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1.
Twelve-week-old Landes male geese were overfed with corn for 21 d in order to induce liver steatosis (fatty liver). Lipid
composition of hepatocyte plasma membranes from fatty livers was compared to that of lean livers obtained from geese fed a
normal diet. The ratio cholesterol/phospholipids was higher in fatty hepatocyte plasma membranes (0.63 vs. 0.47), whereas
the phospholipid/protein ratio was less than half. Overfeeding induced changes in fatty acid composition of hepatocyte plasma
membranes, including a greater than twofold increase in the percentage of oleic acid (29.7 vs. 13.8%) and a somewhat lesser
increase in lauric, palmitic, and palmitoleic acid contents of plasma membrane lipids of fatty livers. A concomitant reduction
in the proportion of stearic acid (18.4 vs. 25.1%) was also observed. In fatty livers, the increased ratio of saturated to
polyunsaturated fatty acids (PUFA) (1.5 vs. 1.0) was related to a significant decrease in PUFA content. Among all the PUFA,
only the eicosatrienoic acid (20∶3n−9) percentage was increased by liver steatosis. Overfeeding with corn appeared to induce
competition between de novo synthesized and dietary fatty acids incorporated in hepatocyte plasma membranes. This resulted in an accumulation of de novo synthesized monounsaturated and derived fatty acids in plasma membranes from overfed birds. A defect in the incorporation
of linoleic acid and linoleic- and linolenic-derived PUFA was observed despite the high proportion of these essential fatty
acids in the diet. It was conclued that in overfed palmipeds, de novo hepatic lipogenesis prevails over dietary lipid intake to modulate lipid composition of the fatty liver plasma membrane. 相似文献
2.
The objectives of this work were to study the FA composition of milk gangliosides, as well as to gain further insight into
the characterization of human milk gangliosides. The potential capacity of human milk gangliosides to adhere to human enterotoxigenic
Escherichia coli (ETEC-strains) was also studied. Human milk gangliosides were isolated and identified by high-performance TLC or immunoassay.
The latter also was used to assay bacterial adhesion. The FA composition of gangliosides was studied by GC. The presence of
O-acetyl GD3 (Neu5,9Ac2α2–8 NeuAcα2–3Galβ1–4GlcCer) and trace amounts of GM1 [Galβ1–3GalNAcβ1,−3(NeuAcα2–3)Galβ1–4GlcCer] in human milk was confirmed.
Medium-chain FA were almost absent in colostrum, whereas in the subsequent stages they rose to 20%. The levels of long-chain
FA decreased after colostrum. With respect to the degree of saturation, gangliosides from colostrum were richer in monounsaturated
FA than gangliosides synthesized during the rest of the lactation period, opposite to the pattern for PUFA. A human-ETEC colonization
factor antigen II-expressing strain showed binding capacity to human milk GM3 (NeuAcα2–3Galβ1–4GlcCer). New data on human
milk gangliosides have been gathered. A thorough knowledge of their composition is needed since they may have important biological
implications in regard to newborns' defense against infection.
The ganglioside nomenclature of Svennerholm (34) is followed. 相似文献
3.
The online version of the original article can be found at 相似文献
4.
The adaptive changes in the fatty acid (FA) composition of plasma phospholipids (PL) in response to alterations in environmental
water temperature were investigated in juvenile rainbow trout (Oncorhynchus mykiss). The changes observed during thermal adaptation from 22°C in summer to 8°C in winter were reproduced by laboratory cold
acclimation (CA) at 6°C of 22°C-summer-acclimated animals. In cold-acclimated and winter-acclimated trout, the increase in
the unsaturation of PL fatty acids was mainly due to an enrichment of approximately 7% in the total weight percentage of 22∶6n−3,
while a concomitant significant decrease in the levels of 18∶0 and of the monoenoic n−9 FA was observed. A time course study
revealed that the changes in PL fatty acids became significant after 10 d of CA and were complete after one month. These changes
in the composition of the fatty acyl chains of plasma total PL indicate that the FA composition of plasma lipoprotein PL does
not remain constant during thermal adaptation. This would suggest that plasma lipoproteins provide a rapid systemic supply
of lipids containing more or less unsaturated FA during thermal adaptation of poikilothermic animals. 相似文献
5.
