[GAS CHROMATOGRAPHY RESEARCH ON THE FATTY ACIDS OF HUMAN ADIPOSE TISSUE].
Explore the source record for details and available documents.
Abdomen↗
SEARCH · Search PubMed
Results for “STEARIC ACID”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
[STUDIES ON SUCROSE ESTERS. 3. EFFECT OF SUCROSE ESTERS ON THE ABSORPTION OF DRUGS FROM THE ALIMENTARY TRACT].
Explore the source record for details and available documents.
Esters↗
Catalytic properties, tissue and intracellular distribution of neurofibromin.
The neurofibromatosis type 1 (NF1) gene encodes a protein, neurofibromin, that shows homology with members of the GTPase-activating protein (GAP) family. To study neurofibromin, rabbit polyclonal antisera were raised against two synthetic peptides. These antisera immunoprecipitated a specific protein of about 240 kDa in lysates of adult murine and rat tissues both in the soluble (S100) and to a lesser degree in the particulate (P100) fractions. The neurofibromin immunoprecipitated from the lysates of several murine organs stimulated the intrinsic GTPase activity of p21 c-Ha-ras protein. Based on immunoblotting, immunoprecipitation and GTPase assays, neurofibromin appears to be at least 10-fold more abundant in the brain than in the other murine organs. The GTPase-stimulatory activity of full-length neurofibromin, like the catalytic GAP-related domain, is inhibited by arachidonic acid and the detergent dodecyl maltoside, while phosphatidic acid, containing arachidonic and stearic acid, is non-inhibitory. Immunofluorescence analysis with anti-neurofibromin sera in NIH3T3 cells suggests that at least some of the cellular protein associates with cytoplasmic structures that are distinct from actin or tubulin filaments.
Amino Acid Sequence↗
Glycolipids of the fish testis.
Glycolipids were purified from the total lipid extract of the testis or milt of a kind of puffer (Fugu rubripes rubripes) by adsorption column chromatography using silicic acid and magnesium silicate and by preparative silica gel TLC. The glycolipids were identified as glucosylceramide (116 mug/g wet tissue) and galactosylceramide 26.7 mug/g). Seminolipid, a sulfagalactolipid specific to mammalian testis was not detected, but the presence of a small amount of sulfatide (15.2 mug/g) was demonstrated. The long-chain bases of both cerebrosides were mainly C18-sphingenine, but in sulfatide, C20-sphingenine was more abundant than C18-sphingenine. In both cerebrosides and sulfatide, the fatty acid compositions were similar, with nervonic acid as the predominant component. Two species of gangliosides were also obtained and were identified as N-acetylgalactosaminyl(1 leads to 4)[N-acetylneuraminyl(2 leads to 3)]galactosyl(1leads to 4)glucosylceramide (59.8 mug/g) and N-acetylneuraminyl(2 leads to 3)galactosyl(1 leads to 4)N-acetylglucosaminyl(1 leads to 3)galactosyl(1 leads to 4)glucosylceramide (45.0 mug/g). The long-chain bases of the two gangliosides consisted of C18-spingenine and C20-sphingenine, and the major fatty acids were palmitic and stearic acids.
Animals↗
Histamine lipolysis I: changes in the free fatty acid levels of dog plasma after intravenous infusion of histamine.
The effects of histamine (Hi) and related compounds on free fatty acid (FFA) levels and % changes in FFA composition of dog plasma were studied after intravenous infusion. Hi at doses of 2-10 micrograms/kg while affecting no changes in the cardiovascular system elicited a dose-related increase in FFA levels in plasma, as did epinephrine. Though all of the FFA concentrations in plasma were increased by Hi infusion, % change of each FFA in the composition did not correspond to that of plasma concentration; % increases in palmitoleic acid, linolenic acid and linoleic acid were remarkable, while stearic acid (18:0) was lowest. The increase in arachidonic acid was not marked, but a dose-related increase was observed after Hi infusion. The H2-agonist 4-methylHi produced an increase in FFA levels, whereas the H1-agonist 2-methylHi was not effective. 4-MethylHi increased all of the plasma FFA levels and the relative changes were similar to those caused by Hi. The effect induced by Hi was blocked by the H2-antagonists cimetidine and ranitidine. Pretreatment with aminophylline potentiated the Hi effect, indicating that Hi lipolysis may be intimately related to cyclic AMP.
Aminophylline↗
New sialic acid-containing sulfolipid: "ungulic acid".
