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1.
E. L. Thomas J. D. Hanrahan M. Ala-Korpela G. Jenkinson D. Azzopardi R. A. Iles J. D. Bell 《Lipids》1997,32(6):645-651
In vivo
13C magnetic resonance spectroscopy (MRS) was applied noninvasively to analyze the fatty acid composition of adipose tissue
in 21 full-term newborn infants and 6 mothers. In order to assess the effects of gestational and postnatal age on adipose
tissue composition, we studied preterm infants at birth, term infants at the ages of 6 wk and at 6 mon. We also investigated
the influence of maternal diet on infant adipose tissue composition by studying the breast-fed infants of women who maintained
either an omnivore or a vegan diet. Significant differences were observed in adipose tissue composition of neonates compared
with their mothers. Neonates had more saturated and less unsaturated fatty acids than their mothers (P<0.01). We also observed changes in adipose tissue composition with maturity. From birth to 6 wk of age 13C MR spectra showed a significant increase in the amount of unsaturated fatty acids, particularly polyunsaturated fatty acids
(P<0.01). Similarly, differences were seen as a result of gestational age. Preterm infants had relatively fewer unsaturated
fatty acids than full-term infants. A greater proportion of these unsaturated fatty acids were polyunsaturated. Our results
demonstrate that 13C MRS can be utilized to assess noninvasively neonatal adipose tissue lipid composition and to monitor the effects of developmental
changes due to gestational age and oral feeding. 相似文献
2.
Arthur D. Hartman 《Lipids》1985,20(5):255-261
The objectives of the present study were to determine if adipocyte trigly ceride fatty acid (TGFA) mobilization in vivo varied
among the different adipose tissue depots and whether these rates were affected by age. In order to accomplish these objectives,
two groups of rats were studied. The first group initially weighed 84±1 and the second group 333±2. Both groups were placed
on a semisynthetic diet containing 6% corn oil (w/w) and 14% triundecanoin (w/w) for a period of 4 wk. Triundecanoin contains
an 11-carbon (C-11) fatty acid (undecanoic acid) that was used to label the adipocyte TGFA. At the end of the 4-wk feeding
period, triundecanoin was removed from the diet and replaced with an equivalent amount of corn oil. At this time and at weekly
intervals for the next 4 wk, 5 rats from each age group were killed for the determination of TGFA composition in isolated
dipocytes from the epididymal (Epi), perirenal (PR), subcutaneous (SC) and mesenteric (M) adipose tissue depots. When the
content of C-11 was expressed as mole percent of the total fatty acids, mobilization was significantly more rapid from the
PR and M depots than in the other two depots in the young rats. In the older rats mobilization was significantly slower in
all depots compared to the younger group. The rates of mobilization were not different between the depots in the older animals.
Since fat cell size continued to increase throughout the duration of the study, part of the decrease in C-11 content can be
accounted for by dilution by newly acquired TGFA. When data were compared on the basis of the actual pmoles of C-11 per cell,
rates of mobilization were not different between the depots nor was mobilization affected by age. These results emphasize
again the impact the manner in which adipocyte metabolic data are expressed has on interpretation(s) when comparing adipocytes
of different depots or from rats of different age. 相似文献
3.
Martin R. L. Scheeder Didier Gumy Ruth Messikommer Caspar Wenka Pierre Lambelet 《European Journal of Lipid Science and Technology》2003,105(2):74-82
The influence of the distribution of polyunsaturated fatty acids on the glycerol backbone of dietary triacylglycerols on the fatty acid profile of adipose tissue and muscle phospholipids was investigated in growing‐finishing pigs (48) and broiler chicken (84). The animals were fattened on barley/soybean meal diets supplemented with a blend of soybean oil and beef tallow, either in the ratio 3:1 w/w (high‐PUFA) or 1:3 w/w (low‐ PUFA). Part of the high‐ and low‐PUFA blends was chemically interesterified to randomly distribute all fatty acids over the three positions of the glycerol. Thus, two sets of diets of identical overall fatty acid composition, but differing in the distribution of fatty acids in the triacylglycerols, were fed. Growth performance and carcass composition were neither affected by fatty acid composition nor by randomisation of dietary fats in either animal species. Apparent digestibility of energy was slightly lower in pigs fed the low‐PUFA blends. Fatty acid profile of subcutaneous fat of pigs and broilers as well as of internal body fat (lamina subserosa) and muscle phospholipids of pigs varied according to the dietary fatty acid composition but was not affected by randomisation of dietary fats. These findings are explained in terms of the hydrolysis of TAG during transport of lipids from enterocytes to adipose tissue cells and the continuous lipolysis and re‐esterification of fatty acids that take place in adipose tissue cells. 相似文献
4.
