共查询到20条相似文献,搜索用时 31 毫秒
1.
Day-old male broiler chickens were fed semipurified diets containing 5% lipid from one of four different lipid sources: corn
oil (CO), partially hydrogenated soybean oil (HSBO), a spent restaurant grease (SRG) and a purified mixture of triolein, tripalmitin
and tristearin (OPS). Diets CO and HSBO contained adequate amounts of linoleic acid, but diets SRG and OPS were deficient
in linoleate. In addition, SRG and HSBO containedtrans isomers of 16∶1 and 18∶1. The diets were fed for 3 wk to determine the effects of low linoleate levels andtrans isomers on fatty acid profiles in liver microsomes, mitochondria and cytosol. Chicks fed HSBO had the highest body weights,
while those fed SRG and OPS had the lowest. The incidence and severity of dermatitis were similar for all treatments. The
proportions of linoleate and arachidonate in lipids from liver subcecullar fractions were reduced significantly in chicks
fed OPS and SRG; however levels of 20∶3ω9 were not increased. Feeding HSBO, which is high in both linoleate and linolenate,
resulted in higher levels of 18∶3ω3 and 20∶5ω3 in liver subcellular fractions and lower levels of 20∶4ω6 than those seen in
chicks fed CO. The isomeric forms of 18∶1 present in the partially hydrogenated fats (HSBO and SRG) appeared to be incorporated
into the lipids of liver fractions. The results of this study show that dietary lipids influence fatty acid, profiles of chick
liver microsomes, mitochondria and cytosol. Decreases in linoleate and arachidonate in these organelles occur before overt
essential fatty acid (EFA) deficiency signs in chicks fed EFA-deficient diets.
Published as Scientific Paper No. 7512, College of Agriculture and Home Economics Research Center, Project No. 4723, Washington
State University, Pullman, WA. 相似文献
2.
The effect of corn oil, coconut oil, and medium-chain triglyceride (MCT, a glyceride mixture consisting almost exclusively
of fatty acids of 8 and 10 carbons in length) ingestion on lipid metabolism was studied in chicks. In chicks fed cholesterol-free
diets, MCT ingestion elevated plasma total lipids and cholesterol and depressed liver total lipids and cholesterol when compared
to chicks receiving the corn oil diet. As a consequence of the opposite effects of MCT ingestion on plasma and liver cholesterol
and total lipids, the plasma-liver cholesterol pool was not altered. When cholesterol was included in the diets, dietary MCT
depressed liver and plasma total lipids and cholesterol as compared with corn oil, consequently also lowered the plasmaliver
cholesterol pool.
The in vitro cholesterol and fatty acid synthesis from acetate-1-14C was higher in liver slices from chicks fed MCT than in those from chicks fed corn oil. The percentage of radioactivity from
acetate-1-14C incorporated into the carboxyl carbon of fatty acids by liver slices was not altered by MCT feeding, indicating that the
increased acetate incorporation represented de novo fatty acid synthesis. The conversion of palmitate-1-14C to C18 acids was increased in liver of chicks fed MCT, implying that fatty acid chain elongating activity was also increased. Studies
on the conversion of stearate-2-14C to mono- and di-unsaturated C18 acids showed that hepatic fatty acid desaturation activity was enhanced by MCT feeding. Data are presented on the plasma
and liver fatty acid composition of chicks fed MCT-, corn oil-, or coconut oil-supplemented diets.
The principles of laboratory animal care, as promulgated by the National Society for Medical Research, were observed. 相似文献
3.
