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1.
A study was made with sheep on the formation in vitro of long chain fatty acid esters of cholesterol by the lecithin-cholesterol-acyltransferase
system present in the plasma and the acyl CoA-cholesterol-acyltransferase system present in the liver. The rate of cholesterol
esterification in the plasma was 0.024 μmoles/ml/hr. The relative pattern of fatty acids esterified during incubation of the
plasma remained constant over the 8 hr period of incubation and was similar to the fatty acids in the plasma cholesteryl esters
before incubation began and to the fatty acids in the 2-position of the plasma lecithin. The predominant cholesteryl esters
synthesized contained monoenoic and dienoic fatty acids. Unlike the bovine, there was no apparent discrimination in favor
of the 18∶2 containing species of plasma lecithin as donors of fatty acids. This difference could be accounted for by the
similarity in the 18∶2 content of the phospholipids present in the high density (density >1.062 and < 1.21) and the low density
(density > 1.006 and <1.063) lipoprotein fractions of the sheep plasma. The possibility of some discrimination against 20∶4
during cholesterol ester synthesis in the plasma of the sheep cannot be excluded. In the liver, the predominant cholesteryl
esters synthesized contained saturated and monoenoic fatty acids; cholesteryl linoleate was synthesized to a very much less
extent. There was considerable similarity between the composition of the unesterified fatty acid fraction of the liver before
incubation began and the fatty acid composition of the cholesteryl esters synthesized during incubation. Addition of sonicated
suspensions of free fatty acids altered markedly the fatty acid pattern of the cholesteryl esters synthesized by the liver
slices. From the evidence presented it is concluded that the cholesteryl esters in sheep plasma are syntheized mainly by the
plasma lecithin-cholesterol-acyltransferase system. The results are discussed in relation to cholesterol esterification systems
demonstrated in the plasma and liver of monogastric animals. 相似文献
2.
Groups of normal and hepatoma (7288CTC) bearing rats were maintained on normal chow and fat-free diets for 4 weeks. Normal liver, host liver, and hepatoma neutral lipids were examined in detail and compared. Water content, unaffected by diet was: hepatoma, 82 percent; host liver, 71 percent; and normal liver, 67 percent. The fat-free diet had no effect upon the hepatoma neutral lipids but elevated the triglyceride level in normal and host liver, shifted the triglyceride carbon number distribution to lower mol wt, and elevated the percentage of monoenoic acids in triglycerides and cholesteryl esters. Host triglyceride concentrations were ca. half, and cholesterol levels were reduced moderately relative to normal liver values. Hepatoma cholesterol levels were higher and triglyceride concentrations lower than normal and host liver values. Hepatoma triglycerides differed dramatically from liver and were characterized by increased concentrations of high mol wt species and a fivefold increase in the percentage of C-20 and C-22 fatty acids. The percentage of C-20 and C-22 fatty acids in hepatoma cholesteryl esters also increased ca. fivefold relative to liver. The data indicate that the systems that regulate triglyceride and cholesteryl ester fatty acid composition in liver do not control the compositions of these lipid classes in this hepatoma. The unchanged high level of essential fatty acids in the hepatoma lipids from the fat-free fed animals demonstrates the hepatoma's ability to absorb and conserve specific fatty acids. 相似文献
3.
The reversible endogenous hyperlipemia in dogs, elicited by the detergent Triton which was given intravenously, was used to
study the interrelations of serum lipids. In the cholesterol ester fraction an increase occurs in both monounsaturated and
in saturated fatty acids, excepting myristic; while a decrease occurs in polyunsaturated fatty acids. The fatty acids of cholesterol
esters of normal dogs contain 22% oleic acid, and only 24% when serum lipids are increased to almost double their normal value
(TC=400–500 mg/100 ml). However there is a critical level above which a rapid rise in oleic acid occurs and, in severe hyperlipemia
(TC=1500 ±430 mg/100 ml), this acid constitutes almost half of the esterified fatty acid component.
Since there is no evidence that Triton directly regulates fatty acid synthesis, the lipid fraction-fatty acid interrelationship
may be secondary to lipid mobilization from endogenous sources. This concept is supported by the fact that the increased serum
fatty acids are only those which can be synthesized by animals. It is suggested, on the basis of a marked increased of endogenously
produced fatty acids, that, at critical lipid levels, shortage of polyunsaturated fatty acids from exogenous sources occurs.
