共查询到20条相似文献,搜索用时 31 毫秒
1.
Thein vitro incorporation of elongated fatty acyl products into various lipid classes was studied in the American cockroach,Periplaneta americana (L.) and the houseflyMusca domestica L. Stearoyl-CoA (18∶0-CoA) and linoleoyl-CoA (18∶2-CoA) were each elongated in microsomal preparations from abdominal epidermal
tissue of the adult cockroach. Incorporation of radioactive tracer into different lipid classes was determined by thin-layer
chromatography (TLC). In the American cockroach, 40–45% of the total radioactive label was incorporated into the free fatty
acid fraction, with smaller amounts in the triglyceride (12–31%) and phospholipid (12–19%) fractions. Of the elongated products
analyzed by radio-high performance liquid chromatography (HPLC), 53–60% was found in the free fatty acid fraction. In the
housefly, the substrates 18∶0-CoA and 18∶1-CoA were used to determine into which lipids the elongated products would become
incorporated. The saturated fatty acyl elongated products were found mainly in the free fatty acid (41%), triglyceride (23%),
and acyl-CoA (17%) fractions. The monounsaturated fatty acyl elongated products were found in the triglyceride (44%), free
fatty acid (11%), acyl-CoA (35%) and phospholipid (10%) fractions in three-day-old males. In three-day-old females, the elongated
products were found in the triglyceride (45%), free fatty acid (28%), acyl-CoA (11%) and phospholipid (15%) fractions. From
these data, it is not possible to determine the identity of the substrate for the conversion of the elongated fatty acyl products
to the corresponding hydrocarbon (Hy). In the cockroach, incubations with 18∶0-CoA and with 18∶2-CoA resulted in small incorporations
into 25∶0 Hy and into 27∶2 Hy, respectively. In the housefly, incubations with 18∶1-CoA resulted in a very small production
of 27∶1 Hy in mature males and 23∶1 Hy in mature female houseflies. These data support the idea that the preparation of subcellular
fractions results in an uncoupling of fatty acid chain elongation from the conversion of the fatty acid to the corresponding
hydrocarbon in both insects. 相似文献
2.
This study reports on the plasma lipid compositions of sheep fed either a control diet (C), a control diet supplemented with
tallow (A) or polyunsaturated fatty acid (B) that had been protected against hydrolysis and hydrogenation in the rumen, or
a control diet supplemented with maize oil (D). Diet B considerably increased the 18∶2 content of all the major plasma lipid
fractions. Although the feeding of diet D also resulted in an increase in the 18∶2 contents within the cholesteryl ester,
unesterified fatty acid, and phospholipid fractions the increases were considerably less than those observed with diet B;
the levels of 18∶2 within the triglyceride fraction remained similar to that for the sheep which received the control diet.
The effect of feeding diet A was confined solely to the triglyceride fraction where the concentrations of 16∶0 and 18∶1 were
increased. The lipoproteins of the plasma were separated into very low density lipoproteins (d<1.006), low density lipoproteins
(1.006<d<1.063), and high density lipoproteins (1.063<d<1.21), and the distribution of the major lipids between these lipoprotein
fractions was investigated. Diet B increased considerably the proportion of triglyceride found in association with the very
low density fraction and the concentrations of 18∶2 within all the lipoprotein fractions; these increases in the concentrations
of 18∶2 were not confined to any particular lipid fraction of the lipoproteins. In contrast, the increases in the concentrations
of 18∶2 produced as a result of feeding diet D were confined to the low and high density lipoproteins. The effect of feeding
diet A was confined to fatty acid changes within the triglycerides of the low and very low density lipoproteins. 相似文献
3.
