Hydroxylation of oleic acid by cell-free extracts of a species of torulopsis.
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Azides↗
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The recovery of 13C-labeled oleic acid in rat lymph after administration of long chain triacylglycerols or specific structured triacylglycerols.
BACKGROUND: Consumption of specific structured triacylglycerols, MLM (M = medium chain fatty acid, L = long chain fatty acid), delivers fast energy and long chain fatty acids to the organism. AIM OF THE STUDY: The purpose of the present study was to compare lymphatic absorption of (13)C-labeled MLM and (13)C-labeled LLL in rats. Stable isotope labeling enables the separation of the endogenous and exogenous fatty acids. METHODS: Lymph was collected during 24 h following administration of MLM or LLL. Lymph fatty acid composition and (13)C-enrichment were determined and quantified by gas chromatography combustion isotope ratio mass spectrometry. RESULTS: The recovery of 18:1n-9 was higher after administration of LLL compared with MLM (58.1% +/- 7.4% and 29.1% +/- 3.9%, respectively, P < 0.001). This may be due to a higher chylomicron formation stimulated by a higher amount of long chain fatty acids in the intestine after LLL compared with MLM administration. This was confirmed by the tendencies of higher lymphatic transport of endogenous fatty acids. CONCLUSION: The study revealed a higher lymphatic recovery of the administered long chain fatty acids after LLL compared with MLM consumption.
Administration, Oral↗
Intestinal absorption of oleic acid 131-I and triolein 131-I in the differential diagnosis of malabsorption syndrome and pancreatic dysfunction in the dog.
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Animals↗
Effect of oleic acid on the oxidation and gluconeogenesis from [1-14C]pyruvate in the perfused rat liver.
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Animals↗
Effects of oleic acid and oxygen restriction followed by re-oxygenation on rhythm and contractile activity of the isolated rat heart; protective action of glucose.
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Aerobiosis↗
Oleic acid (18:1) in plasma, liver and brain myelin lipid of piglets fed from birth with formulas differing in 18:1 content.
Recent studies have shown reduced 18:1 fatty acids in brain total lipid of piglets fed formula with 17% 18:1 fatty acids rather than sow milk providing 37% 18:1. Because 18:1 is a major fatty acid in brain myelin lipid and is rapidly deposited during myelination, it is important to know if this reflects deposition of myelin lipid containing reduced 18:1 and/or delayed myelination, or is related to changes in other brain membranes. Therefore, these studies determined the myelin total lipid, phosphatidylethanolamine and plasma and liver phospholipid fatty acids in piglets fed from birth to 15 d with formula containing (g/100 g fatty acids): 18:1, 17 and 18:3(n-3), 0.8; 18:1, 38 and 18:3(n-3), 0.6 fatty acids; or 18:1, 40 and 18:3(n-3), 4; or sow milk. Different levels of formula 18:3(n-3) fatty acids were studied because of the known effect of essential fatty acid deficiency on myelination. The brain 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNPase) activity and cerebroside concentration were also determined and used as indicators of myelination. Piglets fed the low 18:1 formula had lower 18:1 fatty acids in their plasma and liver phospholipid than sow milk-fed piglets. Formula providing a similar level of 18:1 to sow milk resulted in higher 18:1 fatty acids in the piglet plasma and liver phospholipid than in the sow milk-fed piglets. The brain myelin monoenoic fatty acids, CNPase activity and cerebroside concentration were similar in sow milk- and formula-fed piglets, irrespective of the formula 18:1 or 18:3(n-3) content.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
[Respiratory coefficient and the metabolic effect of an oleic acid emulsion in white rats in the process of experimental hyperthyroidism development].
RQ changes were studied in rats, depending on the degree of the organism saturation with triiodthyronin, and the metabolic action of free acid (FA). Animals with a relative hyperthyroidism had an increased RQ as compared with the control. RQ was decreased in the animals with a high degree of hyperthyroidism. FA injection was followed by a decrease of RQ and the body temperature elevation. These changes progressed with the advance of hyperthyroidism.
Animals↗
Erythrocyte stearic to oleic acid ratio in patients with ocular melanoma.
The main characteristics of malignant cells include increased metabolism and capacity for division which are associated with high membrane fluidity. Membrane fluidity is in turn controlled by multiple factors which include the ratio of saturated to unsaturated fatty acids in the cell wall i.e. the Saturation Index (SI). The SI is known to be reduced in neoplastic cells as well as in the circulating erythrocytes of patients with some malignant tumours but not others. It has been suggested that the SI may be useful as a marker of malignancy.
Adult↗
Mitochondrial oxidative stress is modulated by oleic acid via an epidermal growth factor receptor-dependent activation of glutathione peroxidase.
