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1.
Lynnette S. Walsh Hentges Donald C. Beitz Norman L. Jacobson A. Dare McGilliard 《Lipids》1985,20(11):757-764
In a 2×2 factorial arrangement, miniature pigs were fed four diets containing vegetable protein/fat (soybean) and animal protein
(egg white)/fat (beef tallow) to demonstrate the effects of protein and fat source on tissue cholesterol concentrations, uptake
of intact low density lipoproteins (LDL) and free cholesterol exchange from LDL to tissues. Soybean oil feeding, compared
with beef tallow feeding, resulted in greater concentrations of cholesterol in aorta, heart, and large and small intestines.
Similar trends were seen in liver, adipose tissue and skeletal muscle. Dietary protein source had little or no effect on tissue
cholesterol concentrations. Uptake of intact LDL, as measured by using [14C]sucrose-LDL, tended to be greater in pigs fed soybean oil or soy protein. Net exchange of free cholesterol from LDL, as
measured with [3H]cholesterol, tended to be greater when vegetable products were fed. Relative contributions of whole tissues to total uptake
by either mechanism were not influenced by diet. Mechanisms in addition to uptake of cholesterol from LDL seem to be involved
in the greater accumulation of tissue cholesterol resulting from polyunsaturated fat feeding.
Data taken from a dissertation submitted to Iowa State University by L. S. Walsh Hentges as partial fulfillment of the requirements
for the Ph.D. degree. A preliminary paper was presented at the 68th Annual Meeting of the Federation of American Societies
for Experimental Biology in St. Louis, Missouri, April 1984 (Fed. Proc. 43:796). 相似文献
2.
The Mongolian gerbil,Meriones unguiculatus, may be a suitable animal model for the investigation of dietary lipid effects on cholesterol metabolism. The effects of
dietary cholesterol, and its possible interaction with the type of dietary fat, on the lipoprotein status of this animal have
not been examined previously. In the present research, the effects of adding 0.5% cholesterol to diets high in saturated (19.5%
beef tallow: 0.5% safflower oil) or polyunsaturated (20% safflower oil) fats on the lipoprotein status of the gerbil were
determined after 11 and 22 days of feeding. Lipoproteins (VLDL, LDL and HDL) were separated by sequential ultracentrifugation.
Their cholesterol, phospholipid and protein concentrations were determined colorimetrically. In the absence of 0.5% cholesterol,
safflower oil lowered the concentration (mg/100 ml) of cholesterol in each of the VLDL, LDL and HDL relative to beef tallow
(BT) without greatly influencing the cholesterol distribution amongst them. The HDL carried the majority of the serum cholesterol
and the VLDL transported the smallest amount. However, inclusion of 0.5% dietary cholesterol resulted in a redistribution
of cholesterol amongst the lipoproteins so that the VLDL and LDL became the major and the HDL the minor carriers. Dietary
cholesterol also brought about a rise in the VLDL and LDL concentrations (mg/100 ml) of cholesterol, phospholipid and protein
and altered the VLDL and LDL compositions. No such changes were observed in the HDL, indicating that the HDL are relatively
resistant to any of the possible effects of cholesterol feeding measured in this experiment. The specific mechanisms responsible
for the changes observed in the lipoprotein status of the gerbil remain to be elucidated.
Presented in part at the Triennial Joint Meeting of the AIN/ASCN/CSNS, July 1982 相似文献
3.
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
4.
José M. Martins José A. Neves Amadeu Freitas José L. Tirapicos 《European Journal of Lipid Science and Technology》2010,112(3):295-303
This study was undertaken to investigate the effects of long term betaine intake on the cholesterol and lipid profile of Alentejano (AL) pigs. At ?36 kg body weight (BW), castrated male and female pigs fed a commercial (C) diet, were divided into two groups: i) Group C, consuming the C diet; and ii) Group CB, consuming the C diet supplemented with 1 g/kg betaine. Pigs were slaughtered at ?100 kg BW. Fasting plasma concentrations of protein, urea, glucose, TAG, phospholipids, homocysteine, total and LDL‐ and HDL‐cholesterol were determined. Liver TAG, phospholipids, and total and free cholesterol were analyzed, as well as total lipids, cholesterol contents, and fatty acid (FA) composition of M. semimembranosus and dorsal subcutaneous fat. Betaine supplemented pigs presented significantly higher plasma concentrations of TAG, phospholipids, cholesterol, and lipoprotein cholesterol. Dorsal subcutaneous fat cholesterol concentration was also significantly higher in CB than in C pigs. No differences were detected in the most abundant FA profile (including the unsaturated to saturated FA ratio) of muscle and subcutaneous fat tissues among treatments. These data suggest that betaine induces dyslipidemia, and increases cholesterol concentration in dorsal subcutaneous fat, without affecting the FA profile of M. semimembranosus and dorsal subcutaneous fat. 相似文献
5.
