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1.
To examine whether dietary fat alters membrane lipid composition and peroxidation of polyunsaturated fatty acids in “non-proliferative”
and “proliferative” cells in the large intestine, Sprague-Dawley rats were fed diets providing a polyunsaturated-to-saturated
fatty acid ratio of 1.2 or 0.3 at a high or low level of fat intake for a 25-day period. Cell populations were isolated and
the effect of dietary fat on membrane polyunsaturated fatty acid content and peroxide levels was determined. Neither fat level
nor fatty acid composition of diet influenced total cholesterol, total phospholipids, and percentage of phospholipid classes
in membrane phospholipids. Feeding the high fat and/or high polyunsaturated-to-saturated fatty acid ratio diet increased polyunsaturated
fatty acid content of mucosal cell phospholipids. Increase in polyunsaturated fatty acid content was paralleled by a decrease
in the monounsaturated fatty acid content of mucosal cell phospholipids. Membrane content of total saturated fatty acids was
not significantly affected by diet. Variation in phospholipid fatty acid composition between “non-proliferative” and ”proliferative”
cells was observed. Lipid peroxide levels in mucosal cell lipid fractions were altered by dietary fat treatment. Animals fed
high fat diets, compared to groups fed low fat diets, exhibited higher membrane peroxide levels when results are expressed
as nmol/mg protein. Higher peroxide levels were observed in mucosal cells for rats fed high polyunsaturated-to-saturated fatty
acid ratio diets when results were expressed per nmol of phospholipid. It is concluded that changes in fat level and fatty
acid composition of the diet alters the mucosal cell membrane lipid composition in the rat large intestine and influences
susceptibility of mucosal cell lipid to peroxidation. Further research is required to delineate which dietary factors—fat
level, polyunsaturated-to-saturated fatty acid ratio, or both—have a primary influence on the degree of lipid peroxidation. 相似文献
2.
Ghafoorunissa 《Lipids》1996,31(1):S287-S291
To arrive at fat requirements for Indians; the contribution of invisible fat should be determined. Total lipids were extracted
from common Indian foods, and their fatty acid compositions were determined. This data and information on intake of various
foods were used to estimate the contents of “invisible” fat and fatty acids in Indian diets. Taking into account World Health
Organization (WHO) guidelines and the invisible-fat intake of Indians, recommendations were made for lower and upper limits
of visible fats. In the rural poor, the “visible”-fat intakes are much lower than estimated minimum requirements. Therefore,
to meet the energy needs of low-income groups, particularly young children, visible-fat intakes must be increased to recommended
levels. The urban high-income group, however, should reduce dietary fat. Data on intake of various fatty acids in total diet
shows that even the recommended lower limit of oil can meet linoleic acid requirements. Intake of α-linolenic acid is low,
however. Increase in dietary n-3 polyunsaturated fatty acid (PUFA) produces hypolipidemic, anti-inflammatory, and antithrombotic
effects. Effects of n-3 PUFA on blood lipids, platelet fatty acid composition, and platelet aggregation were therefore investigated
in Indian subjects consuming cereal-based diets. Supplementation of fish oils (long-chain n-3 PUFA) as well as the use of
rapeseed oil (α-linolenic acid) produced beneficial effects. Since the requirements of α-linolenic acid and/or long-chain
n-3 PUFA are related to linoleic acid intake, use of more than one oil (correct choice) is recommended for providing a balanced
intake of various fatty acids. Analysis of Indian food showed that some foods are good sources of α-linolenic acid. Regular
consumption of these foods can also improve the quality of fat in Indian diets. Nonvegetarians, however, have the choice of
eating fish to accomplish this. 相似文献
3.
R. B. Alfin-Slater P. Wells L. Aftergood D. Melnick 《Journal of the American Oil Chemists' Society》1973,50(12):479-484
In a long-term multigeneration study, conducted in our laboratories for 32-years, with occasional longevity and histopathological
evaluations included, rats of our own inbred strain (originally of Wistar derivation) were fed semisynthetic diets comprising
whole wheat, skim milk powder, and fat in the form of margarine products. The total source of tocopherols was the dietary
fat itself. Saturated fatty acid content (S) remained relatively constant at about 20% of the fat and total tocopherol level
also remained constant at about 0.12% of the fat. Polyunsaturated fatty acid (P) content, however, progressively increased
almost fourfold, from 7.5% to 28.5% and alphatocopherol levels decreased to one-half level, from 0.033% to 0.016% of the fat.