The in vivo fatty acid synthesis rate, selected enzyme activities and fatty acid composition of rat white adipose tissue from
animals fed semisynthetic diets of differing fat type and content were studied. All animals were starved for 48 hr and then
refed a fat-free (FF) diet for 48 hr. They were then divided into three groups. One group was continued on the FF diet for
48 hr. Another group was fed a diet containing 44% of calories from corn oil (CO). The final group was fed a diet containing
44% of calories from completely hydrogenated soybean oil (HSO). The animals on the FF diet had a marked increase in adipose
tissue fatty acid synthesis during the 96-hr feeding peroid (as measured by3H incorporation into adipose fatty acids). Addition of either CO or HSO to the diets did not significantly inhibit fatty acid
synthesis in dorsal or epididymal adipose tissue. The activities of the enzymes' fatty acid synthetase, ATP-citrate lyase
and glucose-6-phosphate dehydrogenase increased on the FF diet and generally were not inhibited significantly by the addition
of either fat to the diets. Linoleic acid was the major polyunsaturated fatty acid (ca. 22%) in adipose tissue. Monounsaturated
fatty acids (palmitoleic, oleic,cis-vaccenic) made up ca 38% of the total adipose fatty acids, while saturated fatty acids accounted for about 32% (myristic,
palmitic and stearic). White adipose tissue in mature male rats was a major depot for n−3 fatty acids. There were differences
in the fatty acid composition of epididymal and dorsal adipose tissue, particularly in their content of long chain, polyunsaturated
fatty acids with epididymal tissue containing more of these compounds than dorsal fat. The fatty acid composition of the white
adipose tissue did not change significantly during fasting or 96 hr of refeeding the FF diets. The addition of HSO to the
diet for 48 hr had little influence on the adipose tissue fatty acid composition, but the addition of CO to the diet caused
a 7% increase in the dorsal adipose tissue linoleate content (as percentage of total dorsal adipose tissue fatty acids) within
48 hr compared to animals fed the stock diet and those starved for 48 hr. The fatty acid synthesis data indicated that adipose
tissue in the rat can continue to be a source of de novo fatty acid synthesis in animals consuming high-fat diets. 相似文献
5.
The emperor penguin (Aptenodytes forsteri) is an Antarctic seabird feeding mainly on fish and therefore has a high dietary intake of n-3 polyunsaturated fatty acids.
The yolk is accumulated in the developing oocyte while the females are fasting, and a large proportion of the fatty acid components
of the yolk lipids are derived by mobilization from the female's adipose tissue. The fatty acid composition of the total lipid
of the yolk was characterized by high levels of n-3 polyunsaturated fatty acids. However, it differed in several respects
from that of the maternal adipose tissue. For example, the proportions of 14∶0, 16∶1n−7, 20∶1n−9, 22∶1n−9, 20∶5n−3, and 22∶6n−3
were significantly greater in adipose tissue than in yolk. Thus adipose tissue lipids contained 7.6±0.3% and 8.0±0.3% (wt%
of total fatty acids; mean ±SE; n=5) of 20∶5n−3 and 22∶6n−3, respectively, whereas the yolk total lipid contained 1.6±0.1 and 5.5±0.3% of these respective
fatty acids. The proportions of 16∶0, 18∶0, 18∶1n−9, 18∶2n−6, and 20∶4n−6 were significantly lower in the adipose tissue than
in the yolk lipids. The proportions of triacylglycerol, phospholipid, free cholesterol, and cholesteryl ester in the yolk
lipid were, respectively, 67.0±0.2, 25.4±0.3, 5.3±0.2, and 1.8±0.2% (wt% of total yolk lipid). The proportions of 20∶4n−6,
20∶5n−3, 22∶5n−3, and 22∶6n−3 were, respectively, 5.7±0.3, 2.8±0.2, 1.4±0.1, and 11.7±0.5% in phospholipid and 0.4±0.0, 1.2±0.1,
0.8±0.1 and 3.6±0.3% in triacylglycerol. About 95% of the total vitamin E in the yolks was in the form of α-tocopherol with
γ-tocopherol forming the remainder. Two species of carotenoids, one identified as lutein, were present. 相似文献
6.