A Lacera Rúa M R Molina L A Mejía R Gómez Brenes R Bressani 《Archivos latinoamericanos de nutrición》1985,35(1):130-147
A flour proposed as a protein source for chick feeding was evaluated. The flour consisted in a 1.00:1.15 dry mixture of by-products from shark filleting (dt) and shrimp by products (cc). It had a crude protein content of 55.66%, a Ca:P ratio of 5.76 and an essential amino acid pattern similar to that of fish meal and/or shark meat. Methionine proved to be the first limiting essential amino acid. The shark meat and the by-products from shark filleting had adequate levels of available lysine (from 337 to 383 mg/g N). The flour had a fineness modulus (F.M.) of 3.95, an average particle diameter of 0.0175 inches (0.444 mm) and a uniformity index of 1:5:4 (coarse:medium:fine parts). The flour was considered suitable for chick feeding. The protein quality of the flour mixture (dt-cc) was evaluated in rats using diets which contained 3, 6, 9 and 12% protein from the product, and determining the PER, NPR and NGI values. Diets containing similar protein levels prepared from dried shark meat flour, mixed with casein, were used as standards. The flour mixture (dt-cc) had a PER of 1.60, an NGIo of 2.46, an NGI of 2.49 and an apparent digestibility of 88.80%. These values proved to be significantly (p less than 0.05) lower than those found for the corresponding shark meat flour-casein standard diets. The above results are partially explained by the high mineral content, high Ca:P ratio and high Na and K of the dt-cc mixture, factors which could interfere with the utilization of the most limiting essential amino acids and other nutrients, as some vitamins, in these diets. The Kruskal-Wallis test of the feed efficiency (EA) data obtained in growing chicks revealed that there was a significant (p less than 0.05) difference between the EA values obtained with the dried shark meat-containing diets and the standard commercial diets (Purina and a diet based on a 1.6:1.0 soybean meal:cottonseed meal mixture). No significant differences were found between the dt-cc mixture-containing diets and the commercial ones used as standard. The diet containing 6% shark meat flour was found to be the best based on the EA data. The diet with 12% of the dt-cc mixture gave similar EA values than all those containing shark meat flour; however, the greater nutritional-economic impact based on the EA data was found for the diets containing 3 and 6% of the dt-cc flour mixture.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
4.
Effects of dietarytrans acids on the interconversion of linoleic acid was studied using the liver microsomal fraction of rats fed a semipurified
diet containing fat supplements of safflower oil (SAFF), hydrogenated coconut oil (HCO) at 5 and 20% levels or a 5% level
of a supplement containing 50.3% linolelaidic and 24.3% elaidic acids devoid ofcis,cis-linoleic acid (TRANS). Growth rate was suppressed to a greater extent with the animals fed the 20% than the 5% level of the
HCO-supplemented diets and still further by the TRANS diet compared to the groups fed the SAFF diets. Food intake was greater
in the groups fed the HCO than the SAFF-supplemented diets, demonstrating the marked effect of an essential fatty acid (EFA)
deficiency on feed efficiency. In contrast to an EFA deficiency produced by the HCO supplement, which stimulated the in vitro
liver microsomal biosynthesis of arachidonic acid, diets containing the TRANS supplement exacerabated the EFA deficiency and
depressed 6-desaturase activity of the liver microsomal fraction. The liver microsomal fraction of the animals receiving this
supplement also was more sensitive to fatty acid inhibition of the desaturation of linoleic acid than those obtained from
animals fed either the SAFF or HCO diets. It is suggested that dietarytrans acids alter the physical properties of the 6-desaturase enzyme system, suppressing its activity, which increases the saturation
of the tissue lipids and, in turn, the requirement for EFA or polyunsaturated fatty acids. 相似文献
5.