Hence, the ratio of polyunsaturated fatty acids to alpha-tocopherol content changed markedly from 227∶1 to 1780∶1, with other
factors (relative to fat composition) held constant during the 32-year period of feedings and observations. Fat level in the
diet increased over the years from 9.2% to 16.0% or from about 21% to about 33% of the caloric intake. Thus, quality and quantity
of the fat in the diet progressively changed, and the impact of these changes was evaluated by comparing biological performances
of the successive generations. Growth and reproduction and lactation performances were noted to be regularly satisfactory
and comparable from generation to generation throughout the experimental period. Longevity studies conducted on arbitrarily
selected generations also provided data showing no deleterious effects associated with a dietary change. Histopathological
examinations of tissue revealed minimal myocarditis and no malignant tumors which could be attributed to a dietary factor.
No vitamin E deficiencies were observed. Even the in vitro peroxide hemolysis values for the red blood cells of the animals,
fed the diets containing the higher levels of polyunsaturated fatty acids, were low, indicating that the dietary fats provided
sufficient absorbable tocopherol to protect the potentially oxidizable unsaturated fatty acids in the erythrocyte membrane.
Biochemical data reflected responses to aging and not to any specific diet fed. It is concluded that a diet providing as much
as 33% of the calories as a fat, the latter containing up to 28.5% polyunsaturated fatty acids, substantially of the essential
fatty acid type, with a P/S ratio of up to 1.6∶1 and a polyunsaturated fatty acid to alphatocopherol ratio as high as 1780∶1]
produces no undesirable effects in the rat.
Presented in part at a symposium entitled “Long Term Nutritional Effects of Dietary Fats” at the International Society for
Fat Research World Congress, September 30, 1970, Chicago, Illinois. 相似文献
4.
The effects of dietary n−3 and n−6 polyunsaturated fatty acids on the fatty acid composition of phospholipid, Ca++· Mg++ ATPase and Ca++ transport activities of mouse sarcoplasmic reticulum were investigated. Mice were fed a 2 weight percent fat diet containing
either 0.5 weight percent ethyl esters of 18∶3n−3, 20∶5n−3 or 22∶6n−3 as a source of n−3 polyusaturated fatty acid or 0.5
weight percent safflower oil as a cource of n−6 polyunsaturated fatty acid for 10 days. Olive oil (2 weight percent) was used
as a control diet. Although feeding n−6 polyunsaturated fatty acid induced very little modifications of the phospholipid sarcoplasmic
reticulum fatty acid composition, feeding n−3 polyunsaturated fatty acid altered it markedly. Inclusion of 18∶−3, 20∶5n−3
or 22∶6n−3 in the diet caused an accumulation of 22∶6n−3, which replaced 20∶4n−6 and 18∶2n−6 in phospholipid sarcoplasmic
reticulum. The saturated fatty acids were significantly increased with a concurrent reduction of 18∶1n−9. These changes in
the fatty acid composition resulted in a decrease in the values of the n−6/n−3 polyunsaturated fatty acid ratio and a decrease
in the ratio of 20 carbon to 22 carbon fatty acids esterified in the phospholipid sarcoplasmic reticulum. This was associated
with a decrease in Ca++ uptake by n−3 polyunsaturated fatty acid enriched sarcoplasmic reticulum vesicles as compared with n−6 fatty acid and control
diet sarcoplasmic reticulum vesicles. However, neither the affinity for Ca++ nor the maximal velocity of ATP hydrolysis activity of Ca++·MG++ ATPase were altered by the different diets. The data suggest that the incorporation of 22∶6n−3 and/or the decrease of 20∶4n−6
plus 18∶2n−6 in the phospholipid sarcoplasmic reticulum may affect the membrane lipid bilayer structure and make it more permeable
to Ca++. 相似文献
5.