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
6.
Kenneth D. Wiggers Marlene J. Richard Jeanne W. Stewart Norman L. Jacobson P. Jeffrey Berger 《Lipids》1977,12(7):586-590
Sixteen male Holstein calves consumed by nipple a reconstituted milk containing nonfat dry milk and either soybean oil or
tallow for 24 weeks. Calves fed milk in this manner (with no dry feed) are functionally nonruminants because the milk bypasses
the ruminoreticulum. The fat in these diets contributed about 30% of total dietary calories. The calves consuming soybean
oil milk had significantly greater amounts of cholesterol in blood plasma and adipose tissue than did the calves consuming
tallow milk. 相似文献
7.
Triplicate groups of Atlantic salmon (Salmo salar L.) were fed four diets containing different oils as the sole lipid source, i.e., capelin oil, oleic acid-enriched sunflower
oil, a 1∶1 (w/w) mixture of capelin oil and oleic acid-enriched sunflower oil, and palm oil (PO). The β-oxidation capacity,
protein utilization, digestibility of dietary fatty acids and fatty acid composition of lipoproteins, plasma, liver, belly
flap, red and white muscle were measured. Further, the lipid class and protein levels in the lipoproteins were analyzed. The
different dietary fatty acid compositions did not significantly affect protein utilization or β-oxidation capacity in red
muscle. The levels of total cholesterol, triacylglycerols, and protein in very low density lipoprotein (VLDL), low density
lipoprotein (LDL), high density lipoprotein (HDL), and plasma were not significantly affected by the dietary fatty acids.
VLDL, LDL, and HDL fatty acid compositions were decreasingly affected by dietary fatty acid composition. Dietary fatty acid
composition significantly affected both the relative fatty acid composition and the amount of fatty acids (mg fatty acid per
g tissue, wet weight) in belly flap, liver, red and white muscle. Apparent digestibility of the fatty acids measured by adding
yttrium oxide as inert marker, was significantly lower in fish fed the PO diet compared to the other three diets. 相似文献
8.
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
9.
Ground Beef High in Total Fat and Saturated Fatty Acids Decreases X Receptor Signaling Targets in Peripheral Blood Mononuclear Cells of Men and Women 下载免费PDF全文
Seong H. Choi Ghazal Gharahmany Rosemary L. Walzem Thomas H. Meade Stephen B. Smith 《Lipids》2018,53(3):279-290
We hypothesized that consumption of saturated fatty acids in the form of high‐fat ground beef for 5 weeks would depress liver X receptor signaling targets in peripheral blood mononuclear cells (PBMC) and that changes in gene expression would be associated with the corresponding changes in lipoprotein cholesterol (C) concentrations. Older men (n = 5, age 68.0 ± 4.6 years) and postmenopausal women (n = 7, age 60.9 ± 3.1 years) were assigned randomly to consume ground‐beef containing 18% total fat (18F) or 25% total fat (25F), five patties per week for 5 weeks with an intervening 4‐week washout period. The 25F and 18F ground‐beef increased (p < 0.05) the intake of saturated fat, monounsaturated fat, palmitic acid, and stearic acid, but the 25F ground‐beef increased only the intake of oleic acid (p < 0.05). The ground‐beefs 18F and 25F increased the plasma concentration of palmitic acid (p < 0.05) and decreased the plasma concentrations of arachidonic, eicosapentaenoic, and docosahexaenic acids (p < 0.05). The interventions of 18F and 25F ground‐beef decreased very low‐density lipoprotein C concentrations and increased particle diameters and low‐density lipoprotein (LDL)‐I‐C and LDL‐II‐C concentrations (p < 0.05). The ground‐beef 25F decreased PBMC mRNA levels for the adenosine triphosphate (ATP) binding cassette A, ATP binding cassette G1, sterol regulatory element binding protein‐1, and LDL receptor (LDLR) (p < 0.05). The ground‐beef 18F increased mRNA levels for stearoyl‐CoA desaturase‐1 (p < 0.05). We conclude that the increased LDL particle size and LDL‐I‐C and LDL‐II‐C concentrations following the 25F ground‐beef intervention may have been caused by decreased hepatic LDLR gene expression. 相似文献
10.