Two groups of rats were fed diets containing 20% by weight of either partially hydrogenated marine oil supplemented with sunflower
seed oil (PHMO) or palm oil (PO) for 8 wk. Using a liver perfusion system, the effect of dietary long chain monoenoic fatty
acids on the uptake and metabolism of [14-14C]erucic acid was studied. The perfusion times were 15 and 60 min, respectively. The two groups showed equal ability for erucic
acid uptake in the liver but differed in the channeling of the fatty acids into various metabolic pathways. A higher metabolic
turnover of 22∶1 in the PHMO livers relative to the PO livers was demonstrated by an increased recovery of total [14C]labeling in the triglyceride (TG) and phospholipid (PL) fractions, already evident after 15 min of perfusion. The chainshortening
capacity was highest in the PHMO group, reflected by a higher [14C]18∶1 incorporation in both TG and PL, and increasing from 15 to 60 min of perfusion. The amount of [14C]18∶1 found in PL and TG after 60 min of perfusion of livers from rats fed PO corresponded to that shown for the PHMO group
after 15 min. The PL demonstrated a discrimination against 22∶1 compared to TG, and, when available, 18∶1 was highly preferred
for PL-synthesis.
The total fatty acid distribution in the TG, as determined by gas liquid chromatography (GLC), reflected the composition of
the dietary fats. In the total liver PL, 22∶1 and 20∶1 were present in negligible amounts, although the PHMO diet contained
12–13% of both 22∶1 and 20∶1. In the free fatty acid fraction (FFA), the major part of the radioactivity (≈80%) was [14-14C]erucic acid, and only small amounts of [14C]18∶1(<2%) were presents, even after 60 min of perfusion. The shortened-chain 18∶1 was readily removed from the FFA pool
and preferentially used for lipid esterification. 相似文献
4.
Studies are reported on the composition of the lipids of human liver and hepatoma tissues from male adults. Liver tissues
were obtained from individuals who died from causes other than liver disease or cancer. The hepatoma tissues were obtained
from individuals shortly after they succumbed to cancer. The total lipid of each tissue was fractionated quantitatively by
silicic acid column chromatography into neutral lipid, glycolipid, and phospholipid fractions. These fractions were analyzed
by thin layer chromatography and converted to methyl esters for analysis of their constituent fatty acids by gas liquid chromatography.
In comparison to liver tissue, the total amount of lipid in the hepatoma tissues was generally higher and more variable; the
lipid of one hepatoma was ca. 92% of the dry wt of the tissue. The greater lipid content of the hepatoma tissues was due to
the high percentage of neutral lipid. Except for one specimen, there was ca. the same amount of glycolipid in the hepatoma
as in the liver tissues, but the composition of the glycolipid fraction of the hepatoma lipid differed considerably, particularly
in the ganglioside fraction. The phospholipid fraction of hepatoma lipid was much lower than that of liver but exhibited only
quantitative differences in composition. No glyceryl ether diesters and only traces of plasmalogens of phosphatidyl choline
or phosphatidyl ethanolamine were detected in the liver and hepatoma lipids. The levels of monoenoic acids were higher and
those of linoleic and polyunsaturated fatty acids lower in the hepatoma lipids. Positional isomers of trienoic acids not normally
present in liver tissue were detected in hepatoma lipids. The abnormalities observed in lipid composition indicated interferences
in the regulatory processes of lipid metabolism in human hepatoma similar to those observed in animals. 相似文献
5.
The fatty acid composition of the triglyceride and the total phospholipid fractions of ovine liverEchinococcus granulosus protoscolices was determined by gas chromatography and compared with that of the healthy and Echinococcus infected livers.
The chain length of the major saturated fatty acids identified in both the host tissues and the parasite ranged from 12–22
carbons. Oleic and linoleic acids were the only detectable unsaturated fatty acids identified in protoscolices and the liver
samples. Comparison of the amounts of the fatty acids from the three different sources mentioned above by analysis of variance
and the contrast method of Scheffe, revealed a significant decrease in the level of oleic acid in triglyceride fraction of
the infected livers compared with normals. Thinlayer chromatography of the polar lipid fraction of the protoscolices resulted
in tentative identification of lysolecithin, sphingomyelin, lecithin, phosphatidyl inositol, sulfatides, cerebrosides, cephalins
and cholesterol. 相似文献
6.
P. G. Satyaswaroop 《Lipids》1971,6(9):661-665
The lipid composition of the freshly slaughtered bovine thyroid tissue has been investigated. The phospholipid patterns of
microsomal and mitochondrial fractions obtained from homogenates of bovine thyroids have also been determined. They resemble
the phospholipid composition of the corresponding subcellular fractions from other tissues. The fatty acid composition of
the various phospholipid species of these subcellular components have also been estimated by gas liquid chromatography. These
analyses reveal that the fatty acids are not particularly characteristic of the subcellular organelle but tend to be characteristic
of the lipid species. There is a high percentage of nervonic acid (C24∶1) in all the subcellular phospholipid species examined. 相似文献
7.
