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1.
This study was designed to examine the effects of dietary n−3 and n−6 polyunsaturated fatty acids (PUFA) on postprandial lipid
levels and fatty acid composition of hepatic membranes. Male Sprague-Dawley rats were trained for a 3−h feeding protocol and
fed one of five semipurified diets: one fat-free diet or one of four diets supplemented with 10% (by weight) each of corn
oil, beef tallow, perilla oil, and fish oil. Two separate experiments were performed, 4-wk long-term and 4-d short-term feeding
models, to compare the effects of feeding periods. Postprandial plasma lipid was affected by dietary fats. Triacylglycerol
(TG) and total cholesterol levels were decreased in rats fed perilla oil and fish oil diets compared with corn oil and beef
tallow diets. Hepatic TG and total cholesterol levels were also reduced by fish oil and perilla oil diets. Fatty acid composition
of hepatic microsomal fraction reflected dietary fatty acids and their metabolic conversion. The major fatty acids of rats
fed the beef tallow diet were palmitic, stearic, and oleic. Similarly, linoleic acid (LA) and arachidonic acid in the corn
oil group, α-linolenic acid (ALA) and eicosapentaenoic acid (EPA) in the perilla oil group, and palmitic acid and docosahexaenoic
acid (DHA) in the fish oil group were detected in high proportions. Both long- and short-term feeding experiments showed similar
results. In addition, microsomal DHA content was negatively correlated with plasma lipid levels. Hepatic lipid levels were
also negatively correlated with EPA and DHA contents. These results suggest that n−3 ALA has more of a hypolipidemic effect
than n−6 LA and that the hypolipidemic effect of n−3 PUFA may be partly related to the increase of EPA and DHA in hepatic
membrane. 相似文献
2.
Ethyl linoleate was substituted in part for the 20% of butterfat, hydrogenated coconut oil, lard, or tallow in an atherogenic
diet fed to rats throughout a 40-week experimental period. Aortic degeneration, evidenced by lipid infiltration of the intima,
was observed in the control groups but not in the linoleate-fed groups. Groups that received butterfat or hydrogenated coconut
oil showed reduced plasma and hepatic cholesterol levels when fed 2% of ethyl linoleate; groups that received lard or tallow
showed no significant change in plasma and hepatic cholesterol levels when fed 2% of ethyl linoleate; and groups that received
a fat-free diet with 2% of ethyl linoleate showed lower plasma and hepatic cholesterol levels and more complete aortic protection
than groups that were fed 20% of corn oil or cottonseed oil. The data suggest that, in the cholesterol-fed rat, the kind and
amount of dietary fatty esters may influence aortic condition via some route(s) other than control of plasma and hepatic cholesterol
levels.
Presented at the AOCS Meeting, Los Angeles, April 1966. Journal Paper No. 2952 of the Agricultural Experiment Station, Purdue
University, Lafayette, Ind. 相似文献
3.
Bertram I. Cohen Erwin H. Mosbach Nariman Ayyad Shigeo Miki Charles K. McSherry 《Lipids》1992,27(7):526-532
We tested two hypotheses, i) whether the type and the amount of fat in the diet will affect the formation of cholesterol gallstones
in the hamsters, and ii) whether palmitic acid, a major fatty acid component of butterfat, can act as a potentiator of cholesterol
cholelithiasis in the hamster. Young, male golden Syrian hamsters (Sasco) were fed a semipurified diet containing casein,
corn starch, cellulose and cholesterol (0.3%) to which various types and amounts of fat (butterfat, olive oil, menhaden oil,
corn oil) were added. All diets contained 2% corn oil to supply essential fatty acids to the growing hamsters. No deaths or
illness occurred during the experiment. Animals fed the semipurified diet plus 4% butterfat (group 1) had a gallstone incidence
of 63%. Replacement of butterfat with either olive oil, corn oil or menhaden oil prevented the formation of cholesterol gallstones
entirely (groups 2–4). When total butterfat was increased from 4% to 8% (group 8), the incidence of cholesterol gallstones
increased to 80%. Substitution of 4% olive oil (group 5), corn oil (group 6), or menhaden oil (group 7) for the additional
4% butterfat significantly reduced gallstones to 35%, 45% and 30%, respectively. The replacement of 4% butterfat with 1.2%
palmitic acid gave the highest incidence of cholesterol gallstones (95%). These results suggest that butterfat (and one of
its components, palmitic acid) intensifies gallstone formation in this model whereas mono- and polyunsaturated fats act as
inhibitors of cholesterol cholelithiasis. A fatty acid, possibly palmitic acid, appears to act as lithogen in our model. 相似文献
4.