In 24 healthy pregnant women, parameters related to the oxidative stability of low density lipoproteins (LDL) were determined
at three times during pregnancy and shortly after delivery. The fatty acid composition of plasma phospholipids (PL) and the
plasma concentrations of vitamin E, vitamin A, and β-carotene were assessed in the same samples. Total triglyceride (TG),
total cholesterol, LDL-cholesterol, and high density lipoprotein (HDL)-cholesterol concentrations were also determined. The
length of the lag phase of isolated LDL challenged with Cu2+ ions significantly increased with the progression of pregnancy. The oxidation rate and the amount of conjugated dienes formed
increased and reached a maximum at 29–37 wk of pregnancy. Total TG, cholesterol, and LDL-cholesterol reached a maximum in
the third trimester of pregnancy. β-Carotene remained stable, vitamin A decreased, and vitamin E significantly increased throughout
pregnancy. Vitamin E plasma concentration correlated positively with the length of the lag phase. The increased levels of
vitamin E could contribute to the higher resistance of LDL toward oxidation with progressing gestation, measured by the prolonged
lag phase. Furthermore, vitamin E plasma levels correlated positively with TG concentration but not with LDL-cholesterol.
The level of polyunsaturated fatty acids in PL decreased with the progression of pregnancy. No correlation was found between
the fatty acid composition of plasma PL, nor with the cholesterol concentration, and the parameters studied related to the
oxidative stability of LDL. The major finding of this study is the increased oxidative resistance of LDL with progressing
gestation. 相似文献
11.
Comparative effects of feeding dietary linoleic (safflower oil) and α-linolenic (linseed oil) acids on the cholesterol content
and fatty acid composition of plasma, liver, heart and epididymal fat pads of rats were examined. Animals fed hydrogenated
beef tallow were used as isocaloric controls. Plasma cholesterol concentration was lower and the cholesterol level in liver
increased in animals fed the safflower oil diet. Feeding the linseed oil diet was more effective in lowering plasma cholesterol
content and did not result in cholesterol accumulation in the liver. The cholesterol concentration in heart and the epididymal
fat pad was not affected by the type of dietary fatty acid fed. Arachidonic acid content of plasma lipids was significantly
elevated in animals fed the safflower oil diet and remained unchanged by feeding the linseed oil diet, when compared with
the isocaloric control animals fed hydrogenated beef tallow. Arachidonic acid content of liver and heart lipids was lower
in animals fed diets containing safflower oil or linseed oil. Replacement of 50% of the safflower oil in the diet with linseed
oil increased α-linolenic, docosapentaenoic and docosahexaenoic acids in plasma, liver, heart and epididymal fat pad lipids.
These results suggest that dietary 18∶2ω6 shifts cholesterol from plasma to liver pools followed by redistribution of 20∶4ω6
from tissue to plasma pools. This redistribution pattern was not apparent when 18∶3ω3 was included in the diet. 相似文献
12.
Using an experimental model that enables the effects of alcohol to be distinguished from the effects of the nonalcoholic components
present in wine, we determined whether wine has effects other than those of alcohol on the metabolism of cholesterol. Male
rats were fed a standard diet and had free access to water and either wine or an equivalent alcohol solution for 45 d or 6
mon. Alcohol intake was similar in the two groups of animals. Consumption of the alcohol solution or wine did not influence
plasma cholesterol or high density lipoprotein-cholesterol. At 45 d, the consumption both of wine and of alcohol solution
reduced low density lipoprotein (LDL)-cholesterol and very low density lipoprotein cholesterol. At 6 mon, only the rats that
consumed wine had reduced LDL-cholesterol. After 45 d of consuming alcohol solution, total cholesterol in the aorta was significantly
increased mainly as a result of the rise in free cholesterol. In the aorta, the effect of wine consumption was similar to
the effect of alcohol solution consumption, although it was less intense. The only clear effect that could be ascribed to
the nonalcoholic components in wine was that the LDL-cholesterol was reduced in the long term, although aortic cholesterol
was not. 相似文献
13.