This might be of sufficient degree to accelerate fatty acid synthesis to meet the need for fatty acids for energy requirements.
There may also be need of fatty acid for esterification of chiefly the accumulated free cholesterol split from lipoprotein
by Triton.
Triton-induced changes in cholesterol ester fatty acids result in patterns which closely resemble those in the adipose tissue
of dog and man and in the serum of human endogenous hyperlipemia. 相似文献
4.
The influence of different fat diets on liver phospholipid, cholesterol and dolichol was studied. Rats were separated into
four groups and fed standard laboratory chow (control), a diet containing linolenic acid, a coconut oil diet, or a corn oil-containing
diet. After five weeks, microsomes and mitochondrial/lysosomal fractions were prepared from the liver, and lipid compositions
were analyzed. No changes in phospholipid content were observed. In control animals, the fatty acid compositions of phosphatidylcholine
and phosphatidylethanolamine in the two subfractions were similar. However, these two phospholipids showed different fatty
acid patterns, which were altered independently upon dietary treatment. The dietary treatments resulted, in most cases, in
decreased cholesterol and dolichol contents and, especially in microsomes, in a decreased level of esterification of both
lipids. The fatty acid compositions of cholesteryl esters in the two subfractions showed significant differences and cholesterol
was esterified to a large extent with linolenic acid when this fatty acid was supplied in the diet. The same dietary treatment
exerted different effects on the cholesterol localized in the two different intracellular compartments. This difference was
most pronounced in rats fed the corn oil-containing diet; microsomal cholesteryl esters exhibited increased saturation, whereas
cholesteryl esters in the mitochondrial/lysosomal fraction displayed decreased saturation. Dolichyl esters in the two cellular
compartments had different fatty acyl compositions, with a considerably higher degree of saturation in microsomes. The various
diets influenced the nature of the fatty acid moieties present in the isolated fractions and the effects on the two subfractions
were opposite. The diet containing linolenic acid decreased the degree of saturation in microsomal dolichyl esters and increased
the degree of saturation in the mitochondrial/lysosomal fraction. The results demonstrate that the fatty acid compositions
of both dolichyl and cholesteryl esters display organelle specificity. Both the content of these lipids and their fatty acid
compositions are greatly influenced by dietary conditions, and the esterification processes at different cellular locations
exhibit independent regulation, regardless of the fatty acid content of the diet. 相似文献
5.
Total lipids from whole pig adrenal glands as well as from their mitochondria, microsomes, liposomes, and cell sap were extracted and fractionated first into neutral lipids and phospholipids. The highest percentage of neutral lipids was found in the cell sap, and the lowest in the microsomal fraction. Neutral lipids were subfractionated into cholesteryl esters, free cholesterol, triglycerides, and free fatty acids. Cholesteryl esters were distributed throughout the liposomes. Free fatty acids represented a substantial part of cell sap lipids, but were present also in the mitochondria, microsomes, and liposomes. Fatty acids of all fractions were analyzed by gas liquid chromatography. Free fatty acids and cholesteryl ester fatty acids from all cellular fractions were similar in composition and were characterized by considerable quantities of linoleic and arachidonic acid. Triglycerides were characterized by an increased percentage of palmitic and a low content of arachidonic acid. Phosphatidyl choline, phosphatidyl ethanolamine, diphosphatidyl glycerol, and sphingomyelin plus phosphatidyl inositol were isolated from the lipids by preparative thin layer chromatography, and their fatty acids analyzed by gas liquid chromatography. Phosphatidyl choline and phosphatidyl ethanolamine from mitochondria, microsomes, and cell sap were very similar in respect of their fatty acid composition. Sphingomyelin plus phosphatidyl inositol was characterized by a high content of C22:2omega6. Diphosphatidyl glycerol was present in mitochondria and in the cell sap. 相似文献
6.