Alterations in lipid composition occur in the retinal pigment epithelium and photoreceptor cells of the Royal College of Surgeons
(RCS) dystrophic rat, a model for inherited retinal degeneration. With respect to lipid composition of nonretinal tissues,
the developmental timing of lipid alterations and the incidence of dystrophy are unknown. We determined the fatty acid composition
in choline phosphoglycerides (ChoGpl) and ethanolamine phosphoglycerides (EtnGpl) in the brain, liver, and retina from dystrophic
RCS rats and from their nondystrophic congenics (controls) at the ages of 3 and 6 wk. At 3 wk, the fatty acid compositions
were specific to individual phospholipid classes without any difference between dystrophic and nondystrophic tissues. In plasma
phospholipids, there was an age-related increase in the relative contents of monounsaturated and n-3 polyunsaturated fatty
acids, with only minor differences between dystrophic and nondystrophic rats. At 6 wk, the fatty acid compositions in ChoGpl
and EtnGpl from dystrophic brain and retina were significantly different from those of nondystrophics. The effect of strain
on developmental changes in brain fatty acid composition was significant for 18∶0 and 22∶6n−3 in EtnGpl and for 16∶0, 18∶0,
18∶1n−9, and 20∶4n−6 in ChoGpl. The brain ChoGpl fatty acid composition in nondystrophic rats was similar at 6 wk to that
of normal rats, and there were almost no postweaning changes in the dystrophics. In retinal phospholipids, the effect of dystrophy
was to increase the 20∶4n−6 content in EtnGpl and to decrease 22∶6n−3 in ChoGpl. The 18∶2n−6 and 22∶6n−3 contents in dystrophic
liver ChoGpl were also significantly affected, while no difference was observed in the EtnGpl fraction. The dystrophy affected
the phospholipid fatty acid developmental changes in a tissue- and class-specific manner. Fatty acid metabolism could be selectively
altered in neural and nonneural tissues of developing dystrophic RCS rats. 相似文献
8.
The linoleic acid content of phosphatidylethanolamine (PE), phosphatidylcholine (PC) and triglyceride (TG) rapidly fell in
rat hepatocytes in primary culture up to four days and in coculture with liver epithelial cells up to eight days. At the same
time, the level of polyunsaturated fatty acids (PUFA), especially arachidonic acid, remained constant in PE, slightly decreased
in PC and dropped in TG. There was no variation of the nonessential PUFA, 20∶3n−9.
Linoleic acid supplementation of cultures 24 hr before the harvest induced a rise in the linoleic acid level of the three
lipid classes. Arachidonic acid remained constant in TG and only slightly decreased in PE and PC at day 4 of primary culture
and day 8 of coculture. The level of 20∶3n−9 increased in PE and PC and much more in TG. This net increase in the arachidonic
acid and 20∶3n−9 levels in TG could not be explained only by a transfer from the phospholipid pools of PUFA because the phospholipid
content of hepatocytes and PUFA levels of phospholipids did not vary under linoleic supplementation. The low percentage of
arachidonic acid in epithelial cells rules out any participation of these cells in the increase of arachidonic acid in supplemented
cocultures.
Triglycerides may act as a storage pool for plasma PUFA up to four days of primary culture and eight days of coculture. Besides,
coculture seems more potent than primary culture to maintain the phospholipid level, to spare the essential PUFA in PE and
to increase the TG synthesis in response to linoleic acid supplementation. 相似文献
9.