Anne Sofie Biong Paula Berstad Jan I. Pedersen 《European Journal of Lipid Science and Technology》2006,108(10):827-834
The aim of this study was to correlate the fatty acids characteristic of dairy fat (14:0, 14:1, 15:0, 17:0 and 17:1) in adipose tissue, serum lipid fractions and the estimated intake of dairy fat, and to investigate whether they can be used as biomarkers for dairy fat/product intake. The highest correlations were observed between 14:0 in adipose tissue and the estimated intakes of 14:0 (r = 0.60) and dairy fat (r = 0.50), and between 15:0 in adipose tissue and the estimated intakes of 15:0 (r = 0.55) and dairy fat (r = 0.55). Among the fatty acids in serum lipid fractions, 15:0 in cholesteryl esters (CE) and triacylglycerols showed the highest correlation to both 15:0 in adipose tissue, intakes of 15:0, dairy fat and dairy products. The results from our study suggest that the contents of fatty acids characteristic of dairy fat (14:0, 14:1, 15:0, 17:0, 17:1) in adipose tissue might be used as markers not only for the intake of dairy fat, but also of dairy products (times/day). When adipose tissue specimens are not available, 15:0 in serum CE appears to be the best marker for dairy fat intake. It was also observed that fatty acids from dairy fat are incorporated differently into serum lipid fractions and adipose tissue. 相似文献
7.
Conjugated linoleic acid supplementation in humans: effects on fatty acid and glycerol kinetics 总被引:2,自引:0,他引:2
Recent studies with mouse adipocytes have shown that dietary conjugated linoleic acid (CLA) may reduce body fat by increasing
lipolysis. The present study examined the effect of CLA supplementation on fatty acid and glycerol kinetics in six healthy,
adult women who were participating in a controlled metabolic ward study. These women were fed six CLA capsules per day (3.9
g/d) for 64 d following a baseline period of 30 d. The subjects were confined to a metabolic suite for the entire 94-d study,
where diet and activity were controlled and held constant. The rate of appearance (Ra) of glycerol, which indicates lipolytic
rates, was similar at baseline and after 4 wk of CLA supplementation at rest (1.87±0.21 and 2.00±0.39 μmol/kg/min, respectively)
and during exercise (7.12±0.74 and 6.40±0.99 μmol/kg/min, respectively). Likewise, the Ra of free fatty acids (FFA) was not
significantly different after 4 wk of dietary CLA at rest (2.72±0.06 and 2.74±0.12 μmol/kg/min, respectively) or during exercise
(6.99±0.40 and 5.88±0.29 μmol/kg/min, respectively). CLA supplementation also had no effect on the percentage of FFA released
from lipolysis that were re-esterified. The apparent rate of FFA re-esterification was 65.2±4.2% at rest and 32.1±3.44% during
exercise. Four weeks of CLA supplementation had no significant effect on fatty acid or glycerol metabolism in healthy, weight-stable,
adult women. 相似文献
8.
The endogenous triglycerides of swine, rat and chicken livers were fractionated by silver ion thin layer chromatography and
the resulting fractions were analyzed for their fatty acid composition and distribution. Whereas the endogenous triglycerides
of swine adipose tissue differ markedly from those of rat and chicken adipose tissue in the location of the major fatty acids,
the liver triglycerides of the three species are quite similar. They also resemble rat and chicken adipose triglycerides. 相似文献
9.
