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1.
Incorporation of polyunsaturated fatty acids (PUFA), particularly 22∶6n−3, into fetal brain at specific gestational ages is
critical for development of normal brain function. We have studied adaptations to maternal liver phospholipid molecular species
compositions that may be related to the supply of PUFA to fetal brain. The increment of 22∶6n−3 in brain phosphatidylethanolamine
(PE) was maximal at day 25 to day 35 of gestation, consistent with early prenatal development of guinea pig brain. At the
same gestational ages, there was a transient increase in maternal liver concentration of 16∶0/22∶6 phosphatidylcholine (PC),
which preceded the progressive increase in total PC concentration toward term (day 68). This effect was specific for thesn-1 16∶0 species, as, there was no significant increase in 18∶0/22∶6 PC concentration. These results are consistent with a
specific role for 16∶0/22∶6 PC in the directed supply of 22∶6n−3 from maternal liver to the fetus. Concentrations of all PE
species in maternal liver decreased at day 25 and day 35 of gestation. The gradual accumulation of 22∶6n−3 in fetal liver
throughout gestation did not correlate with the pattern of acquisition of 22∶6n−3 into fetal brain PE. Maternal plasma PC
and cholesterol concentrations decreased dramatically by day 25 of gestation, and remained low until term. This hypolipidemia
of pregnancy in the guinea pig may be due to increased lipase-mediated turnover of plasma lipoproteins and contrasts strongly
with the well-characterized hyperlipidemia in human and rat gestation. 相似文献
2.
The molecular species composition of the major glycerophospholipids from white matter of human brain were determined by high-performance
liquid chromatography of the 3,5-dinitrobenzoyl derivatives of the corresponding diradylglycerols. In phosphatidylcholine
(PC) and phosphatidylserine (PS), molecular species containing only saturated fatty acids (SFA) and monounsaturated fatty
acids (MUFA) comprised 85.7 and 82.4% of the respective totals, with 18∶0/18∶1 predominant in PS and 16∶0/18∶1 in PC. These
molecular species were also abundant in phosphatidylethanolamine (PE), but in this phospholipid species containing polyunsaturated
fatty acids (PUFA), largely 18∶0/22∶6n−3 and 18∶0/20∶4n−6, accounted for over half the total; 18∶1/18∶1 was also abundant
in PE. In contrast, 1-O-alk-1′-enyl-2-acylsn-glycero-3-phosphoethanolamine (GPE) had much more SFA- and MUFA-containing species, predominantly 16∶0a/18∶1, 18∶0a/18∶1
and 18∶1a/18∶1, with low amounts of species containing 20∶4n−6 and 22∶6n−3. In alkenylacyl GPE, 22∶4n−6 was the major PUFA
and 16∶0a/22∶4n−6 and 18∶1a/22∶4n−6 the main PUFA-containing species. There was six times more 22∶6n−3, twice as much 20∶4n−6
and half the amount of 22∶4n−6 in PE as compared to alkenylacyl GPE.
Molecular species are abbreviated as follows:e.g., 16∶0/18∶1 PE is 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine; the corresponding alkenylacyl species, 1-O-hexadec-1′-enyl-2-oleoyl-sn-glycero-3-phosphoethanolamine is 16∶0a/18∶1. 相似文献
3.
The lipid composition of the pineal organ from the rainbow trout (Oncorhynchus mykiss) was determined to establish whether the involvement of this organ in the control of circadian rhythms is reflected by specific
adaptations of lipid composition. Lipid comprised 4.9% of the tissue wet weight and triacylglycerols were the major lipid
class present (47% of total lipid). Phosphatidylcholine (PC) was the principal polar lipid, and smaller proportions of other
phospholipids and cholesterol were also present. Plasmalogens contributed 11% of the ethanolamine glycerophospholipids (EGP).