The effects of long term (8–14 wk) essential fatty acid (EFA)-deprived diets in rats are well documented. In the present study,
we compared, in weanling rats, the effect of a short term (two wk) hydrogenated coconut oil, EFA-deprived, diet (D) with that
of a corn oil, EFA-adequate, diet (A), using either sucrose (SU) or starch (ST) as carbohydrate. After two wk, rats fed the
sucrose/hydrogenated coconut oil diet developed some characteristic features of EFA deprivation: slower growth rate, decreases
in linoleic and arachidonic acid of plasma phospholipids and an increase in n−9 eicosatrienoic acid of plasma phospholipids.
When rats ate the starch/hydrogenated coconut oil diet, there was a similar decrease in linoleic acid of plasma phospholipids,
but only a small effect on growth rate and no change in the arachidonic acid content of plasma phospholipids. EFA deprivation
and sucrose had opposite effects on plasma triglyceride (TG) levels: deprivation induced a decrease, whereas the sucrose induced
an increase in very low density lipoprotein (VLDL) triglycerides. The observed decrease in plasma triglyceride during EFA
deporivation might result from an activation of lipoprotein lipase during the early stages of deprivation. 相似文献
5.
Groups of 40 male Charles River rats were fed diets containing cottonseed oil, olive oil, corn oil, soybean oil, coconut oil,
chicken fat, beef fat, butter oil, lard and saturated medium chain triglycerides. The fats were fed fresh and after 40 hr
aeration at 60 C, which hardly changed peroxide values. In addition, fresh and aerated soybean oil and lard were fed to W/Fu
rats. Body weights and life span were significantly influenced by the kind of fat fed, but not by aeration. Many hearts exhibited
unspecific focal myocarditis and focal fibrosis. The latter was graded in a blind test, which revealed highly significant
differences in the incidence of severe lesions; those fed corn oil had the most, followed by cottonseed oil, soybean oil,
olive oil, beef fat, saturated medium chain triglycerides, butter, chicken fat and lard, in that order. Feeding of aerated
fat resulted in an increased incidence with six of the eight fats. The W/Fu rats had lower incidences, but those fed soybean
oil had more than those fed lard, and aeration led to a higher incidence. Some heart sections stained with Light Green SF
Yellowish revealed areas of muscle fibrils that did not accept the stain, probably as a consequence of cellular damage. Higher
incidences of this lesion were associated with the same fats as was severe fibrosis, and feeding of aerated fats led to higher
incidences. Many livers revealed marked proliferation of bile ducts. The groups fed cottonseed, soybean, olive and corn oils
had higher incidences of severe lesions, and feeding of the oxidized oils led to still higher incidences. None of the results
appeared to be associated with the fatty acid composition of the fats, which suggested that these long term effects may have
been due to minor constituents in the individual fats.
One of seven papers presented in the symposium “Biological Significance of Autoxidized and Polymerized Oils,” JOCS-AOCS Joint
Meeting, Los Angeles, April 1972. 相似文献
6.
Interaction between dietary protein and fat in triglyceride metabolism in the rat: Effects of soy protein and menhaden oil 总被引:4,自引:0,他引:4
The objective of the present study was to determine the mechanisms by which dietary proteins interact with dietary lipids
in the regulation of triglyceridemia in rats. Male Sprague-Dawley rats (n=56) were subjected to 28-d experimental diets containing different combinations of proteins (20% w/w) and lipid sources (14%
w/w): (i) casein-menhaden oil, (ii) casein-beef tallow, (iii) soy protein-menhaden oil, and (iv) soy protein-beef tallow.