Masaharu Kamei Sumiko Ohgaki Tamotsu Kanbe Mitsuru Shimizu Shigeru Morita Isao Niiya Isao Matsui-Yuasa Shuzo Otani 《Lipids》1996,31(11):1151-1156
The effects of dietary highly hydrogenated soybean oil (HSO) upon the changes caused by dietary polychlorinated biphenyls
(PCBs) were examined in rats. Six groups of rats were fed the following diets for 30 d: a 20% soybean oil-containing diet
(control diet), a diet in which a half of soybean oil was substituted with HSO (HSO-A diet), a diet in which cellulose powder
was replaced with HSO (HSO-B diet) and these diets supplemented with 100 ppm PCBs (control+PCBs, HSO-A+PCBs and HSO-B+PCBs
diets). Hepatic concentration of PCBs and relative liver weight were markedly decreased in rats fed with the HSO-A+PCBs diet
compared with those fed with the other diets containing PCBs. Liver lipids and liver cholesterol were considerably decreased
with a reciprocal increase in fecal sterol excretion by rats fed the HSO-A+PCBs and the HSO-B+PCBs diets compared with those
fed with the control+PCBs diet. The fatty acid composition in hepatic phospholipids showed an independent increase of the
saturated fatty acid content induced by dietary HSO and PCBs. Dietary PCBs also caused decreases in the amounts of monounsaturated
and n-3 polyunsaturated fatty acids. These results suggest that dietary HSO prevents accumulation of PCBs in the liver and
promotes the excretion of lipids stimulated by PCBs, accompanied by a change in fatty acid metabolism. 相似文献
6.
Minocher C. Reporter Robert S. Harris 《Journal of the American Oil Chemists' Society》1961,38(1):47-51
Three lots of cold-pressed soybean oil were treated with bubbling oxygen for 70, 80, and 180 hrs. at 70°C. and fed to rats
at a level of 18% in diets which were nutritionally adequate but devoid of vitamin A. Untreated soybean oil was fed in similar
control diets. Subgroups of 15 weanling rats each were given graded injections of vitamin A acetate intramuscularly each week.
Diarrhea developed in the rats fed the diets containing oxidized oil. This condition soon subsided in the groups receiving
vitamin A injections but not in the vitamin A-free group. Diarrhea was not noted in the rats receiving the untreated soybean
oil, without respect to the amount of vitamin A they received.
The rats on the vitamin A-free diets developed deficiency more rapidly when the diet contained oxidized rather than the untreated
oil. The food efficiencies of the groups fed the oxidized oils were lower than the controls. The intestines of the groups
receiving the oxidized oils were distended with fluid and were hemorrhagic. Enlarged kidneys were noted in the vitamin A-deficient
control as well as in test rats.
The retroperitoneal lipids of the groups on the oxidized oil were less unsaturated, had lower refractive indices, higher peroxide
values, and higher carbonyl values than comparable groups fed the control oil.
Vitamin A deficiency decreased the unsaturation of the kidney and liver lipids but increased that of the retroperitoneal lipids.
Injections of increasing amounts of vitamin A produced increases in the unsaturation of the body lipids.
The kidney lipids of the groups on the oxidized oil diets were less unsaturated and contained more peroxidic compounds than
the controls. Vitamin A deficiency increased the peroxidic compounds in the kidney and liver lipids, even in rats fed the
control oil. The liver lipids of the groups fed oxidized oil were less unsaturated, lower in vitamin A content, and higher
in peroxide compounds than the controls.
The vitamin A content of the whole blood varied in relation to the amounts injected. The content of tocopherol in the tissues
were not affected significantly by the oxidized oil in the diet.
The evidence indicates that severely oxidized oil may destroy vitamin A in the tissue of the rat, thereby hastening the development
of deficiency on vitamin A-free diets, reducing the storage of injected vitamin A, and increasing the vitamin A requirement.
These effects are with abused oil and should not be interpreted to mean that the mildly oxidized oils and fats, such as those
in the diets of human beings in this country are toxic.
1 Read in part at the 36th Fall meeting. American Oil Chemists' society, Chicago, October 20–22, 1958.
2 Assisted by a grant from the Roche Anniversary, Fund, Hoffmann LaRoche Inc.
3 Contribution No. 414 from the Department of Nutrition. Food Science and Technology, Massachusetts Institute of Technology,
Cambridge, Mass. 相似文献
7.