Male rats were administered 1.5 ml safflower oil by gastric intubation 0, 4, and 8 hr after a 16 hr fast. Plasma, liver, and adipose tissue were collected 16 hr after the last fatty meal. Rats fasted for 16 hr served as controls. Following fat feeding, the fatty acid composition of the very low density lipoprotein, triglyceride, and hepatic triglyceride were similar, as were the percentages of 18:2 in the very low density lipoprotein and hepatic cholesteryl esters. The phospholipids of liver and plasma lipoproteins were similar in the control groups, except that more 16:0 was present in the plasma lipoproteins. After fat feeding, the plasma lipoproein phospholipids were enriched with 18:2 more than were the hepatic phospholipids. Furthermore, the percentage of 18:2 in phospholipid was much less than in triglyceride or cholesteryl esters. Clearly, esterified lipids of liver and plasma lipoproteins (very low density lipoprotein, low density lipoprotein, and high density lipoprotein), and to a lesser extent, adipose tissue, were enriched with 18:2 derived from dietary triglyceride fatty acid even 16 hr after the terminal meal. A major proportion of the very low density lipoprotein isolated by ultracentrifugation in zonal rotors from plasma of fat fed animals had a faster rate-zonal mobility than did the very low density lipoprotein isolated from plasma of control animals. The very low density lipoprotein isolated from plasma of fat fed rats contained fewer moles of phospholipids, cholesterol, and cholesteryl esters, relative to triglyceride than did the very low density lipoprotein from plasma of animals not receiving safflower oil. The molar ratio triglyceride:phospholipid:cholesterol:cholesterol esters in the very low denity lipoprotein was 100:42.0:22.1:44.5 in the control group and 100:35.4:17.8:19.5 in the fat fed animals. It is postulated that an important biochemical mechanism by which dietary triglyceride fatty acids consumed by the animal over a long period of time alter plasma concentrations of triglyceride, phospholipids, and cholesterol esters is the directive influence of plasma free fatty acid, derived from dietary triglyceride, on the secretion of very low density lipoprotein lipids by the liver. 相似文献
7.
Perfluorodecanoic acid (PFDA) is a peroxisome proliferator that causes a dose-dependent (20–80 mg/kg) increase in hepatic
triacylglycerol and cholesteryl ester levels in the rat. We hypothesized that PFDA may cause an increase in thede novo synthesis of fatty acids and cholesterol in this species, which would explain observed effects. The incorporation of3H2O into tissue lipids was examined 7 days after rats received vehicle or 20 or 80 mg/kg of PFDA. PFDA treatment decreased the
rate of synthesis of cholesterol and fatty acids in the liver and in epididymal fat pad. At a PFDA dose (20 mg/kg) that decreasedde novo synthesis of fatty acids and cholesterol, there was no effect on the concentration of fatty acids and cholesterol in the
liver, epididymal fat pads, and plasma. We conclude that PFDA induced fatty liver is due to either a decrease in the oxidation
of fatty acids in the liver, or an impairment of triacylglycerol catabolism and/or export from the liver, and is not the result
of an increase inde novo synthesis of fatty acids and cholesterol. 相似文献
8.
Andrew J. Sinclair Kerin O'Dea Graeme Dunstan Paul D. Ireland Maggie Niall 《Lipids》1987,22(7):523-529
The effects of very low fat diets (<7% energy) enriched with different sources of long chain (C20 and C22) polyunsaturated
fatty acids (PUFA) on plasma lipid levels and plasma fatty acids (PUFA) on plasma lipid levels and plasma fatty acid composition
were studied in 13 healthy volunteers. Three diets provided 500 g/day of tropical Australian fish (rich in arachidonic acid
and docosahexaenoic acid), southern Australian fish (rich in docosahexaenoic acid) or kangaroo meat (rich in linoleic and
arachidonic acids). The fourth diet was vegetarian, similarly low in fat but containing no 20- and 22-carbon PUFA. Subjects
ate their normal or usual diets on weeks 1 and 4 and the very low fat diets in weeks 2 and 3. Weighed food intake records
were kept, and weeks 2, 3 and 4 were designed to be isoenergetic with week 1.
Plasma cholesterol levels fell significantly on all diets within one week. There were reductions in both low density (LDL)
and high density lipoprotein (HDL) cholesterol levels, with effects on HDL cholesterol being more consistent. There were no
consistent or significant effects on total triglyceride levels despite the high carbohydrate content of the diets. On all
diets the percentage of linoleic acid fell in the plasma phospholipid and cholesteryl ester fractions, while the percentage
of palmitic acid in the phospholipids and cholesteryl esters and palmitoleic acid in the cholesteryl ester fraction rose on
all diets. The percentage of arachidonic acid rose in the phospholipid and cholesteryl esters on the two diets that were good
sources of this fatty acid (tropical fish and kangaroo meat). The percentage of docosahexaenoic acid also rose on the two
diets that were the richest sources of this fatty acid (the fish diets), and the percentage of eicosapentaenoic acid rose
in the phospholipid and cholesteryl esters in proportion to the dietary level of this fatty acid (southern fish > kangaroo
> tropical fish). The changes in fatty acid composition were almost completely reversed within seven days of returning to
the usual higher fat diets. 相似文献
9.