6.
The fatty acid profile of cardiolipin (CL) from brain and cardiac mitochondria was measured to determine whether CL isolated
from these two tissue sources responded similarly to alterations in dietary fat composition. Male Wistar rats were fed 20%
(w/w) diets containing 2 to 12% (w/w) 18∶2n-6 for four weeks. Despite higher baseline levels of CL 18∶2n-6 in cardiac (54±1%
of total fatty acids) compared to brain (13±1%) mitochondria, CL 18∶2n-6 levels increased in proportion to dietary 18∶2 levels.
The degree of change in 18∶2n-6 was comparable with both tissues showing an approximate 1.5- to 2-fold increase. The time
course of changes in CL fatty acid profile was examined in a subsequent experiment in which animals were fed 20% (w/w) fat
diets containing either 3 or 15% α-linoleate. Changes in cardiac CL 18∶1, 18∶2n-6, and 22∶6n-3 levels were observed within
one week of feeding. While statistically significant differences were not observed in brain CL until the second week of feeding,
the time course did not differ substantively from that observed in heart. The results from this study suggest that while baseline
fatty acid profile of cardiac and neural CL differ, mitochondria from both tissues show comparable sensitivity to changes
in dietary fat composition. Furthermore, it would appear that the turnover rate of fatty acids in CL is similar in both tissues. 相似文献
7.
Phospholipid classes were separated from mouse brain lipid extracts by preparative thin-layer chromatography (TLC). Methyl
esters were prepared from the intact phospholipids by direct transesterification at room temperature in the presence of silica
gel by using 0.5m NaOH-methanol in order to prevent interference by aldehydes or derivatives. Dimethyl acetal derivatives of phosphoglyceride
alkenyl ethers (alkenyl moiety with a double bond in 1,2-position relative to oxygen linkage) were prepared, using 5% concentrated
HCl in methanol, followed by preparative TLC for isolation.
The major phospholipids present were ethanolamine phosphoglycerides (EPG) 39.8%, choline phosphoglycerides (CPG) 39.7%, serine
phosphoglycerides (SPG) 15.0%, and sphingomyelin (Sph) 5.4%. One-fifth of the total phospholipids (PL) were in the form of
plasmalogens, mainly EPG. Choline and serine plasmalogens were present in trace quantities. The major aldehyde components
of the plasmalogens were 16∶0, 18∶0, and 18∶1.
The EPG were rich in long-chain poly-unsaturated fatty acids, including 28.8% of 22∶6 and 17.0% of 20∶4, but contained only
7.2% of 16∶0. In contrast, the CPG contained 39.6% of 16∶0, and 31.0% of 18∶1 with a small content of polyunsaturated fatty
acids. The SPG exhibited a still different pattern containing 38.2% of 18∶0, 23.2% of 18∶1, 24.3% of 22∶6, 2.9% of 16∶0, and
3.8% of 20∶4.
Presented in part at the AOCS Meeting, New Orleans, May 1967. 相似文献
8.
For eight weeks young male rats were fed diets rich in 18∶2 (stock diet, or 10% corn oil, CO) or those devoid of 18∶2 (fat
free, FF, or 10% hydrogenated coconut oil, HCNO). The CO and HCNO diets were fed in the absence or presence of eicosa-5,8,11,14-tetraynoic
acid (TYA). When 18∶2 was excluded, an increase in the level of 16∶1, 18∶1 and 20∶3 and a decrease in 18∶2 was observed in
the fatty acids of red cells. On feeding TYA, an increase in 18∶2 and in the case of the HCNO+TYA diet, a decrease of 12∶0
and 14∶0 was also observed. In all cases the levels of 20∶4 in erythrocyte fatty acids were similar. Saturated fatty acids
were predominant in phosphatidyl choline (PC), lysophosphatidylcholine, (LPC) and sphingomyelin whereas unsaturated acids
were predominant in phosphatidyl ethanolamine (PE), (PS), and phosphatidyl inositol (PI). Acids containing three or more double
bonds comprised about 90% of the total acids in PI. In all the phospholipids, the characteristic changes in the composition
of fatty acids were observed due to the exclusion of 18∶2 from the diet. However, changes due to the feeding of TYA were found
only in PC and LPC. In rats fed the 18∶2-rich diet, about 60% of the red cells were discocytes. In those fed the 18∶2-free
diet, the level of discocytes decreased to about 23%, and the levels of echinocytes II and III increased. The exclusion of
18∶2 for even a few days decreased the proportion of discocytes. The loss of discoid shape was reversed in a few days by feeding
an 18∶2-rich diet. Fatty acid analysis of erythrocytes of rats of the various dietary manipulations showed that the change
in the proportion of discocytes followed the change in the level of 18∶2. 相似文献
9.
