Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “OLEIC 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.

At least 775 records · Page 43Linked to original sources

High oleic acid oil suppresses lung tumorigenesis in mice through the modulation of extracellular signal-regulated kinase cascade.

This study was undertaken to estimate the effect of dietary high oleic acid oil (OA) on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumorigenesis in mice. Diet containing 10% oil was fed to mice through experimental periods. On day 30 after NNK injection (100 mg/kg body weight, i.p.), the treatment increased the level of prostaglandin E2 (PGE2) as well as proliferating cell nuclear antigen, a marker of cell proliferation in a high linoleic acid oil (LA)-fed group but not in an OA-fed group. The NNK treatment also induced the activation of an extracellular signal-regulated kinase (Erk) cascade (Erk, Mek and Raf-1) in an LA-fed group. On the other hand, OA feeding abolished the NNK-induced activation of the Erk cascade. In conjugation with these events, OA feeding reduced lung tumor incidence and tumor multiplicity (percentage of mice with tumors) in mice compared with LA feeding at the 20th experimental week. These results suggest that OA suppresses lung tumorigenesis and that this suppression is correlated with the inhibition of PGE2 production and inactivation of the Erk cascade.

Animals↗

Diet-induced thermogenesis is lower in rats fed a lard diet than in those fed a high oleic acid safflower oil diet, a safflower oil diet or a linseed oil diet.

The objectives of the present study were to examine the effects of dietary fats differing in fatty acid composition on diet-induced thermogenesis, sympathetic activity in brown adipose tissue and body fat accumulation in rats. Rats were meal-fed for 12 wk an isoenergetic diet based on lard, high oleic acid safflower oil, safflower oil or linseed oil, and norepinephrine turnover rates in brown adipose tissue were then estimated. Whole-body oxygen consumption after the meal indicated that diet-induced thermogenesis was significantly lower in rats fed the lard diet than in those fed the other diets. The norepinephrine turnover rate in the interscapular brown adipose tissue was also significantly lower in the lard diet group than in the other diet groups. The carcass fat content was significantly higher in the lard diet group than in the other diet groups, whereas the abdominal adipose tissue weights were the same in all diet groups. These results suggest that the intake of animal fats rich in saturated fatty acids, compared with the intake of vegetable oils rich in monounsaturated or polyunsaturated fatty acids, decreases diet-induced thermogenesis by a decline of sympathetic activity in brown adipose tissue, resulting in the promotion of body fat accumulation.

Adipose Tissue, Brown↗

Association with oleic acid vesicles enhances manganese III mesoporphyrin absorption and biliary elimination in rats.

OBJECTIVE: To determine whether the association of manganese III mesoporphyrin (MnMeso), an oral MR contrast agent, to oleic acid (OA) vesicles will improve absorption and delivery of MnMeso to the liver. METHODS: MnMeso or MnMeso-OA vesicle suspension was intraduodenally administered to rats and the time course of MnMeso concentration in plasma, bile, and intestinal solution was determined. Tissue concentrations of MnMeso in the liver were also determined. RESULTS: Association of MnMeso to OA reduced the time it took to reach one-half absorption maximum, TC50, and enhanced the rate and the extent of biliary elimination of this contrast agent. In addition, the results obtained from dose-titration studies indicate that MnMeso-OA vesicle complex may enhance MnMeso accumulation in the liver, observed as a lower dose required to reach equivalent tissue concentration. Taken together, complexion to OA vesicles may provide rapid absorption, enhanced liver accumulation, and efficient elimination of MnMeso. CONCLUSIONS: Association with OA vesicles may enhance the rate of MnMeso absorption and biliary excretion while promoting the extent of liver accumulation of MnMeso in rats. This strategy may provide a means to provide safe and effective use of MnMeso as an MR contrast medium.

Animals↗

Biochemical characterization of temperature-induced changes in lipid metabolism in a high oleic acid mutant of Brassica rapa.

