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PubMed1983

Oleic acid transfer from microsomes to egg lecithin liposomes: participation of fatty acid binding protein.

Oleic acid transfer from microsomes or mitochondria to egg lecithin liposomes was stimulated by fatty acid binding protein. By gel filtration, it could be demonstrated that this protein incorporates oleic acid into liposomes. Fatty acid binding protein transfer activity was higher using microsomes rather than mitochondria, which suggests a selective interaction with different kinds of membranes. Transfer of oleic acid by this soluble protein is greater than that of stearic acid. The results indicate that fatty acid binding protein may participate in the intracellular transport of fatty acids.

Animals↗
PubMed1981

Inhibition of pentagastrin-stimulated gastric acid secretion by graded intraduodenal administration of oleic acid in man.

The inhibitory effect of intraduodenally administered oleic acid in volumes of 5--40 ml on pentagastrin-stimulated gastric acid secretion was determined in healthy volunteers. In the control experiments, corresponding volumes of saline were given. Five and 10 ml oleic acid brought about a significant inhibition of gastric acid secretion of 29% and 32%, respectively. After 20 ml of oleic acid the inhibition was 46%, a significantly stronger inhibition than after 5 or 10 ml. Forty milliliters of oleic acid did not further increase the inhibition. Maximal inhibition appeared 30--60 min after the administration of oleic acid. In seven duodenal ulcer patients 20 ml oleic acid evoked an inhibition of gastric acid secretion of 20%, which was significantly less than the inhibition produced in healthy subjects after the same volume of oleic acid. The results suggest that the intraduodenal administration of relatively small volumes of oleic acid elicits a dose-dependent inhibition of pentagastrin-stimulated gastric acid secretion in man and that maximal inhibition is obtained by 20 ml of oleic acid. The results also indicate that duodenal ulcer patients may have a defective fat inhibitory mechanism.

Adult↗
PubMed1997

Up-regulated delta 9-desaturase gene expression by hypolipidemic peroxisome-proliferating fatty acids results in increased oleic acid content in liver and VLDL: accumulation of a delta 9-desaturated metabolite of tetradecylthioacetic acid.

In the liver of rats, monocarboxylic 3-thia fatty acids, tridecylthioacetic acid (C13-S-acetic acid) and tetradecylthioacetic acid (C14-S-acetic acid), increase the mRNA levels of delta 9-desaturase both in a time- and dose-dependent manner. The increased delta 9-desaturase mRNA levels were accompanied by increased delta 9-desaturase activity and increased amounts of oleic acid (18:1 n-9) and delta 9-desaturated C14-S-acetic acid. delta 9-Desaturated C14-S-acetic acid was only detected in phospholipid and cholesterolester species after C14-S-acetic acid treatment. In contrast, C14-S-acetic acid was detected in all the different hepatic lipid fractions, but mainly in the phospholipids. Moreover, C13-S-acetic acid and C14-S-acetic acid were detected in both liver and very low density lipoprotein (VLDL). No delta 9-desaturated 3-thia fatty acid products, however, were found in VLDL. Administration of mono- and dicarboxylic 3-thia fatty acids to rats induced liver expression of the fatty acyl-CoA oxidase gene. After 1 week of C14-S-acetic acid treatment, the levels of fatty acyl-CoA oxidase mRNA increased 5-fold, whereas the delta 9-desaturase mRNA was increased about 1.8-fold. Both fatty acyl-CoA oxidase and delta 9-desaturase mRNA increased about 8-fold after 12 weeks of treatment with C14-S-acetic acid. In conclusion, this study demonstrates that C14-S-acetic acid increases rat delta 9-desaturase gene expression and activity and that changes in hepatic lipids, e.g., 18:1 n-9, are reflected in the VLDL. The peroxisome-proliferating monocarboxylic thia fatty acids are good substrates for desaturases, as delta 9-desaturated metabolites of monocarboxylated thia acids were formed in the liver. Modification of delta 9-desaturation, however, appears not to be related to peroxisome proliferation.

Acyl-CoA Oxidase↗
PubMed1990

Erythrocyte stearic to oleic acid ratio in prostatic carcinoma.