The composition of total fatty acids in serially transplanted mammary adenocarcinomas of C3H mice which were fed a fat free diet or a stock diet containing 4% fat for 8 weeks were significantly different, although fatty acid amounts were similar. The difference in composition was manifested in the triglyceride, phosphatidyl choline, and phosphatidyl enthanolamine fractions. Tumors of mice fed fat free diet has appreciable amounts of eicosatrienoic acid, whereas neoplasms of stock diet fed animals had none. In addition, higher levels of oleic acid and lower contents of linoleic acid were found in tumors from mice fed fat free diet than in those from mice fed the stock diet. Thus, mechanisms which maintained the triglyceride fatty acid composition in some tumors, such as 7288CTC hepatoma, were not observed in mouse mammary adenocarcinomas, and, therefore, were not a general phenomena associated with carcinogenesis. 相似文献
10.
K. S. Chandra 《Journal of the American Oil Chemists' Society》1964,41(4):251-254
Oils from castor seeds at different stages of ripening have been studied. The fatty acid composition has been determined by
paper chromatography. The ratio of the weight of the kernel to the weight of the seed coat changes from 1.0: 1.24 (14 days)
to 1.0:0.48 (45 days) and the oil content of the seed coat is negligible. Amounts of the individual fatty acids in 1 g of
kernel as well as in a single seed have been shown. The amounts of ricinoleic, linoleic and stearic acids gradually increase
with the ripening of the seeds whereas the amounts of oleic and palmitic acid after an initial increase upto 28 days gradually
decrease towards the later stages of growth when the amounts are calculated on the basis of a single seed. 相似文献
11.
The effect of conjugated linoleic acid on plasma lipoproteins and tissue fatty acid composition in humans 总被引:3,自引:10,他引:3
Conjugated linoleic acid (CLA) has been suggested by some animal studies to possess antiatherogenic properties. To determine,
in humans, the effect of dietary CLA on blood lipids, lipoproteins, and tissue fatty acid composition, we conducted a 93-d
study with 17 healthy female volunteers at the Metabolic Research Unit of the Western Human Nutrition Research Center. Throughout
the study, subjects were fed a low-fat diet [30 energy percent (en%) fat, 19 en% protein, and 51 en% carbohydrate] that consisted
of natural foods with the recommended dietary allowances for all known nutrients. After a 30-d stabilization period, subjects
were randomly assigned to either an intervention group (n=10) supplemented daily with capsules containing 3.9 g of CLA or a control group (n=7) that received an equivalent amount of sunflower oil. The CIA capsules (CLA 65%) contained four major cis/trans geometric isomers (11.4% 9 cis-,11 trans-18∶2; 10.8% 8 trans-,10 cis-18∶2; 15.3% 11 cis-,13 trans-18∶2; and 14.7% 10 trans-, 12 cis-18∶2) and their corresponding cis/cis (6.74% total) and trans/trans (5.99% total) varieties in smaller amounts. Fasting blood was drawn on study days 30 (end of the stabilization period), 60
(midpoint of the intervention period), and 93 (end of the intervention period). Adipose tissue samples were taken on days
30 and 93. CLA supplementation for 63 d did not change the levels of plasma cholesterol, low density lipoprotein cholesterol,
high density lipoprotein cholesterol, and triglycerides. The weight percentage of CLA in plasma increased from 0.28±0.06 to
1.09±0.31 (n=10, P<0.05) after the supplementation. The 9 cis-,11 trans-isomer was the most prominent variety followed by the 11 cis-,13 trans- and 10 trans-,12 cis-isomers in lesser amounts. CLA in adipose tissue was not influenced by the supplementation (0.79±0.18 to 0.83±0.19 wt%) (n=10) and the 9 cis-,11 trans-variety was the only isomer present. Thus, contrary to findings from some animal studies, CLA does not seem to offer health
benefits, in the short term, regarding the prevention of atherosclerosis in humans. CLA supplementation for 2 mon did not
alter the blood cholesterol or lipoprotein levels of healthy, normolipidemic subjects. The supplementation did increase CLA
in the plasma but only 4.23% of the ingested CLA was present in the plasma at any given time. No adverse effect of CLA supplementation
was detected in this study. 相似文献
12.