No cerebrosides were detected. The fatty acid composition of triacylglycerols was generally similar to that of total lipids
in which saturated, monounsaturated and polyunsaturated fatty acids (PUFA) were present in almost equal proportions. Each
of the polar lipid classes had a specific fatty acid composition. With the exception of phosphatidylinositol (PI), in which
20∶4n−6 comprised 27.4% of the total fatty acids, 22∶6n−3 was the principal PUFA in all lipid classes. The proportion of 20∶5n−3
never exceeded 6.0% of the fatty acids in any lipid class. The predominant molecular species of PC were 16∶0/22∶6n−3 and 16∶0/18∶1,
which accounted for 33.2 and 28.5%, respectively, of the total molecular species of this phospholipid. Phosphatidylethanolamine
(PE) contained the highest level of di-22∶6n−3 (13.0%) of any phospholipid. There was also 4.9% of this molecular species
in phosphatidylserine (PS) and 4.1% in PC. In PE, the species 16∶0/22∶6, 18∶1/22∶6 and 18∶0/22∶6 totalled 45.1%, while in
PS 18∶0/22∶6 accounted for 43.9% of the total molecular species. The most abundant molecular species of PI was 18∶0/20∶4n−6
(37.8%). The lipid composition of the pineal organ of trout, and particularly the molecular species composition of PI, is
more similar to the composition of the retina than that of the brain.
Molecular species are abbreviated as follows: e.g., 16∶0/22∶6 PC is 1-palmitoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine. 相似文献
4.
Phospholipid molecular species from human placenta lipids 总被引:1,自引:0,他引:1
The phospholipid molecular species from a large-scale preparation of human placenta lipids were analyzed. The major placental
phospholipids were choline glycerophospholipids (CPL) (53.2 wt%), sphingomyelin (21.7 wt%) and ethanolamine glycerophospholipids
(EPL) (14.6 wt%). 1,2-Diacyl-glycerophosphocholine was the most abundant subclass of CPL (91.7 mol%), while EPL contained
1,2-diacyl (54.6 mol%) and 1-alk-1′-enyl-2-acyl (43.8 mol%) subclasses. The level of polyunsaturated fatty acids (PUFA) in
total phospholipids was remarkably constant (38.4–39.9 mol%) within all placental batches tested. The long-chain PUFA, mainly
20∶4n−6 and 22∶6n−3 of the n−6 and n−3 series, respectively, were found in high proportion in all phospholipid classes, especially
in EPL (46.7 mol%) and in inositol glycerophospholipids (IPL) (39.9 mol%). CPL and serine glycerophospholipids were much richer
in 18∶1n−9 and 18∶2n−6. High levels of molecular species with arachidonic acid in thesn-2 position were found particularly in 1-alk-1′-enyl-2-acyl-glycerophospho-ethanolamine (with 24.0 mol% 16∶0 and 22.0 mol%
18∶0 insn-1 position) and in 1,2-diacyl glycerophosphoinositol with 42.6 mol% 18∶0 insn-1 position. EPL subclasses were rich in 22∶6n−3, which occurs mainly as 16∶0/22∶6n−3 (11.7 mol%) in the polasmalogen form
and as 18∶0/22∶6n−3, 16∶0/22∶6n−3 and 18∶1/22∶6n−3 in the diacyl forms. Based on their availability and composition, placental
phospholipids could be of interest, for example, for supplementing artificial milk preparations with n−3 and n−6 long-chain
PUFA for newborn infants with insufficiently developed 18∶2n−6 and 18∶3n−3 desaturation/elongation. 相似文献
5.
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
6.
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
7.
The distribution of D5-22∶6n−3 following ingestion of a pulse of D5-18∶3n−3 was measured quantitatively by GC-negative chemical ionization MS in lipid classes from liver, cecal mucosa, and
brain from rainbow trout to further our understanding of the processes determining accretion and turnover of 22∶6n−3 in fish.
The accretion of D5-22∶6n−3 was expressed in two ways, as percent enrichment and as ng D5-22∶6n−3/μg 22∶6n−3/mg D5-18∶3n−3 eaten. In cecal mucosa at 2 d post-dose, PC was the most enriched lipid class followed by PE and then TAG. Enrichment
fell in all lipid classes in cecal mucosa from 2 to 7 d post-dose of D5-18∶3n−3. In liver, PC was also the most enriched lipid class at 2 d, but in this tissue all lipid classes were more enriched
in D5-22∶6n−3 by 7 d. When expressed in terms of the 22∶6n−3 content of the different lipid classes, TAG became relatively less
important in cecal mucosa and more important in liver. Over a time course of 3 to 35 d, the percent enrichment of D5-22∶6n−3 in liver peaked at 7 d in PC, PE, PS, and PI and fell rapidly in TAG from 3 d. PC from liver was the most enriched
lipid class at 3 and 7 d, and thereafter PE was the most enriched lipid class. However, TAG had the highest specific activity
at all times except 7 d. In brain, the enrichment of D5-22∶6n−3 was very low in all lipid classes at 3 d and increased progressively to 35 d with PC and PE similarly enriched. TAG
from brain had the highest specific activity at all times. This study is the first to present quantitative information on
rates of accretion and depletion of newly synthesized 22∶6n−3 into the main lipid classes of fish tissues. 相似文献
8.