The present study was designed to determine if dietary supply of long-chain fatty acid (LCFA, C20∶4n-6, and/or C22∶6n-3),
reflecting levels that might be incorporated into infant formulas, influences the fatty acid composition of the visual cell
membrane. The rod outer segment (ROS) of the retina was analyzed from rats fed diets varying in the ratio of 18∶2n-6 to 18∶3n-3
with or without 20∶4n-6 [arachidonic acid (AA)] and 22∶6n-3 (docosahexaenoic acid) from birth to six weeks of age. The level
of very long chain fatty acids (VLCFA, C24−C36) was identified using gas chromatography and gas chromatography-mass spectrometry. In the ROS, the highest relative percent
of AA was attained in phosphatidylcholine (PC) and phosphatidylethanolamine (PE) of animals fed 1% AA diet, whereas feeding
0.7% docosahexaenoic acid (DHA) diet significantly increased the DHA level in PC, phosphatidylserine, and phosphatidylinositol
compared to feeding diets containing AA. VLCFA of n-6 and n-3 up to C36 were found in PC, with the most abundant fatty acids being C32 and C34. In PC, phosphatidylserine and PE, the n-6 tetraenoic VLCFA level was highly increased in animals fed 1% AA compared to other
dietary groups. This study suggests that dietary fat containing small amounts of AA or DHA is an important factor influencing
membrane fatty acid composition of the visual cell during development.
Based on a presentation at the AOCS Annual Meeting & Expo in San Antonio, Texas, May 7–11, 1995. 相似文献
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.
The lipid concentration and fatty acid composition of the whole liver and of cultured hepatocytes isolated from the livers
of rats fed ad libitum (fed), fasted for 24 hr (fasted), or fasted for 48 hr and then refed a fat-free, high carbohydrate
diet for 48 hr (refed) was studied. Hepatocytes were maintained as monolayer cultures in serum-free, lipid-free media and
their fatty acid composition was analyzed at 3, 24, 48, 72 and 96 hr. The livers of fed animals, as well as their hepatocytes,
contained less total lipid than those from animals on either of the other dietary regimes. Livers of fasted animals had three
times the amount of lipid found in the livers of fed animals, and the livers of refed animals contained five times the amount
of lipid as the livers of fed animals (all based on mg lipid/g wet weight of liver). The fatty acid composition of hepatocytes
after 3 hr of culturing was very similar to that of fresh liver when compared in each of the dietary regimes. However, while
the fatty acid compositions of livers and hepatocytes from fed and fasted animals were similar, the pattern in liver of refed
animals was quite distinct from that of the fed animals. In the fed and fasted animals palmitic acid (16∶0), stearic acid
(18∶0), oleic acid (18∶1[n-9]), linoleic acid (18∶2[n-6]) and arachidonic acid (20∶4[n-6]) were the major fatty acids of the
liver; in refed animals 16∶0, palmitoleic acid (16∶1[n-7]), 18∶0, 18∶1(n-9) andcis-vaccenic acid (the n-7 isomer of oleic acid) were the major fatty acids. During maintenance in culture the 18∶1(n-9) content
of the hepatocytes increased in cells from livers of animals on all three dietary regimes. The polyunsaturated fatty acid
content was similar in fresh livers and isolated hepatocytes in all samples when compared on the basis of μg fatty acid/mg
of hepatocyte or liver protein. It was also found that the polyunsaturated fatty acid content of hepatocytes was remarkedly
stable with time of culture when the cells were incubated in serum-free, lipid-free medium. Thus, isolated hepatocytes maintained
in serum-free medium appear to be a possible system for the evaluation of the effects of prior nutritional status on fatty
acid metabolism in the whole animal, not subject to hormonal and other somatic influences which often complicate the interpretation
of such nutritional studies. 相似文献
8.
This study evaluated the effects of conjugated linoleic acids (CLA) on tissue fatty acid composition and ex vivo prostaglandin E2 (PGE2) production in rats given diets varying in n-6 and n-3 fatty acids. Four groups of rats were given a basal semipurified diet
(AIN-93G) containing 70 g/kg of added fat for 42 d. The fat treatments were formulated to contain CLA (0 vs. 10 g/kg of diet)
and n-6 (soybean oil having an n-6/n-3 ratio of 7.3) and n-3 fatty acids (menhaden oil+safflower oil having an n-6/n-3 ratio
of 1.8) in different ratios in a 2×2 factorial design. Fatty acids in liver, serum, muscle, heart, brain, spleen, and bone
(cortical, marrow, and periosteum) were analyzed by capillary gas-liquid chromatography. The various dietary lipid treatments
did not affect growth; however, CLA improved feed efficiency. The CLA isomers were found in all rat tissues analyzed although
their concentrations varied. Dietary CLA decreased the concentrations of 16∶1n−7, 18∶1, total monounsaturates and n−6 fatty
acids, but increased the concentrations of n−3 fatty acids (22∶5n−3 and 22∶6n−3), and saturates in the tissues analyzed. Ex vivo PGE2 production in bone organ culture was decreased by n−3 fatty acids and CLA. We speculate that CLA reduced the concentration
of 18∶1 fatty acids by inhibiting liver Δ9-desaturase activity. The fact that CLA lowered ex vivo PGE2 production in bone organ culture suggests that these conjugated fatty acids have the potential to influence bone formation
and resorption. 相似文献
9.