Normal, healthy male volunteers (n=6) were fed diets [high docosahexaenoic acid-DHA] containing 6 g/d of DHA for 90 d. The stabilization (low-DHA) diet contained
less than 50 mg/d of DHA. A control group (n=4) remained on the low-DHA diet for the duration of the study (120 d). Blood samples were drawn on study days 30 (end of
the stabilization period), 75 (midpoint of the intervention period), and 120 (end of the intervention period). Adipose tissue
(AT) samples were taken on days 30 and 120. The plasma cholesterol (C), low density lipoprotein (LDL)-C and apolipoproteins
(apo) [Al, B, and lipoprotein (a)] were unchanged after 90 d, but the triglycerides (TAG) were reduced from a mean value of
76.67±24.32 to 63.83±16.99 mg/dL (n=6, P<0.007 using a paired t-test) and the high density lipoprotein (HDL)-C increased from 34.83±4.38 mg/dL to 37.83±3.32 mg/dL (n=6, P<0.017 using a paired t-test). The control group showed no significant reduction in plasma TAG levels. Apo-E, however, showed a marked increase in
the volunteers’ plasma after 90 d on the high-DHA diet, from 7.06±4.47 mg/dL on study day 30 to 12.01±4.96 mg/dL on study
day 120 (P<0.002 using a paired t-test). The control subjects showed no significant change in the apo-E in their plasma (8.46±2.90 on day 30 vs. 8.59±2.97
on day 120). The weight percentage of plasma DHA rose from 1.83±0.22 to 8.12±0.76 after 90 d on the high-DHA diet. Although
these volunteers were eating a diet free of eicosapentaenoic acid (EPA), plasma EPA levels rose from 0.38±0.05 to 3.39±0.52
(wt%) after consuming the high-DHA diet. The fatty acid composition of plasma lipid fractions—cholesterol esters, TAG, and
phospholipid—showed marked similarity in the enrichment of DHA, about 10%, after the subjects consumed the high-DHA diet.
The DHA content of these plasma lipid fractions varied from less than 1% (TAG) to 3.5% (phospholipids) at baseline, study
day 30. EPA also increased in all plasma lipid fractions after the subjects consumed the high-DHA diet. There were no changes
in the plasma DHA or EPA levels in the control group. Consumption of DHA also caused an increase in AT levels of DHA, from
0.10±0.02 to 0.31±0.07 (wt%) (n=6, P<0.001 using a paired t-test), but the amount of EPA in their AT did not change. Thus, dietary DHA will lower plasma TAG without EPA, and DHA is
retroconverted to EPA in significant amounts. Dietary DHA appears to enhance apo-E synthesis in the liver. It appears that
DHA can be a safe and perhaps beneficial supplement to human diets. 相似文献
13.
Diabetes-induced and age-related proportional changes in plasma fatty acids of triglycerides (TG), phospholipids (PL), and
cholesteryl esters (CE) were investigated using streptozotocin-induced diabetic and control rats. Among n-6 fatty acids from
diabetic rat plasma, increased proportions of 18∶2n-6 and 20∶3n-6 in all three lipid classes and of 18∶3n-6 in PL at 1–3 months
old and in TG at 3–5 months old were observed. The proportions of 20∶4n-6 decreased in both PL and CE, but were unchanged
in diabetic TG. Among the n-3 fatty acids, in the early stage, diabetes caused increases in the proportions of 18∶3n-3 in
PL and CE and of 20∶5n-3 and 22∶6n-3 in TG, while 22∶5n-3 was decreased later in the disease course. These results suggest
reduced Δ5-desaturase activities on 20∶3n-6 but not on 20∶4n-3, while Δ6-desaturase activity on 18∶2n-6 was essentially unaffected.