The effect of the nature and amount of dietary calories on the lipid composition of bone marrow of rats was studied. Male weanling rats were fed 3 isocaloric diets, containing high carbohydrate, normal protein, and high protein, and a fourth high fat diet for 49 days. Feeding of the high carbohydrate, high protein, and high fat diets caused a significant increase in the level of total lipids compared to the normal protein diet. This increase of total lipids was due primarily to the increase in the level of triglycerides. There was no significant difference in fatty acid composition of either nonpolar or polar lipids of bone marrow among rats fed high carbohydrate diet and those fed normal protein diet. A comparison of fatty acid compositions between bone marrow lipids of rats fed high protein diet and the other 2 isocaloric diets revealed that the proportion of palmitic acid was higher and the proportion of oleic acid was lower in animals fed high protein diet than in animals fed the other 2 diets. Compared to the 3 isocaloric low fat diets, dietary feeding of high fat diet caused a decrease in the proportion of palmitic and palmitoleic acids and an increase in the proportion of oleic and linoleic acids in total fatty acids of both nonpolar and polar lipids. 相似文献
8.
Fatty livers and the similarity between the skin lesions in kwashiorkor and those described in experimental essential fatty
acid (EFA) deficiency have led to the hypothesis that protein and EFA deficiencies may both occur in chronic malnutrition.
The relationship between serum very low density lipoprotein (VLDL) and hepatic lipid composition was studied after 28 d of
protein depletion to determine the interactions between dietary protein levels and EFA availability. Rats were fed purified
diets containing 20 or 2% casein and 5% fat as either soybean oil rich in EFA, or salmon oil rich in eicosapentaenoic (EPA)
and docosahexaenoic (DHA) acids, or hydrogenated coconut, oil poor in EFA. Animals were divided into six groups, SOC (20%
casein +5% soybean oil), SOd (2% casein +5% soybean oil), COC (20% casein +5% hydrogenated coconut oil), COd (2% casein +
5% hydrogenated coconut oil), SAC (20% casein +5% salmon oil) and SAd (2% casein +5% salmon oil). After 28 d, liver steatosis
and reduced VLDL-phospholipid contents (P<0.001) were observed in protein-deficient rats. In protein deficiency, triacylglycerol and phospholipid fatty acid compositions
in both liver and VLDL showed a decreased polyunsaturated-to-saturated fatty acid ratio. This ratio was higher with the salmon
oil diets and lower with the hydrogenated coconut oil diets. Furthermore, independent of the oil in the diet, protein deficiency
decreased linoleic and arachidonic acids in VLDL phospholipids. Conversely, despite decreased proportions of EPA at low protein
levels, DHA levels remained higher in rats fed salmon oil diets. While in rats fed the hydrogenated coconut oil-fed diets
the amount of 22∶5n−6 was lower in liver, it was higher in VLDL lipids at low protein levels. Both EPA and arachidonic acid
are precursors of eicosanoids and their diminution may be related to certain clinical symptoms seen in infants suffering from
kwashiorkor. 相似文献
9.
Soybean protein and casein supplemented with 1% Arg were compared for their ability to prevent fatty livers caused by excess
dietary Lys. The concentrations of serum lipids and lipoproteins of rats fed 5% Lys and having vatty livers were also compared
with those of rats fed the identical diet but lacking fatty livers when killed. The total liver lipids, triglycerides and
cholesterol of rats fed 15% casein +5% Lys were 3.9, 12.4 and 2 times control values, respectively. Rats fed 5% Lys +1% Arg
or 5% Lys with 15% soybean protein had liver lipid concentrations similar to controls fed no supplemental Lys. Serum total
lipids, triglycerides, cholesterol, phospholipids and free fatty acids also did not change, and serum ketone bodies were slightly
elevated with Lys feeding whether the rats had fatty livers or not. The concentrations of circulating HDL were slightly depressed
in all rats fed 5% Lys while LDL were significantly elevated, particularly in rats without fatty livers. Serum VLDL did not
change with 5% dietary Lys. Overall, excessive dietary Lys caused fatty livers which were prevented by varying the diet or
length of feeding. Excess Lys feeding altered lipoprotein metabolism shown by decreased serum HDL and a substantial elevation
in LDL. The latter was more apparent when the fat accumulation in liver was less severe or absent. The data suggest that the
fatty liver from Lys excess is probably unrelated to increased fat mobilization from storage, decreased fat oxidation or to
a major block in the transport of triglycerides from the liver to the circulation. 相似文献
10.