We have characterized a Brassica rapa mutant (WR586) that has low levels of polyunsaturated fatty acids (D.L. Auld et al., 1992, Crop Sci. 32, 657-662). The mutant lacked oleoyl-phosphatidylcholine desaturase (ODS) activity when assayed in 6-day-old seedlings. To further characterize the mutant, the leaf fatty acid composition and major galactolipids and phospholipids were characterized in mutant (WR586) and control (cultivar "Tobin") plants grown at either 26 degrees C/26 degrees C or 10 degrees C/5 degrees C. Fatty acid profiles show significantly higher 18:1 levels in WR586 throughout 12 days of germination. The amount of saturated fatty acids decreased with a concomitant increase of 18:1. Ratios of 18:1/18:2 revealed that WR586 maintains higher mole percent of 18:1 than Tobin at all times and temperature regimes because of a lack of desaturation to 18:2. Values for monogalactosyl-diacylglycerol and digalactosyldiacylglycerol 18:1/18:2 ratios indicate a disparity in the concentration of 18:1 between WR586 and Tobin grown in either temperature during early germination. The phosphatidylcholine and phosphatidylethanolamine 18:1/18:2 ratios were higher in WR586 compared to Tobin and remained higher throughout the 12-day period. In WR586, 18:1 always accumulated to higher levels in the cooler temperature. In Tobin, 18:1 concentrations paralleled 18:2 in both temperature regimes. These results indicate that the lesion in the mutant WR586 resides at the ODS locus, 18:1 synthesis is chilling induced, and the microsomal desaturation pathway is the most prominent in early developing Brassica seedlings.

Brassica↗

[Influence of different doses of porcine pulmonary on the therapeutic effects in rats with oleic acid induced acute lung injury].

OBJECTIVE: To investigate the therapeutic effects and dose effect relationship of intratracheal instillation of different doses of porcine pulmonary surfactant (PPS) in rats with oleic acid (OA) induced acute lung injury (ALI). METHODS: Arterial blood gases and respiratory rate during the experiments, survival rate, lung index, total protein (TP) content in bronchoalveolar lavage fluid (BALF), tumor necrosis factor-alpha (TNF-alpha) level in plasma, light microscopy examination of lung specimens after the experiments were determined and performed in control group, OA (0.2 ml/kg) + saline, OA + PPS 50 mg/kg, OA+PPS 80 mg/kg, OA+PPS 100 mg/kg, OA+PPS 150 mg/kg, OA+PPS 200 mg/kg groups, respectively. RESULTS: In PPS 50 mg/kg group, arterial blood gases were improved and respiratory rate was reduced during the first 2 hours (P<0.05). Arterial blood gases and reduced breath rates respiratory rate were not improved in other PPS treatment groups but 4 hours-survival rate was lowered, lung index was decreased, protein content s in BALF and TNF-alpha level in serum were lowered, and pathological changes were ameliorated compared with group given saline after OA, especially in high dosage of PPS (150-200 mg/kg) group (P<0.05). CONCLUSION: Administration of PPS via trachea provides obvious effects on respiratory functions in rats with OA induced ALI, moreover PPS (> or =80 mg/kg) alleviates lung injury. There is no dose-effect relationship of PPS in PPS-treatment groups.

Acute Lung Injury↗

Effects of oleic acid on distinct populations of neurons in the hypothalamic arcuate nucleus are dependent on extracellular glucose levels.