Palmitoleic acid has been classified as an insulin-sensitizing lipokine, but evidence for this from human studies has been inconsistent. We hypothesized that this is related to either the types of samples or conditions under which samples are collected. We measured plasma palmitoleic acid and total free fatty acids (FFA) using ultra-performance liquid chromatography in blood samples collected from 34 adults under a variety of conditions. We collected duplicate samples of adipose (n = 10), FFA (n = 9), and very low density lipoprotein triacylglycerol (VLDL-TAG) (n = 7) to measure the palmitoleic acid as a percentage of total fatty acids. We tested whether the percentage of palmitoleic acid was correlated with insulin resistance, as measured by homeostatic model of insulin resistance (HOMA-IR). Adipose stearoyl-coenzyme A desaturase 1 (SCD-1) protein was measured by capillary Western blotting. FFA-palmitoleic acid percentage increased as a function of total FFA and was greater (p < 0.005) in females than males. Adipose palmitoleic acid percentage was greater in females than males (p < 0.001), as was adipose SCD-1. Palmitoleic acid was greater in femoral fat than in abdominal fat in both females and males (p < 0.001), and correlated positively with HOMA-IR only in females. The test–retest reliability values for percentage palmitoleic acid were 7 ± 10% for adipose, 24 ± 26% for VLDL, and 53 ± 31% for FFA. Because FFA-palmitoleic acid percentage varies as a function of total FFA, investigators should re-evaluate how palmitoleic acid data is presented. The positive relationship between adipose palmitoleic acid and HOMA-IR in females suggests that it is not a potent insulin-sensitizing lipokine in humans. 相似文献
10.
Seong Ho Choi David T. Silvey Bradley J. Johnson Matthew E. Doumit Ki Yong Chung Jason E. Sawyer Gwang Woong Go Stephen B. Smith 《Lipids》2014,49(1):15-24
We hypothesized that exogenous fatty acids, and especially or 18:2 trans-10, cis-12 conjugated linoleic acid (CLA), would decrease adipogenic and lipogenic gene expression and de novo fatty acid biosynthesis in intramuscular (i.m.) and subcutaneous (s.c.) adipose tissues. Fresh i.m. and s.c. adipose tissues were collected from the longissimus thoracis muscle of Angus steers at 12, 14, and 16 months of age (n = 4 per time point). Adipose tissue explants were incubated in duplicate for 48 h with 40 μM α-linolenic (ALA), oleic, stearic, trans-vaccenic, or CLA. Adipocyte size, acetate and glucose incorporation into fatty acids in vitro and mRNA levels for C/EBPβ, CPT1β, GPR43, PPARγ, PRKAA1 (AMPKα) and SCD1 were measured following the incubations. PRKAA1 and SCD1gene expression were greater (P < 0.001) in s.c. adipose tissue than in i.m. adipose tissue and acetate incorporation into lipids and C/EBPβ, PPARγ, and SCD1gene expression were greater at 16 months of age than at 12 months of age in i.m. adipose (P < 0.01). C/EBPβ gene expression increased by 16 months of age and PRKAA1 gene expression decreased by 16 months of age in s.c. adipose tissue. All fatty acids increased s.c. adipocyte volumes whereas CLA decreased acetate incorporation into lipids in s.c. adipose tissue (P < 0.05), but none of the fatty acids affected gene expression in i.m. or s.c. adipose tissue (P > 0.10). Thus, CLA depressed de novo fatty acid biosynthesis from acetate but neither CLA nor other fatty acids significantly affected adipogenic or lipogenic gene expression. 相似文献
11.
We show in this paper that 13-methyltetradecanoic acid (13-MTD) can be used as a structurally labeled marker for investigating
the mobility of fatty acyl chains in adipose tissue in the rat. The presence of an ω-1 methyl group allows easy quantitation
by gas liquid chromatography (GLC) and permits an assessment to be made of any oxidation and chain elongation reactions with
reincorporation of the label into the adipose tissue, since the iso-acyl chain is well resolved from odd or even-numbered
homologous fatty acids with straight chains. The kinetics of uptake and loss of the structural label were different for adipose
tissue taken from the various sites which were sampled, namely post abdominal, mesenteric, perirenal, pericardiac and subcutaneous
adipose tissue as well as the epidydimal fat pads. We also report preliminary results in man which confirm that the method
is applicable to human clinical studies and that 13-MTD kinetics differ for adipose tissue taken from the 3 different subcutaneous
sites-waist, arm and thigh. 相似文献
12.