Furan fatty acids (F acids) have been found in the livers and/or testes of 20 species, representing 9 families of male freshwater
fish. In 9 species they are major components of the lipids while in the remaining 11 species they occur to a much lesser extent.
The F acids in some species reach a maximum concentration in the testes lipids, and minimum liver lipid concentration, at
spawning. In all species in the testes, the F acids are confined almost exclusively to the triglyceride fraction while, in
the liver lipids, they are found, in order of decreasing concentration, in the cholesteryl esters, the triglycerides, and
the phospholipids. In the lipids of many individuals F6 12,15-epoxy-13,14-dimethyleicosa-12,14-dienoic acid, is the major fatty acid present. It is presumed that these acids perform
some as yet unidentified metabolic function. Isolation technology and identification of F acids by a specific thin layer chromatographic
spray reagent are discussed.
Scientific Journal Series 9910, Agricultural Experiment Station, University of Minnesota, St. Paul, MN 55108. 相似文献
10.
To address the role of cell membrane neutral sphingomyelinase (EC 3.1.4.12; SMase) in the regulation of cholesterol metabolism
in the liver parenchymal cell, we examined the effect of exogenous neutral SMase on the metabolism of cholesteryl esters and
the secretion of VLDL and biliary lipids in isolated rat hepatocytes. We show that treatment of hepatocytes with SMase (20
mU/mL) resulted in the intracellular buildup of cholesteryl esters, increased ACAT (EC 2.3.1.26) activity without affecting
the ACAT2 mRNA level, and increased cytosolic and microsomal cholesteryl ester hydrolase (EC 3.1.1.13) activity. This was
accompanied by increases in the secretion of biliary. bile acid, phospholipid, and cholesterol and in increased cholesterol
7α-hydroxylase (EC 1.14.13.17) activity and levels of mRNA, as well as decreased levels of apoB mRNA and a decreased secretion
of VLDL apoB (apoB-48, ∼45%; apoB-100, ∼32%) and lipids (∼55%). Moreover, the VLDL particles secreted had an abnormal size
and lipid composition; they were larger than controls, were relatively enriched in cholesteryl ester, and depleted in TG and
cholesterol. Cell-permeable ceramides did not replicate any of the reported effects. These findings demonstrate that the increased
cholesteryl ester turnover, oversecretion of biliary cholesterol and bile acids, and undersecretion of VLDL cholesterol and
particles are concerted responses of the primary hepatocytes to exogenous neutral SMase brought about by regulation at several
levels. We suggest that plasma membrane neutral SMase may have a specific, ceramide-independent effect in the regulation of
cholesterol out-put pathways in hepatocytes. 相似文献
11.
Markus Schröder Halima Abdurahman Tanja Ruoff Katja Lehnert Walter Vetter 《Journal of the American Oil Chemists' Society》2014,91(10):1695-1702
Bovine milk fat contains a large variety of structurally different fatty acids. In this study, we describe the presence of aromatic fatty acids in a butter fat sample. Fatty acids were released from butter fat and converted into the corresponding methyl esters (FAME). Urea complexation was used to separate the main saturated fatty acids. GC/MS screening of the FAME in the filtrate of the urea complexation indicated the presence of aromatic fatty acids. By (1) conversion of two representatives into picolinyl esters which were analyzed by GC/MS, (2) linear log tR over carbon number plots (R2 = 0.95) and by the use of two reference standards we were able to show that the phenyl unit was located on the terminal carbon of the straight acyl chain of the FAME. In a fraction gathered by countercurrent chromatography we were able to identify 3‐phenylpropionic acid (Ph‐3:0), 4‐phenylbutyric acid (Ph‐4:0), 5‐phenylpentanoic acid (Ph‐5:0), 6‐phenylhexanoic acid (Ph‐6:0), 7‐phenylheptanoic acid (Ph‐7:0), 8‐phenyloctanoic acid (Ph‐8:0), 9‐phenylnonanoic acid (Ph‐9:0), 10‐phenyldecanoic acid (Ph‐10:0), 11‐phenylundecanoic acid (Ph‐11:0), 12‐phenyldodecanoic acid (Ph‐12:0), 13‐phenyltridecanoic acid (Ph‐13:0), along with one unsaturated phenyldecenoic acid (Ph‐10:1) isomer. Preliminary results indicate that the aromatic fatty acids may have been formed exogenously in the rumen of the cows. The total amount of the aromatic fatty acids was estimated at 0.15 mg/g butter fat, which corresponds with an average daily intake of ~5 mg per day in Germany and ~4.4 mg per day in Europe. 相似文献
12.