Significant protein-lipid interactions were observed on triglyceridemia and hepatic cholesterol in fasted rats. The combination
of casein and beef tallow was associated with high plasma TG and hepatic cholesterol concentrations, which were reduced by
substitution either of soy for casein or of menhaden oil for beef tallow. Therefore, triglyceridemia and liver cholesterol
remained low with soy protein feeding, independently of the lipid source, as well as with menhaden oil feeding, regardless
of the protein source. The menhaden oil diets reduced plasma cholesterol, hepatic TG, and TG secretion compared with beef
tallow diets independently of the dietary protein source. Modifying the source of dietary proteins and lipids had no effect
on post-heparin plasma lipoprotein lipase activity. These results demonstrate that soy protein can lower rat triglyceridemia
relative to casein when associated with beef tallow consumption, whereas menhaden oil can attenuate hypertriglyceridemia when
rats are fed casein. The data further suggest that part of the hypotriglyceridemic effect of soy protein in the rat may be
mediated by reduced hepatic lipid synthesis, as is the case for menhaden oil. 相似文献
7.
Interrelationship of stearic acid content and triacylglycerol composition of lard,beef tallow and cocoa butter in rats 总被引:4,自引:0,他引:4
We investigated modes whereby stearic acid (18∶0) exerts a neutral or cholesterol-lowering effect using dietary fats which
provided graded levels of 18∶0 and distinct triacylglycerol (TAG) profiles. Male Sprague-Dawley rats (150–175 g) were fed
diets containing 0.2% cholesterol and 16% fat from corn oil, or from 1% corn oil plus 15% lard (13.2% 18∶0), beef tallow (19.2%
18∶0) or cocoa butter (34.7% 18∶0) for 3 wk, and then killed in a fasted or fed state. Chylomicron (CM) fatty acid profiles
suggested reduced absorption of 18∶0 with greater 18∶0 intake. CM TAG profiles indicated a reduction or loss of two TAG species
compared to the TAG profiles of the stearate-rich diets: 1-palmitoyl-2-oleoyl-3-stearoyl glycerol (POS) and 1,3-distearoyl-2-oleoyl
glycerol (SOS). Hepatic total cholesterol concentrations were 54–77% lower (P<0.01) in the cocoa butter-fed than the lard- and beef tallow-fed groups. The cocoa butter group showed a significantly lower
ratio of high-density lipoprotein esterified/free cholesterol than all other groups. Hepatic stearoyl-CoA and oleoyl-CoA concentrations,
the substrate and product for hepatic δ9 desaturase, were not significantly different for corn oil-fed and cocoa butter-fed
groups in spite of a large difference in 18∶0 intake. These data suggest that the neutral or cholesterol-lowering effect of
18∶0 is not due to hepatic conversion of stearic to oleic acid, and that POS and SOS are poorly absorbed from stearate-rich
dietary fats. 相似文献
8.
Male and female weanling rats were fed diets containing 2 or 42% of calories as corn oil or 40% as beef tallow plus 2% as
corn oil until they were 12 or 18 weeks of age. Incorporation of C14-acetate into lipids of serum and liver and concentration of lipids in serum, liver, and carcass at the end of these periods
were determined.
Net synthesis of noncholesterol lipid was repressed by changing the diet from 2% to 42% of calories from either dietary fat
in both sexes and at both ages. Cholesterol net synthesis was enhanced 29-fold in males and 22-fold in females fed 42% corn
oil compared to 2% corn oil to the age of 12 weeks. It was enhanced only 2.6-fold for males and 3.4-fold for females by 40%
beef tallow plus 2% corn oil. At 18 weeks of age cholesterol synthesis in males fed 42% corn oil was 7.3 and in females 9.1
times the value for those fed 2% corn oil. At this age the values for rats fed 40% beef tallow plus 2% corn oil were 1.2 and
3.7 times those for 2% corn oil fed rats of the respective sexes. 相似文献
9.
