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1.
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
2.
Analyses of renal medullary lipid droplets from normal,hydronephrotic, and indomethacin treated rabbits 总被引:1,自引:0,他引:1
Lipid droplets isolated from rabbit renal medullary tissue were analyzed and found to be composed of triglyceride and free fatty acids in a ratio of 2.9:1. These triglycerides were unique when compared to triglycerides of other rabbit tissues examined, in that they contained high percentages of octadecanoic acid (stearic acid, 9.8%), 5,8,11,14-eicosatetraenoic acid (arachidonic acid, 6.8%), and 7,10,13,16-docosatetraenoic acid (adrenic acid, 10%). Lipid droplet triglycerides were found to increase during experimental hydronephrosis and after administration of indomethacin, a prostaglandin synthetase and phosphodiesterase inhibitor. From gas liquid chromatography of fatty acid methyl esters of these triglycerides, it was determined that they were enriched further in their percent composition of 9,12-octadecadienoic acid (linoleic acid) and arachidonic acid, a prostaglandin precursor. The inverse relationship between lipid droplets and prostaglandin content in the inner medulla suggested a significant role of lipid droplet triglycerides as storage pools for prostaglandin precursors. 相似文献
3.
4.
Inge N. Bojesen 《Lipids》1980,15(7):519-523
The osmolality has been determined for the papillary interstitial fluids obtained from the isolated papillae of rats in different
states of water balance. Hypertonic buffers for in vitro experiments were prepared by addition of urea to regular Krebs-Ringer
phosphate buffers (340 mosmol/kg H2O) since urea is the most changeable solute of the renal papillary tissue in response to external influences. The effect of
such hypertonic buffers on papillary lipogenesis was very pronounced. The fatty acid synthesis from acetate decreased by a
factor of 7–9 in response to increased osmolality from 340 to 1370 mosmol/kg H2O. In the physiological range of osmolalities (500–1800 mosmol/kg H2O), the de novo synthesis of papillary glycerolipids from glucose decreased by a factor of ca. 5. A possible specific inhibitory
effect of hypertonic buffers on the pentose phosphate cycle was studied with a negative result. It is concluded that the addition
of urea causes a decrease of total energy metabolism in the tissue. 相似文献
5.
Data are presented on the composition of jojoba seed harvested from randomly selected individual plants (175 in 1973, 139
in 1974) of the native population at Aguanga, CA. Except for seed yield per plant, which was 2.7 times higher in 1974, wax,
protein, and hull content of the seed, as well as fatty acid and alcohol composition of the wax, were not very different in
the 2 years. A significant (P<0.01) positive correlation was found between seed wt and wax content of the seed. Highly significant
(P<0.01) correlations were found in pairs of fatty acids and alcohols except where fatty acid 20∶1 was included. Comparison
of data from 22 plants of known identity for the 2 years also showed no significant change in wax content and composition
of the seed. By contrast, correlations for seed wt, protein, hull percent, and yield per plant for the same period were all
nonsignificant. 相似文献
6.
G. I. O. Badifu 《Journal of the American Oil Chemists' Society》1991,68(6):428-432
The seed oils ofCucumeropsis mannii, two varieties ofLagenaria sicceraria andTelfairia occidentalis were evaluated. The oil contents by mechanical expression were 33.2%, 33.4%, 34.2% and 32.8% from the roasted kernels ofC. mannii, L. sicceraria var. 1,L. sicceraria var. 2 andT. occidentalis, respectively. Lower oil contents (26.4-28.6%) were obtained from unroasted kernels of the species. The difference in oil
yield between the unroasted and roasted kernels was significant (p ≤ 0.05). Roasting of the kernels did not affect the quality factors of the oils, except for the color. The color of oil from
roasted kernels was golden, whereas that from unroasted kernels was pale yellow. The predominant fatty acids were palmitic,
stearic, oleic and linoleic. The oils from the varieties ofL. sicceraria were more unsaturated (80.2-80.3%) than the oils fromC. mannii (71.4%) andT. occidentalis (69.3%). The smoke (149.5-180.1°C) and flash (204.8-291.5°C) points varied considerably among the oils.Cucumeropsis mannii andT. occidentalis kernel oils failed a cold test, while the oils fromL. sicceraria passed. 相似文献
7.