Synthetic cholesteryl 5-oxovalerate and 9-oxononanoate were used as reference standards for the isolation and identification
of cholesteryl ester core aldehydes fromtert-butyl hydroperoxide/Fe++ oxidation of synthetic and natural cholesteryl esters. The core aldehydes were recovered from the peroxidation products by
thin-layer chromatography as the free aldehydes or the 2,4-dinitrophenylhydrazones and were identified, respectively, by gas-liquid
chromatography (GLC) and by GLC combined with mass spectrometry (GC/MS) or by reverse-phase high-performance liquid chromatography
(HPLC) and by HPLC with MS (LC/MS). The core aldehydes produced by peroxidation of cholesteryl linoleate were identified as
mainly 9-oxononanoates of cholesterol and oxycholesterols, with smaller amounts of the 8-oxooctenoates, 10-oxodecenoates,
11-oxoundecenoates and 12-oxododecenoates. Peroxidation of cholesteryl arachidonate yielded 5-oxovalerates of cholesterol
and the oxycholesterols as the main products with smaller amounts of the 4-oxobutyrates, 6-oxohexenoates, 7-oxoheptenoates,
8-oxooctenoates, 9-oxononenoates, 9-oxononadienoates and 10-oxodecadienotes. The oxycholesterols resulting from the peroxidation
of the steroid ring were identified as mainly 7-keto-, 7α-hydroxy- and 7β-hydroxy-cholesterols and 5α, 6α-and 5β,6β-epoxy-cholestanols.
Cholesteryl palmitate and oleate did not yield core aldehydes in the present peroxidation system. In these esters, the sterol
and linoleic acid moieties appeared to be oxygenated at about the same rate, while the arachidonic acid moiety reacted more
rapidly than did the sterol moiety. 相似文献
13.
Klaus Vosmann Erhard Schulte Erika Klein Nikolaus Weber 《European Journal of Lipid Science and Technology》1998,100(8):334-342
Base-catalyzed transesterification of acyl lipids with methanol in the presence of trimethylsulfonium hydroxide (TMSH) is an easy and convenient method for the preparation of fatty acid methyl esters for GC analyses. However, lipids containing functional groups such as amino, amide and hydroxy groups are converted in varying degrees to the corresponding N- and O-methyl derivatives by the pyrolytic reaction of TMSH occurring in the injector of the gas chromatograph. For example, lipids containing amino or amide groups are converted into the corresponding N-methyl and N,N-dimethyl derivatives, fatty acid ethanolamides to the corresponding N-methyl, O-methyl and N,O-dimethyl derivatives, whereas alkyl methyl ethers are formed from long-chain alcohols. Furthermore, 2-O- and 3-O-monomethyl ethers as well as 2,3-di-O-methyl ethers are formed from 1-O-alkylglycerols, methoxy fatty acid methyl esters from hydroxy fatty acids as well as steryl 3β-O-methyl ethers from cholesterol and other sterols. Since some of the mentioned artefacts may interfere with fatty acid methyl esters in GC separations the TMSH derivatization method is recommended only with caution for lipids containing amino, amide and hydroxy groups. The methylation reactions, which finally lead to the corresponding N-methyl, O-methyl, N,N-dimethyl or N,O-dimethyl derivatives of fatty acids and lipids may, however, be of some diagnostic value for the structural analysis of such lipids by GC/MS. 相似文献
14.
It has long been recognized that hair is coated with nonpolar lipids originating in the sebaceous glands, and recently it
has been shown that hair also contains cholesterol sulfate and small amounts of ceramides, similar to those found in the keratinized
portion of the epidermis. In the present study, it is demonstrated that significant amounts of several additional lipids are
tightly associated with hair in such a way as to be highly resistant to solvent extraction.
