reported. 相似文献
4.
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
5.
Nervonic acid in red blood cell sphingomyelin in premature infants: An index of myelin maturation? 总被引:4,自引:0,他引:4
F. Babin P. Sarda B. Limasset B. Descomps D. Rieu F. Mendy A. Crastes de Paulet 《Lipids》1993,28(7):627-630
The present study addresses the question whether nervonic acid (24∶1n−9) accumulation in sphingomyelin (SM) of red blood cells
(RBC) could yield information on cerebrum maturation in premature infants. The study included 28 premature eutrophic infants
of 31.5 wk gestational age. Eleven were fed with human milk, nine with a regulator formula and eight with an α-linolenate-enriched
formula. The fatty acid composition of the SM fraction was determined by gas-liquid chromatography on a 50-m fused silica
capillary column. At 32 wk gestational age, the main fatty acids in SM were 16∶0, 18∶0, 20∶0, 22∶0, 24∶0 and 24∶1n−9. After
five weeks of feeding, at week 37 of postconceptional age, the most striking variation was a rise in 24∶1n−9, from 9.9±0.7
to 12.8±0.9 (P<0.02), regardless of regimen in all three feeding groups. The rise in 24∶1n−9 after birth in premature eutrophic infants
is the beginning of a trend toward the higher levels in 24∶1n−9 observed in mature newborns and older infants. The 24∶1n−9
level in SM of RBC from premature infants may reflect 24∶1n−9 levels in SM of brain and could thus reflect brain maturity. 相似文献
6.
Poumès-Ballihaut C Langelier B Houlier F Alessandri JM Durand G Latge C Guesnet P 《Lipids》2001,36(8):793-800
Animal and human studies have indicated that developing mammals fed only α-linolenic acid (18∶3n−3) have lower docosahexaenoic
acid (22∶6n−3) content in brain and tissue phospholipids when compared with mammals fed 18∶3n−3 plus 22∶6n−3. The aim of this
study was to test the hypothesis that low bioavailability of dietary 18∶−3 to be converted to 22∶6n−3 could partly explain
this difference in fatty acid accretion. For that purpose, we determined the partitioning of dietary 18∶3n−3 and 22∶6n−3 between
total n−3 fatty acid body accumulation, excretion, and disappearance (difference between the intake and the sum of total n−3
fatty acids accumulated and excreted). This was assessed using the quantitative method of whole-body fatty acid balance in
growing rats fed the same amount of a 5% fat diet supplying either 18∶3n−3 or 22∶6n−3 at a level of 0.45% of dietary energy
(i.e., 200 mg/100 g diet). We found that 58.9% of the total amount of 18∶3n−3 ingested disappeared, 0.4% was excreted in feces,
21.2% accumulated as 18∶3n−3 (50% in total fats and 46% in the carcass-skin compartment), and 17.2% accumulated as long-chain
derivatives (14% as 22∶6n−3 and 3.2% as 20∶5n−3+22∶5n−3). Similar results were obtained from the docosahexaenoate balance
(as % of the total amount ingested): disappearance, 64.5%; excretion, 0.5%; total accumulation, 35% with 30.1% as 22∶6n−3.
Thus, rats fed docosahexaenoate accumulated a twofold higher amount of 22∶6n−3, which was mainly deposited in the carcass-skin
compartment (68%). Similar proportions of disappearance of dietary 18∶−3 and 22∶6n−3 lead us to speculate that these two n−3
polyunsaturated fatty acids were β-oxidized in the same amount. 相似文献
7.
Pre-term infants, that are not breast-fed, are deprived of vital intrauterine fat accretion during late pregnancy and must
rely on formula to obtain fatty acids essential for normal development, particularly of the visual system. Preterm infants
(30 wk postconception) receiving human milk were compared to infants given one of the following formulae: Formula A was a
commercial preterm formula with predominantly 18∶2ω6 (24.2%) and low (0.5%) 18∶3ω3; Formula B was based on soy oil and contained
similar 18∶2ω6 levels (20%) and high 18∶3ω3 (2.7%); Formula C was also a soy oil-based formula (20% 18∶2, 1.4% 18∶3) but was
supplemented with marine oil to provide ω3 long-chain polyunsaturated fatty acids (LCP) at a level (docosahexaenoic acid,
DHA, 0.35%) equivalent to human milk. At entry (10 days of age), the fatty acid composition of plasma and red blood cell (RBC)
membrane lipids of the formula groups were identical. By 36 wk postconception, the DHA content in lipids of group A was significantly
reduced compared to that in the human milk and marine oil formula groups. Omega-3 LCP results were further amplified by 57
wk with compensatory increases in 22∶5ω6 in both plasma and RBC lipids. Provision of 2.7% α-linolenic acid in formula group
B was sufficient to maintain 22∶6ω3 levels equivalent to those in human milk-fed infants at 36 wk but not at 57 wk. Effects
on the production of thiobarbituric acid reactive substances and fragility of RBC attributable to the marine oil supplementation
were negligible. The results support the essentiality of ω3 fatty acids for preterm infants to obtain fatty acid profiles
comparable to infants receiving human milk. Formula for preterm infants should be supplemented with ω3 fatty acids including
LCP.