Dietary polyunsaturated fat versus saturated fat in relation to mammary carcinogenesis 总被引:3,自引:0,他引:3
High levels of dietary fat have been shown to promote the development of mammary tumors induced in rats by 7,12-dimethylbenz(α)anthracene,
and polyunsaturated fats were found to be more effective than saturated fats. In further studies it was found that diets containing
3% sunflowerseed oil (polyunsaturated fat) and 17% beef tallow or coconut oil (saturated fats) enhance tumorigenesis as much
as a diet containing 20% sunflowerseed oil. Rats on these diets developed at least twice as many tumors as those fed diets
containing either 3% sunflowerseed oil or 20% of the saturated fats alone. These results are in accord with human epidemiological
data which show that breast cancer mortality in different countries is positively correlated with total fat intake but not
with intake of polyunsaturated fat. Total fat intake varies greatly in different countries, but most human diets probably
contain levels of polyunsaturated fat at least equivalent to 3% sunflowerseed oil. 相似文献
10.
Beef tallow and cottonseed oil were mixed with a pure butterfat in the ratios of 2%, 4% and 6% to obtain admixtures of beef
tallow with butterfat and cottonseed oil with butterfat. The hydrolysis of individual triglycerides was carried out using
the lipase to obtain 2-monoglycerides. The results indicated that butterfat had a higher percentage of C14:0 and C16:0 acids
than found in the triglycerides and 2-monoglycerides of beef tallow and cottonseed oil.
Beef tallow contained a higher proportion of C18:0 and C18:1 acids than butterfat and cottonseed oil triglycerides or 2-monoglycerides.
Cottonseed oil had a higher percentage of C18:2 acid located in triglyceride or 2-monoglyceride than found in butterfat or
beef tallow triglycerides and 2-monoglycerides.
The analysis of the samples of butterfat containing 2%, 4% and 6% beef tallow revealed that the addition of beef tallow to
butterfat affected the fatty acid composition of butterfat triglycerides and 2-monoglycerides with C18:0 and C18:1 acids;
the effect was increased with increasing percentages of beef tallow.
The addition of cottonseed oil to butterfat in the ratios of 2%, 4% and 6% affected the fatty acid composition of butterfat
triglycerides and 2-monoglycerides. It was found that both C18:1 and C18:2 increased as the added cottonseed oil percentages
increased. 相似文献
11.
Male Sprague-Dawley rats were fed diets with 10%, 30%, or 50% of energy derived from fat for two weeks. The fats used were
beef tallow, olive oil, peanut oil and butter. Aortic prostacyclin (PGI2) production, platelet aggregation and thromboxane A2 (TXA2) production and plasma and aortic phospholipid (PL) content were measured. Butter- and beef tallow-feeding reduced aortic
PGI2 production and collagen-induced TXA2 production in a dosedependent manner as the level of fat in the diet increased. Neither olive oil nor peanut oil had any
effect on aortic PGI2 production or collagen-induced TXA2 production. Butter-feeding also resulted in a decrease in collageninduced platelet aggregation; however, none of the other
fats had any effect on collagen-induced platelet aggregation. The observed decreases in aortic PGI2 and collagen-induced TXA2 production were paralleled by similar decreases in aortic and plasma PL arachidonic acid content and an increase in eicosapentaenoic
acid (EPA) and docosahexaenoic acid (DHA). Only the most saturated fats, butter and beef tallow, had significant inhibitory
effects on prostanoid production and platelet aggregation. 相似文献
12.