This experiment was designed to evaluate the effects of dietary red wine phenolic compounds (WP) and cholesterol on lipid
oxidation and transport in rats. For 5 wk, weanling rats were fed polyunsaturated fat diets (n−6/n−3=6.4) supplemented or
not supplemented with either 3 g/kg diet of cholesterol, 5 g/kg diet of WP, or both. The concentrations of triacylglycerols
(TAG, P<0.01) and cholesterol (P<0.0002) were reduced in fasting plasma of rats fed cholesterol despite the cholesterol enrichment of very low density lipoprotein
+ low density lipoprotein (VLDL+LDL). The response was due to the much lower plasma concentration of high density lipoprotein
(HDL) (−35%, P<0.0001). In contrast, TAG and cholesteryl ester (CE) accumulated in liver (+120 and +450%, respectively, P<0.0001). However, the cholesterol content of liver microsomes was not affected. Dietary cholesterol altered the distribution
of fatty acids mainly by reducing the ratio of arachidonic acid to linoleic acid (P<0.0001) in plasma VLDL+LDL (−35%) and HDL (−42%) and in liver TAG (−42%), CE (−78%), and phospholipids (−28%). Dietary WP
had little or no effect on these variables. On the other hand, dietary cholesterol lowered the α-tocopherol concentration
in VLDL+LDL (−40%, P<0.003) and in microsomes (−60%, P<0.0001). In contrast, dietary WP increased the concentration in microsomes (+21%, P<0.0001), but had no effect on the concentration in VLDL+LDL. Cholesterol feeding decreased (P<0.006) whereas WP feeding increased (P<0.0001) the resistance of VLDL+LDL to copper-induced oxidation. The production of conjugated dienes after 25 h of oxidation
ranged between 650 (WP without cholesterol) and 2,560 (cholesterol without WP) μmol/g VLDL+LDL protein. These findings show
that dietary WP were absorbed at sufficient levels to contribute to the protection of polyunsaturated fatty acids in plasma
and membranes. They could also reduce the consumption of α-tocopherol and endogenous antioxidants. The responses suggest that,
in humans, these substances may be beneficial by reducing the deleterious effects of a dietary overload of cholesterol. 相似文献
14.
Studies investigated the effects of dietary fatty acid composition and saturation on the regulation of very low density lipoprotein
(VLDL) apo B flux, clearance, and conversion to low density lipoprotein (LDL) in guinea pigs fed semipurified diets containing
15% (w/w) corn oil (CO), lard (LA), or palm kernel oil (PK). Plasma cholesterol levels were highest with dietary PK (3.1±1.0
mmol/L) followed by LA (2.4±0.4 mmol/L) and CO (1.6±0.4 mmol/L) intake. VLDL particles were larger (P<0.05) in the LA (78±7 nm) and PK (69±10 nm) groups compared to animals fed CO (49±5 nm). VLDL-apo B fractional catabolic
rates (FCR) were highest in guinea pigs fed the LA diet (P<0.05) and VLDL apo B flux, estimated from VLDL 125I-apo B turnover kinetics, were higher in LA compared to PK or CO fed guinea pigs. In the case of PK consumption, the kinetic
estimates of VLDL apo B flux significantly underestimated rates compared to direct VLDL apo B secretion measurements and LDL
turnover analyses. These data demonstrate that differences in the composition and amount of saturated fatty acids have differential
effects on VLDL apo B flux, catabolism, and conversion to LDL which, together with changes in LDL receptor-mediated catabolism,
determine plasma LDL cholesterol levels in guinea pigs. The data also indicate that kinetic analysis of VLDL metabolism in
PK fed animals is inaccurate possibly due to the presence of a small, nonequilibrating pool of newly synthesized VLDL which
is rapidly converted to LDL. 相似文献
15.
Purified diets varying in dietary protein, namely casein (CA), soy protein (SP), fish protein (FP), and lipid origin (corn
oil (CN), coconut oil (CO)) were fed to rabbits to evaluate the effects of protein and fat source, as well as protein-lipid
interactions, on serum total, lipoprotein and hepatic lipid levels. Dietary proteins and lipids exerted a separate effect
on serum total cholesterol (C), very low-density lipoprotein cholesterol (VLDL-C), and low-density lipoprotein cholesterol
to high density lipoprotein cholesterol (LDL-C/HDL-C) ratio. Hence, CA increased serum cholesterol compared to SP, while coconut
oil enhanced serum and VLDL-C, and decreased LDL-C/HDL-C compared to corn oil. Dietary proteins interacted with dietary lipids
to modulate HDL-C levels. Thus, FP maintained a high level of HDL-C regardless of lipid origin, compared to CA and SP whose
HDL-C levels were decreased by corn oil, compared to coconut oil. A dietary protein-lipid interaction was also observed in
the regulation of liver cholesterol levels. Coconut oil, compared to corn oil, decreased liver cholesterol in rabbits fed
FP, whereas hepatic cholesterol concentration was unaltered by dietary lipid source in CA- and SP-fed rabbits. These results
demonstrate that dietary proteins act synergistically with dietary lipids to regulate cholesterol metabolism in the rabbit.