These integral hair lipids included cholesterol sulfate (3.3 mg/g of extracted hair), cholesterol (0.6 mg/g), fatty alcohols
(0.2 mg/g) and free fatty acids (4.3 mg/g). The principal fatty acid, comprising 40% of the total fatty acids, was identified
as 18-methyl-eicosanoic acid by cochromatography with authentic standard on gas-liquid chromatography (GLC) and by mass spectrometry
(MS). 相似文献
15.
Studies were made of the enzymic synthesis and hydrolysis of cholesteryl esters in rat testes. Weanling rats were fed for
14 weeks diets containing 5% by wt of hydrogenated coconut oil (HCO), a concentrate of ethyl elaidate and linolelaidate (TRANS),
devoid of essential fatty acids (EFA), or safflower oil (SAFF). Cholesterol esterifying activity was localized in the soluble
fraction, and cholesteryl ester hydrolase activity was distributed in both particulate and soluble fractions obtained from
tissue homogenates. The optimum pH was 6.0 for esterification and 6.9–7.0 for hydrolysis. Neither esterifying nor hydrolytic
activity was affected by freezing and thawing, but both reactions were inhibited by heat or sonication. The animals of both
the HCO and TRANS groups had developed an EFA deficiency before they were sacrificed. The EFA deficiency produced upon feeding
the HCO diet had no apparent effect on the synthesis and hydrolysis of cholesteryl esters in rat testes. The TRANS diet influenced
the development of the testes as judged by their size, and cholesterol esterifying and cholesteryl ester hydrolyzing activities
were suppressed in the testes of the animals of this group. A major difference in the effects of the HCO and TRANS diets on
the lipids of the testes was the relatively minor amount of eicosatrienoic acid (20∶3) and the elevated level of docosapentaenoic
acid (22∶5) in the cholesteryl esters of the testicular lipids of the TRANS group. 相似文献
16.
Yuji Shimada Yoshinori Hirota Takashi Baba Akio Sugihara Shigeru Moriyama Yoshio Tominaga Tadamasa Terai 《Journal of the American Oil Chemists' Society》1999,76(6):713-716
Steryl esters of long-chain fatty acids have water-holding properties, and polyunsaturated fatty acids (PUFA) have various
physiological functions. Because steryl ester of PUFA can be expected to have both features, we attempted to synthesize steryl
esters of PUFA by enzymatic methods. Among lipases used, Pseudomonas lipase was the most effective for the synthesis of cholesteryl docosahexaenoate. When a mixture of cholesterol/docosahexaenoic
acid (3:1, mol/mol), 30% water, and 3000 units/g of lipase was stirred at 40°C for 24 h, the esterification extent attained
89.5%. Under the same reaction conditions, cholesterol, cholestanol, and sitosterol were also esterified efficiently with
docosahexaenoic, eicosapentaenoic, arachidonic, and γ-linolenic acids. 相似文献
17.
Fatty acid content of marine oil capsules 总被引:2,自引:0,他引:2
Kew M. Chee Jun Xian Gong Deirdre M. Good Rees Mohsen Meydanl Lynne Ausman Julia Johnson Edward N. Siguel Ernst J. Schaefer 《Lipids》1990,25(9):523-528
The use of dietary ω3 fatty acid capsules has been associated with a decrease in plasma triglyceride levels. In addition,
populations consuming diets rich in fish appear to have a decreased incidence of cardiovascular disease. Eicosapentaenoic
acid (EPA, 20∶5ω3) and docosahexaenoic acid (DHA, 22∶6ω3) are major fatty acids in fish oils. It is believed that fish oils
exert their biolotic effect through these fatty acids. Many individuals are currently taking fish oil capsules to lower lipids,
increase bleeding time, and possibly decrease cardiovascular risk. These capsules also have been classified as food additives
with less stringent controls on content. We assessed the fatty acid, cholesterol, and vitamin A and E content of eight commercially
available capcules along with cod liver oil. The content of EPA was found to range from 8.7–26.4% (wt%) with a mean of 17.3%
(82.4% of labeled content), and that of DHA from 8.9–17.4% with a mean of 11.5% (90.0% of labeled content) as assessed by
capillary column gas-liquid chromatography. The mean content of the polyunsaturated ω3 fatty acids was 31.9%, and that of
the ω6 fatty acids was 1.4%. The content of saturated fatty acids was 32,0%, and that of monounsaturated fatty acids was 25.1%.