Furthermore, the reduction in Δ9-desaturase activity in diabetic rats may well explain the decreases in the proportions of
16∶1n-7 and 18∶1n-7. However, the proportion of 18∶1n-9, another product of Δ9-desaturase, was significantly increased in
CE and PL as compared to the controls. Thus, there was a discrepancy between our results and those of earlier studies with
respect to the n-9, n-6, and n-3 fatty acid proportions of plasma lipids in diabetic rats. We also investigated age-related
changes in the proportions of plasma fatty acids. Although rather small, age-related changes were evident in both diabetic
and control rats. 相似文献
14.
Diplodom patagonicus is a freshwater bivalve mollusk living in lakes of the patagonian Andes mountains in Argentina. Lipid composition and seasonal
changes in the mollusk were studied in the natural habitat. In addition to common nonpolar and polar lipids, small amounts
of alk-1-enyldiacylglycerol ethers and significant quantities of ceramide aminoethyl phosphonate were present. Total lipid
content changed during the year, primarily because of decreased triacylglycerols in winter. The fatty acid composition of
the lipids, remarkably different from that of marine bivalves, and even from other fresh water animals, was especially rich
in the ω6 fatty acids, linoleic and arachidonic (ca. 25%), and poor in the ω3 acids, 20∶5 and 22∶6. The ω6/ω3 acid ratio was
ca. 2, which is very high compared to marine bivalves. The fatty acid composition and the ω6/ω3 acid ratio were constant during
the whole year, suggesting a very stable diet, rich in vegetal detritus and poor in diatoms. The influence of environmental
temperature fluctuation with season on fatty acid composition also was negible. Modest proportions of 22∶2 nonmethylene-interrupted
(NMI) acids were detected and confirmed by mass spectrometry. It was shown that 20∶2 NMI acids were absent. 相似文献
15.
Concentrations of albumin in excess of 1% in the incubation mixture inhibited the elongation of added fatty acids and their
incorporation into microsomal lipids whereas these reactions were not inhibited with endogenous microsomal membrane fatty
acids. The results of these and other studies support the idea that such reactions of membrane lipid fatty acids with membrane-bound
enzymes normally occur entirely within the membrane without release of free fatty acids to equilibrate with the fatty acid
pool during the process. 相似文献
16.
This study investigated the potential of dietary fats to modulate the arachidonic acid content of mouse lung phospholipids
and the formation of lipoxygenase products from arachidonic and eicosapentaenoic acids. Prior to breeding, female mice were
fed for five months diets with 10 wt% of either olive oil, safflower oil, fish oil, or linseed oil. The same diets were fed
to the females during gestation and to the pups from day 18 to day 42 postpartum. On day 42, the phospholipids were extracted
from fresh lung tissue and separated into classes [phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylcholine
(PC), and phosphatidylinositol (Pl)] by thin-layer chromatography. Methyl esters of phospholipid fatty acids and unesterified
fatty acids were analyzed by gas chromatography. At comparable dietary n-3/n-6 ratios, arachidonic acid was reduced 85 and
75% in lungs from mice fed linseed oil and fish oil, respectively, compared to lungs of safflower oil-fed mice. Dietary fats
affected the proportion of arachidonic acid in phospholipids in the order: PE>PS>PS>Pl. Following incubation of homogenized
lung tissue, the total amount of 12-lipoxygenase products was lowest in lungs from mice fed olive oil, and 12-hydroxyeicosatetraenoic
acid was lowest in incubated lungs from mice fed linseed oil. Comparison of the amounts of lipoxygenase substrate fatty acids
in the individual phospholipids with the lipoxygenase products suggested that the major substrate pool for the 12-lipoxygenase
pathway in mouse lung homogenates was PC. 相似文献
17.