In this study, we examined the effect of dietary arachidonic acid (AA) and sesame lignans on the content and n-6/n-3 ratio
of polyunsaturated fatty acid (PUFA) in rat liver and the concentrations of triglyceride (TG) and ketone bodies in serum.
For 4 wk, rats were fed two types of dietary oils: (i) the control oil diet groups (CO and COS): soybean oil/perilla oil=5∶1,
and (ii) the AA-rich oil group (AO and AOS): AA ethyl esters/palm oil/perilla oil=2∶∶1, with (COS and AOS) or without (CO
and AO) 0.5% (w/w) of sesame lignans. Dietary AA and sesame lignans significantly affected hepatic PUFA metabolism. AA content
and n-6/n-3 ratio in the liver were significantly increased in the AO group, despite the dietary total of n-6 PUFA being the
same in all groups, while AOS diet reduced AA content and n-6/n-3 ratio to a level similar to the CO and COS groups. These
results suggest that (i) dietary AA considerably affects the hepatic profile and n-6/n-3 ratio of PUFA, and (ii) dietary sesame
lignans reduce AA content and n-6/n-3 ratio in the liver. In the AO group, the concentration of acetoacetate was significantly
increased, but the ratio of β-hydroxybutyrate/acetoacetate was decreased. On the other hand, the AO diet increased the concentration
of TG in serum by almost twofold as compared to other groups. However, the AOS diet significantly reduced serum IG level as
compared to the AO group. In addition, the AOS diet signicantly increased the acetoacetate level, but reduced the β-hydroxybutyrate/acetoacetate
ratio. These results suggest that dietary sesame lignans promote ketogenesis and reduce PUFA esterification into TG. This
study resulted in two findings: (i) sesame lignans inhibited extreme changes of the n-6/n-3 ratio by reducing hepatic PUFA
content, and (ii) the reduction of hepatic PUFA content may have occurred because of the effects of sesame lignans on PUFA
degradation (oxidation) and esterification. 相似文献
10.
Cardiolipins (CL) have unique fatty acid profiles with generally high levels of polyunsaturated fatty acids, primarily 18∶2n−6,
and low levels of saturated fatty acids. In order to study the effect of dietary fatty acid isomers on the fatty acid composition
of cardiolipins, rats were fed partially hydrogenated marine oils (HMO), rich in 16∶1, 18∶1, 20∶1, and 22∶1 isomeric fatty
acids, supplemented with linoleic acid at levels ranging from 1.9% to 14.5% of total fat. Although the dietary fats contained
33%trans fatty acids, the levels oftrans fatty acids in CL were below 2.5% in all organs. The fatty acid profiles of cardiolipins of liver, heart, kidney and testes
showed different responses to dietary linoleic acid level. In liver, the contents of 18∶2 reflected the dietary levels. In
heart and kidney, the levels of 18∶2 also parallelled increasing dietary levels, but in all groups fed HMO, levels of 18∶2
were considerably higher than in the reference group fed palm oil. In testes, the 18∶2 levels were unaffected by the dietary
level of 18∶2 and HMO. 相似文献
11.
The essential fatty acid requirement for the development of intestinal carcinogenesis was determined and compared to the overall
essential fatty acid status of the animals as measured by the triene/tetraene ratio in the plasma, liver and colon. To induce
tumors, male Sprague-Dawley rats were given two weekly injections (20 mg/kg body wt) of azoxymethane. Two weeks after the
last injection, the rats were divided into groups of 25 and given one of six diets containing various levels of essential
fatty acids (as linoleate). The diets contained 5% total fat and were prepared by mixing safflower oil (high essential fatty
acids, beef fat (low essential fatty acids), and medium chain triglyceride oil (no essential fatty acids). One group of rats
was fed a 20% beef fat diet. The range of essential fatty acids was from <0.03% to 1.28% (w/w). Twenty-six weeks after the
first azoxymethane injection, the animals were killed and intestinal tumor incidence and multiplicty were determined. Samples
of plasma, liver and colon were also taken for measurement of the triene/tetraene ratio by gas chromatography.