To clarify the effects of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on prostaglandin biosynthesis, diets
supplemented with oils rich in one fatty acid or the other were fed to rats over a 4-wk period. Animals fed the Max EPA diet
showed a significant decrease in plasma and tissue phospholipid arachidonic acid content. While plasma levels of DHA increased
on a shark liver oil diet enriched in DHA, the liver and kidney phospholipid contents of DHA were not altered. In addiition,
the DHA-enriched diet did not decrease the arachidonic acid content of either liver or kidney phospholipids. Whole blood thromboxane
and vascular prostacyclin synthesis were decreased by 65% and 36%, respectively, in animals fed the Max EPA diet. No such
decrease was seen in the rats fed DHA-enriched diets. We conclude from these results that in the rat DHA is not likely to
have a significant effect on prostaglandin synthesis when given as a dietary supplement. 相似文献
11.
Steers were given diets containing formaldehyde-treated casein-safflower oil supplements, in which the constituent 18∶2 was
protected from ruminal hydrogenation. A similar group was given unsupplemented diets. The fatty acid compositions of plasma,
liver, muscle and adipose tissue lipids were determined in both groups of cattle after 0, 2, 4 and 8 weeks of experimentation.
The proportion of 18∶2 in the triglycerides was markedly increased on feeding the supplement and the rate of incorporation
into the plasma triglycerides was higher than that in the triglycerides of muscle and adipose tissue. Associated with this
increase there were compensatory decreases in the proportions of 16∶0 and 18∶1 but no consistent change in the proportion
of 18∶0. The proportion of 18∶2 in the plasma phospholipids and cholesteryl esters was initially much higher than in the triglycerides
and this was further increased by feeding the safflower oil supplement. A linear relationship existed between the proportion
of 18∶2 in the phospholipids and cholesteryl esters of plasma. The supplement also caused substantial increases in the proportion
of 18∶2, both in phospholipids from liver and muscle and in cholesteryl esters from liver, and there were compensatory decreases
in the proportions of other unsaturated fatty acids, e.g., 18∶1, 18∶3, 22∶6. These studies demonstrate that when ruminal hydrogenation
was circumvented by feeding formaldehyde-treated casein-safflower oil particles, the linoleic acid was absorbed and the pattern
of incorporation into plasma and tissue lipids was similar to that in nonruminants. 相似文献
12.
The purpose of this study was to examine the effects of feeding n−3 polyunsaturated fatty acid (PUFA)-enriched chicken eggs
on plasma and liver cholesterol levels and fatty acid composition in rats. Eggs were collected from laying hens fed diets
containing 10% flax seed (Hn−3), 12% sunflower seed (Hn−6), or wheat and soybean meal control (CON). Yolk powders were prepared
and fed at the 15% level to weanling female Sprague-Dawley rats for 28 days. Consumption of n−3 PUFA-enriched yolks significantly
reduced both plasma and liver total cholesterol. Liver total lipids and phospholipids of rats fed Hn−3 diet were enriched
with linolenic, eicosapentaenoic, and docosahexaenoic acids with a concomitant reduction of arachidonic acid in liver phospholipids.
The plasma cholesterol of rats fed yolk powders enriched with n−6 PUFA (mainly linoleic acid) was reduced to the same extent
as in those fed the n−3 enriched, but the liver cholesterol was significantly increased, indicating differential effects of
dietary n−3 and n−6 PUFA. The results demonstrated that the cholesterolemic and tissue lipid modulating properties of chicken
eggs could be modified in a favorable way by altering the fatty acid composition of yolk lipids through manipulation of laying
hen diets. 相似文献
13.
Terminalia bellirica Roxb. is a valuable tree of Indian forests. The seeds are valued medicinally and also industrially, for tanning purposes.