The red cell membrane stearic acid to oleic acid ratio was analysed in 34 men with histologically proven carcinoma of the prostate and distant metastases. This ratio was expressed as the saturation index (SI). A mean SI of 0.97 was found in control patients without evidence of any malignancy whereas all patients with advanced prostatic cancer showed a reduced stearic to oleic acid ratio (mean SI 0.466). Untreated patients had a significantly lower SI (mean 0.36) than those who had responded to hormonal therapy (mean 0.547; P less than 0.0001). A drop in SI correlated well with more advanced disease as judged by radiological findings and serum PSA. It is suggested that red cell membrane SI correlates well with radiological and biochemical markers of advanced prostatic carcinoma and may be used as a marker to assess progress and response to treatment.

Biomarkers, Tumor↗
PubMed1994

Regulation of neutrophil activation by oleic acid.

Physiological concentrations of oleic acid inhibited C5a-induced myeloperoxidase release from neutrophils. The inhibition occurred promptly following the addition of oleic acid, was dose-dependent and saturable, and was greater at low concentrations of C5a. Kinetic analysis of the curve for 1/myeloperoxidase release against 1/[C5a] in the presence of oleic acid, was compatible with a cooperative pattern of interaction. The inhibitory effect persisted after repeated washings of cells preincubated with oleic acid. The effect of oleic acid was not specific for C5a-induced neutrophil activation; oleic acid also inhibited myeloperoxidase release induced by the Ca2+ ionophore A-23187, as well as zymosan activated serum-induced chemotaxis. In experiments designed to localize the site of action of oleic acid on neutrophil activation, an intracellular oleic acid-binding protein M(r) = 13,000) was isolated. The results suggest that acute changes in plasma fatty acid levels may have significant effects on neutrophil function under physiological conditions.

Complement C5a↗
PubMed1997

Perfluorodecanoic acid enhances the formation of oleic acid in rat liver.

The feeding of perfluorodecanoic acid (PFDA) to male rats at a dietary concentration of 0.005% (w/w) for 7 days resulted in a marked increase in the activity of microsomal stearoyl-CoA desaturation in the liver. This increase in the overall desaturation activity was due to the induction of terminal desaturase among the components comprising the desaturation system. In contrast, PFDA inhibited desaturation in vitro, seemingly due to interference with electron transport through the desaturation system. Accordingly, PFDA can be an inducer and also an inhibitor of delta9-desaturation. PFDA feeding enhanced the conversion of radioactive stearic acid into oleic acid in the liver in vivo, indicating that the induction of delta9-desaturase by PFDA functions in vivo. PFDA feeding increased the mass of octadecenoic acid (C18:1) in the liver and the proportion of C18:1 in microsomal lipid. A highly significant linear correlation existed between the microsomal desaturase activity and the proportion of C18:1 in microsomal lipid when compared using rats in five different physiological states: control, PFDA-fed, p-chlorophenoxyisobutyric acid (clofibric acid)-fed, starved and starved/refed. These results suggest that the increase in the hepatic level of C18:1 caused by feeding of PFDA to rats can be explained by the common concept of regulation, i.e. the hepatic level of C18:1 is under the control of delta9-desaturase. The dietary administration of PFDA also increased the content of cytochrome P-450 and the activity of 7-ethoxycoumarin O-de-ethylase in the liver.

Acyl Coenzyme A↗
PubMed2005

Reactive uptake of O3 by multicomponent and multiphase mixtures containing oleic acid.

The heterogeneous reaction of O3 with lauric acid/oleic acid (LA/OA) mixtures and myristic acid/oleic acid (MA/OA) mixtures were studied as a function of composition, physical state, and microstructure at 298 K. Lauric acid and myristic acid are both alkanoic acids, whereas oleic acid is an alkenoic acid. Additionally, we investigated the uptake of O3 by multicomponent mixtures that closely represent the composition of meat-cooking aerosols. These measurements were performed with a rotating-wall flow-tube reactor coupled to a chemical ionization mass spectrometer. The reactive uptake coefficients (gamma) of O3 on liquid LA/OA and MA/OA solutions range from 4 x 10(-4) to 7.2 x 10(-4). The gamma values measured for solid-liquid LA/OA and MA/OA mixtures (which consist of solid LA or solid MA in equilibrium with a liquid) range from 2 x 10(-5) to 1.7 x 10(-4). These experiments show that only 7% solid by mass in the solid-liquid mixture can decrease gamma by an order of magnitude compared to the liquid mixtures. The gamma values for solid-liquid mixtures that closely represent the composition of meat-cooking aerosols range from 1.6 x 10(-5) to 6.9 x 10(-5). We found that gamma of solid-liquid mixtures depends on the microstructure of the mixtures, which in turn depends on the method of preparing the films. Furthermore, experiments employing solid-liquid mixtures show an increase in gamma with increasing film age. This can be explained either by the formation of a nonequilibrium phase followed by its relaxation to the stable phase or by Ostwald's ripening, which refers to a change in the solid microstructure due to a tendency to minimize the total surface free energy of the solid. We used the obtained gamma values to estimate OA lifetimes for polluted atmospheric conditions. For liquid solutions, the lifetimes were on the order of a few minutes. The lifetimes derived for solid-liquid mixtures are up to 75 min, significantly longer than for liquid solutions. Our study emphasizes the effect of the physical state and microstructure of multicomponent mixtures on the heterogeneous chemistry.