Large bowel tumor incidence showed a dependence on the essential fatty acid content of the diet. The results were as follows:
(percent essential fatty acids: percent tumor incidence) Group A (1.28∶ 72.4), Group B (0.60∶ 73.3), Group C (0.11∶ 55.2),
Group D (0.08∶ 39.3), Group E (<0.03∶ 37.9) and Group F, which was fed 20% beef fat, (0.34∶ 88.5). These data suggest the
essential fatty acid requirement for colon tumorigenesis is much lower than values previously reported for tumorigenesis in
the breast and pancreas. The plasma and liver triene/tetraene ratios showed clear-cut essential fatty acid deficiency (ratio
>0.4) in Groups D and E, although no clinical symptoms were evident. In all dietary groups, the triene/tetraene ratio in the
colon was lower than 0.3. In addition in the colon, the percentage of fatty acids present as 20 carbon polyunsaturated fatty
acids was lower than in the plasma and liver. These data suggest the colon possesses low levels of the fatty acid desaturase
and elongase needed for conversion of linoleate to 20 carbon fatty acids, and therefore, that the colonic requirement for
essential fatty acids may be low. Furthermore, in the absence of other clinical symptoms, the reduced tumorigenesis observed
in the groups fed low essential fatty acids suggests the essential fatty acid requirement of tumor tissue may be higher than
that of normal colon mucosa. 相似文献
12.
Richard J. Jones 《Journal of the American Oil Chemists' Society》1974,51(6):251-254
Recent scientific evidence is reviewed which shows that some modest success at improving the morbidity due to atherosclerotic
disease has been achieved by a diet lower in fat and cholesterol and higher in polyunsaturated fatty acids than the usual
American diet. This has shown a group correlation with serum cholesterol reduction. The effect is small enough that no statistically
significant improvement in overall mortality rate has yet been seen in groups studied. Many imponderables remain in the use
of a high polyunsaturated fatty acids diet: not only is the optimal daily dietary intake uncertain, but its effects upon the
body economy are just beginning to receive attention. While it seems reasonable to attempt nomalization of abnormal blood
lipid patterns through dietary or pharmacological efforts in those individuals with acquired or inherited hyperlipidemias,
the presently available data do not warrant major revision of the dietary pattern for the remaining 80–90% of the population.
One of five papers presented at the symposium, “Status of Fat in Food and Nutrition,” AOCS Fall Meeting, Chicago, September
1973. 相似文献
13.
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
14.
Primary cultures of smooth muscle cells were established from the medial layer of guinea pig aorta. Cells at passage level
4 were treated with different series of fatty acids belonging to the n-9, n-6 and n-3 families. Lipid peroxidation was measured
by the thiobarbituric acid assay and prostaglandin biosynthesis was measured by the radioimmunoassay of PGE and 6-keto-PGF1α. Cell proliferation was estimated from the total cell number of cultures seeded at low density. 18∶1(n-9) did not form lipid
peroxides and this fatty acid stimulated cell proliferation. All fatty acids which generated lipid peroxides inhibited cell
proliferation, but inhibition was correlated with the degree of lipid peroxidation only in the n-9 fatty acid family. 22∶4(n-6)
and 22∶6(n-3) inhibited prostaglandin biosynthesis. 18∶2(n-6), 18∶2(n-9), 18∶3(n-3), 20∶2(n-9), 20∶3(n-3) and 20∶5(n-3) had
no effect on prostaglandin biosynthesis. 18∶3(n-6), 20∶3(n-6) and 20∶4(n-6) generated prostaglandins. 20∶3(n-9) generated
metabolites with prostaglandin immunoreactivity. The inhibition of cell proliferation did not correlate with enhanced or inhibited
prostaglandin synthesis. The inhibition of cell proliferation was related to the structures of the different polyunsaturated
fatty acid families decreasing in the order n-9>n-6>n-3. Eicosatrienoic acids were the most effective inhibitors of cell proliferation
in each fatty acid family and 20∶3(n-9) was the most potent eicosatrienoic acid. These data show that specific as yet unrecognized
products of fatty acid metabolism are responsible for the inhibition of cell proliferation.