Pharmacological manipulation of fatty acid metabolism in the hypothalamic arcuate nucleus (ARC) alters energy balance and glucose homeostasis. Thus, we tested the hypotheses that distinctive populations of ARC neurons are oleic acid (OA) sensors that exhibit a glucose dependency, independent of whether some of these OA sensors are also glucose-sensing neurons. We used patch-clamp recordings to investigate the effects of OA on ARC neurons in brain slices from 14- to 21-day-old Sprague-Dawley (SD) rats. Additionally, we recorded spontaneous discharge rate in ARC neurons in 8-wk-old fed and fasted SD rats in vivo. Patch-clamp studies showed that in 2.5 mM glucose 12 of 94 (13%) ARC neurons were excited by 2 microM OA (OA-excited or OAE neurons), whereas six of 94 (6%) were inhibited (OA-inhibited2.5 or OAI2.5 neurons). In contrast, in 0.1 mM glucose, OA inhibited six of 20 (30%) ARC neurons (OAI0.1 neurons); none was excited. None of the OAI0.1 neurons responded to OA in 2.5 mM glucose. Thus OAI2.5 and OAI0.1 neurons are distinct. Similarly, in seven of 20 fed rats (35%) the overall response was OAE-like, whereas in three of 20 (15%) it was OAI-like. In contrast, in fasted rats only OAI-like response were observed (three of 15; 20%). There was minimal overlap between OA-sensing neurons and glucose-sensing neurons. In conclusion, OA regulated three distinct subpopulations of ARC neurons in a glucose-dependent fashion. These data suggest that an interaction between glucose and fatty acids regulates OA sensing in ARC neurons.

Action Potentials↗

Perfusion characteristics of oleic acid--injured canine lung on Gd-DTPA--enhanced dynamic magnetic resonance imaging.

RATIONALE AND OBJECTIVES: We conducted an animal study to describe and interpret the perfusion characteristics of oleic acid (OA)-injured lungs on gadopentetate dimeglumine (Gd-DTPA)-enhanced dynamic perfusion magnetic resonance (MR) imaging. METHODS: Fourteen dogs received an intravenous OA infusion in the supine (n = 4), prone (n = 4), and right lateral decubitus (n = 6) positions, and 10 minutes later these animals in the same postures underwent the dynamic MR study. Regional Gd-DTPA kinetics was analyzed by the time-signal intensity (SI) curves and by qualitative functional map images of the mean transit time that was representative of the mean circulation time in the vascular bed and the average cumulative sum of the relative increases in SI representative of Gd-DTPA distribution volume during Gd-DTPA first pass. The results were compared with those in six control animals and in another six animals that underwent the MR study 3 minutes (n = 3) and 60 minutes (n = 3) after OA infusion. The MR findings were correlated with the distribution of lung damage and the infused OA particles as assessed by histology. RESULTS: The dynamic MR study showed postural shifts on the gravity-dependent perfusion map of normal lungs. Contrast enhancement during Gd-DTPA first pass in the lung was lower and more heterogeneous in the OA-injured lung models than in controls but was followed by conversely greater and persistent enhancement during the Gd-DTPA redistribution phase. Regardless of the postures for OA infusion, these abnormalities were predominant in the dependent lungs and became more pronounced with time after OA infusion, where more prominent capillary obstruction with OA droplets and alveolar/interstitial edema were histologically observed. On the functional map images, greater mean transit time and the average cumulative sum of the relative increases in SI values were also predominantly distributed in the dependent lungs. CONCLUSIONS: Low and heterogeneous enhancement was observed during Gd-DTPA first pass but was followed by persistent enhancement during the Gd-DTPA redistribution phase, and predominant abnormalities in the dependent lungs may be characteristic features of the perfusion of OA-injured lungs. The histological correlations indicate that these abnormalities may reflect OA-induced pathophysiologies associated with capillary OA obstruction, increased vascular resistance, and capillary permeability/extravascular spaces and that lung damage may be gravity dependent.

Animals↗

Oleic acid reduces oxidant stress in cultured pulmonary artery endothelial cells.