Effects of pregnancy and lactation on lipid metabolism in mouse mammary fat pads and nonmammary adipose tissues have been
studied. In order to address the question whether the influence of hormonal milieu on lipid metabolism in mammary epithelial
cells during pregnancy and lactation is the same as in fat cells, we have studied the mobilization of lipids and metabolism
of fatty acids in the intact mammary glands, parenchyma-free mammary fat pads and in the perimetrial fat tissues of virgin,
pregnant and lactating mice. Compared to parenchyma-free mammary fat pads, the perimetrial adipose tissues accumulated 5-fold
higher levels of triglycerides during pregnancy. Mammary fat cells maintained overall lipid levels during pregnancy and lactation
(16–20 μg/fat pad). In contrast, lactation depleted total lipid stores from 108 ± 5 to 24 ± 4.5 μg/fat pad in perimetrial
fat pads. Results of comparative analysis of fatty acid composition of mammary fat pads, with and without epithelial tissue,
from virgin and lactating mice showed stimulation of 18∶2ω6 metabolism leading to 130% increase in the ratio 20∶4ω6 to 18∶2ω6
in the epithelial compartment. Pregnancy and lactation resulted in the elevation of 20∶4ω6 levels probably due to a 4-fold
increase in Δ5 desaturase activity and a decrease in oxidative degradation of 18∶2ω6. These results suggest that, unlike other
adipose tissues, the metabolic pathways in mammary fat cells are not dedicated to sequestration and accumulation of dietary
lipids during pregnancy. Lactation favors mammary epithelial cell-stimulated production of precursors of eicosanoids which
are known to have agonist-like effect on mammary epithelial cells. 相似文献
13.
The fatty acid composition of triacylglycerols from fifteen distinct adipose depots taken from each of seven adult male human
subjects was compared. Oleic, palmitic, linoleic, stearic, myristic, palmitoleic and vaccenic acids accounted for more than
90% of the triacylglycerol fatty acids in all sites from all subjects; a number of other fatty acids were also identified
and quantified. There were large differences in theaverage fatty acid composition between individual subjects. There were
no site-specific differences in the proportions of myristic (3.8–4.7% of triacylglycerol fatty acids), palmitic (23–29%),
linoleic (6.7–9.8%) or vaccenic (4.1–4.7%) acids or in the proportions of any of the less abundant fatty acids. There were
some significant site-specific differences in the proportions of palmitoleic, oleic and stearic acids. The calf depot contained
more palmitoleic acid (6.41±1.09%) than the trapezius (3.12±0.55%), perirenal (3.59±0.50%) and mesenteric (3.70±0.43%) depots,
more oleic acid (42.13±1.27%) than the trapezius (36.03±2.18%), perirenal (36.50±1.56%) and breast (37.13±1.55%) depots and
less stearic acid (5.18±0.89%) than the trapezius (8.57±0.97%), perirenal (8.49±0.75%), mesenteric (7.87±0.42%), breast (8.02±0.75%)
and clavicular (8.34±0.78%) depots. The buttock depot contained less stearic acid (6.06±0.65%) than the perirenal, mesenteric
and clavicular depots, while the anterior thigh depot contained less stearic acid (6.07±0.70%) than the perirenal depot. These
findings indicate that, while most human adipose depots differ little in fatty acid composition, some sites, in particular
the calf, perirenal, trapezius and mesenteric depots, have site-specific properties. 相似文献
14.