Aerosols↗
PubMed2004

Solid-liquid phase behavior of binary fatty acid mixtures. 2. Mixtures of oleic acid with lauric acid, myristic acid, and palmitic acid.

Solid-liquid phase behavior was investigated for binary fatty acid mixtures composed of oleic acid (OA; cis-9-octadecenoic acid) and saturated fatty acids, lauric acid (LA; dodecanoic acid), myristic acid (MA; tetradecanoic acid), and palmitic acid (PA; hexadecanoic acid), by means of differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR). When the mixture was heated immediately after the solidification from the melt, the heat effect due to the gamma-to-alpha transformation of OA varied depending on the composition of the mixture. However, the mixture subjected to an annealing at the temperature slightly below the melting temperature provided the transformation at constant temperature which corresponds to the gamma-to-alpha transformation temperature of pure OA. This suggests that a solid phase formed by cooling of the melt of the mixture is not in an equilibrium state, but it relaxes to a stable solid during the annealing process. The T-X phase diagrams of these mixtures constructed from the DSC measurements demonstrate that the two fatty acid species are completely immiscible in a solid phase regardless of the type of polymorphs of OA, alpha- or gamma-form. According to a thermodynamic analysis of liquidus line basing on the regular solution model for the melt, the non-ideality of mixing tends to increase with the decrease in the acyl chain length of the saturated fatty acid, although the mixing is rather close to ideal.

Calorimetry, Differential Scanning↗
PubMed2001

High linoleic acid, low vegetable, and high oleic acid, high vegetable diets affect platelet activation similarly in healthy women and men.

Upregulation of protein kinase C (PKC), an important enzyme in platelet activation, could be one step toward platelet hyperactivity. PKC activation can be modulated by dietary components in vitro, but few data are available concerning the in vivo effects. In this strictly controlled human dietary intervention, the influence of dietary unsaturated fatty acids and vegetable compounds on platelet activation was investigated. A high linoleic acid diet (10% of energy) with small amounts of vegetables (no berries or apples) was consumed by 9 women and 4 men (24.1 +/- 3.9 y), and was compared with a high oleic acid diet (12% of energy) with considerable amounts of vegetables, berries and apples consumed by 8 women and 4 men (24.2 +/- 5.5 y). Subjects were healthy Finnish volunteers. Compliance with the experimental protocol was good, as indicated by changes in plasma fatty acids and concentrations of vitamin C, beta-carotene and alpha-tocopherol. No differences between groups were seen in indices of platelet activation, including platelet aggregation, total PKC activity and distribution of PKC isoenzymes alpha, beta(II) and delta. The results indicate that in apparently healthy and fairly young subjects with adequate vitamin intakes, diets differing markedly in their amounts of linoleic and oleic acids, and vegetables, berries and apples do not differ in platelet activation.

Antioxidants↗
PubMed1991

Dietary alpha-linolenic acid is as effective as oleic acid and linoleic acid in lowering blood cholesterol in normolipidemic men.

The effect of dietary oleic acid (OA), linoleic acid (LA), and linolenic acid (LNA) on plasma lipid metabolism was studied in eight normolipidemic men. A mixed-fat diet composed of conventional foods was fed during 6-d pre- and post-experimental periods. The same basic diet but with 75% of the fat (26% of total energy) provided by sunflower and olive; canola; soybean; and sunflower, olive, and flax oils was fed during four 18-d experimental periods. Mean plasma total cholesterol (-18%), low-density-lipoprotein-cholesterol, (-22%) and very-low-density-lipoprotein-cholesterol (-41%) concentrations were significantly (P less than 0.004) lower after the experimental diets than after the mixed-fat diet. Mean serum apolipoprotein B (-19%) and apolipoprotein A-I (-9%) concentrations were also significantly (P less than 0.0007) lower after the experimental diets. The experimental diets were equally effective in lowering total and lipoprotein cholesterol and apolipoprotein concentrations in plasma, indicating that dietary OA, LA, and LNA were equally hypocholesterolemic.