Human epidermis, hair, nails, and kidney as well as bovine and horses' hooves were found to contain a lipid fraction, which on thin-layer chromatography migrated slightly ahead of the cerebroside sulfate esters and gave the color reaction specific for sialic acid. This fraction was isolated from horse hoof, in which it constituted nearly half of the total lipids. The purified fraction contained sulfur, but no phosphorus. The IR spectrum revealed the presence of a sulfate group, which was also determined by the benzidine method. Thin-layer and gas-liquid chromatography of the products of acid hydrolysis revealed the presence of sphingosine, galactose, galactosamine, and sialic acid. Fatty acid analysis showed that stearic acid was the major component, with minor amounts of palmitic and arachidic acids. The fraction isolated contained ceramide, sialic acid, galactose, galactosamine, and sulfate in equimolar amounts. We conclude that the new lipid is a ganglioside sulfate, which we have called "ungulic acid" because it was first separated and identified from a horse's hoof (Latin, ungula).
Amino Alcohols↗
[Fatty acid and lipid peroxidation in human atherosclerosis].
Plasma fatty acids and lipid peroxidation were studied in human atherosclerosis. Analysis of fatty acids in 16 controls and 32 hyperlipidemic patients showed, in the latter, a decrease in saturated fatty acids, especially palmitic and stearic acids, and an increase in unsaturated fatty acids, especially arachidonic acid. Compared to hyperlipidemic patients without arterial injury, patients with arterial injury exhibit a significant increase in malonaldehyde (MDA). In the former, MDA concentrations are significantly increased compared to controls. Therefore, peroxidation of unsaturated fatty acids may have a deleterious effect on arteries in atheroma, through the release of toxic endoperoxydes and the metabolization of arachidonic acid into thromboxane, which is a platelet aggregator. Lipid peroxidation can also be demonstrated in other diseases: we found very high MDA concentration in 11 alcoholic patients (alcoholic hepatitis, cirrhosis) and 6 patients with inflammatory conditions such as Crohn disease.
Adult↗
High performance liquid chromatography preparation of the molecular species of GM1 and GD1a gangliosides with homogeneous long chain base composition.
A semi-preparative, analytical high performance liquid chromatographic (HPLC) procedure is described for the isolation of molecular species of GM1 and GD1a gangliosides containing a single long chain base, C18 or C20 sphingosine, C18 or C20 sphinganine, each in its natural erythro or unnatural threo form. The threo forms were obtained from 2,3-dichloro-5,6-dicyanobenzoquinone/NaBH4 -treated gangliosides. The ganglioside molecular species separated by HPLC were analyzed for carbohydrate, fatty acid, and long chain base composition. In particular, long chain bases were submitted to gas-liquid chromatographic-mass spectrometric analyses as their trimethylsilyl (TMS) or N-acetyl-TMS derivatives, and chain length, presence or absence of C4-C5 double bond, and C-3 steric configuration were ascertained. The final preparations of individual molecular species of GM1 and GD1a gangliosides were more than 99% homogeneous in their saccharide moiety, contained a single long chain base (homogeneity higher than 99%), and had a fatty acid composition primarily of stearic acid (92 to 97%). All the individual molecular species of GM1 and GD1a gangliosides were also prepared in radioactive form by selective tritiation at C-3 of the long chain base. Their specific radioactivity ranged from 1.3 to 1.45 Ci/mmol. The availability of these molecular species of gangliosides is expected to facilitate studies aimed at ascertaining the role played by the hydrophobic portion in the functional behavior of gangliosides.
Chromatography, High Pressure Liquid↗
[Fatty acid content in the lipid fraction of pork].
Studies were carried out to determine the contents of fatty acids in the lipid fraction of m. Longissimus dorsi from Bulgarian White pigs having a live weight of 25 to 40 kg. A Varian 2100 gas chromatograph with a flame-ionizing Detector, produced in the USA, was used for determination of fatty acids. It was found that, in the lipid fraction of the muscle studied the average content of myristic acid C14, was 1.25%; of palmitic acid C16, 29.08%; of stearic acid C18, 10.21% of palmitoleic acid C16:1, 3.24%; of oleic acid C18:1, 50.21%; and of linoleic acid C18:2, 6.01%.
Animals↗
Fatty acid composition of mammary gland lipids of lactating and nonlactating buffaloes.