The effects of clofibrate on the content and composition of liver and plasma lipids were studied in mice fed for 4 wk on diets
enriched in n−6 or n−3 polyunsaturated fatty acids (PUFA) from sunflower oil (SO) or fish oil (FO), respectively; both oils
were fed at 9% of the diet (dry weight basis). Only FO was hypolipidemic. Both oil regimes led to slightly increased concentrations
of phospholipids (PL) and triacylglycerols (TG) in liver as compared with a standard chow diet containing 2% fat. Clofibrate
promoted hypolipidemia only in animals fed SO. Its main effect was to enlarge the liver, such growth increasing the amounts
of major glycerophospholipids while depleting the TG. SO and FO consumption changed the proportion of n−6 or n−3 PUFA in liver
and plasma lipids in opposite ways. After clofibrate action, the PUFA of liver PL were preserved better than in the absence
of oil supplementation. However, most of the drug-induced changes (e.g., increased 18∶1n−9 and 20∶3n−6, decreased 22∶6/20∶5
ratios) occurred inrrespective of lipids being rich in n−6 or n−3 PUFA. The concentration of sphingomyelin (SM), a minor liver
lipid that virtually lacks PUFA, increased with the dietary oils, decreased with clofibrate, and changed its fatty acid composition
in both situations. Thus. oil-increased SM had more 22∶0 and 24∶0 than clofibrate-decreased SM, which was significantly richer
in 22∶1 and 24∶1. 相似文献
18.
Streptozotocin diabetes in the rat diminishes the synthesis of both monounsaturated and polyunsaturated fatty acids. Rat liver
microsomal fatty acid composition and fatty acid desaturation were studied in the streptozotocin diabetic rat. The major alterations
in fatty acid composition found in the diabetic rat were decreased proportions of palmitoleic, oleic and arachidonic acids
and an increased proportion of linoleic and docosahexaeneoic acids. These findings, other than the increased docosahexaeneoic
acid, probably result from the diminished liver microscomal δ9 and δ6 desaturase activities found in these animals. These
changes are not due to the diminished weight gain of the diabetic animals since restricting food intake of control animals
to achieve a similar weight gain failed to reproduce either the changes in fatty acid composition or the decrease in fatty
acid desaturation. The increased food intake of the diabetic animal may contribute to the altered proportions of linleic and
arachidonic acids since limiting food intake in diabetic animals to that of normal controls diminished the magnitude of these
changes. Insulin therapy for 2 days not only reverses and overcorrects the diminished desaturase activities, but likewise
reverses and overcorrects the altered fatty acid composition, with the exception of the diminished arachidonic aicd levels
which are further decreased following insulin therapy. These findings strongly suggest that most of the changes in fatty acid
composition in the diabetic rat are indeed caused by the diminished fatty acid desaturase activities. 相似文献
19.
Christof Stoll Wilfried Lühs M. Karim Zarhloul Monika Brummel Friedrich Spener Wolfgang Friedt 《European Journal of Lipid Science and Technology》2006,108(4):277-286
In contrast to the dominating unsaturated C18 fatty acid, medium‐chain fatty acids (MCFA) are nearly absent in the oil of common canola. Modification of canola oil towards higher contents of C8 to C14 fatty acids would create new possibilities for oleo‐chemical usages, in both the nutritional and the non‐food sectors. For this purpose, spring oilseed rape (cv. ‘Drakkar’) was genetically modified by introduction of MCFA‐encoding genes from Cuphea species containing approximately 90% MCFA in their seed oil. Two different single constructs involving the 3‐ketoacyl‐acyl carrier protein synthase (KAS)III from C. lanceolata were used, one harbouring the wild‐type gene, ClKASIIIbwt, and the other containing the point‐mutated gene, ClKASIIIbmut, along with two double constructs containing ClKASIIIbmut in combination with a medium‐chain thioesterase gene from C. lanceolata (ClFatB3) or C. hookeriana (ChFatB2). For both single‐gene constructs, a phenotype with an increased content of MCFA was not detected; however, the ClKASIIIbwt transformants produced up to 6.7% palmitic acid (C16). In T2 seeds bearing the ClKASIIIbmut/ClFatB3 double‐gene construct, contents of up to 2.9% capric (C10) and 11.4% palmitic acid were achieved. The best transformant with the gene construct ClKASIIIbmut/ChFatB2 contained 1.4% caprylic acid (C8) and 7.9% C10, and these results were confirmed in T3 seeds. 相似文献
20.
Efforts to improve the composition of soybean oil by breeding the beans for low linolenic acid in the oil have continued since
1968. This paper reports recent work using hybrid crosses and induced mutations. No lines are yet available that contain oil
having less than 3% linolenic acid.
Journal Paper No. J-11466 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa, Project No. 2475. 相似文献