The effect of a diet containingtrans-fatty acids (tFA) on the fatty acid composition and fat accumulation in adipose tissue was investigated in mice. Male C57BI/6J mice were
fed Control or Trans Diets that were similar, except that 50% of the 18∶1, which was allcis in the Control Diet, was replaced bytFA in the Trans Diet. At selected ages, body weight, epididymal fat pad weight, perirenal fat yield, adipose tissue cellularity
and fatty acid composition were examined. Over the time period studied (2–24 mon), the proportion of 18∶0 and 16∶0 tended
to decrease whilecis-18∶1 levels increased. Compared to the Control Diet, the Trans Diet resulted in adipose tissue lipids with higher percentages
of 14∶0 and 18∶2n−6 and lower percentages ofcis-18∶1 and 20∶4n−6. In polar lipids,tFA replaced saturated fatty acids, whereastFA replacedcis-18∶1 in the nonpolar lipids. Body weights at 16 and 24 mon of age and epididymal fat pad weights at 8–24 mon of age were
lower in mice fed the Trans Diet as compared to those fed the Control Diet. At the ages studied, the Trans Diet also resulted
in lower values for perirenal fat weights, triacylglycerol to polar lipid ratios, and adipose cell size. The data suggest
that chronic consumption oftFA affects lipid metabolism and results in decreased fat accumulation in murine adipose tissue. 相似文献
15.
The present study was designed to investigate the metabolism of the n−3 olyunsaturated fatty acids (PUFA) in adipose tissue
and its dependence upon dietary factors. Changes in the positional distribution of the fatty acids in triacylglycerols from
retroperitoneal adipose tissue were studied as a function of time on rats fed for 4 wk a diet enriched with fish oil. The
stereospecific analysis of triacylglycerols was based on random formation ofrac-1,2-diacylglycerols by Grignard degradation. This was followed by synthesis ofrac-phosphatidic acids and treatment with phospholipase A2. In the triacylglycerols of the fish oil diet, 57% of the total n−3 fatty acids were in position 3,i.e., two-thirds of 22∶5n−3 and 22∶5n−3 were esterified insn-3 position, whereas 22∶6n−3 was equally distributed in positions 2 and 3. After 4 wk of feeding fish oil, the fatty acid
composition of adipose tissue triacylglycerols reached a steady state. Half of the n−3 fatty acids were found in position
3, namely 75% of 22∶5n−3, 50% of 20∶5n−3 and 18∶4n−3 and 45% of 22∶6n−3, the latter being equally distributed in positions
2 and 3. This pattern of distribution resembled that found in triacylglycerols of the fish oil diet, except for a higher proportion
of 20∶5n−3 in adipose tissue in position 1 at the expense of position 3. Throughout the 4-wk period of fish oil feeding, the
distribution pattern of minor n−3 fatty acids (18∶4n−3 and 22∶5n−3) in adipose tissue triacylglycerols remained unchanged.
On the other hand, at the onset of fish oil feeding, 20∶5n−3 and 22∶6n−3 became concentrated in position 3, but thereafter
20∶5n−3 was progressively incorporated into position 1 and 22∶6n−3 into position 2. We thus conclude that n−3 fatty acids
are differentially esterified in triacylglycerols of white adipose tissue. Despite the complex sequence of hydrolysis and
acylation steps involved, the positional distribution of n−3 fatty acids was found to be similar in both the fish oil diet
and the stored fat, in contrast to what was observed for nonessential fatty acids. 相似文献
16.