Altering the fatty acid composition of cultured porcine pulmonary artery endothelial cells (PAEC) modulates their susceptibility to oxidant stress. This study demonstrates that supplementing PAEC with oleic acid (18:1 omega 9), but not gamma-linolenic acid (18:3 omega 6), provided dose-dependent protection from hydrogen peroxide (H2O2)-induced cytotoxicity. It was hypothesized that 18:1 reduced PAEC susceptibility to oxidant stress by altering H2O2 metabolism. To test this hypothesis, confluent PAEC monolayers were treated with 100-200 microM H2O2 or control conditions 24 h after supplementation with 0.1 mM 18:1, 18:3, or vehicle for 3 h. Intracellular [H2O2] in control cells (14.4-29.0 pM), estimated from the rate of aminotriazole-mediated inactivation of endogenous catalase activity, increased following treatment with 200 microM H2O2 (19.0-37.3 pM). Supplementation with 18:1 attenuated increases in intracellular [H2O2] only in oxidant-exposed cells, whereas supplementation with 18:3 attenuated intracellular [H2O2] only in control cells. Supplementation with 18:1 or 18:3 tended to reduce or enhance PAEC lipid hydroperoxide content following H2O2 exposure, respectively, but did not alter PAEC reduced glutathione content, the activities of glutathione peroxidase or catalase, or H2O2 uptake and release. Alteration of H2O2 metabolism in cultured PAEC may contribute to the ability of fatty acids to modulate cellular oxidant susceptibility.

Animals↗

Distal effects of tracheal gas insufflation: changes with catheter position and oleic acid lung injury.

We separated distal (turbulence-related) and proximal (dead space washout-related) effects of tracheal gas insufflation (TGI) by comparing the effects of straight and inverted catheters. We reasoned that the inverted catheter was unlikely to remove CO2 from conducting airways distal to its orifice. In six normal dogs during TGI at 10 l/min, advancing the catheters from 10 to 1 cm above the main carina decreased dead space volume by 29 +/- 12 and 12 +/- 6 ml (P < 0.04) with the straight and inverted catheters, respectively. By comparison, the tracheal volume between 10 and 1 cm above the carina was 15 +/- 2 ml. In another set of dogs (n = 5), we examined the distal effects of TGI before and after oleic acid-induced lung injury. During TGI at 10 l/min before and after oleic acid injury, the differences in arterial PCO2 between the straight and inverted catheters were 5 +/- and 9 +/- 6 Torr (P < 0.18), respectively. Our data suggest that distal effects of TGI become more pronounced as the catheter tip is positioned closer to the main carina. The distal effects of TGI were not diminished after oleic acid injury when minute ventilation was maintained constant.

Animals↗

From dysbiosis to homeostasis: Oleic acid matters in the vagina.

The role of fatty acids in shaping vaginal microbiota remains unclear. In an issue of Cell, Zhu et&#xa0;al. use genomic and transcriptomic analyses to reveal that oleic acid (OA) selectively inhibits L.&#xa0;iners while promoting L.&#xa0;crispatus, suggesting new strategies for the treatment of bacterial vaginosis (BV).

Female↗

Effects of oleic acid on the high threshold barium current in seabass Dicentrarchus labrax ventricular myocytes.

The present study employed a patch clamp technique in isolated seabass ventricular myocytes to investigate the hypothesis that oleic acid (OA), a mono-unsaturated fatty acid, can exert direct effects upon whole-cell barium currents. Acute application of free OA caused a dose-dependent depression of the whole-cell barium current that was evoked by a voltage step to 0 mV from a holding potential of -80 mV. The derived 50% inhibitory concentration (IC50) was 12.49+/-0.27 micromol l(-1). At a concentration of 30 micromol l(-1), OA significantly reduced the current density to about 45% of control values, but did not modify either the shape of the current-density voltage relationship or the apparent reversal potential. In addition, OA did not modify the voltage dependence of either steady state inactivation or activation curves. Taken together, these results indicate that physiological concentrations of free OA decrease the conductance of the L-type inward current, without altering its properties of selectivity and its voltage dependence. The inhibitory effect of OA upon the L-type calcium channel may translate, in vivo, into a protective effect against arrhythmias induced by Ca2+ overload.

Animals↗