8.
A comparative study of the lipid composition of isolated rat sertoli and germinal cells 总被引:1,自引:0,他引:1
The lipid composition of enriched preparations of sertoli cells and of germinal cells, isolated from the testes of mature
rats, has been investigated. Sertoli cells contained a much lower content of phospholipids (in particular, much less phosphatidylcholine
and phosphatidylethanolamine) and a higher content of triacylglycerols than did germinal cells. In addition, the Sertoli cells
had a higher ratio of esterified to unesterified cholesterol than did germinal cells. Total lipids of Sertoli cells contained
considerably lower levels of palmitic and docosa-4,7,10,13,16-pentaenoic acids and higher levels of stearic and oleic acids
than did the total lipids of germinal less palmitic and docosa-4,7,10,13,16-pentaenoic acids, more stearic and oleic acids
and also more arachidonic acid than did the corresponding lipid classes of the germinal cells. Minor differences between cell
types were also noted for the content of palmitoleic, linoleic, docosa-7,10,13,16-tetraenoic, docosa-4,7,10,13,16,19-hexaenoic
and tetracosa-9,12,15,18-tetraenoic acids. 相似文献
9.
The effect of various steroids on the incorporation and desaturation of eicosa-8,11,14-trienoic acid in normal hepatocytes
and HTC cells was investigated. After 3 hr incubation with 11-deoxycorticosterone, both kinds of cells showed an increase
in the incorporation of eicosatrienoic acid. In contrast, progesterone, cortexolone, 17-β-estradiol, testosterone, estriol,
aldosterone, corticosterone, dexamethasone, dehydroepiandrosterone, 11-β-hydroxyandrosterone, 11-ketoaetiocholanolone, epiaetiocholanolone
and 5-β-pregnane-3α,20α-diol, provoked no significant changes in the uptake of the exogenous acid. Of all the steroids tested,
only 11-dexycorticosterone, dexamethasone and 17-β-estradiol evoked a significant inhibition on the arachidonate biosynthesis
in both kinds of cells. Testosterone, estriol, aldosterone and corticosterone provoked a significant inhibition of Δ5-desaturase
in HTC cells. In dexamethasone, this effect was dose-dependent (0 to 10−4 M). Simultaneous incubation with 17-β- estradiol or 11-deoxycorticosterone with dexamethasone led to an extent of inhibition
on arachidonate biosynthesis that did not surpass the effect of each drug. Pretreatment of isolated hepatocytes with the antiglucocorticoid,
cortexolone, prevented the dexamethasone-induced inhibition of arachidonate biosynthesis. Normal rat liver microsomes preincubated
in vitro with dexamethasone, 11-deoxycorticosterone, 17-β-estradiol, corticosterone or estriol (10−6 or 10−4 M concentration), showed no significant changes in the Δ5-desaturase activity. The results obtained suggest that the effect
of the steroids on arachidonic acid biosynthesis in normal hepatocytes and HTC cells requires receptor occupancy and probably
is mediated through a common biochemical mechanism. 相似文献
10.
11.
Ion-exchange HPLC systems using POROS 20 HQ and Mono Q HR 10/10 columns were applied to isolate glycinin subunits under denaturing
conditions. Analyses by SDS-PAGE, N-terminal amino acid sequence, and sucrose density gradient centrifugation showed that
the pseudoglycinin from the highly purified homo-subunit, A3B4, was reconstituted. The A3B4 pseudoglycinin was similar to the native glycinin with respect to molecular size, subunit structure, and secondary structure.
The hexameric pseudoglycinin dissociated into trimers after long storage at pH 7.6. 相似文献
12.