The sn-position of FA in membrane lipids has an influence on the physiological function of cells, is predictive for diseases, and
therefore is useful for diagnostics. The current study compares the compositions of acyl chain substituents in the sn-1 and sn-2 positions of the glycerol backbones of phospholipids derived from human erythrocytes by using RP-HPLC coupled with on-line
electrospray ionization ion trap MS. Preferential loss of the acyl group in the sn-1 position was used to determine the degree of regiospecific preference exhibited by the phospholipid molecules. The identities
of the molecular species and the positions of the acyl substituents were identified using product-ion spectra of major precursor
ions selected from the mass spectra averaged across peaks in the total ion chromatogram. Saturated FA were found to be located
mainly in the sn-1 position of the glycerol backbones of erythrocyte phospholipids, whereas PUFA were found primarily in the sn-2 position. All measured phospholipids revealed palmitic acid (16∶0) at the sn-1 position. Linoleic acid (18∶2n−6) and arachidonic acid (20∶4n−6) were found to be attached exclusively to the sn-2 position of the backbone, whereas eicosadienoic (20∶2n−6) and eicosatrienoic acid (20∶3n−9) occurred in both positions
of the backbone of PC. Oleic (18∶1n−9), linoleic (18∶2n−6), and octadecatrienoic (18∶3) acids of PE and PS were linked to
both positions. Lignoceric acid (24∶1n−9) was found to be strictly localized at the sn-2 position, whereas nervonic (24∶1n−9) acid of PS was associated with both positions of the backbone. A detailed analysis
of the blood cell membrane lipids by MS might be helpful to characterize postprandial kinetics of pharmacological or dietary
lipid applications, as well as environmental influences on cell membranes. 相似文献
9.
Phosphatidylethanolamine (PE) and phosphatidylglycerol (PG) were isolated from aVibrio species of bacterium, known to produce eicosapentaenoic acid (20∶5n−3) andtrans-hexadecenoic acid (16∶1n−7), and subjected to phospholipase A2 degradation to determine the positional distribution of component fatty acids. At the two growth temperatures studied (20
and 5°C), both 20∶5n−3 andtrans 16∶1 n−7 were located mainly at positionsn−2 in PE. Increases in the proportions of 20∶5n−3 andtrans 16∶1n−7 in positionsn−2 with decreasing growth temperature were balanced mainly by decreases in the level ofiso-15∶0. In PG,trans 16∶1n−7 was located predominantly in positionsn-1, although the difference between the two positions was not as great as in PE. Eicosapentaenoic acid was preferentially
located in positionsn-2 of PG, particularly at 5°C when it comprised 29.9% of the total fatty acids in this position. It is concluded thattrans 16∶1n−7/20∶5n−3 is not a major molecular species of phospholipid in this species ofVibrio and that changes in the levels of molecular species of PE containingiso-15∶0 may feature in thermal acclimation. 相似文献
10.
Molecular species of 1-O-alk-1′-enyl-2-acyl-, 1-O-alkyl-2-acyl-, and 1,2-diacyl-sn-glycero-3-phosphoethanolamine (EPL) andsn-glycero-3-phosphocholine (CPL) of Japanese oysterCrassostrea gigas were analyzed by selectedion monitoring gas chromatography/mass spectrometry using electron impact ionization. The characteristic
fragment ions, [RCH=CH+56]+ due to the alkenyl residue in thesn-1 position and [RCO+74]+ due to the acyl residue in thesn-2 position of alkenylacylglycerols, [R+130]+ due to the alkyl residue in thesn-1 position and [RCO+74]+ due to the acyl residue in thesn-2 position of alkylacylglycerols, [RCO+74]+ due to the acyl residues in thesn-1 and/orsn-2 positions of diacylglycerols, and [M−57]+ being indicative of the corresponding molecular weight, were used for structural assignments.
For alkenylacyl EPL and CPL, 19 and 16 molecular species were determined, respectively. Two molecular species, 18∶0alkenyl-22∶6n−3
and 18∶0-alkenyl-22∶2-non-methylene interrupted diene (NMID), amounted to 53.2% and 47.9%, respectively. The alkylacyl EPL
and CPL consisted of 16 and 20 molecular species, respectively, and the prominent components were 18∶0alkyl-22∶2NMID, 20∶1alkyl-20∶1n−11
(27.4%) and 20∶1alkyl-20∶2NMID (16.3%) in the former, and 16∶0alkyl-20∶5n−3 (23.0%) and 16∶0alkyl-22∶6n−3 (21.6%) in the latter.