Cholesterol content was low, with a range of 0.7–8.3 mg/g, the α-tocopherol range was 0.62–2.24 mg/g, and the range of retinyl
esters was 0.4–298.4 μg/g. Cod liver oil had substantially more retinyl esters (2450.1 μg/g) than did fish oil capsules. Our
data serve as an independent guide to fish oil capsule fatty acid content upon single lot analysis, and indicate that these
capsules contain as much saturated fat as they contain ω3 fatty acids. 相似文献
18.
Rapid separation of neutral lipids,free fatty acids and polar lipids using prepacked silica sep-Pak columns 总被引:6,自引:10,他引:6
A method is described for the separation of neutral lipid, free fatty acid and polar lipid classes using small (600 mg), prepacked
silica Sep-Pak columns. Combinations of hexane and methyltertiarybutylether were used to progressively elute cholesteryl ester
first then triglyceride from the column. After column acidification, fatty acids were eluted followed by cholesterol. Recoveries
of these lipids were 96% or greater. Polar lipids were eluted from the column using combinations of methyltertiarybutylether,
methanol and ammonium acetate. Phospholipid classes could not be separated completely from each other. Phosphatidylethanolamine
and phosphatidylinositol eluted together, whereas the more polar phosphatidylcholine, sphingomyelin and lysophosphatidylcholine
were eluted as a second fraction. Recoveries of each phospholipid was greater than 98%. 相似文献
19.
A high cholesterol diet was found to induce fatty liver in spontaneously hypertensive rats. Although cholesterol ester and
triacylglycerol accumulated in large amounts in liver, the increases of these lipids in plasma were relatively small and no
increase in cholesterol and cholesterol ester was observed in aorta. In rats fed normal diet, plasma cholesterol ester mainly
consisted of arachidonate species; however, oleate and linoleate esters became the most prominent species in rats fed a high-cholesterol
diet. The amounts of oleate and linoleat at the 2-position of phosphatidylcholine in both plasma and liver were increased
slightly, but the fatty acids of aorta lipids changed little by feeding a high cholesterol diet. These results indicate that
the livers of rats fed the high cholesterol diet do not secrete cholesterol ester and triacylglycerol with altered fatty acids
as rapidly as they are synthesized and that the increased levels of cholesterol oleate in liver and plasma are not directly
correlated with atherogenic lesions under these conditions. 相似文献
20.
Influence of n-3 Fatty Acids on Mitochondrial Function and Stability of Erythrocyte Membrane of Rats in Long Term Experiments with Cod Liver Oil The influence of different amounts of polyunsaturated fatty acids (PUFA) (1.3, 2.6 and 6.3% of total energy intake) on mitochondrial respiration and the stability of erythrocyte membrane was tested in experiments with rats lasting 12 and 32 weeks. The fat component of the semisynthetic diets (6g/100 g diet) was made up of coconut fat and cod liver oil (Gr. I, II, III) and cod liver oil and linoleic methylester (G1. IV). The n-3 fatty acids amounted to 1.18 cal% (I), 2.35 cal% (II,III) and 2.1cal% (IV). The diets of the groups I, III and IV wre supplemented with 6 mg D-α-tocopherylequivalents per 100g; the tocopherol/PUFA-ratios (mg/g) in the diets I, II, III, IV were 10.7, 0.1, 5.4 and 2.3 respectively. After 12 weeks cod liver oil had no significant influence on total lipids of the liver, hemolysis rate of red blood cells as well as the respiration of liver mitochondria. Highest weight gained was reported for the animals of group I receiving 1.3 cal% of PUFA derived from cod liver oil. All groups had similar relative liver weights. After 32 weeks the consequences of the insufficient supply tocopherol in group II were a significantly increased hemolysis rate of the erythrocytes and a decreased respiratory control index as well as the ADP/O-ratios of liver mitochondria using succinate and malate/glutamate as substrates. The highest PUFA amount fed (6.3 cal%; derived from cod liver oil and linoleic methylester) with the adequate vit. E supplementation did not cause any major alterations. The results show that fatty acids of the α-linolenic acid group can replace in part the n-6 fatty acid in their essential role for integrity of the membranes of mitochondria and erythrocytes. This is possible only if the increased antioxidant requirement of the body caused by ingestion of fish oil PUFA's is adequately compensated through additional supplements with antioxidants like α-tocopherol. 相似文献