Royan M Meng GY Othman F Sazili AQ Navidshad B 《International journal of molecular sciences》2011,12(12):8581-8595
An experiment was conducted on broiler chickens to study the effects of different dietary fats (Conjugated linoleic acid (CLA), fish oil, soybean oil, or their mixtures, as well as palm oil, as a more saturated fat), with a as fed dose of 7% for single fat and 3.5 + 3.5% for the mixtures, on Peroxisome Proliferator-Activated Receptors (PPARs) gene expression and its relation with body fat deposits. The CLA used in this experiment was CLA LUTA60 which contained 60% CLA, so 7% and 3.5% dietary inclusions of CLA LUTA60 were equal to 4.2% and 2.1% CLA, respectively. Higher abdominal fat pad was found in broiler chickens fed with a diet containing palm oil compared to chickens in the other experimental groups (P ≤ 0.05). The diets containing CLA resulted in an increased fat deposition in the liver of broiler chickens (P ≤ 0.05). The only exception was related to the birds fed with diets containing palm oil or fish oil + soybean oil, where contents of liver fat were compared to the CLA + fish oil treatment. PPARγ gene in adipose tissue of chickens fed with palm oil diet was up-regulated compared to other treatments (P ≤ 0.001), whereas no significant differences were found in adipose PPARγ gene expression between chickens fed with diets containing CLA, fish oil, soybean oil or the mixture of these fats. On the other hand, the PPARα gene expression in liver tissue was up-regulated in response to the dietary fish oil inclusion and the differences were also significant for both fish oil and CLA + fish oil diets compared to the diets with palm oil, soybean oil or CLA as the only oil source (P ≤ 0.001). In conclusion, the results of present study showed that there was a relationship between the adipose PPARγ gene up-regulation and abdominal fat pad deposition for birds fed with palm oil diet, while no deference was detected in n-3 and n-6 fatty acids, as well as CLA on PPARγ down regulation in comparison to a more saturated fat. When used on its own, fish oil was found to be a more effective fat in up-regulating hepatic PPARα gene expression and this effect was related to a less fat deposition in liver tissue. A negative correlation coefficient (-0.3) between PPARα relative gene expression and liver tissue fat content confirm the anti-lipogenic effect of PPARα, however, the change in these parameters was not completely parallel. 相似文献
17.
Although migrating birds use stored triacylglycerol as their primary fuel for flight, they must retain sufficient stores of
ω6 and ω3 fatty acids to sustain reproduction after the spring migration. Hepatic monoacylglycerol:acyl-coenzyme A acyltransferase
(EC 2.3.1.22) (MGAT) activity is associated with physiological periods in which lipolysis and β-oxidation are prominent, and
it may also play a role in the selective retention of certain essential fatty acids. Therefore, we characterized MGAT activity
in adipose tissue from the whitethroated sparrow (Zonotrichia albicollis), a migratory bird. MGAT specific activity from adipose tissue and liver, respectively, was 22.2±7.27 and 0.79±0.35 nmol/min/mg
of total particulate protein. Activity did not vary seasonally or between male and female birds. Specific activity increased
4.3-fold in the presence of 75 μg of phosphatidylcholine and phosphatidylserine (1∶1, w/w). MGAT acylatedsn-1(3)-monooleoyglycerol,sn-2-monoolyelglycerol ether andsn-1(3)-monooleylglycerol ether at 7.5, 5.7 and 1.7%, respectively, of the rate observed withsn-2-monooleoylglycerol. An initial lag phase observed at low concentrations of palmitoyl-CoA was corrected by adding 2 mM MgCl2 Mg(NO2)2 or CaCl2, suggesting a requirement for divalent cations. MGAT acylatedsn-2-monolinolenoylglycerol andsn-2-monolinoleoylglycerol in preference tosn-2-monooleoylglycerol. Specificity of MGAT forsn-2-monoacylglycerols and the probable enhanced affinity forsn-2-monoacylglycerols of specific acyl chains may allow selected ω6 and ω3 fatty acids to be retained within the adipocyte,
white nonessential fatty acids are released for β-oxidation in flight muscles. 相似文献
18.
To investigate the mechanism by which free fatty acids (FFA) affect glucose uptake, we studied the effect of chronic elevation
(24 h) of plasma FFA in rats on whole body glucose disposal and glucose utilization index (GUI) in the basal state and under
a euglycemic hyperinsulinemic clamp in relation to the amount of insulin-responsive glucose transporter (IRGT, i.e., GLUTU),
protein in different muscles (oxidative and glycolytic) and adipose tissue. Infusion of Intralipid in the basal state led
to a∼40% increase in whole body glucose uptake and a∼250% increase in GUI in adipose tissue as compared to control rats. There
was no change in the amount of IRGT protein in any of the muscle types whereas in fat depots it was either unchanged or decreased.