For the diacyl EPL and CPL, 14 and 51 molecular species were determined, respectively. The major molecular species were 18∶0–20∶5n−3
(37.4%), 16∶0–20∶5n−3 (14.2%) and 18∶1n−7–22∶2NMID (13.2%) in the former, and 16∶0–20∶5n−3 (33.4%) and 16∶0–22∶6n−3 (22.3%)
in the latter. It was found that there were significant differences in the molecular species between the alkylacyl and diacyl
EPL and the alkylacyl and diacyl CPL; the number of molecular species was larger in CPL than in EPL, while the number of total
carbons and double bonds of the major molecular species were larger in the EPL than in the CPL. Alkenylacyl EPL were similar
to alkenylacyl CPL in molecular species composition. 相似文献
11.
The incorporation of 18∶2n−6, 18∶3n−3, 20∶4n−6 and 20∶5n−3 was greater at 10°C than at 22°C in Atlantic salmon (AS), rainbow
trout (RTG-2) and turbot (TF) cells. However, there were generally no significant differences between the amount of incorporation
of all four polyunsaturated fatty acids (PUFA) into total lipid within a cell type at either 22°C or 10°C. The distributions
of the PUFA between individual phospholipid classes at 22°C was essentially the same in AS and TF cells—with the C18 PUFA the order of incorporation in these cells was phosphatidylcholine (PC) > phosphatidylethanolamine (PE) > phosphatidic
acid/cardiolipin (PA/CL); with 20∶4n−6 the order was PE and phosphatidylinositol (PI)>PC; with 20∶5n−3, PE>PC. In RTG-2 cells
at 22°C the distributions of the C18 PUFA were similar to the other cell lines, but with 20∶4n−6 the order was PC>PI>PE, and with 20∶5n−3 it was PC>PE. At 10°C
the incorporation of C18 PUFA into PC increased and into PE and PA/CL decreased, in general, in all cell lines. Incorporation of 20∶5n−3 into PC and
PE was increased and decreased at 10°C, respectively, in AS and TF cells, whereas in RTG-2 cells the changes at 10°C were
opposite i.e., increased in PE and decreased in PC. With 20∶4n−6, incorporation into PC at 10°C was increased in all cell
lines with decreased incorporation into PI in AS and RTG-2 cells and into PE in AS and TF cells, whereas incorporation of
20∶4n−6 into PE increased in RTG-2 cells. The metabolismvia desaturation and elongation of the n−3 PUFA was greater than that of the equivalent n−6 PUFA in all cell lines, irrespective
of temperature. There was less conversion of the C18 PUFA at 10°C than at 22°C in RTG-2 and TF cells, but the conversion of 18∶3n−3 by AS cells was increased at 10°C. Temperature
had no effect on the conversion of the C20 PUFA. 相似文献
12.
The effect of the water-soluble fraction (WSF) of crude oil on lipid contents, lipid classes, FA, and PC molecular species
was studied in high-phospholipid (hepatopancreas) and low-phospholipid (egg) tissues of a freshwater crustacean. After a 21-d
exposure to a sublethal concentration of WSF, a significant decrease in shrimp total lipids was observed, although no alterations
could be detected in the hepatopancreas or egg lipid contents. TAG/phospholipid ratios increased in the hepatopancreas and
decreased in the eggs, suggesting alterations either in the mobilization of TAG to phospholipid pools or in the energy balance.
The FA composition of phosphoglycerides in the hepatopancreas and eggs was dominated by PUFA, whereas the n−3/n−6 ratio was
not affected by WSF exposure, although there was a significant increase in hepatopancreas 18∶1n−9. Analysis of the PC molecular
species by HPLC-ELSD showed the presence of 15 species, with 16∶0/18∶1, 18∶1/18∶2, 16∶0/20∶5, and 16∶1/20∶5 being the major
species in the hepatopancreas. The PC molecular species in the eggs showed a different pattern, dominated by 16∶0/18∶1 and
18∶1/18∶2. Of the PC molecular species, 10 contained 22∶6n−3, 20∶5n−3, and 20∶4n−6. Small amounts of di-PUFA species were
also found. Exposure to WSF altered the PC molecular species in both tissues. The four major hepatopancreas molecular species
and most of the ones containing PUFA decreased. This was compensated for by an increase in 16∶1/18∶1 (152%) and 18∶1/18∶1
(50%). The two major egg PC molecular species decreased, whereas the PUFA-containing ones increased. The contrasting responses
of both tissues of WSF contamination suggests the presence of different homeostatic mechanisms. 相似文献
13.