The kernels, which are not currently used for edible purposes, have 40% oil and 35% protein. The oil extracted from the kernels
is sweet-smelling and has palmitic (35%), oleic (24%) and linoleic (31%) acids as major fatty acids. The proximate principles,
antinutritional factors and amino acid composition of the protein of the kernel are analyzed. Short term feeding of the oil
at 10% level in a 10% casein protein diet to rats for 4 weeks resulted in growth comparable to that observed with animals
fed a similar diet containing 10% groundnut oil. The protein utilization of casein used in the diet, as judged by the protein
efficiency ratio (PER) and net protein utilization (NPU), was not adversely affected by theT. bellirica oil in the diet. The liver and heart lipid profiles of both the groups as reflected by the parameters, total lipids, total
cholesterol and triglycerides content were comparable except for the heart triglycerides of the TBO-fed group, which were
elevated. The absorption of nutrients like calcium, phosphorus and nitrogen was not adversely affected by the intake ofT. bellirica oil.T. bellirica oil is absorbed to the same extent as groundnut oil. The results of this preliminary study indicate thatT. bellirica kernel oil may be used for edible purposes because it is a good source of linoleic acid. However, long term toxicological
studies are necessary to establish its safety before it can be recommended as an edible oil for human consumption.
Feeding a diet containing 10%T. bellirica kernel protein as a raw diet as well as a cooked diet to rats, mice and chicks resulted in low food intake and death in all
three species, probably due to heat stable antinutritional factors in the kernel. 相似文献
14.
We compared the effects of three different high-lipid diets on plasma lipoproteins and phospholipids in mink (Mustela vison). The 18 mink studied were fed one of the three diets during a 25-d period in a parallel group design. The compared diets
had 0,17, and 67% extracted lipids from natural gas-utilizing bacteria (LNGB), which were rich in PE. The group with 0% LNGB
was fed a diet for which the lipid content was 100% soybean oil. The total cholesterol, LDL cholesterol, and HDL cholesterol
of animals consuming a diet with 67% LNGB (67LNGB-diet), were significantly lowered by 35, 49, and 29%, respectively, and
unesterified cholesterol increased by 17% compared with the animals fed a diet of 100% lipids from soybean oil (SB-diet).
In addition, the ratio of LDL cholesterol to HDL cholesterol was 27% lower in mink fed the 67LNGB-diet than those fed the
SB-diet. When the mink were fed the 67LNGB-diet, plasma PC, total phospholipids, lysoPC, and PI were lowered significantly
compared with the mink fed a SB-diet. Plasma total cholesterol was correlated with total phospholipids as well as with PC
(R=0.8, P<0.001). A significantly higher fecal excretion of unesterified cholesterol, cholesteryl ester, PC, lysoPC, and PE was observed
in the 67LNGB-fed mink compared with the SB-fed mink. We conclude that phospholipids from the 67LNGB-diet decreased plasma
lipoprotein levels, the LDL/HDL cholesterol ratio, and plasma phospholipid levels, especially lysoPC and PC, compared with
the highly unsaturated soybean oil. Our findings indicate that the decrease of plasma cholesterol is mainly caused by a specific
mixture of phospholipids containing a high level of PE, and not by the dietary FA composition. The lack of significant differences
in the level of plasma PE due to the diets indicates that most of the PE from LNGB has been converted to PC in the liver.
Thus, plasma cholesterol may at least be partly regulated by phospholipid methylation from PE to PC in the liver. 相似文献
15.
The influence of the linoleic acid levels of diets containing partially hydrogenated marine, oils (HMO) rich in isomeric 16∶1,
18∶1, 20∶1 and 22∶1 fatty acids on the fatty acid profiles of lipids from rat liver, heart and adipose tissue was examined.
Five groups of rats were fed diets containing 20 wt% fat−16% HMO+4% vegetable oils. In these diets, the linoleic acid contents
varied between 1.9% and 14.5% of the dietary fatty acids, whereas the contents oftrans fatty acids were 33% in all groups. A sixth group was fed a partially hydrogenated soybean oil (HSOY) diet containing 8%
linoleic acid plus 32%trans fatty acids, mainly 18∶1, and a seventh group, 20% palm oil (PALM), with 10% linoleic acid and notrans fatty acids.