Under moderate or supraphysiological hyperinsulinemia, increment of whole body glucose disposal was significantly lower in
Intralipid perfused rats when compared to controls (∼110 μU/mL: 0.7±0.1 vs. 1.3±0.1 mg/min,P<0.02; ∼1000 μU/mL: 3.0±0.2 vs. 3.9±0.4 mg/min,P<0.02). Under moderate hyperinsulinemia stimulation, GUI was significantly reduced in different muscles and adipose tissue
as compared to controls. We conclude that peripheral insulin resistance which occurs after elevation of plasma FFA levels
does not seem to be explained by changes in the amount of IRGT protein in either oxidative or glycolytic skeletal muscle.
Thus fatty acid infusion appears to be associated with a defect in IRGT translocation to the plasma membrane, fusion with
the membrane, or intrinsic activity. 相似文献
19.
Trans fatty acids in adipose tissue of French women in relation to their dietary sources 总被引:4,自引:4,他引:0
Boué C Combe N Billeaud C Mignerot C Entressangles B Thery G Geoffrion H Brun JL Dallay D Leng JJ 《Lipids》2000,35(5):561-566
This study reports the fatty acid composition of subcutaneous adipose tissue in French women with special emphasis on the
content of trans fatty acids originating from two main dietary sources, ruminant fats and partially hydrogenated vegetable oils (PHVO). Adipose
tissue trans fatty acid levels from 71 women, recruited between 1997 and 1998, were determined using a combination of capillary gas chromatography
and silver nitrate thin-layer chromatography. Results indicate that on average cis monounsaturates accounted for 47.9% of total fatty acids, saturates for 32.2%, and linoleic acid for 14.4%. Cis n−3 polyunsaturates represented only 0.7%. Total content of trans fatty acids was 2.32±0.50%, consisting of trans 18∶1 (1.97±0.49%), trans 18∶2 (0.28±0.08%), and trans 16∶1 (0.06±0.03%). Trans 18∶3 isomers were not detectable. The level of trans fatty acids found in adipose tissue of French women was lower than those reported for Canada, the United States, and Northern
European countries but higher than that determined in Spain. Therefore, trans fatty acid consumption in France appears to be intermediate between that of the United States or North Europe and that of
Spain. Based on the equation of Enig et al., we estimated the mean daily trans 18∶1 acid intake of French women at 1.9 g per person. The major trans 18∶1 isomer in adipose tissue was Δ11trans, as in ruminant fats. Estimates of relative contribution of trans fatty acid intake were 55% from ruminant fats and 45% from PHVO. This pattern contrasts sharply with those established for
Canada and the United States where PHVO is reported to be the major dietary source of trans fatty acids. 相似文献
20.
Magdi M. Mossoba Cynthia Tyburczy Srigley Samantha Farris John K G Kramer Stuart Chirtel Jeanne Rader 《Journal of the American Oil Chemists' Society》2014,91(10):1651-1663
The performance of a novel, transmission‐mode, portable, Fourier transform infrared (FTIR) analyzer was evaluated and compared to that of a benchtop attenuated total reflection (ATR)‐FTIR spectrometer. The total concentration of trans fatty acids in the fat extracted from 19 representative fast foods was rapidly (<5 min) quantified in a single measurement after conversion to fatty acid methyl esters (FAME). While the FTIR determination is rapid, the time required for extraction and derivatization is not. For all extracts, the total trans FAME concentration varied from approximately 0.5 to 11 % (of total FAME) as determined using the portable FTIR analyzer. The trans fat contents (mean ± SD), expressed in grams per serving and calculated on the basis of total fat content and FTIR determination of trans fat content, were found to be 1.00 ± 0.42 for hamburgers, 0.67 ± 0.78 for chicken tenders, 1.00 ± 1.24 for French fries, and 0.27 ± 0.23 for apple pies. Determinations of total trans‐unsaturated FAME were consistent with those obtained by use of ATR‐FTIR and GC official methods (AOCS Cd 14e‐09 and AOCS Ce 1j‐07, respectively). These results indicate that the portable FTIR analyzer is suitable for the rapid and routine quantification of total trans fat measured as FAME prepared from fats extracted from fast foods. 相似文献