Yanis Caro Pierre Villeneuve Michel Pina Max Reynes Jean Graille 《Journal of the American Oil Chemists' Society》2000,77(8):891-902
The protein contents in crude latices from various varieties of papaya (Carica papaya) and their catalytic activities in proteolysis, lipolysis, and interesterification reactions were studied with regard to
the variety, the geographic location of cultures, and the frequency of fruit tapping. Biocatalytic activities of these raw
materials were compared to several commercially available crude and purified preparations of papain. These investigations
were carried out in order to have a better physicochemical characterization of these raw materials, to select the adequate
papaya latex for protein or lipid bioconversions, and to valorize them on an industrial scale. For the purified preparations
of papain, only proteolytic activity was obtained. All crude papaya latices exhibit proteolytic, lipolytic, and interesterification
activities, and no relationship between the proteolytic and lipolytic activities was observed. The high multiple correlation
coefficient (R) on the order of R=0.93–0.99, obtained from the regression analysis for the lipolytic and interesterification activities for all crude papaya
latices investigated suggested that there was a correlation between these enzyme activities. However, for the same lipase
preparation, the interesterification activity differed substantially depending on the type of interesterification reaction. 相似文献
13.
A comparison is made of the sialic acid and hexose content of crude gangliosides from the brains of 13 species, including
mammals, a bird, and amphibian, a reptile and fish. The sialic acid content is relatively constant from species to species.
Gangliosides are less abundant in tissues other than the brain. Four species (cat, dog, pig and sheep) were selected for the
determination of their major ganglioside subfractions. The ganglioside subfractions were isolated (after extraction and partition
dialysis) using descending thin layer chromatography. The population of ganglioside molecules varied from species to species.
From dog and sheep a mono-, a di- and a trisialoganglioside were obtained; from cat a mono-, a di- and two trisialogangliosides;
and from pig a mono- and two disialogangliosides. Each ganglioside subfraction was found to contain glucose, galactose and
galactosamine in the ratio of approximately 1∶2∶1. The fatty acid moieties consisted of more than 80% stearic acid with lesser
amounts of arachidic, palmitic and behenic acid. Sphingosine analyses indicated ratios of sphingosine to icosisphingosine
of 7∶3 for the monosialo-, 1∶1 for the disialo- and 3∶7 for the trisialogangliosides. 相似文献
14.
Reduction of tartrazine by a Proteus species isolated from rats 总被引:2,自引:0,他引:2
15.
Henk F. J. Hendriks Pieter J. A. M. Brekelmans Rien Buytenhek Adriaan Brouwer A. Margreet de Leeuw Dick L. Knook 《Lipids》1987,22(4):266-273
The neutral lipid and phospholipid compositions of purified sinusoidal (fat-storing, endothelial and Kupffer) cells, parenchymal
cells and liver homogenates were determined by thin layer chromatography. In addition, the retinoid content of the same purified
cell populations was determined by high performance liquid chromatography. From each cell type, both a lipid droplet fraction
and a pellet fraction (containing the majority of the remaining cell organelles) were prepared by differential centrifugation.
Electron microscopic analysis showed that lipid droplets isolated from fat-storing cells were larger (up to 8 μm) than those
isolated from parenchymal cells (up to 2.5 μm). Moreover, the parenchymal lipid droplets seemed to be surrounded by a membranous
structure, while the fat-storing lipid droplets seemed not to be. Both fat-storing and parenchymal cells contained high concentrations
of neutral lipids, 57.9 μg and 71.0 μg/106 cells, respectively, while endothelial and Kupffer cells contained only 8.6 μg and 13.8 μg/106 cells of neutral lipids, respectively. Sixty-five percent of fat-storing cell lipid droplet fractions comprised esters of
retinol and cholesterol. This combined ester fraction contained mainly retinyl esters. In addition, considerable quantities
(20%) of triglycerides were present. Parenchymal cell lipid droplet fractions comprised triglycerides (62%) and cholesteryl
esters (up to 30%). The pellet fractions prepared from all four cell types consisted mainly of cholesterol (41–67%) and free
fatt acids (20–28%). The phospholipid content was much higher in parenchymal cells than in the sinusoidal liver cell types.
The relative proportions of the four major phospholipid classes were comparable in all liver cell types analyzed. It is concluded
that parenchymal cell lipid droplets comprised mainly triglycerides and cholesteryl esters, which is in agreement with the
function of parenchymal cells in lipid metabolism. Fat-storing cell lipid droplets consisted of retinyl esters and triglycerides,
which correlates well with their function in retionid storage and metabolism. 相似文献
16.