Randall Wood 《Lipids》1982,17(11):763-770
Groups of rats were fed a fat-free diet supplemented with 0.5% safflower oil (control) or the control diet containing 0.5%
of 5,8,11,14-eicosatetraynoic acid (TYA). Blood was collected weekly and plasma lipids analyzed. After 4 weeks, the animals
were killed and the liver lipids were analyzed in detail. The acetylenic fatty acid perturbed plasma neutral lipid and phospholipid
class concentrations and reduced growth rates. Liver triglyceride concentrations were reduced dramatically in the TYA fed
animals, suggesting interference with complex lipid synthesis. Plasma and liver triglycerides were shifted to higher molecular
weight species suggesting that TYA affected fatty acid metabolism. The phospholipids showed an accumulation of 18∶2 and a
fall in 20∶4 percentages indicating an inhibition in the conversion of linoleate to arachidonate. All major lipid classes
exhibited an increase in 18∶1 levels. Analysis of the octadecenoate positional isomers indicated the proportion of oleate
increased substantually in all lipid classes whereas vaccenate proportions had fallen dramatically. All of the data collectively
suggest that TYA inhibits the elongation of unsaturated fatty acids. A group of rats bearing hepatoma 7288CTC were also fed
the TYA diet. Host liver lipids were affected by TYA similar to normal TYA fed animals, but the effects on hepatoma lipids
were marginal. 相似文献
10.
J. T. Venkatraman R. K. Tiwari B. Cinader J. Flory T. Wierzbicki M. T. Clandinin 《Lipids》1991,26(3):198-202
Inbred congenic mice of strains MRL/Mp-lpr/lpr (lpr/lpr) and MRL/Mp-+/+ (+/+) were fed nutritionally adequate semipurified
diets containing 20% (w/w) fat and differing in linoleic acid content. Levels of linoleic acid (18∶2n−6) and arachidonic acid
(20∶4n−6) in phospholipids of splenocytes, liver mitochondria and liver nuclear envelopes were determined. Membranes of lpr/lpr
mice exhibited significantly lower levels of 18∶2n−6 and 20∶4n−6 in phospholipids compared with the +/+ strain. The high linoleic
acid diet increased incorporation of 18∶2n−6 and 20∶4n−6 in most phospholipid fractions of these membranes. These observations
indicate that genotype as well as dietary 18∶2n−6 content significantly influenced incorporation of 18∶2n−6 and 20∶4n−6 into
membrane phospholipids. The results also suggest that membrane compositional abnormalities found in the lpr/lpr mice, which
develop lymphoma and age faster than +/+ mice, are not restricted to the immune system but also extend to other organs. Differences
observed in phospholipid fatty acid composition in splenocytes and liver subcellular membranes for mice fed diets differing
in linoleic acid content suggest that the early expression of the lpr gene resulting in progression of autoimmunity may be
delayed through dietary manipulation. 相似文献
11.
The purpose of this study was to examine the effects of two purified isomers of CLA (c9,t11-CLA and t10,c12-CLA) on the weights and FA compositions of hepatic TG, phospholipids, cholesterol esters, and FFA. Eight-week-old female
mice (n=6/group) were fed either a control diet or diets supplemented with 0.5% c9,t11-CLA or t10, c12-CLA isomers for 8 wk. Weights of liver total lipids and those of individual lipid fractions. did not differ between the
control and the c9,t11-CLA groups. Livers from animals fed the t10,c12-CLA diet contained four times more lipids than those of the control group; this was mainly due to an increase in the TG
fractions (fivefold), but cholesterol (threefold), cholesterol esters (threefold), and FFA (twofold) were also significantly
increased. Although c9,t11-CLA did not significantly alter the weights of liver lipids when compared with the control group, its intake was associated
with significant reductions in the weight percentage (wt% of total FAME) of 18∶1n−9 and 18∶1n−7 in the TG fraction and with
significant increases in the weight percentage of 18∶2n−6 in the TG, cholesterol ester, and phospholipid fractions. on the
other hand, t10,c12-CLA intake was linked with a significant increase in the weight percentage of 18∶1n−9 and a decrease in that of 18∶2n−6
in all lipid fractions. These changes may be the result of alterations in the activity of Δ9-desaturase (stearoyl CoA desaturase)
and the enzymes involved in the metabolism of 18∶2n−6. Thus, the two isomers differed not only in their effects on the weights
of total liver lipids and lipid fractions but also on the FA profile of the lipid fractions. 相似文献
12.