Response of free and esterified plasma cholesterol levels in the mongolian gerbil to the fatty acid composition of dietary lipid 总被引:2,自引:0,他引:2
The present study was undertaken to investigate the potential suitability of the Mongolian gerbil as a useful animal model
to study the effects of dietary fats on plasma cholesterol levels. Semipurified diets containing either 20% lard, 20% safflower
oil, or 19.5% beef tallow +0.5% safflower oil were equalized to contain 0.01% cholesterol and 0.05% plant sterol and were
fed for a four week experimental period. The proportions of total calories contributed by fat, protein and carbohydrate (starch/sucrose
ratio of 2∶1) were 40, 14 and 46%, respectively, so as to approach the distribution of calories within the average North American
diet. Free, esterified, and total plasma cholesterol levels of male gerbils were determined weekly by gas liquid chromatography
after drawing blood via a serial sampling technique. After 1, 2, 3, and 4 weeks of feeding the experimental diets, total cholesterol
levels were lowest in the safflower oil fed animals; the corresponding values were 19–64% greater in gerbils fed lard and
68–91% greater in those consuming the beef tallow diet. Cholesterol in the free form generally responded more dramatically
to the type of dietary lipid than did cholesterol in the ester form. Irrespective of the type of dietary lipid or the length
of the feeding trial, 18–23% of the total plasma cholesterol was in the free form and 77–82% was present as the ester. In
view of the similarity to the human of the relative proportions of free versus esterified cholesterol, the type of cholesteryl
esters, and their response to dietary manipulation, the gerbil appears to be a useful animal model for studying the regulatory
effect of dietary lipid on plasma cholesterol levels.
Presented in part at the A.O.C.S. Annual Meeting, San Francisco, CA, May 1979. 相似文献
13.
By means of cellulose acetate electrophoresis and measurement of radioactivity, lipoproteins (d≤1,006) of lymph collected
from rats fed a diet containing fats added to labeled fatty acids for 20–24 hr, have been separated into two kinds differing
in their size. Fats with different saturated and unsaturated fatty acid content were tested: corn oil, lard, mutton tallow,
tripalmitin, corn oil-lard mixture, and randomized palmitic-linoleic triglycerides. Factors studied were: (a) increased amounts
of these fats given alone or included in a test meal; (b) added amounts of nutrients (other than fats) in the test meal; (c)
adaptation to a diet containing 20% fat for 10 days. The major part of the labeled lymph lipid was always transported by the
smaller particles. Size distribution of lymph fat particles was influenced by some of the factors studied. Generally, unsaturated
fats produced higher amounts of larger particles. 相似文献
14.
Because lipoproteins and platelet aggregation have been implicated in atherogenesis, relative differences in the response
of these variables to dietary fat saturation were compared in three species of monkeys differing in their susceptibility to
atherosclerosis (cebus, rhesus, and squirrel monkeys). Both long-term (8–12 years) and short-term (8 weeks) responses to diets
containing 31% fat calories were examined in the same monkeys. As expected, long-term feeding of coconut oil by comparison
to corn oil produced significantly higher plasma concentrations of total cholesterol, LDL cholesterol, apoB, and triglycerides,
as well as higher ratios of LDL/HDL cholesterol and apo B/apo A-I. These responses were characteristic of all species with
cebus being most responsive and rhesus the least. The shortterm plasma cholesterol response to animal fats (butter, lard,
beef tallow) was significantly less than that to coconut oil. When fish oil was substituted for two-thirds of either corn
oil or coconut oil, exceptional decreases occurred in plasma cholesterol and triglycerides, as well as in HDL cholesterol
and apo A-I concentrations despite the fact that the fish oil diets contained more saturated fat and less polyenes than the
corn oil diet. Platelet aggregation tended to increase with saturated fat consumption and greatly decreased with fish oil
intake in all monkeys, although cebus monkeys were ten-fold more resistant to platelet aggregation than the other two species.
The molecular species of platelet phosphatidylcholine (PC) varied with both the dietary fat fed and species of monkey. An
inverse correlation (r=−0.60; p<0.001) was found between changes in one such PC molecular species (18∶0−20∶4) induced by diet
and the platelet aggregation threshold. These results demonstrate that the lipemic and platelet responses to dietary saturated
fat depend upon both the type of fat (i.e., the specific combination of dietary fatty acids, including the chain length of saturated fatty acids and the degree of polyunsaturation)
and the species of monkey (genetic component) in which the response is elicited. 相似文献
15.