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
8.
Neuronal membranes are highly enriched with docosahexaenoic acid (22∶6n−3), and its content can be altered by ethanol consumption.
We have previously reported that the 22∶6n−3 status in membrane affects the biosynthesis of phosphatidylserine (PS), a phospholipid
class which contains an exceptionally high proportion of 22∶6n−3. The aim of the present study is to investigate the effect
of chronic ethanol exposure on PS accumulation in relation to the 22∶6n−3 status. C-6 glioma cells were enriched with 25 μM
22∶6n−3 for 48 h and the PS accumulation was first evaluated in comparison to nonenriched cells as well as cells enriched
with arachidonic acid (20∶4n−6). Electrospray liquid chromatography-mass spectrometry analysis revealed that cells treated
with 22∶6n−3 showed significantly higher accumulation of PS in comparison to nonenriched or 20∶4n−6-enriched cells, primarily
due to an increase of 1-stearoyl-2-docosahexaenoyl-glycerophosphoserine (18∶0,22∶6-PS). Chronic ethanol exposure selectively
affected the accumulation of PS in 22∶6n−3-enriched cells. After cells were exposed to 20 or 50 mM ethanol for 4 wk, accumulation
of 18∶0,22∶6-PS upon 22∶6n−3 supplementation was significantly lower, resulting in a drastic reduction of total PS. Concomitantly,
ethanol-treated cells showed lower incorporation of serine in comparison to control cells. From these data, it was concluded
that supplementation of cells with 22∶6n−3 promotes the accumulation of PS and chronic ethanol treatment diminishes this effect
at least in part through impaired serine incorporation processes. Attenuated accumulation of 22∶6n−3 in PS and the reduction
of PS thus may have significant implications in pathophysiological effects of ethanol, especially in tissues with abundant
22∶6n−3. 相似文献
9.
The addition of long-chain polyunsaturated fatty acids (LCP: C20, and C22) to infant formula may permit fatty acid accretion
rates similar to breast-fed infants, and may have long-term outcome benefits, such as improved visual acuity and cognitive
development. Although fish oil may provide a source of n-3 LCP, sources of n-6 LCP have been more difficult to identify. The
present study evaluates the effects of n-3 and n-6 LCP derived from single-cell oils on liver, plasma, and brain fatty acid
levels in a neonatal animal model. Newborn rat pups were suckled for 14 d by dams receiving diets containing n-3 LCP alone
or combinations of n-3 LCP and increasing doses of linoleic acid (18∶2n−6) or arachidonic acid (20∶4n−6). Dietary groups received
2% n−3 LCP and 1, 2, or 5% of either 18∶2n−6 or 20∶4n−6. The 20∶4n−6 source also contained modest levels of 18∶2n−6. At the
termination of the study, liver, plasma, and brain were obtained from the rat pups and the phospholipid fatty acid profiles
determined. The results indicate complex interactions of n−3 and n−6 fatty acids. Groups receiving dietary 20∶4n−6 incorporated
higher levels of n−6 LCP into tissues than did the groups receiving 18∶2n−6. The brain was relatively resistant to changes
in fatty acid composition compared with the liver and plasma. As expected, tissue n−3 LCP levels were reciprocally related
to n−6 levels. The present results document that single-cell LCP oils are bioavailable in a neonatal animal model. The use
of 20∶4n−6 is a more effective means of supporting n−6 status than the use of 18∶2n−6. These results may have implications
for the addition of LCP to infant formula. 相似文献
10.