Normal phase high performance liquid chromatography methods are described for the separation of neutral lipid, fatty acid
and five phospholipid classes using spectrophotometric detection at 206 nm. Separations were accomplished in less than 10
min for each lipid class. A mobile phase consisting of hexane/methyltertiarybutylether/acetic acid (100∶5∶0.02) proved effective
in separating cholesteryl ester and triglyceride with recoveries of 100% for radiolabeled cholesteryl oleate and 98% for radiolabeled
triolein. Free fatty acid and cholesterol were separated by two different mobile phases. The first, hexane/methyltertiarybutylether/acetic
acid (70∶30∶0.02) effectively separated free fatty acids and cholesterol, but did not separate cholesterol from 1,2-diglyceride.
A mobile phase consisting of hexane/isopropanol/acetic acid (100∶2∶0.02) effectively separated free fatty acid, cholesterol,
1,2-diglyceride and 1,3-diglyceride. Recoveries of oleic acid and cholesterol were 100% and 97%, respectively. Five phospholipid
classes were separated using methylteriarybutylether/methanol/aqueous ammonium acetate (pH 8.6) (5∶8∶2) as the mobile phase.
The recoveries of phosphatidylinositol, phosphatidylethanolamine, phosphatidylcholine, sphingomyelin and lysophosphatidylcholine
were each greater than 96%. 相似文献
13.
Yung-Sheng Huang X. Lin R. S. Smith P. R. Redden D. K. Jenkins D. F. Horrobin 《Lipids》1992,27(9):711-715
The present study examined the effect of varying dietary linoleate intake (0.01, 0.24, 2.4, 24, 80 or 160 g/kg diet) for 24
weeks on the distribution of triacylglycerol (TG) molecular species in rat epididymal adipose tissue. Adipose TG fractions
were purified by thin-layer chromatography and separated into different molecular species by reversephase high-performance
liquid chromatography. The identification of TG species was based on fatty acid composition, retention time and the theoretical
carbon number. When the dietary 18∶2n−6 content was equal to or less than 24 g/kg, no significant amounts of n−6 fatty acids
(mainly 18∶2n−6) were observed in adipose tissue TG despite the fact that the levels of 20∶4n−6 in liver phospholipids increased
significantly. There were 12 major molecular species in adipose tissue when the dietary 18∶2n−6 content was less than 2.4
g/kg. When the diteary 18∶2n−6 content reached 24 g/kg, an additional six TG species containing one, two or three molecules
of 18∶2n−6 were observed. The levels of TG molecules containign two or three 18∶2n−6 residues were further increased when
the diet contained very large amounts of linoleic acid (160 g/kg). Conversely, those TG species containing only one 18∶2n−6
residue became less abundant. It is suggested that the accumulation of these linoleate-rich TG molecular species in adipose
tissue, particularly di- and trilinoleoyl containing TG, is the result of an adequate or an excessive intake of linoleic acid. 相似文献
14.
We have utilized transgenic technology to develop a new source of γ-linolenic acid (GLA) using the canola plant as a host.
The aim of the present study was to compare the growth and fatty acid metabolism in rats fed equal amounts of GLA obtained
from the transgenic canola plant relative to GLA from the borage plant. Young male Sprague-Dawley rats (n=10/group) were randomized and fed a purified AIN93G diet (10% lipid by weight) containing either a mixture of high GLA canola
oil (HGCO) and corn oil or a control diet containing borage oil (BO) for 6 wk. GLA accounted for 23% of the triglyceride fatty
acids in both diets. Growth and diet consumption were monitored every 2–3 d throughout the study. At study termination, the
fatty acid composition of the liver and plasma phospholipids was analyzed by gas chromatography. The growth and diet consumption
of the HGCO group were similar to the BO group. There were no adverse effects of either diet on the general health or appearance
of the rats, or on the morphology of the major organs. There was no significant difference between the diet groups for total
percentage of n−6 polyunsaturated fatty acids present in either the total or individual phospholipid fractions of liver or
plasma. The relative percentage of GLA and its main metabolite, arachidonic acid, in each phospholipid fraction of liver or
plasma were also similar between groups. The percentage of 18∶2n−6 in liver phosphatidylethanolamine and phosphatidylinositol/serine
was higher (P<0.05) and 22∶5n−6 was lower in the HGCO group than the BO group. This finding could be attributed to the higher 18∶3n−3 content
in the HGCO diet than the BO diet. Results from this long-term feeding study of rats show for the first time that a diet containing
transgenically modified canola oil was well-tolerated, and had similar biological effects, i.e., growth characteristics and
hepatic metabolism of n−6 fatty acids, as a diet containing borage oil. 相似文献
15.