Adult↗
PubMed1996

Metabolic fate of oleic acid, palmitic acid and stearic acid in cultured hamster hepatocytes.

Unlike other saturated fatty acids, dietary stearic acid does not appear to raise plasma cholesterol. The reason for this remains to be established, although it appears that it must be related to inherent differences in the metabolism of the fatty acid. In the present study, we have looked at the metabolism of palmitic acid and stearic acid, in comparison with oleic acid, by cultured hamster hepatocytes. Stearic acid was taken up more slowly and was poorly incorporated into both cellular and secreted triacylglycerol. Despite this, stearic acid stimulated the synthesis and secretion of triacylglycerol to the same extent as the other fatty acids. Incorporation into cellular phospholipid was lower for oleic acid than for palmitic acid and stearic acid. Desaturation of stearic acid, to monounsaturated fatty acid, was found to be greater than that of palmitic acid. Oleic acid produced from stearic acid was incorporated into both triacylglycerol and phospholipid, representing 13% and 6% respectively of the total after a 4 h incubation. Significant proportions of all of the fatty acids were oxidized, primarily to form ketone bodies, but by 8 h more oleic acid had been oxidized compared with palmitic acid and stearic acid.

Analysis of Variance↗
PubMed2005

Daily supplementation with (n-3) PUFAs, oleic acid, folic acid, and vitamins B-6 and E increases pain-free walking distance and improves risk factors in men with peripheral vascular disease.

A number of nutrients are known to be effective in preventing cardiovascular disease (CVD). We investigated the possible effects of a daily intake of low amounts of these nutrients on risk factors and clinical parameters in patients with peripheral vascular disease and intermittent claudication (PVD-IC). Male PVD-IC patients (n = 60) were randomly allocated into 2 groups. The supplement (S) group consumed 500 mL/d of a fortified dairy product containing eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), oleic acid, folic acid, and vitamins A, B-6, D, and E. The control (C) group consumed 500 mL/d of semiskimmed milk with added vitamins A and D. The patients received lifestyle and dietary recommendations, and they were instructed to consume the products in addition to their regular diet. Blood extractions and clinical explorations were performed after 0, 3, 6, 9, and 12 mo. Plasma concentrations of EPA, DHA, oleic acid, folic acid, and vitamins B-6 and E increased after treatment with supplements (P < 0.05). Plasma total cholesterol and ApoB concentrations decreased in the S group, and total homocysteine decreased in those patients with high initial concentrations. Walking distance before the onset of claudication increased in the S group (P < 0.001), and ankle-brachial pressure index values increased (P < 0.05). The inclusion in the everyday diet of certain nutrients known to promote cardiovascular health improved clinical outcomes while reducing a variety of risk factors in men with PVD-IC, providing new evidence of the potential role of nutrition in the reduction of PVD-IC symptoms.

Aged↗
PubMed1983

Intraduodenal emulsions of oleic acid augment acid-induced canine pancreatic secretion.

To study interactions between intraduodenal acid and emulsified oleic acid, dogs with chronic gastric and pancreatic fistulas received two sets of intestinal perfusates. The first set contained HCl plus bovine serum albumin (BSA) with or without 20 mM oleic acid. The BSA and HCl were varied so that each 50 ml contained 1, 2, or 4 meq of acid titratable from an initial pH of 2.0 or 3.5 to an end-point pH of 4.5. Oleic acid significantly enhanced pancreatic bicarbonate and protein outputs induced by acidified BSA. In additional studies, a less soluble protein solution, a 1:1 mixture of bovine hemoglobin and ovalbumin (HB-OV), was utilized. Fixed amounts of HCl (1, 2, or 4 meq/50 ml) were added to native or pepsin-digested HB-OV solution with or without 20 mM oleic acid. In these studies, initial pH and titratable acid (to end-point pH 4.5) varied with the nature of the HB-OV (undigested or digested), as well as with the amount of HCl added. Under these conditions, digested HB-OV and oleic acid potentiated acid-induced bicarbonate output, but only in those solutions with the greatest amount of added HCl. Acid-induced bicarbonate or protein outputs were not further augmented upon combination of HB-OV digests with oleic acid. We conclude that acid-induced pancreatic bicarbonate secretion is potentiated by intraduodenal protein digests and emulsified fatty acids.