Mitochondria generate reactive oxygen species (ROS) under various pathophysiological conditions. In isolated mitochondria, fatty acids (FA) exhibit an uncoupling effect of the respiratory activity and modulate ROS generation. The effect of FA on intact cultured cells remains to be elucidated. The present study reports that FA (buffered by BSA) decrease the level of cellular ROS generated by the mitochondrial respiratory chain in cultured cells incubated with antimycin A. Both saturated and unsaturated FA are effective. This fatty acid-induced antioxidant effect does not result from a decrease in ROS production, but is subsequent to cellular glutathione peroxidase (GPx) activation and enhanced ROS degradation. This fatty acid-induced GPx activation is mediated through epidermal growth factor receptor (EGFR) signalling, since this response is (i) abrogated by the EGFR inhibitor AG1478 or by a defect in EGFR (in EGFR-deficient B82L fibroblasts), (ii) restored in B82LK+ cells expressing EGFR and (iii) mimicked by epidermal growth factor. These findings indicate that FA contribute to enhance cellular antioxidant defences against mitochondrial oxidative stress through EGFR-dependent GPx activation.
Cell Line↗
Oleic acid desaturation in Tetrahymena pyriformis.
The desaturation of oleoyl-CoA by a microsomal preparation from Tetrahymena has been studied. Desaturation of oleoyl-CoA required oxygen and NADH, and was inhibited by cyanide. HPLC analysis of fatty acid phenacyl esters, prepared from TLC-purified phospholipid, confirmed that radioactivity appeared in oleate, linoleate and gamma-linolenate. Both the time course of desaturation and the apparent desaturation of 1-palmitoyl-2-[14C]oleoylphosphatidylcholine suggested that phospholipid-bound oleate could be a substrate for desaturation. In the crude microsomal preparation, acylation of oleoyl-CoA to give oleoyl phospholipid was rapid. Therefore, preincubation in the absence of NADH was employed to create [14C]oleoyl phospholipids, and kinetic studies were carried out upon subsequent addition of NADH. When data were plotted in a double reciprocal form, a linear function was observed.
Acyl Coenzyme A↗
Release of neurotensin by selective perfusion of the jejunum with oleic acid in dogs.
Plasma neurotensin concentrations are rapidly elevated after oral ingestion or intraduodenal infusion of fat, apparently before fat reaches the ileum where neurotensin is highly concentrated. The purpose of this study was to investigate the site of neurotensin release and to determine whether neurotensin is released by direct luminal stimulation by fat in conscious dogs. Dogs were prepared with isolated jejunal or ileal segments and portal vein catheters. Release of neurotensin into the portal venous blood was examined by selective perfusion of each intestinal segment with sodium oleáte. The results of this study show that selective perfusion of the jejunum, but not the ileum, with sodium oleate, caused a significant release of neurotensin. We speculate that release of ileal neurotensin is not due to direct luminal stimulation, but is mediated by local neural or humoral intermediates.
Animals↗
Stereospecific distribution of palmitic acid in the triacylglycerols of rat adipocytes. Effects of varying the composition of the substrate fatty acid in vitro.
The effects of inclusion of different fatty acids in the medium on the rate of esterification of palmitic acid and its stereospecific distribution among the three positions of the triacyl-sn-glycerols by preparations of rat adipocytes in vitro have been determined. Myristic acid, stearic acid, oleic acid and linoleic acid were used as diluents and the concentration of the combined unesterified fatty acids in the medium was held constant; only the proportion of palmitic acid was varied. The amount of palmitic acid esterified was always linearly related to its relative concentration in the medium and was not significantly affected by the nature of the diluent fatty acid chosen. Constant relative proportions were recovered in triacylglycerols and in intermediates in each instance. The amount of palmitic acid esterified to each of the positions of the triacyl-sn-glycerols was linearly dependent on the relative proportion in the medium but the nature of the relationship was markedly influenced by which fatty acid was present. When stearic acid was present, simple relationships were found over the whole range tested. When either myristic acid, oleic acid or linoleic acid was present, abrupt changes in the manner of esterification of palmitic acid were observed in position sn-1 when the relative concentrations of palmitic acid and the diluent reached critical values, which differed with each fatty acid. In position sn-2 when oleic acid or linoleic acid was present, a similar change was observed, and in position sn-3 it was obtained with myristic acid as diluent. The results are discussed in terms of changes in the relative affinities of the acyltransferases for palmitic acid. Palmitic acid was esterified into various molecular species in proportions that indicated acylation with non-correlative specificity at higher relative concentrations but not at lower.
Adipose Tissue↗
Involvement of cholinergic processes in cholecystokinin (CCK) release [corrected] by luminal oleic acid.