The fatty acid composition of total lipids, triglycerides, free fatty acid pool, esterified cholesterol, phosphatidyl choline, and phosphatidyl ethanolamine of mammary tissue of lactating and nonlactating buffalo has been studied. The distribution of long chain triglycerides, free fatty acids free cholesterol and esterified cholesterol in nonlactating mammary tissue was 76.1,4.2,4 and 0.5 percent of total lipids respectively and in lactating mammary tissue it was 68.3, 1.2, 2.7 and 0.3 percent respectively. Short chain triglycerides constituting about 6.6% of total lipids and could be detected only in lactating mammary tissue. Among phospholipids, phosphatidyl choline, phosphatidyl ethanolamine and sphingomyelin constituted about 39.4, 21.5 and 15.6 percent respectively of total phospholipids in nonlactating tissue and 39.3, 22.6 and 10.7 percent respectively in lactating tissue. All the major fatty acids viz myristic, palmitic, stearic acid oleic were present in various lipid components of both lactating and nonlactating mammary tissue. Linoleic acid was present only in the lactating mammary tissue. Differences were observed in the distribution of fatty acids in lipid components of lactating and nonlactating mammary tissue.
Animals↗
The presence of fatty acids in human alpha-fetoprotein.
alpha-Fetoprotein has been prepared from human fetal tissue by procedures utilizing DEAE-Sephadex, concanavalin A-Sepharose, and isoelectric focusing. A major and a minor component with isoelectric points of 4.7 and 5.3, respectively, have been isolated and are similar to those prepared under various conditions by other investigators. The 4.7 material contains 2.4 mol of fatty acids/mol of protein, whereas the minor component is fat-free. The relative amounts of fatty acid vary somewhat with different preparations. The ranges found in three isolates were as follows: palmitic acid (8 to 11%), stearic acid (2 to 5%), oleic acid (10 to 28%), linoleic acid (7 to 15%), arachidonic acid (12 to 39%), and 4,7,10,13,16,19-docosahexaenoic acid (16 to 42%). Human fetal serum albumin contained 0.7 mol of fatty acid/mol of protein, with arachidonic acid and the docosahexaenoic acid comprising only 11.4% of the total. Removal of fatty acids by treatment with charcoal converted alpha-fetoprotein into material with an isoelectric point of pH 5.3. Addition of arachidonic acid to the lipid-free protein restored it to protein with a pH 4.7 isoelectric point, typical of the major native component. The possible role of the fatty acids in alpha-fetoprotein on the inhibition of various lymphocyte functions is projected.
Chromatography, Gas↗
Free fatty acids enhance hypochlorous acid production by activated neutrophils.
Activated polymorphonuclear neutrophils (PMNs) may contribute to the genesis of chronic obstructive lung disease in long-term cigarette smokers. However, it is not presently known which elements in smoke are important in triggering this progressive pulmonary damage or in affecting the activities of inflammatory cells such as PMNS. We earlier found substances in organic concentrates of cigarette smoke that bound ferrous iron and transferred the metal into organic phases. These substances were later identified as saturated free fatty acids, predominantly palmitic and stearic acids (16:0 and 18:0). We now report investigations of the effects of fatty acids on the oxidative metabolism of PMNs. In accord with most earlier reports, we find that saturated fatty acids have little direct effect on PMN oxidative metabolism. However, micromolar amounts of free fatty acids will more than double production of hypochlorous acid (HOCl) by PMNs stimulated with small amounts of phorbol myristate acetate. Similar fatty acid-mediated increases in HOCl production also occur when PMNs are stimulated with 1,2-dioctanoyl-sn-glycerol and 1-oleoyl-2-acetyl-sn-glycerol (also thought to be agonists of protein kinase C) but not when cells are stimulated with the calcium ionophore A23187, the formylated tripeptide f-met-leu-phe, or opsonized zymosan. Fatty acid-mediated enhancement of PMN HOCl production evidently arises from increased release of myeloperoxidase from stimulated PMNs. Furthermore, in the presence of free fatty acids, stimulated PMNs are much more cytotoxic toward cultured mink lung epithelial cells, a toxicity that is blocked by scavengers of HOCl. These results suggest that the relatively large amounts of free fatty acids present in tobacco smoke may act to amplify PMN-mediated oxidative damage to the lungs of smokers.
Adult↗
Nervonic acid and demyelinating disease.