As the level of linoleic acid in the HMO diets increased from 1.9% to 8.2%, the contents of (n−6) polyunsaturated fatty acids
(PUFA) in the phospholipids increased correspondingly. At this dietary level of linoleic acid, a plateau in (n−6) PUFA was
reached that was not affected by further increase in dietary 18∶2(n−6) up to 14.5%. Compared with the HSOY- or PALM-fed rats,
the plateau value of 20∶4(n−6) were considerably lower and the contents of 18∶2(n−6) higher in liver phosphatidylcholines
(PC) and heart PC. Heart phosphatidylethanolamines (PE) on the contrary, had elevated contents of 20∶4(n−6), but decreased
22∶5(n−6) compared with the PALM group.
All groups fed HMO had similar contents oftrans fatty acids, mainly 16∶1 and 18∶1, in their phospholipids, irrespective of the dietary 18∶2 levels, and these contents were
lower than in the HSOY group.
High levels of linoleic acid consistently found in triglycerides of liver, heart and adipose tissue of rats fed HMO indicated
that feeding HMO resulted in a reduction of the conversion of linoleic acid into long chain PUFA that could not be overcome
by increasing the dietary level of linoleic acid. 相似文献
16.
Hans Kaunitz Charles A. Slanetz Ruth Ellen Johnson Vigen K. Babayan 《Journal of the American Oil Chemists' Society》1959,36(8):322-325
- Effects of medium-chain (C6–C12) saturated triglycerides (MCT) and long-chain (C14–C18) saturated triglycerides (LCT) with and without linoleic acid (LA) supplementation were studied on rats fed purified diets
- With 2% linoleic acid rats fed MCT and LCT grew somewhat better than those on a low-fat diet with the same supplement. Without linoleic acid those fed MCT grew better, and those fed LCT grew worse than those on the corresponding low-fat diet. MCT seemed to decrease, and LCT to increase linoleic acid requirements.
- In survival studies 14 out of 18 rats fed 20% MCT were alive after 2 years; of their controls fed 20% lard, 10 out of 19 survived.
- Reproduction studies in females gave equally poor results on unsupplemented low-fat, MCT, and LCT diets regarding implantation, birth weight, and survival rate. The weaning weights of the young on MCT were however the highest. With 2% LA weaning weights were equally high with LCT and MCT but lower with low-fat diet.
- In animals fed low-fat diets not supplemented with LA, low serum cholesterol was associated with high liver cholesterol. With MCT, serum values were higher and liver values were significantly lower. With unsupplemented LCT, serum and liver values were high. When the three diets were supplemented with 2% LA, there were no longer any differences in the serum levels and in the liver levels. Whether ar not the presence of some oleate in the MCT and LCT influenced the cholesterol results is not certain.
- The differences in the effects of MCT and LCT are discussed.
17.
The liver and plasma lipids and fatty acid composition of rats fed synthetic diets of differing fat type and content were
studied. All animals were starved for 48 hr and then refed a high carbohydrate, fat-free diet for 48 hr. They were then divided
into three groups and fed for an additional 48 hrs the following: group 1, the fat-free diet; group 2, a diet containing 44%
of calories from corn oil; and group 3, a diet containing 44% calories from completely hydrogenated soybean oil. The total
lipid concentration of the liver in the animals on the fat-free diet was elevated at 72 and 96 hr. The addition of either
saturated or unsaturated fat in the diet at 48 hr prevented this accumulation. The total phospholipid and cholesterol concentrations
of the liver were relatively uninfluenced by any diet in this study. Plasma total fatty acid concentration was elevated at
72 hr in the animals on a fat-free diet compared to those fed the stock diet, starved for 48 hr or fed the fat-containing
diets. By 96 hr, however plasma fatty acid concentrations in all groups were similar to those in animals fed only the stock
diet. The release of de novo synthesized fatty acids into plasma from the liver was strongly inhibited by dietary fat, either
saturated or polyunsaturated. With the fat-free diet there was a significant increase in the saturated and monounsaturated
fatty acids in both liver and plasma. The addition of corn oil to the diet facilitated a reversion of the fatty acid composition
in liver and plasma to that found in the animals fed the stock diet ad libitum, but saturated fat did not. No effect of diet
on the fatty acid composition of the red cells was observed during the course of this study. Exogenous saturated fatty acids,
although similar chemically to the fatty acids synthesized by the liver, may have physiological actions that differ from endogenously
synthesized fat. 相似文献
18.