Fatty acids are designated by the number of carbon atoms: number of double bonds and the position of the first double bond
from the methyl terminus of the acyl chain is noted in parenthesis: 18∶1(n-9), 9-octadecenoic acid; 18∶2(n-9), 6,9-octadecadienoic
acid; 18∶2(n-6), 9,12-octadecadienoic acid; 18∶3(n-6), 6,9,12-octadecatrienoic acid, 18∶3(n-3), 9,12,15-octadecatrienoic acid;
20∶2(n-9), 8,11-eicosadienoic acid; 20∶3(n-9), 5,8,11-eicosatrienoic acid; 20∶3(n-6), 8,11,-14-eicosatrienoic acid, 20∶4(n-6),
5,8,11,14-eicosatetraenoic acid; 20∶5(n-3), 5,8,11,14,17-eicosapentaenoic acid; 22∶4-(n-6), 7,10,13,16-docosatetraenoic acid,
22∶6(n-3), 4,7,10,13,16,19-docosahexaenoic acid.
Presented at the 73rd AOCS annual meeting, Toronto, Canada, May 1982. 相似文献
15.
The lipids of the hepatic tumor cell line, PLHC-1, from the topminnow (Poeciliopsis lucida), were found to contain considerable amounts of a range of n−9 polyunsaturated fatty acids despite culture in serum containing
significant amounts of essential fatty acids. The structural identity of all the n−9 polyunsaturated fatty acids was confirmed
by gas chromatography/mass spectrometry. Of particular interest, PLHC-1 cell total lipid contained 1.9% of 22∶3n−9 and 3.3%
of 22∶4n−9. As the culture medium contained virtually no n−9 polyunsaturated fatty acids, these fatty acids are all formed
by the PLHC-1 cells, presumably form 18∶1n−9. The 22∶3n−9 and 22∶4n−9 are presumably formed by processes of elongation and
“Δ4” desaturation of Mead acid, 20∶3n−9, present at over 11% in fatty acids of total lipid. Both 22∶3n−9 and 22∶4n−9 were
primarily located in phosphatidylserine (4.1 and 8.5% respectively) and, to a lesser extent, in phosphatidylethanolamine (2.2
and 6.5%, respectively), in common with the C22 derivatives of the n−3 and n−6 series, whereas 20∶3n−9 was preferentially located in phosphatidylinositol (31.2%). The results
establish that long-chain polyunsaturated fatty acids of the n−9 series can be formed in vertebrate tissue other than in conditions
of classical essential fatty acid deficiency. 相似文献
16.
The fatty acid composition of oyster larvae at various stages, as well as of the algal diet, were determined by gas liquid
chromatography (GC). Saturated fatty acids are the major fatty acid components in all larval stages and account for 34–62%,
30–35% and 35–81% of the neutral, polar and total lipids of algal-fed larvae respectively. Weight percentage of saturated
fatty acid in “starved” larvae was consistently higher (63–81%) during the whole period. The total polyunsaturated fatty acids
were higher in the polar lipids than in the neutral lipids. The concentration of the ω3 fatty acids also was comparatively
higher in the polar lipids than in the neutral lipids. In the total and neutral lipid fractions, the weight percentage of
polyunsaturated and ω3 fatty acids was higher in the eyed than in the pre-eyed (pediveliger) larvae. Eicosapentaenoic acid
(20∶5ω3) and 22∶6ω3 were not detected in lipids of “starved” and young larvae. There was an accumulation of 20∶5ω3, 22∶6ω3,
and total ω3 fatty acids in the older larvae. Lipid classes were separated by thin layer chromatography (TLC). There was no
qualitative change in lipid composition during larval development, but a marked increased of triacylglycerol in larvae up
to the stage of maturation in algae-fed larvae.
Contribution number 1195 of the Virginia Institute of Marine Science, Gloucester Point, VA 23062 相似文献
17.
Three- to four-week-old C57BL/6 mice were maintained for four weeks on diets in which the 10% lipid component was the ethyl
esters of either corn oil or n-3 polyunsaturated fatty acids (n-3 PUFA). Incubation of macrophagesex vivo for 14 h, a normal incubation time used for macrophage studies, in the absence of fetal calf serum, did not diminish the
extent of incorporation of 20∶5n-3 (eicosapentaenoic acid) and 22∶6n-3 (docosahexaenoic acid) moieties into membrane phospholipids
and into diradylglycerol (DG) relative to that after a very abbreviated incubation time. We conclude that studies examining
the effects of dietary n-3 PUFA on DG formation and related physiological effects in macrophages can be performed after a
normalex vivo incubation of at least 14 h without experiencing a significant loss of incorporated n-3 PUFA. 相似文献
18.