排油圈法对生物表面活性剂的定性与定量 总被引:16,自引:0,他引:16
测定生物表面活性剂产生的方法有:滴液法、排油圈法和血平板裂解法。排油圈法是较为常用的一种方法。表面活性剂浓度与排油圈直径和培养液表面张力之间都呈线性关系,通过它们之间的线性图,根据其中的一个参数就能计算出另外两个参数。用上述方法对从大港油田分离出来的一株菌DG-1进行实验,证明了排油圈法能快速准确地对生物表面活性剂的产生,进行定性和定量。 相似文献
17.
Quantitative and qualitative IR analysis of some synthesized aromatic homo polysulfides and copolysulfides based on 4,4-oxydibenzenethiol (IV), 4,4 -dimercaptodiphenyl sulfide (I) and bis-(4-fluorophenyl) Sulfone (II) in 1-methyl-2-pyrrolidone (NMP) has been done. A satisfactory agreement of experimental results with theory was observed. 相似文献
18.
The fatty acid composition and distribution in egg yolk triglycerides and phosphatides from the turkey, duck, prairie chicken,
bobwhite quail, Japanese quail, and inbred-hybrid and midget mutant hens were determined after all species had been fed diets
of similar fat and fatty acid content for 90 days. Total volk lipids were composed of ca. two-thirds neutral lipids and one-third
polar lipids. The predominant fatty acids were palmitic and stearic. There were statistically significant differences in the
my ristic, palmitic, palmitoleic, linoleic, and linolenic acids in the yolk triglycerides and in the proportion of 16∶1, 18∶0,
18∶2, arachidonic, docosanoic, docosahexaenoic, and tetracosanoic acids in the phosphatides among the various species. Linoleic
acid predominantly was linked at the 2-position in the yolk triglycerides followed by the 20∶4 acid. The 18∶1 acid also was
found preferentially at the 2-position. There was a low level of 18∶2 in the yolk triglycerides and phosphatides from the
duck and an especially high level of 20∶4 acid in the phosphatides. The triglycerides in the species studied have essentially
the same distribution of fatty acids in the 2-position. In all the species, the affinity for the fatty acids at the 2-position
is in the following order: 18∶2=20∶4>18∶1 =18∶3>18∶0=16∶1>14∶0>16∶0 Differences observed among the various genera did not
appear to follow taxonomic boundaries. The duck has an efficient system for converting 18∶2 into 20∶4 by elongation and desaturation.
The prairie chicken apparently has a high requirement for 18∶2 but an inadequate system for its conversion into 20∶4. 相似文献
19.
This article reviews the development and potential application of novel food‐grade materials based on heteroaggregation of oppositely charged particles. These particles typically consist of a hydrophobic lipid core and an electrically charged emulsifier shell. Heteroaggregation leads to the formation of emulsion‐based products that are highly viscous or gel‐like at much lower droplet concentrations than in nonaggregated systems. Heteroaggregation may therefore be useful for developing food products with novel textural characteristics or for creating reduced‐calorie versions of full fat foods. We give an overview of the principles of heteroaggregation, the relationship between emulsion microstructure and texture, and possible commercial applications of this method. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3833–3841, 2013 相似文献
20.
The lipid composition of a Bacillus sp., isolated from Lake Pomorie in Bulgaria, was unusual and consisted of 26 different fatty acids between C12 and C26, with anteiso C15-C17 saturated fatty acids predominating. The furan fatty acid, 10,13-epoxy-11-methyloctadeca-10,12-dienoic acid, was also identified, a new finding for this genus. The hydrocarbons consisted of 30 different monounsaturated hydrocarbons, between C25 and C30, with the iso-iso, iso-anteiso, anteiso-anteiso, iso-normal, and anteiso-normal methyl branching for odd-numbered chains, and the iso-iso, iso-anteiso, iso-normal, and anteiso-normal methyl branching for even-numbered chains. The double bond positions in these hydrocarbons were determined by dimethyl disulfide derivatization followed by GC-MS, and the double-bond cis configuration was confirmed by infrared spectroscopy. Some previously unknown hydrocarbons in bacteria, such as (Z)-3,21-dimethyl-9-tricosene, (Z)-3,21-dimethyl-10-tricosene, (Z)-2,24-dimethyl-11-pentacosene, and (Z)-2,25-dimethyl-13-hexacosene were identified. Sterols were detected and were based on the sitosterol nucleus. 相似文献