Weanling male Wistar rats were fed for five weeks on standard rat chow (23 g fat/kg diet) or one of four synthetic diets with
butterfat, coconut oil, corn oil, or fish oil as the main lipid source (100 g fat/kg diet). In all diets, 10% of the fat was
provided as corn oil to prevent essential fatty acid deficiency. Significant differences were observed in the saturated, monounsaturated,
and polyunsaturated fatty acid composition, and in the ratio of cholesterol to phospholipid, in the hepatocyte membranes.
The fluidity of hepatocyte plasma membranes was assessed using the fluorescence recovery after photobleaching technique and
steady-state fluorescence anisotropy of diphenylhexatriene. No significant differences were found in the fluidity of plasma
membranes between animals on the different fat diets, despite diet-induced changes in their fatty acid composition. However,
the proportion of lipid free to diffuse in the plasma membrane varied with diet, being significantly greater (P<0.05) in animals fed chow (63.7%), coconut oil (61.5%), and butterfat (57.6%) diets than in those fed the corn oil (47.3%)
diet. Animals fed fish oil showed an intermediate (50.0%) proportion of lipid free to diffuse. The data support the hypothesis
that dietary lipids can change both the chemical composition and lateral organization (lipid domain structure) of rat hepatocyte
plasma membranes. 相似文献
16.
Rats were fed diets high in either saturated fat (beef tallow) or α-linolenic acid (linseed oil) or eicosapentaenoic and docosahexaenoic
acids (fish oil) with or without 2% cholesterol supplementation. Consumption of linseed oil and fish oil diets for 28 days
lowered arachidonic acid content of plasma, liver and heart phospholipids. Addition of 2% cholesterol to diets containing
beef tallow or linseed oil lowered 20∶4ω6 levels but failed to reduce 20∶4ω6 levels when fed in combination with fish oil.
Feeding ω3 fatty acids lowered plasma cholesterol levels. Addition of 2% cholesterol to the beef tallow or linseed oil diet
increased plasma cholesterol concentrations but not when fish oil was fed. Feeding the fish oil diet reduced the cholesterol
content of liver, whereas feeding the linseed oil diet did not. Dietary cholesterol supplementation elevated the cholesterol
concentration in liver in the order: linseed oil > beef tallow > fish oil (8.6-, 5.5-, 2.6-fold, respectively). Feeding fish
oil and cholesterol apparently reduced 20∶4ω6 levels in plasma and tissue lipids. Fish oil accentuates the 20∶4ω6 lowering
effect of dietary cholesterol and appears to prevent accumulation of cholesterol in plasma and tissue lipids under a high
dietary load of cholesterol. 相似文献
17.
Effect of an essential fatty acid (EFA) deficiency in the rat on the incorporation of leucine-14C and glucosamine-14C into serum and liver protein are reported. Weanling male rats of the Sprague-Dawley strain were raised on a fat-free diet
for 10–12 weeks and then switched to diets supplemented with 10% corn oil or 10% hydrogenated coconut oil. Leucine-14C or glucosamine-14C was injected into the tail veins of the animals of each group. At selected intervals up to 120 min after the injections,
the animals were sacrificed and the radioactivity of the liver and serum proteins was measured. The levels of triglyceride
(TG) in the serum and the liver were also determined. Less radio-activity was incorporated into the serum β-lipoprotein (β-LP)
fraction of the hydrogenated coconut oil than the corn oil fed animals injected with leucine-14C, but no differences were observed in the incorporation of radioactivity into the liver protein and both albumin and globulin
fractions of the serum of these groups of animals. In the similar experiments with glucosamine-14C less radioactivity was incorporated into the β-LP fraction of the serum and into the smooth endoplasmic reticulum of the
liver in the hydrogenated coconut oil (EFA deficient) than the corn oil fed animals. Time course studies also indicated that
less radioactivity was incorporated into the β-LP fraction than into the albumin and globulin fractions of the serum of the
hydrogenated coconut oil group. These findings suggest that an EFA deficiency results in an impairment of the synthesis or
release of lipoprotein. 相似文献
18.