Jim-Wen Liu Stephen DeMichele Marti Bergana Emil Bobik Jr. Christine Hastilow Lu-Te Chuang Pradip Mukerji Yung-Sheng Huang 《Journal of the American Oil Chemists' Society》2001,78(5):489-493
The seed oil from a genetically transformed canola (Brassica napus) containing 43% (w/w) of γ-linolenic acid (G, 18∶3n−6), 22% linoleic acid (L, 18∶2n−6), and 16% oleic acid (O, 18∶1n−9) was
evaluated. In this high γ-linolenic acid canola oil (HGCO), the predominant 18∶3n−6-containing triacylglycerol (TG) molecular
species were GGL (23%), GLO (20%), and GGG (11%). In the total TG, approximately 75% of the 18∶3n−6 was located at the sn-1,3 positions, while only 34% of linoleic acid was at the sn-1,3 positions. The GGL molecular species of HGCO contained approximately equal amounts of GLG and GGL positional isomers,
while the GLO molecular species had 95% GOL and 5% GLO isomers. The general characteristics and the tocopherol and phytosterol
contents were mostly similar between HGCO and nontransformed canola oil. No detectable amounts of amino acids and nucleotides
were observed in the HGCO. 相似文献
14.
Ethanolamine glycerophospholipids from the brains of both trout and cod comprised 36–38% of 1-O-alk-1′-enyl-2-acyl-glycerophosphoethanolamine (GPE) determined using two methods. In 1-O-alk-1′-enyl-2-acyl-GPE from trout brain, the main molecular species were 18∶1a/18∶1, 18∶0a/18∶1 and 16∶0a/18∶1, which totalled
63.3%, while polyunsaturated fatty acid (PUFA) containing species totalled only 18.2%. 1-O-Alk-1′-enyl-2-acyl-GPE from cod brain was much more unsaturated with PUFA containing species totalling 52.6%, of which 18∶0a/20∶5n−3,
18∶1a/20∶5n−3 and 18∶1a/22∶6n−3 were predominant. In cod 18∶1a/18∶1, 18∶0a/18∶1 and 16∶0a/18∶1 were the only other species
present at over 5% each, totalling 31.8%. In both cod and trout, small amounts of species containing 22∶4n−6 were found. The
results of this and earlier studies indicate that there is considerable specificity of composition at the level of molecular
species between different lipid classes and subclasses.
Molecular species of 1-O-alk-1′-enyl-2-acyl-GPE are abbreviated as follows:e.g., 16∶0a/18∶1 GPE is 1-O-hexadec-1′-enyl-2-oleoyl-sn-glycero-3-phosphoethanolamine. The corresponding diacyl species, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine, is abbreviated as 16∶0/18∶1. 相似文献
15.
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
16.
(n−3) and (n−6) polyunsaturated fatty acids in the phosphoglycerides of salt-secreting epithelia from two marine fish species 总被引:3,自引:0,他引:3
Fatty acid analyses were carried out on phosphoglycerides isolated from microsomal fractions of the rectal gland of the dogfish,Scyliorthinus canicula, and gills of the cod,Gadus morhua. Ratios of (n−3)/(n−6) polyunsaturated fatty acids were ca. 10 for phosphatidylcholine, (PC), phosphatidylethanolamine (PE)
and phosphatidylserine (PS) from cod gills, reflecting high concentrations of 20∶5 (n−3) and 22∶6(n−3). The ratio for phosphatidylinositol
(PI) from cod gills was 1.3, reflecting high concentrations of 20∶4(n−6) as well as (n−3) polyunsaturates. PC, PE and PS from
rectal glands all had much lower (n−3)/(n−6) ratios than in cod gills, reflecting higher concentrations of 20∶4(n−6), but
the lowest ratio was again present in PI. The latter phospholipid had high concentrations of 18∶0 in both tissues. The relative
constancy of the fatty acid composition of PI in the two salt-secreting tissues and its similarity to mammalian phospholipids
is considered to reflect its specialized role in biomembranes. 相似文献
17.