The impact of a moderate Zn deficiency on growth and plasma and liver lipids was investigated in two 4-week experiments with
male weanling rats fed fat-enriched diets. Semisynthetic, approximately isocaloric diets containing 3% soybean oil were supplemented
with either 7 or 100 mg Zn/kg diet and with 22% beef tallow (BT) or sunflower oil (SF). In Experiment 1, which compared the
dietary fat level and the fat source in a factorial design of treatments, all diets were fed ad libitum to 6 × 8 animals,
whereas intake of the high-Zn BT and SF diets was restricted in Experiment 2 (5 × 6 rats) to the level of intake of the respective
low-Zn diets. The low-Zn SF diet consistently depressed food intake and final live weights of the animals to a greater extent
than the other low-Zn diets, while intake and growth were comparable among the animals fed the high-Zn diets. The marginal
Zn deficit per se did not alter plasma triglyceride and cholesterol concentrations nor hepatic concentrations of triglyceride,
cholesterol and phospholipids. The fatty acid pattern of liver phospholipids did not indicate that chain elongation and desaturation
of fatty acids was impaired by a lack of zinc. It was concluded that dietary energy and fat intake, and fat source have a
greater effect on plasma and liver lipids than a moderate Zn deficiency. Marginally Zn-deficient diets enriched with sunflower
oil as a major energy source cause a greater growth retardation than diets rich in carbohydrates or beef tallow. 相似文献
19.
Male Sprague Dawley rats were fed semipurified diets containing 20% fat for 15 weeks. The dietary fats were corn oil, soybean
oil, palm oil, palm olein and palm stearin. No differences in the body and organ weights of rats fed the various diets were
evident. Plasma cholesterol levels of rats fed soybean oil were significantly lower than those of rats fed corn oil, palm
oil, palm olein or palm stearin. Significant differences between the plasma cholesterol content of rats fed corn oil and rats
fed the three palm oils were not evident. HDL cholesterol was raised in rats fed the three palm oil diets compared to the
rats fed either corn oil or soybean oil. The cholesterol-phospholipid molar ratio of rat platelets was not influenced by the
dietary fat type. The formation of 6-keto-PGF1α was significantly enhanced in palm oil-fed rats compared to all other dietary treatments. Fatty acid compositional changes
in the plasma cholesterol esters and plasma triglycerides were diet regulated with significant differences between rats fed
the polyunsaturated corn and soybean oil compared to the three palm oils. 相似文献
20.
Epididymal fat pad lipids from rats fed trivernolin at the 4.8% level in the diet for 90 days were found to contain 6.1% epoxyoleic
acid. No epoxides were detected in the serum lipids and only trace amounts were found in the liver lipids. TLC, GLC and a
specific color reaction with picric acid were used to identify this fatty epoxide in the tissues. Epoxyoleic acid was shown
to be present as a mixture of predominately monovernoloyl triglycerides with some divernoloyl triglycerides and small amounts
of trivernolin. Lipase hydrolysis of the first two triglycerides has demonstrated that the vernoloyl groups are present mostly
in the 1,3 positions. In a separate experiment, rats were fed cholesterol epoxide at the 0.5% and 1.5% levels in the diet
for 90 days. TLC and GLC examination of lipids from these rats failed to reveal the presence of any cholesterol epoxide. Only
one-half of the sterol fed could be accounted for in the fecal lipids.
Presented in part at the AOCS Meeting, Chicago, October 1967. 相似文献