Demyelination in adrenoleukodystrophy (ALD) is associated with an accumulation of very long chain saturated fatty acids such as 26:0 stemming from a genetic defect in the peroxisomal beta oxidation system responsible for the chain shortening of these fatty acids. Long chain monoenoic acids such as erucic acid, 22:1(n-9), can normalise elevated serum levels of 26:0 in ALD by depressing their biosynthesis from shorter chain saturated fatty acids. Sphingolipids from post mortem ALD brain have decreased levels of nervonic acid, 24:1(n-9), and increased levels of stearic acid, 18:0. Increased levels of 26:0 are accompanied by decreased nervonic acid biosynthesis in skin fibroblasts from ALD patients. Sphingolipids from post mortem MS brain have the same decreased 24:1(n-9) and increased 18:0 seen in post mortem ALD brain. The 24:1(n-9) content of sphingomyelin is depressed in erythrocytes from multiple sclerosis (MS) patients. Defects in the microsomal biosynthesis of very long chain fatty acids including 24:1(n-9) in 'jumpy' and 'quaking' mice are accompanied by impaired myelination. An impairment in the provision of nervonic acid in demyelinating diseases is indicated, suggesting that dietary therapy with oils rich in very long chain monenoic acid fatty acids may be beneficial in such conditions.
Adrenoleukodystrophy↗
A comparison of absorption of glycerol tristearate and glycerol trioleate by rat small intestine.
Generally, fats rich in saturated fatty acids raise serum cholesterol, whereas fats rich in polyunsaturated fatty acids lower it. There appear to be exceptions; e.g., stearic acid (18:0)-rich fats have little or no effect on serum cholesterol concentrations. This apparent lack of cholesterolemic effect of stearic acid-rich fat could be because intestinal absorption of fat is poor or subsequent plasma and/or tissue metabolism of fat is different. To investigate mechanisms involved, we compared intestinal digestion, uptake, and lymphatic transport of glycerol tristearate (TS) and glycerol trioleate (TO, 18:1). Two groups of rats bearing intestinal lymph fistulas were used. TO rats were fed intraduodenally for 8 h at a constant rate a lipid emulsion of 25 mumols/h of TO (labeled with glycerol tri[9,10 (n)-3H]oleate), 7.8 mumols of egg phosphatidylcholine, and 57 mumols of sodium taurocholate in 3 ml of phosphate-buffered saline. TS rats were fed the same lipid emulsion except that TS replaced TO and the emulsion was labeled with glyceryl [1,3-14C]tristearate. The lymph triglyceride and radioactivity were determined. After infusion, the luminal and mucosal radioactive lipid content was analyzed. The results showed that there was significantly less lipid transported in the lymph of TS rats compared with TO rats. The results also showed a significant decrease in the absorption of TS as compared with TO. This was due in part to poor lipolysis. In addition, the lipid absorbed by the intestine of the TS rats was transported into lymph less efficiently than in TO rats.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Transfer of long-chain fluorescent fatty acids between small and large unilamellar vesicles.
Transfer of 12-(9-anthroyloxy)stearic acid (12AS) was measured between small unilamellar vesicles (SUV) and between large unilamellar vesicles (LUV), over a temperature range of 5-50 degrees C. The results of this study clearly establish the biexponential nature of the time dependence of the transfer in a variety of vesicle types and confirm our previous results using egg phosphatidylcholine (EPC) SUV at 25 degrees C (Storch & Kleinfeld, 1986). In our previous study we developed a kinetic model of the transfer process and concluded that the observed time dependence of the transfer of long-chain 12-(9-anthroyloxy) fatty acids (AOFA) was due to transbilayer flip-flop that was much slower than the rate at which the fatty acids (FA) move from the vesicle and into the surrounding aqueous phase (the off step). In the present study, experimental and theoretical advances have allowed us to examine, in detail, predictions of the kinetic model that critically depend upon the slow rate of flip-flop. The current results verify these predictions and demonstrate that slow AOFA flip-flop is rate limiting in at least three different vesicle systems and at all temperatures studied. Moreover, both flip-flop and the off rate constants were almost an order of magnitude smaller in EPC-LUV than in EPC-SUV. Flip-flop was found to be asymmetric (the rate constant for transfer from the inner to outer hemileaflet of the bilayer is approximately twice that from the outer to inner hemileaflet) in SUV but virtually symmetric in LUV. The temperature dependence of transfer was used to determine the thermodynamic activation potentials for the flip-flop and off rate constants.(ABSTRACT TRUNCATED AT 250 WORDS)
Dimyristoylphosphatidylcholine↗
Metabolism of exogenous long-chain fatty acids by spinach leaves.