Lipids were extracted from the roots and shoots of four species of theCapsicum (pepper) genus and separated into three fractions: triglycerides; free fatty acids, mono- and diglycerides; and phospholipids.
The component fatty acids were determined by subjecting the methyl esters to gasliquid chromatography. The predominate fatty
acids obtained were palmitic (16∶0) and linoleic (18∶2), with lesser amounts of linolenic (18∶3), stearic (18∶1), and oleic
(18∶0). Differences existed in the neutral lipid fractions which might be of value from taxonomic interests; however, the
phospholipids from each of the species and plant parts did not differ so greatly. A comparison of the amount of unsaturated
fatty acids in the phospholipid fractions indicates that differences exist which might be of value in determining the relative
sensitivity of the several species to chilling temperatures. 相似文献
16.
Clofibrate administration significantly altered the amount and fatty acid composition of lipids in mouse liver. The net content
of phospholipids (PL) increased and that of triacylglycerols (TG) decreased concomitantly with liver enlargement in mice treated
for two weeks with this drug (0.5% w/w in the food). The highest increase among PL was in phosphatidylcholine; other components
either showed lower increases or, as in the case of sphingomyelin and the plasmalogens, decreased. In all lipid classes the
treatment resulted in altered ratios between major saturates, between saturates and monoenes, and between major polyenes.
Among these, 20∶3n–6 and 22∶5n–3 increased several-fold, and the 20∶3n–6/20∶4n–6 and 22∶5n–3/22∶6n–3 ratios increased due
to a more active formation of the precursors than of the corresponding products. This change affected all glycerolipid classes.
Liver sphingomyelin showed a relative enrichment in monoenoic fatty acids like 22∶1 and 24∶1, caused by a net decrease in
the amount of saturates, particularly 22∶0 and 24∶0. The stimulated membrane proliferation imposed by clofibrate must increase
phospholipid synthesis and, hence, the need for fatty acids. The results suggest that these demands are met mostly by TG acyl
groups, either directly or after oxidation/desaturation processes. This was apparently the case for the polyenoic fatty acids
of the n-6 and n-3 series. The longer chain (C22 and C24) components decreased, suggesting that their oxidation was stimulated to provide part of the required (C20 and C22) polyenes. 相似文献
17.
Fatty acid composition of neutral and polar lipid fractions from rat hearts was determined in rats of different ages as their
diet source changed. Piebald rats were weaned at 21 days and were fed standard lab chow. Lipids from rat hearts, mothers milk
and lab chow were purified on a Sephadex G-25 fine column and separated into neutral and polar lipid fractions by silicic
acid column chromatography. These lipid fractions were then hydrolyzed and methylated with BF3 in methanol, prior to gas liquid chromatographic separation on a 1/8 in. × 10 ft aluminum column of 15% EGS on 80–100 mesh
acid-washed Chromosorb W. Three major fatty acids in the neutral lipid fraction comprised 72% of total neutral lipid fatty
acids from young hearts. At sexual maturity (at least 74 days old) C18∶1 was the major fatty acid, followed by C16∶0 and C18∶0. The same three fatty acids comprised 83% of total polar lipid fatty acids, but C18∶0 was the major fatty acid, followed by C16∶0 and C18∶1. The fatty acid composition of dietary lipids influenced the total neutral lipid fatty acid composition of the rat heart,
but had little influence on the fatty acid composition of the polar lipid fraction.
Presented in part at the AOCS Meeting, New Orleans, April 1970. 相似文献
18.