This work was presented in part at the 74th Annual FASEB meeting held in Washington, D.C., April 1–5, 1990. 相似文献
16.
The influence of dietary restriction on cholesterol transport and metabolism was investigated in rabbits given standard or
cholesterol-rich diets (0.2 g cholesterol/kg body weight daily) eitherad libitum or with 50% caloric ration. Dietary restriction which has only a slight influence in control rabbits markedly aggravated
the disturbances induced by exogenous cholesterol. With limited feeding, control rabbits presented a moderate increase in
plasma cholesterol, whereas marked aggravation of hypercholesterolemia was observed in cholesterol-fed rabbits. Analysis of
the lipoprotein profile showed that the excess of plasma cholesterol with the restricted cholesterol-rich diet corresponded
to an increase in the concentration of very low density lipoprotein (VLDL) and low density lipoproteins (LDL) without any
additional changes in the composition of these lipoproteins. No significant change appeared in the high density lipoprotein
(HDL) concentration. The parameters of cholesterol metabolism were determined, from the curves of [3H] cholesterol radioactivity decrease, using a two-pool model. The increase in cholesterol turnover rate induced by the cholesterol-rich
diet was accentuated by dietary restriction, whereas rabbits on standard restricted diet showed a slight decrease. The large
increase in the size of both pools A and B in cholesterol-fed rabbits was even more pronounced with limited feeding. Dietary
restriction induced additional accumulation of cholesterol in the aortic wall and the grade of the lesions was also aggravated. 相似文献
17.
Ethyl-14C-acetoacetate was used to trace oxidation and metabolism of acetoacetate when rats were fed a high fat diet (80% of total
calories from beef tallow or corn oil, carbohydrate free), a high carbohydrate diet (2% corn oil) or a high carbohydrate diet
with restriction of calories to one half of ad lib. consumption for two weeks. The rate of expiration of14CO2 in all groups of animals did not differ significantly and was not related to plasma concentration of acetoacetate. The high
fat diets slightly enhanced the oxidation of acetoacetate to14CO2 over a 3 hr period compared to other diets. Incorporation of acetoacetate into fatty acids did not differ significantly among
groups. Rats fed the high carbohydrate diet ad lib. incorporated into liver cholesterol more acetoacetate than did any other
group, but dietary unsaturated fat resulted in greater incorporation of acetoacetate into cholesterol than saturated fat.
High calorie and high beef tallow groups were ketonemic but the low concentration of plasma acetoacetate in rats fed a high
corn oil diet indicates that unsaturated fatty acids are not ketogenic. The data show that utilization of acetoacetate is
not significantly reduced in a ketonemic condition and support the premise that overproduction of ketone bodies is the cause
of ketonemia. Rats appeared to be normal during the two-week period when no carbohydrate was included in the diet.
Presented at the AOCS Meeting, Chicago, October, 1967. 相似文献
18.
The comparative influence on plasma and tissue lipids of dietary soybean and egg lecithins, which have contrasting fatty acid
compositions, was studied in the hypercholesterolemic guine apig. The polyunsaturated to saturated fatty acid (P/S) ratios
of the soybean and egg lecithins were 3.4 and 0.38, respectively. Hypercholesterolemia was induced by feeding guinea pigs
a purified diet that contained 15% lard enriched with 0.5% cholesterol. Subsequently, guinea pigs were fed for six wk the
same diet supplemented with either soybean or egg lecithin as 7.5% of the diet. A control group continued to be fed the lecithin-free
diet. Parameters measured included body weight and relative liver weight; in plasma, total cholesterol, high density lipoprotein
cholesterol (HDLC), phospholipid, and nonesterified cholesterol; in liver, total fat, cholesterol, and the specific activity
of the catabolic enzyme cholesterol 7α-hydroxylase; (EC 1.14.13.17); and in the aorta, cholesterol. Among the most noteworthy
observations were the 49% decrease in total plasma cholesterol of the soybean lecithin group without decreasing HDLC and the
177% increase in HDLC of the egg lecithin group without a significant increase in total cholesterol compared with those values
in the control group. These data suggest that dietary lecithin is particularly effective in increasing the HDLC/total cholesterol
ratio in plasma. However, the absolute concentrations of those plasma lipids seem to depend upon the fatty acid composition
of the lecithin.
Presented in part at the annual meeting of the American Oil Chemists' Society, New Orleans LA, May 1987. 相似文献
19.
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
20.
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