Cholecystokinin (CCK) is an important bioactive peptide that stimulates pancreatic enzyme secretion. Circulating CCK is secreted from endocrine cells in the upper small intestine in response to various luminal stimuli and to vascular administration of gastrin releasing peptides. However, the mechanism of its release has not been fully elucidated. In the present study, the vascularly perfused duodenojejunum was isolated from male Wistar rats. The effects of luminal infusion of sodium oleate (2 or 0.4%) or intra-arterial infusion of neuromedin C(10(-7) M) with or without atropine and with a recently synthesized specific bombesin antagonist (EABI) were examined. The CCK release produced by intra-arterial infusion of neuromedin C was inhibited by EABI in a dose-dependent manner. The CCK release produced by luminal sodium oleate was inhibited by atropine, but not affected by EABI. The CCK release stimulated by luminal sodium oleate is mediated, at least in part, by a cholinergic mechanism, but neuromedin C directly stimulates CCK release via its receptor on CCK-producing cells.
Animals↗
Alternative splicing of human plasma cholesteryl ester transfer protein mRNA in Caco-2 cells and its modulation by oleic acid.
Cholesteryl ester transfer protein (CETP) is a plasma protein involved in the reverse cholesterol transport and expressed in several human tissues and cell lines. We studied CETP expression in Caco-2 cell line, a model of the human enterocyte epithelium. By reverse-transcriptase polymerase chain reaction, we could demonstrate that in basal condition Caco-2 cells have a low rate of expression of active CETP mRNA. Furthermore, we found that even in this cell line CETP mRNA alternative splicing occurs with deletion of exon 9 sequence. Densitometric analysis of the in vitro amplified fragments showed that under basal conditions about 60% of reverse transcribed CETP cDNA corresponds to exon 9-deleted transcripts. After challenge with 50 microM sodium oleate, there is a approximately 2 fold increase in the transcription rate of the full-length CETP cDNA, as measured by competitive PCR, which is accompanied to an increased activity measured in the cell-conditioned medium. On the contrary, no significant change is seen in the amount of exon 9-deleted cDNA. Consequently, an inversion in the ratio of full-length and exon 9-deleted CETP cDNA is evident, suggesting that sodium oleate selectively enhances the expression of full-length CETP mRNA.
Alternative Splicing↗
Effect of electrochemical treatment of oleic acid on anaerobic digestion.
Electrochemical pre-treatment of oleate on anaerobic digestion was investigated using two anaerobic filters (AF and AFm) working, respectively, with increasing concentrations of electrochemically pre-treated oleate and oleate. Influents containing 25% and 50% of chemical oxygen demand (COD) of these substrates did not cause relevant alterations in either digester's performance. Comparatively, the pre-treated oleate unit (AF) showed a higher gas production but a lower COD removal than AFm (2.0 vs 1.5 m(3) CH4 m(-3) d(-1) 76-85 vs 91-93% COD removal). The raised AFm COD removal together with the larger proportion of VSS in its effluent than in AF (5.69 vs 0.26 kg m(-3)) indicate that the biomass washout can be a consequence of the encapsulated solids by lipidic compounds that were not fairly degraded. Further increases of oleate in AFm feed (75 and 100% COD) led to decreases of biogas production to half and COD removal from values higher than 90% to 83-75%. The simultaneous increase of effluent VSS concentrations to 10-12 kg m(3) emphasizes the oleate negative effect. The use of pretreated oleate as the only carbon source did not influence negatively the AF behaviour in terms of methane production. COD removal was maintained at values higher than 80% and the effluent VSS at low concentrations (0.15 kg m(-3)). The significantly higher methane yield achieved by AF than AFm indicates a higher accumulation of oleate than pre-treated oleate. Therefore, electrochemical process stands for a suitable pre-treatment for lipid rich effluents, allowing the application of higher organic loads keeping a higher methane yield.
Anaerobiosis↗
Effects of hypocaloric dietary treatment enriched in oleic acid on LDL and HDL subclass distribution in mildly obese women.