Evidence suggests that differences in fatty acid composition among various fish species may be due to differences in diet
or to environmental factors such as temperature, salinity, and depth at which the fish are caught. The beneficial effects
of a diet containing fish on cardiovascular or other diseases have been associated with their high content of eicosapentaenoic
(20∶5n-3) and docosahexaenoic (22∶6n-3) acids. In this study we analyzed the fatty acid composition of the flesh of 18 different
species of marine fish and of cultured rainbow trout. The fish were obtained from the Black and the Marmara Seas, both of
which have unique biological and ecological systems as well as eutrophication and pollution. The contents of 20∶5n-3 and 22∶6n-3
in the marine fish ranged from 4.2 to 13.3 wt% of total fatty acids, and from 6.6 to 40.8 wt%, respectively. The most important
differences from other studies on oceanic fish were the tendencies toward higher percentages of 16∶0 and 22∶6n-3. The n-3
series of polyunsaturated fatty acids were present as 32.4±1.9% of the total fatty acids. The present study suggests that
mature and immature Pomatomus saltator, as well as Engraulis encrasicolus, Mullus surmuletus, Sardina pilchardus, Mugil cephalus, and Sarda sarda may be preferred for the Turkish diet as a result of their high 20∶5 n-3 and 22∶6 n-3 contents. The cultured rainbow trout
Oncorhynchus mykiss is not as good a source of n-3 fatty acids as are the marine fish. 相似文献
19.
trans Isometric fatty acids of partially hydrogenated fish oil (PHFO) consist oftrans 20∶1 andtrans 22∶1 in addition to thetrans isomers of 18∶1, which are abundant in hydrogenated vegetable oils, such as in partially hydrogenated soybean oil (PHSBO).
The effects of dietarytrans fatty acids in PHFO and PHSBO on the fatty acid composition of milk were studied at 0 (colostrum) and 21 dayspostpartum in sows. The dietary fats were PHFO (28%trans), or PHSBO (36%trans) and lard. Sunflower seed oil (4%) was added to each diet. The fats were fed from three weeks of age throughout the lactation
period of Experiment 1. In Experiment 2 PHFO or “fully” hydrogenated fish oil (HFO) (19%trans), in comparison with coconut oil (CF) (0%trans), was fed with two levels of dietary linoleic acid, 1 and 2.7% from conception throughout the lactation period. Feedingtrans-containing fats led to secretion oftrans fatty acids in the milk lipids. Levels oftrans 18∶1 andtrans 20∶1 in milk lipids, as percentages of totalcis+trans 18∶1 andcis+trans 20∶1, respectively, were about 60% of that of the dietary fats, with no significant differences between PHFO and PHSBO. The
levels were similar for colostrum and milk. Feeding HFO gave relatively lesstrans 18∶1 andtrans 20∶1 fatty acids in milk lipids than did PHFO and PHSBO. Only low levels ofcis+trans 22∶1 were found in milk lipids. Feedingtrans-containing fat had no consistent effects on the level of polyenoic fatty acids but reduced the level of saturated fatty acids
and increased the level ofcis+trans monoenoic fatty acids. Increasing the dietary level of linoleic acid had no effect on the secretion oftrans fatty acids but increased the level of linoleic acid in milk. The overall conclusion was that the effect of dietary fats
containingtrans fatty acids on the fat content and the fatty acid composition of colostrum and milk in sows were moderate to minor. 相似文献
20.
Twenty-one groups of weanling male Wistar rats were fed semipurified diets containing 5% (w/w) of different dietary fats.
After 2 wk, liver sphingomyelin (SM) fatty acid composition was determined. The ratio of 24∶1 to 24∶0 in liver SM varied over
a tenfold range in response to dietary fat type. Stepwise multiple regression analysis indicated that dietary 24∶1, 24∶0,
and 22∶1 were the most significant factors in predicting the 24∶1/24∶0 ratio of liver SM. The mathematical relation between
the dietary fatty acid composition and liver SM 24∶1/24∶0 was y=1.88 (24∶1)−1.49 (24∶0)+0.21 (22∶1)+0.01 (18∶1)+0.26, r
2=0.95, P<0.0001. These results were confirmed by a second experiment in which the rats were fed olive oil-based diets supplemented
with various fatty acid ethyl esters. 相似文献