Male and female rats were fed diets containing 2% of calories as corn oil or that plus 40% of calories as beef tallow or corn
oil. After 3, 6, 12 and 18 months groups were given 4-14C-cholesterol ip, and feces were collected for 9 days. Just prior to necropsy3H-acetate was administered ip. Samples of serum, liver, heart and carcass were obtained for analysis. Concentrations of fatty
acids and cholesterol, synthesis of those and recovery of ring-labeled steroid are reported. Mortality from acute respiratory
disease was very high in male rats fed beef tallow or low fat diets and very low in those fed the corn oil diet. In females,
only beef tallow diet resulted in a high mortality rate, and this was lower and at a later age than in males. The most notable
effects of age were in relation to fatty acid synthesis and presence of14C-acidic steroid in the carcass. In 3-month-old rats both fats depressed fatty acid synthesis in comparison to the low fat
diet. At later ages beef fat ceased to depress fatty acid synthesis in both sexes. Corn oil continued to depress fatty acid
synthesis up to 12 months in males and 18 months in females. The presence of14C-acidic steroid in carcass was substantial in 6-month-old rats and constituted ca. 40% of recovered14C in 18-month-old rats. The possibility that the increase in acetate incorporation into fatty acids with age in fat feeding
is related to chain elongation rather than de novo synthesis is discussed. Both the presence and amount of acidic steroid
in the carcass are notable and may be of importance in constructing models of cholesterol turnover.
Presented in part at the AOCS Sterol Symposium, April 1970, and the Federation of American Societies for Experimental Biology,
April 1971.
Scientific Series Paper No. 1536, Colorado Agricultural Experiment Station. 相似文献
19.
The fate of an oral dose of [4-14C] cholesterol given to rats grown on diets with 20% safflower oil or 20% hydrogenated coconut oil was determined by analysis
of digestive tract, feces and tissues. The pattern of isotope distribution did not support the view that rats fed a saturated
fat absorb less cholesterol than those fed an unsaturated fat. Fasted animals growth on the diet with 5% of these two fats
and beef fallow showed no clear difference in the amount of digitonin-peecipitable sterol in their intestines. A shorter transit
time for intestinal contents was observed with the saturated fat groups. It is concluded that neither absorption of cholesterol
from the gut nor secretion of β-hydroxy sterol into the gut accounts for the hypocholesterolemic effect of polyunsaturated
fat.
Journal Paper No. 4951 AES, Purdue University. 相似文献
20.
This study investigates the effect of various dietary saturated fatty acid (SFA) profiles on plasma lipid parameters and tissue
fatty acid composition in rats. The experiment was designed to monitor polyunsaturated fatty acids (PUFA) levels, while examining
different amounts and types of SFA. Four isocaloric diets were prepared, containing 10–11 mol% of fatty acids (FA) as linoleic
acid (LNA) and 2.5 mol% as α-linolenic acid (ALA), leading to an identical and well-balanced LNA/ALA ratio. The initial rapeseed
oil/corn oil mixture providing ALA and LNA was enriched with olive oil to prepare the olive oil diet. The butterfat diet was
supplemented with butterfat, containing short-chain SFA (C4:0–C10:0, 17 mol% of FA), lauric acid (C12:0, 3.2 mol%), myristic
acid (C14:0, 10.5 mol%) and palmitic acid (C16:0, 14.5 mol%). The saturates diet was supplemented with trilaurin, trimyristin
and tripalmitin to obtain the same level of lauric, myristic and palmitic acids as the butterfat diet, without the short-chain
SFA. The trimyristin diet was enriched with trimyristin only. The results showed that the butterfat diet contributed to specific
effects, compared to the olive oil diet and the saturates and trimyristin diets: a decrease in plasma total, LDL- and HDL-cholesterol,
higher tissue storage of ALA and LNA, and a higher level of (n-3) highly unsaturated fatty acids in some tissues. This study
supports the hypothesis that in diets with identical well-balanced LNA/ALA ratios, short chain SFA may decrease circulating
cholesterol and increase tissue polyunsaturated fatty acid content in the rat. 相似文献