Four sources of long-chain polyunsaturated fatty acids (LCP) differing in their chemical structure (triglycerides or phospholipids)
and in their origin (tuna triglycerides, fungal triglycerides, egg phospholipids, and pig brain phospholipids) were analyzed
to determine the distribution of the component fatty acids within the molecule. Lipase and phospholipase A2 hydrolysis was performed to obtain 2-monoacylglycerols and lysophospholipids, respectively, which allowed us to determine
the distribution of fatty acids between the sn-2 and sn-1,3 positions of triglycerides or between the sn-1 and sn-2 position of phospholipids. Fatty acids in the LCP sources analyzed were not randomly distributed. In tuna triglycerides,
half of the total amount of 22∶6n−3 was located at the sn-2 position (49.52%). In fungal triglycerides, 16∶0 and 18∶0 were esterified to the sn-1,3 (92.22% and 91.91%, respectively) 18∶1 and 18∶2 to the sn-2 position (59.77% and 62.62%, respectively), and 45% of 20∶3n−6 and only 21.64% of 20∶4n−6 were found at the sn-2 position. In the lipid sources containing phospholipids, LCP were mainly esterified to the phosphatidylethanolamine fraction.
In egg phospholipids, most of 20∶4n−6 (5.50%, sn-2 vs. 0.91%, sn-1) and 22∶6n−3 (2.89 vs. 0.28%) were located at the sn-2 position. In pig brain phospholipids, 22∶6n−3 was also esterified to the sn-2 (13.20 vs. 0.27%), whereas 20∶4n−6 was distributed between the two positions (12.35 vs. 5.86%). These results show a different
fatty acid composition and distribution of dietary LCP sources, which may affect the absorption, distribution, and tissue
uptake of LCP, and should be taken into account when supplementing infant formulas. 相似文献
18.
Total lipid, phospholipid, and FA composition and distribution of FA between polar lipids (PL) and neutral lipids (NL) were
investigated in the boreal soft coral Gersemia rubiformis from the Bering Sea. The total lipids were mostly hydrocarbons and waxes (33.7%) and PL (33.1%). The content of monoalkyldiacylglycerols
(9.7%) exceeded the content of TAG (6.7%). PC and PE constituted 31.4% and 25.6% of total phospholipids, respectively. Principal
FA were 16∶0, 16∶1n−7, 18∶0, 18∶1n−9, 18∶1n−7, 20∶1n−7, 20∶4n−6, 20∶4n−3, 20∶5n−3 22∶5n−3, 22∶6n−3, 24∶5n−6, and 24∶6n−3.
Most n−6 PUFA (52% of total FA) were associated with the PL fraction; this was especially true for arachidonic and tetracosapentaenoic
acids. The NL were enriched with mono-, di-, trienoic, and n−3 PUFA. The variation in EPA levels in both NL and PL suggests
an origin of this acid from lipids of diatoms consumed by the corals. 相似文献
19.
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
20.
The lipid and FA composition of the total lipids of the pearl oyster Pinctada fucata martensii, in different seasons and in different areas, were analyzed to clarify its lipid physiology and to estimate the possible
influence of its prey phytoplankton. TAG and sterols were the major components in the neutral lipids in all conditions, whereas
high levels of phospholipids (PE and PC) were found in the polar lipids. The major FA in the TAG in all samples were 14∶0,
16∶0, and 18∶0 as saturated FA (saturates); 16∶1n−7, 18∶1n−9, and 18∶1n−7 as monoenoic FA (monoenes); and 20∶4n−6 (arachidonic
acid: AA), 20∶5n−3 (EPA), and 22∶6n−3 (DHA) as PUFA. The major components found in the polar lipids were 16∶0 and 18∶0 as
saturates; 22∶2n−9, 15 and 22∶2n−7, 15 as non-methylene-interrupted dienes (NMID), and AA, 22∶3n−6, 9, 15, EPA, and DHA as
PUFA. Although it is a marine animal, characteristically high levels of AA were found in both the TAG and phospholipids. This
result suggests that lipids of P. fucata may be influenced by those of its phytoplanktonic prey. The increase in levels of NMID from TAG to PE with a decrease in
those of monoenes suggests that the tissues of this species are able to biosynthesize only the less unsaturated PUFA, such
as NMID. In particular, NMID derivatives are considered to be biosynthesized in the PE; thus, they might play a particular
role in the membrane, because NMID were characteristically localized only in the PE. 相似文献