Alterations in lipid composition occur in the retinal pigment epithelium and photoreceptor cells of the Royal College of Surgeons
(RCS) dystrophic rat, a model for inherited retinal degeneration. With respect to lipid composition of nonretinal tissues,
the developmental timing of lipid alterations and the incidence of dystrophy are unknown. We determined the fatty acid composition
in choline phosphoglycerides (ChoGpl) and ethanolamine phosphoglycerides (EtnGpl) in the brain, liver, and retina from dystrophic
RCS rats and from their nondystrophic congenics (controls) at the ages of 3 and 6 wk. At 3 wk, the fatty acid compositions
were specific to individual phospholipid classes without any difference between dystrophic and nondystrophic tissues. In plasma
phospholipids, there was an age-related increase in the relative contents of monounsaturated and n-3 polyunsaturated fatty
acids, with only minor differences between dystrophic and nondystrophic rats. At 6 wk, the fatty acid compositions in ChoGpl
and EtnGpl from dystrophic brain and retina were significantly different from those of nondystrophics. The effect of strain
on developmental changes in brain fatty acid composition was significant for 18∶0 and 22∶6n−3 in EtnGpl and for 16∶0, 18∶0,
18∶1n−9, and 20∶4n−6 in ChoGpl. The brain ChoGpl fatty acid composition in nondystrophic rats was similar at 6 wk to that
of normal rats, and there were almost no postweaning changes in the dystrophics. In retinal phospholipids, the effect of dystrophy
was to increase the 20∶4n−6 content in EtnGpl and to decrease 22∶6n−3 in ChoGpl. The 18∶2n−6 and 22∶6n−3 contents in dystrophic
liver ChoGpl were also significantly affected, while no difference was observed in the EtnGpl fraction. The dystrophy affected
the phospholipid fatty acid developmental changes in a tissue- and class-specific manner. Fatty acid metabolism could be selectively
altered in neural and nonneural tissues of developing dystrophic RCS rats. 相似文献
11.
The effect of dietary restriction of n−3 fatty acids during development on brain phospholipid fatty acid composition and exploratory
behavior has been studied in male Sprague Dawley rats. Female rats were fed semipurified diets containing either 5.5% safflower
oil or 6% soybean oil for 6 wk prior to mating and throughout gestation and lactation. Control rats were maintained on laboratory
chow. The male pups were weaned to the diets of the dams except for one group which was switched from safflower to soybean
oil at weaning. Behavioral studies and brain phospholipid analyses were conducted at 16–18 wk of age. Rats fed safflower oil
showed significantly lower levels of 22∶6n−3 in phospholipids of synaptic membranes and myelin than rats fed soybean oil or
chow. The decrease in 22∶6n−3 was compensated for by an increase in 22∶5n−6, the total content of polyunsaturated fatty acids
remaining approximately constant. The brain phospholipid fatty acid composition of rats switched from safflower to soybean
oil at weaning was similar to that of rats fed soybean oil throughout the experiment. There was no difference in spontaneous
locomotor activity among the different dietary groups. However, rats raised on safflower oil displayed a significantly lower
exploratory activity (horizontal movements and rearings) in a novel environment than rats fed soybean oil or chow. In contrast
to the brain phospholipid fatty acid composition, there was no recovery of exploratory behavior in rats raised on safflower
oil and switched to soybean oil at weaning suggesting a specific requirement of n−3 fatty acids during development. 相似文献
12.
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
13.
Plasma cholesterol, arachidonic acid (AA, 20∶4n−6), and docosahexaenoic acid (DHA, 22∶6n−3) are higher in breast-fed infants
than in infants fed formula without cholesterol, AA, or DHA. This study investigated differences in plasma, hepatic, and bile
lipids and phospholipid fatty acids, and expression of hepatic proteins involved in sterol metabolism that result from feeding
formula with cholesterol with egg phospholipid to provide AA and DHA. For this study, three groups of piglets were evaluated:
piglets fed formula with 0.65 mmol/L cholesterol, the same formula with 0.8% AA and 0.2% DHA from egg phospholipid, and piglets
fed sow milk. Piglets fed the formula with phospholipid AA and DHA had higher plasma high density lipoprotein, but not apoprotein
(apo) B cholesterol or triglyceride; higher bile acid and phospholipid concentrations in bile; and higher liver and bile phospholipid
AA and DHA than piglets fed formula without AA and DHA (P<0.05). Hydroxy methylglutaryl (HMG)-CoA reductase and 7-α-hydroxylase, the rate-limiting enzymes of cholesterol and bile
acid synthesis, respectively, and low density lipoprotein receptor mRNA levels were not different between piglets fed formula
without and with phospholipid AA and DHA, but HMG-CoA reductase and 7α-hydroxylase mRNA were higher, and plasma apo B containing
lipoprotein cholesterol was lower in all piglets fed formula than in piglets fed milk. These studies show that supplementing
formula with AA and DHA from egg phospholipid alters bile metabolism by increasing the bile AA and DHA, and bile acid and
phospholipid. 相似文献
14.