Martin Gold 《Lipids》1970,5(3):293-298
Unanesthetized, resting dogs were infused through a leg vein for approximately 90 min with 1-14C-palmitate and oleate-9,10-H3 complexed to albumin. The animals were then anaesthetized, exsanguinated, and the kidneys removed. Lipids were extracted
from the medullae and cortices with chloroform-methanol (2∶1) and the lipid classes were analyzed for radioactivity content
and fatty acid composition. Triglyceride subclass species were determined by silver nitrate thin layer chromatography. The
triglyceride content of the medulla was much higher than that of the cortex while the phospholipid level was slightly higher
in the cortex. The fatty acid composition of triglyceride and phospholipid was not demonstrably different, in the medulla,
or cortex. The amount of monounsaturated triglyceride species (001) was lower and the tetra- (022) and more unsaturated species
were higher in the cortex than in the medulla. Most of the radioactivity was found in the phospholipid fraction and a large
portion of the remainder was in triglyceride. Cortical phospholipids contained 80% of the radioactivity versus a value around
60% in the medulla, whereas triglyceride, in the medulla, was approximately 26% compared to the cortical content of 15%. The
results, with respect to the per cent distribution of radioactivity, were similar for radiocarbon and tritium. The cortex
possessed a higher specific activity, for oleate and palmitate in both triglyceride and phospholipid. The total kidney retained
0.25% of the infused palmitate and 0.08% of the infused oleate. 相似文献
19.
Fatty acids ofSterculia foetida were added to the medium used to maintain the Morris hepatoma 7288C in culture. The effect of this supplement on the lipid
composition was examined. Overall, monoene levels were decreased with 18∶1 levels reduced by 40%. Saturated fatty acid levels
were increased, with stearate (18∶0) levels 220% of control values. No effect occurred on the level of polyunsaturates (18∶2,
20∶4, 22∶5, 22∶6). These changes in fatty acid makeup were observed in both neutral and phospholipid fractions, and all lipid
classes were affected. Triglycerides were most affected with a 66% decrease in 18∶1. There appeared to be little specificity
of effect in the phospholipids with 18∶1 levels decreased 40–60% in all classes. All classes were therefore dependent on an
endogenous supply of 18∶1. Examination of the distribution of geometrical isomers of 18∶1 reveals that in all lipid classes,
except diphosphatidylglycerol (DPG), the ratio of Δ11 to Δ9 isomer decreased toward the isomeric distribution displayed by
total medium lipids. In DPG, although 18∶1 levels were lowered, the isomeric distribution increased. DPG, synthesized and
found in the mitochondria, may use a separate pool of 18∶1 during synthesis. Cyclopropene fatty acids (sterculic and malvalic)
were incorporated into both neutral and phospholipid fractions with preferential incorporation into triglycerides. Cyclopropene
fatty acids were not selectively incorporated into any phospholipid species. Sphingomyelin did not incorporate cyclopropene
fatty acids, indicating that a different class of acyltransferase is used in the formation of this phospholipid class. 相似文献
20.
M. A. Ali M. A. Gafur M. S. Rahman G. M. Ahmed 《Journal of the American Oil Chemists' Society》1985,62(3):520-523
The kernels of 10 different mango varieties were extracted. The physico-chemical characteristics and lipid class composition
of fats were studied. The fat content of mango kernels grown under the soil and climatic conditions of Bangladesh varied from
7.1% to 10%, depending on the variety. The total lipid extracts were fractionated into lipid classes by a combination of column
and thin layer chromatography (TLC). The hydrocarbon and sterol esters varied from 0.3% to 0.7%, triglycerides from 55.6%
to 91.5%, partial glycerides from 2.3% to 4% and free sterol from 0.3% to 0.6%. Free fatty acids amounted to 3.0–37% as oleic;
glycolipids were 0.6–1.2% and phospholipids 0.11–0.8%. The fatty acid composition of triglyceride (TG) fractions was analyzed
by gas liquid chromatography (GLC). Palmitic acid varied from 7.9 molar % to 10.0 molar %, stearic from 38.2% to 40.2%, oleic
from 41.1% to 43.8%, linoleic from 6.0% to 7.6%, linolenic from 0.6% to 1.0% and arachidic acid from 1.7% to 2.6%. TLC revealed
the presence of lyso-phosphatidylcholine, phosphatidylcholine, phosphatidylinositol, phosphatidylethanolamine and phosphatidic
acid in the phospholipid fraction. 相似文献