When applied in liquid paraffin to the upper surface of expanding spinach leaves, [1-14C]palmitic acid was efficiently and exclusively incorporated into the sn-1 position of cellular glycerolipids, principally phosphatidylcholine and triacylglycerol. A slow transfer of fatty acids from phosphatidylcholine to chloroplast glycolipids subsequently occurred with the positional specificity of the label remaining intact. Labeled palmitate at the sn-1 position of monogalactosyldiacylglycerol was desaturated to hexadecatrienoate so that 1-[14C]hexadecatrienoyl-2-linolenoyl-3-galactosoylglycerol became the major labeled species of the lipid between 8 and 24 h. There was no evidence of deacylation/reacylation reactions modifying the acyl compositions of spinach leaf glycerolipids for at least 48 h after labeling with [1-14C]palmitic acid; even the partially prokaryotic glycerolipids remained firmly labeled at the sn-1 position. Exogenous [1-14C]stearic acid was also incorporated into the sn-1 position of MGD, presumably by the same mechanism, and was there desaturated to [14C]linolenate. Exogenous [1-14C]oleic acid was initially incorporated equally into both sn-1 and sn-2 positions of phosphatidylcholine, and was desaturated to linoleate at both positions before the label was rapidly transferred to monogalactosyldiacylglycerol. There, desaturation of linoleate to linolenate took place. Galactolipids remained equally labeled at both positions throughout the 6 days of the experiment, but label was concentrated in the 1-saturated-2-[14C]linolenoyl molecular species of phosphatidylcholine as those species with two [14C]linoleoyl residues were drawn off for monogalactolipid synthesis. Glycerolipids synthesised from exogenous [1-14C]acetate by spinach leaves were labeled equally at both the sn-1 and the sn-2 positions. These results are interpreted as providing strong support for the two-pathway scheme of glycerolipid synthesis in plants.
Acetates↗
Interleukin-1 selectively potentiates bradykinin-stimulated arachidonic acid release from human synovial fibroblasts.
Exposure of human synovial fibroblasts prelabelled with [3H]arachidonic acid to bradykinin causes a rapid and sustained increase in arachidonic acid release, a transient increase in cytosolic calcium and an increase in radiolabelled diacylglycerol. Activation of arachidonic acid release by bradykinin was potentiated by interleukin-1 added either simultaneously with bradykinin or to cultures 24 h before addition of bradykinin. In contrast, interleukin-1 did not modify bradykinin-induced increases in cytosolic calcium or diacylglycerol. The stimulation of arachidonic acid release in response to bradykinin, in the absence or presence of interleukin-1, was not affected by RHC-80267, an inhibitor of diacylglycerol kinase, suggesting that deacylation of diacylglycerol was not an important pathway of arachidonic acid production in cultures exposed to bradykinin. This conclusion is supported by the observation that increased release of arachidonic acid was not accompanied by increased release of [14C]stearic acid in cultures labelled with both isotopes. Bradykinin-stimulated release of arachidonic acid was prevented by down-regulating protein kinase C by pretreatment with phorbol 12-myristate 13-acetate and was unaffected by inhibitors of protein synthesis actinomycin D or cycloheximide. On the other hand, interleukin-1 amplification of bradykinin-stimulated release of arachidonic acid was blocked by actinomycin D and cycloheximide. The results from this study point to activation of phospholipase A2 as the source of arachidonic acid in response to bradykinin. Our data further indicate that interleukin-1 selectively potentiates bradykinin activation of a phospholipase A2 by a mechanism requiring protein synthesis, but has no effect on bradykinin activation of phospholipase C.
Arachidonic Acid↗
Evidence for the existence of an aerobic pathway for synthesis of monounsaturated fatty acids by Alcaligenes faecalis.
Studies on the composition of total fatty acids of Alcaligenes faecalis harvested at different growth phases have been carried out. Ability of the organism to desaturate palmitic and stearic acid has also been tested. The organism contained palmitic (16:0), stearic (18:0), palmitoleic (16:1), cis-vaccenic (18:1), cyclopropane (17: big dn tri, open and 19: big dn tri, open), and three hydroxy acids. Increase in cyclopropane acids and corresponding decrease in monounsaturated acids in direct proportion to the age of the culture were observed, whereas other fatty acids remained relatively unaltered. A growing culture of the organism was found to desaturate [1-(14)C]palmitic acid supplied in the medium to hexadecanoic acid. Resting cells desaturated [1-(14)C]palmitic and [1-(14)C]stearic acid giving rise to about 50% of (14)C in the COOH group of corresponding monounsaturated fatty acids.
Acetates↗