14C1-Linolenic acid was incorporated into lipids of hearts, livers, and carcasses of male rats. We studied the influence of diet
composition on extent and distribution of radioactivity. A CHOW diet, a purified, essential fatty acid (EFA)-deficient diet,
a purified control diet, and EFA-deficient diets with four fatty acid supplements were used. Supplements of 18∶2n−6, 20∶4n−6,
18∶3n−3, and 22∶6n−3 were given as single doses. Radioactivities in liver phosphatidyl ethanolamines (PE), phosphatidyl cholines,
and neutral lipids were measured. The distribution of radioactivity among the fatty acids in liver phospholipids was determined.
Rats on CHOW diet incorporated far less radioactivity than any other group into lipids of hearts and livers. Most of the activity
in livers was recovered as 20∶5n−3 and 22∶6n−3 in all rats. In EFA-deficient rats, the radioactivity in 22∶6n−3 of liver PE
was still increasing 36 hr after14C1-linolenic acid had been administered. The n−6 supplements (18∶2n−6 and 20∶4n−6) seemed to reduce the conversion of 20∶4n−3
to 20∶5n−3 (desaturation), whereas the n−3 supplements (18∶3n−3 and 22∶6n−3) reduced the conversion of 20∶5n−3 to 22∶5n−3
(elongation). Formation of 22∶6n−3 may be controlled by 22∶6n−3 itself at the elongation of 20∶5n−3 to 22∶5n−3. 相似文献
15.
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
16.
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
17.
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
18.
The metabolism of α-linolenic acid from canola oil was studied in eight normolipidemic men. The 42-day study was divided into
three periods: a 6-day pre-experimental and two 18-day experimental. Approximately 75% of the dietary fat (28% of total energy)
was provided by a mixture of fats during the pre-experimental period and either canola oil (CO) or sunflower oil (SO) during
the experimental periods. The CO and SO diets were fed in a cross-over design. The ratios of linoleic to linolenic acid were
2.6∶1 and 73.9∶1 in the CO and SO diets, respectively. Dietary fat source had an effect on plasma phospholipid fatty acids:
18∶1n−9, 18∶3n−3 and 20∶5n−3 were higher (p<0.05), and 18∶2n−6 was lower in the phosphatidylcholine fraction; 18∶1n−9 was
higher and 20∶4n−6 lower in the phosphatidyl-ethanolamine fraction; and 18∶1n−9 and 20∶5n−3 were higher and 20∶4n−6 and 22∶6n−3
were lower in the alkenylacyl-ethanolamine phospholipid fraction on the CO diet as compared to the SO diet. Consumption of
the canola oil diet resulted in higher n−3 fatty acid levels and lower n−6 fatty acid levels in plasma phospholipids than
consumption of the sunflower oil diet. 相似文献
19.
Michael V. Bell Robert S. Batty James R. Dick Karen Fretwell Juan Carlos Navarro John R. Sargent 《Lipids》1995,30(5):443-449
In the retina of herring (Clupea harengus L.), rods are recruited from about 8 wk after hatching, and from this time there is a linear relationship between the number
of rods in the photoreceptor cell population and the content of di22∶6n−3 molecular species of phospholipids. Juvenile herring
were reared from four weeks' post-hatching for 15 wk on eitherArtemia nauplii deficient in 22∶6n−3 or on enrichedArtemia nauplii containing 4.3% 22∶6n−3. The visual performance of the fish was then determined at three light intensities (0.01,
0.1, and 1.0 lux) by observing their frequency of striking at liveArtemia nauplii using infrared video recording. Herring reared on the diet containing no 22∶6n−3 were less active predators, especially
at the lowest light intensity where very few strikes were observed. The eyes of these fish contained greatly reduced levels
of di22∶6n−3 molecular species of total phospholipid, 2.1% vs. 12.0% in fish supplemented with 22∶6n−3. The contribution of
saturated and monounsaturated fatty acids in the molecular species of phosphatidylethanolamine (PE), phosphatidylserine (PS),
and phosphatidylcholine (PC) was virtually unchanged, while 20∶5n−3 and 22∶5n−3 largely replaced 22∶6n−3. There was an almost
complete disappearance of di22∶6n−3 PC, while the amounts of di22∶6n−3 PE and PS fell by 18.1 and 20.6% to 2.7 and 7.6%, respectively.
The dipolyunsaturated molecular species di20∶5n−3, 20∶5n−3/22∶5n−3, and di22∶5n−3 made up a substantial part of the deficit.
We conclude that a dietary deficiency of 22∶6n−3 during the period early in rod development impairs visual performance such
that the fish can no longer feed at low light intensities.
Deceased. 相似文献
20.
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