Animals↗
PubMedDate not supplied

Distribution study of radioactivity in rats after oral administration of the lipido/sterolic extract of Serenoa repens (Permixon) supplemented with [1-14C]-lauric acid, [1-14C]-oleic acid or [4-14C]-beta-sitosterol.

The study carried out on rats given orally the n-hexane lipido/sterolic extract of Serenoa repens (LSESR), supplemented with [14C]-labelled oleic or lauric acids or beta-sitosterol, demonstrated that radioactivity uptake in prostatic tissues shows the highest level in the case of administration of LSESR supplemented with [14C]-labelled oleic acid. This was clearly demonstrated on a rat with an induced fibro-muscular hyperplasia of the prostate and by quantitative measurements of radioactivity. Ratios of radioactivity in tissues compared to plasma show an uptake of radioactivity greater in prostate as compared to other genital organs, i.e. the seminal vesicles or to other organs such as liver.

Administration, Oral↗
PubMed1991

Correlation of carotenoid production, decreased membrane fluidity, and resistance to oleic acid killing in Staphylococcus aureus 18Z.

Staphylococcus aureus is susceptible to killing by host-derived fatty acids. Studies were performed to test for a correlation between carotenoid production by S. aureus and protection against oleic acid. Oleic acid killing of cells grown in carotenoid expression medium was determined as the dosage of oleic acid in 2 M NaCl-2 mM EDTA that would kill 20% of the cells in 60 min at 37 degrees C (i.e., the 20% lethal dose). Compared with the wild-type strain (18Z), a carotenoid-deficient mutant strain (18Z-76) and strain 18Z grown in a medium that suppressed carotenoid production both showed increased sensitivity to oleic acid. Spontaneous revertants of strain 18Z-76 that regained the ability to produce carotenoids were as resistant to oleic acid as the wild-type strain. Oleic acid was shown by fluorescence polarization to decrease polarization values. Lower polarization values indicate a more-fluid membrane. To determine whether protection against oleic acid killing might depend on carotenoid stabilization of membranes, fluorescence polarization values were determined for strains showing different levels of carotenoid production. An indirect correlation was found between membrane fluidity and carotenoid production. We were able to conclude that there is a direct correlation between carotenoid production (i.e., cell pigmentation), cell membrane stability, and resistance to oleic acid-induced cell killing.

Carotenoids↗
PubMed1998

Synthesis of an unsaturated fatty acid analogue (18-(4'-azido-2'-hydroxybenzoylamino)-oleic acid) and its interaction with lysophosphatidylcholine: acyl-CoA-O-acyltransferase.

Acylation/deacylation reactions represent a basic requirement of triglyceride as well as phospholipid metabolism, and maintenance of membrane lipid composition. In order to examine enzymes participating in these pathways, we synthesized 18-(4'-azido-2'-hydroxybenzoylamino)-oleic acid, an iodinable photoaffinity analogue of oleic acid as a new tool for analyzing enzymes, especially those binding unsaturated fatty acids or acyl-CoAs. For the synthesis of omega-amino-oleic acid, coupling two bifunctional Cg-components was used. The described synthesis scheme is also suited for the specific generation of other fatty acid analogues with distinct positions of the double bond. The functionality of 18-(4'-azido-2'-hydroxybenzoylamino)-oleic acid was investigated with the enzyme lysophosphatidylcholine:acyl-CoA-O-acyltransferase (LAT) [EC 2.3.1.23], an enzyme that shows high specificity towards (poly)unsaturated fatty acyl-CoAs. It could be shown that the photolabel, esterified with coenzyme A, acts in the dark as a reversible inhibitor of the enzyme activity, but photolysis of the label results in irreversible inactivation of LAT. This inactivation could be prevented by addition of the native substrate arachidonyl-CoA during photolysis. Several proteins could be specifically visualized using the iodinated analogue. The data indicate that this new photoaffinity label may have application to identify and characterize lipid biosynthetic enzymes using unsaturated fatty acids as well as acyl-CoA binding proteins and the active site of these proteins.

1-Acylglycerophosphocholine O-Acyltransferase↗