OBJECTIVE: To study the effects of a carbohydrate-enriched (HiCarbo) or olive-oil-enriched (HiMUFA) hypocaloric diet on plasma lipoprotein levels and physical properties. DESIGN: A six-month follow-up dietary intervention study with a HiCarbo diet providing 60% of total calories as complex carbohydrates, 15% as proteins and 25% as fats [10% saturated (SFA); 7% monounsaturated (MUFA); 8% polyunsaturated fatty acids (PUFA)]; or a HiMUFA diet with 40% complex carbohydrates, 15% proteins and 45% fats (10% SFA; 27% MUFA; 8% PUFA). SUBJECTS: Twenty consecutive, mildly obese, normolipidemic premenopausal women (11 on HiCarbo and nine on HiMUFA diets) and 14 age- and sex-matched, lean controls. MEASUREMENTS: Body mass index (BMI), waist/hip ratio, plasma lipoproteins, apolipoprotein (apo) AI and B, LDL and HDL density distribution, and phospholipid fatty acid composition at baseline, and after 3 and 6 months on dietary treatment. RESULTS: Body weight progressively decreased during the first 3 months and then it stabilized during the following 3 months (-11% vs. baseline in both groups; P < 0.01). LDL-Cholesterol decreased significantly in both groups. HDL-Cholesterol increased significantly in the HiMUFA group, whereas a decreased level was observed in the HiCarbo group. At baseline the obese women had higher very low density lipoprotein (VLDL) and dense LDL-Cholesterol, and lower HDL2 cholesterol levels than the controls; these abnormalities persisted in the HiCarbo diet, whilst a significant decrease in the dense LDL associated with an increase in the HDL2 cholesterol was seen in the HiMUFA diet. HDL3 was not affected by either diet. The LDL/HDL-Cholesterol ratio was not affected by the HiCarbo diet, whilst it was significantly reduced after 6 months of HiMUFA diet as compared with baseline. Apo AI increased in the HiMUFA group, and decreased in the HiCarbo group. CONCLUSIONS: Both diets were effective in decreasing body weight. At steady weight conditions, only the HiMUFA diet improved LDL and HDL subclass distribution abnormalities present in mildly obese normolipidemic women.
Adult↗
Pathological analysis of nonstented Freestyle aortic root bioprostheses treated with amino oleic acid.
We examined 67 explanted Medtronic Freestyle (MF) valves of 0 to 1,490 days of implantation from 66 patients, including 9 full-root, 17 root inclusion, and 41 subcoronary implants derived from a multicenter trial composed of 1,100 patients at 27 centers worldwide (58 valves) and other removed specimens (9 valves). Macroscopic, radiographic and histological examination was performed to establish clinicopathological correlations in retrieved MF stentless aortic bioprostheses. Indications for 30 explants obtained at reoperation were perioperative technical (1 bleeding, 3 iatrogenic valve damage), endocarditis (11), sterile perivalvular leak (4), valve stenosis (1) regurgitation (3), fistula (2), or degeneration (2 cuspal tears, 1 cusp separation). Autopsy specimens were obtained after valve-related (9), non-valve-related (22), or perioperative death (6). Most non-valve-related deaths were cardiac. Valve-related deaths included endocarditis (4), paravalvular leak (1), thrombus (2), subannular occlusion (1), and tamponade (1). No excessive pannus was present. Macroscopic valve thrombosis was noted in two subcoronary implants of 180 and 279 days' duration. Histological analysis on all valves of more than 10 days implant duration or with macroscopic abnormality revealed variable but progressive flattening of the valve cusps; focal, plaquelike unorganized mural thrombus; cuspal fluid insudation; and generalized, nonspecific degenerative changes typical of explanted porcine valves. Aortic wall calcification was seen in two explants of 47 and 49 months' duration, the later with associated cuspal tear. Cusp mineralization was limited to infected valves. No excessive inflammation or fibrosis at the host-device interface was noted. Pathological findings were generally similar to those seen in clinically used glutaraldehyde-fixed xenografts. Potential pathology related to stentless design including pannus, aortic wall calcification, and host-tissue interaction were not clinically significant. Nevertheless, examination of many explanted valves at extended intervals and ongoing clinical data are needed to confirm the long-term efficacy, safety, and characteristic modes of failure of stentless bioprostheses.
Adult↗
Unsaturated fatty acids induce calcium influx into keratinocytes and cause abnormal differentiation of epidermis.
Abnormal follicular keratinization is involved in comedogenesis in acne vulgaris. We recently demonstrated that calcium influx into epidermal keratinocytes is associated with impaired skin barrier function and epidermal proliferation. Based on these results, we hypothesized that sebum components affect calcium dynamics in the keratinocyte and consequently induce abnormal keratinization. To test this idea, we first observed the effects of topical application of sebum components, triglycerides (triolein), saturated fatty acids (palmitic acid and stearic acid), and unsaturated fatty acids (oleic acid and palmitoleic acid) on hairless mouse skin. Neither triglyceride nor saturated fatty acids affected the skin surface morphology or epidermal proliferation. On the other hand, application of unsaturated fatty acids, oleic acid, and palmitoleic acid induced scaly skin, abnormal keratinization, and epidermal hyperplasia. Application of triglycerides and saturated fatty acids on cultured human keratinocytes did not affect the intracellular calcium concentration ([Ca(2+)](i)), whereas unsaturated fatty acids increased the [Ca(2+)](i) of the keratinocytes. Moreover, application of oleic acid on hairless mouse skin induced an abnormal calcium distribution in the epidermis. These results suggest that unsaturated fatty acids in sebum alter the calcium dynamics in epidermal keratinocytes and induce abnormal follicular keratinization.
Acne Vulgaris↗