942 resultados para Linoleic acid (LA)
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The aim of this study was to determine and compare the fatty acid (FA) composition of colostrum and mature milk produced by nursing mothers of preterm and at-term newborns, in Florianopolis, SC, Brazil. Low contents of Eicosapentaenoic acid (EPA) (0.02%/colostrum and 0.01%/mature milk for preterm and term milk) and Docosahexaenoic acid (DHA) (colostrum group: 0.10%/preterm and 0.09%/term; mature milk: 0.05%/preterm and 0.03%/term) were determined. The comparison among the groups showed that the elaidic acid content was significantly higher (1.67%) in mature term milk. The content of rumenic acid (conjugated linoleic acid) was significantly higher in at-term colostrum compared with preterm colostrum. When considering the maturity of the milk, there was a significant increase in the percentage of this FA in the preterm group. The results show that, overall, the greatest differences observed were between the colostrums and mature milks for both groups and not between preterm and at-term mothers.
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The objective in this study was to determine growth, carcass characteristics, chemical composition and fatty acid profile of the longissimus dorsi of crossbred Boer x Saanen kids fed castor oil. Twenty-four kids (12 males and 12 females) were assigned in a randomized complete block design with two treatments and twelve replications. Blocks were defined according to weight, gender and initial age of animals for the evaluation of performance. The experimental treatments consisted of two diets containing 900 g concentrate/kg: a control diet (without addition of oil) and another containing castor oil at 30 g/kg (on a dry matter basis). After they reached an average body weight of 25 kg, males were slaughtered for the evaluation of carcass characteristics, chemical composition and fatty acid profile of the longissimus dorsi muscle. The addition of castor oil in the diet did not affect the intake of dry matter, crude protein and neutral detergent fiber; the average daily gain; and feed conversion, but increased the ether extract intake. No difference was observed for the carcass characteristics, chemical composition of the meat, concentration of C18:2 cis-9, trans-11 (CLA) and total concentration of saturated, monounsaturated and polyunsaturated fatty acids and their relations; however, there was increase in the concentrations of C18:2 trans-10, cis-12 (CLA) and C20:4 omega-6. The addition of castor oil to the diet of crossbred Boer x Saanen kids containing a high content of concentrate did not promote benefit to the characteristics evaluated.
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The toxicity of palmitic acid (PA) towards a human T-lymphocyte cell line (Jurkat) has been previously investigated but the mechanism(s) of PA action were unknown. In the current study, Jurkat cells were treated with sub-lethal concentrations of PA (50-150 mu M) and the activity of various signaling proteins was investigated. PA-induced apoptosis and mitochondrial dysfunction in a dose-dependent manner as evaluated by DNA fragmentation assay and depolarization of the mitochondrial membrane, respectively. PA treatment provoked release of cytochrome c from the inner mitochondrial membrane to the cytosol, activated members of the MAPK protein family JNK, p38, ERK, activated caspases 3/9, and increased oxidative/nitrosative stress. Exposure of cells to PA for 12 h increased insulin receptor (IR) and GLUT-4 levels in the plasma membrane. Insulin treatment (10 mU/ml/30 min) increased the phosphorylation of the IR beta-subunit and Akt. A correlation was found between DNA fragmentation and expression levels of both IR and GLUT-4. Similar results were obtained for PA-treated lymphocytes from healthy human donors and from mesenteric lymph nodes of 48-h starved rats. PA stimulated glucose uptake by Jurkat cells (in the absence of insulin), stimulated accumulation of neutral lipids (triglyceride), and other lipid classes (phospholipids and cholesterol ester) but reduced glucose oxidation. Our results suggest that parameters of insulin signaling and non-oxidative glucose metabolism are stimulated as part of a coordinated response to prompt survival in lymphocytes exposed to PA but at higher concentrations, apoptosis prevails. These findings may explain aspects of lymphocyte dysfunction associated with diabetes. J. Cell. Physiol. 227: 339-350, 2012. (C) 2011 Wiley Periodicals, Inc.
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INTRODUCTION Atopic dermatitis (AD) has been related to a deficiency of delta-6-desaturase, an enzyme responsible for the conversion of linoleic acid to gamma-linolenic acid (GLA). Evening primrose oil (EPO) contains high amounts of GLA. Therefore, this study investigated whether EPO supplementation results in an increase in plasma GLA and its metabolite dihomo-gamma-linolenic acid (DGLA) correlating with clinical improvement of AD, assessed by the SCORing Atopic Dermatitis (SCORAD) index. METHODS The open study included 21 patients with AD. EPO (4-6 g) was administered daily for 12 weeks. Before treatment, and 4 and 12 weeks after initiation of EPO supplementation, objective SCORAD was assessed and plasma concentrations of GLA and DGLA were determined by gas chromatography. RESULTS A significant increase in plasma GLA and DGLA levels and a decrease in the objective SCORAD were observed 4 and 12 weeks after initiation of EPO treatment. In the per-protocol population (n = 14), a significant inverse correlation between the changes in plasma GLA levels and SCORAD was found (P = 0.008). CONCLUSION The clinical disease activity under EPO treatment correlates with the individual increase in plasma GLA levels. Thus, the results of this pilot study indicate that an increase in plasma GLA might be used as predictive parameter for responsiveness of AD to EPO therapy.
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Se evaluó y comparó las características de carcasas de cabritos cruza Saanen y Criollo alimentados durante 60 días con tres sustitutos lácteos diferentes: sustituto formulado en la unidad experimental FCA, sustituto comercial para terneros COM y leche de vaca LEC. Se evaluó la aceptación de la carne obtenida por parte del consumidor de Mendoza, Argentina, y la composición acídica de las carcasas. Las diversas dietas provocaron diferencias significativas (p < 0.05) en el contenido de grasa intramuscular de las carcasas: 8.08; 6.27 y 13.45 % respectivamente para FCA, COM y LEC. También se encontraron diferencias (p < 0.05) en la composición acídica, principalmente en la proporción de ácido linoleico (C18:0) en los cabritos FCA respecto de los otros, resultado de la incorporación de una alta proporción de aceites vegetales en su fórmula. No obstante los distintos contenidos grasos y composición acídica no hubo diferencias significativas de aceptación por parte del consumidor (p < 0.05).
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A total of 200 (Landrace3Large White dam3Pietrain3Large White sire) gilts of 5063 days of age (23.361.47 kg BW) were used to investigate the effects of castration (intact gilt, IG v. castrated gilt, CG) and slaughter weight (SW; 106 v. 122 kg BW) on productive performance, carcass and meat quality. Four treatments were arranged factorially and five replicates of 10 pigs each per treatment. Half of the gilts were ovariectomized at 58 days of age (8 days after the beginning of the trial at 29.861.64 kg BW), whereas the other half remained intact. The pigs were slaughtered at 106 or 122 kg BW. Meat samples were taken at Musculus longissimus thoracis at the level of the last rib and subcutaneous fat samples were taken at the tail insertion. For the entire experimental period, CG had higher ( P,0.05) BW gain and higher ( P,0.001) backfat and Musculus gluteus medius fat thickness than IG. However, IG had higher ( P,0.05) loin and trimmed primal cut yields than CG. Meat quality was similar for IG and CG but the proportion of linoleic acid in subcutaneous fat was higher ( P,0.001) for IG. Pigs slaughtered at 122 kg BW had higher ( P,0.001) feed intake and poorer feed efficiency than pigs slaughtered at 106 kg BW. An increase in SW improved ( P,0.001) carcass yield but decreased ( P,0.05) trimmed primal cut yield. Meat from pigs slaughtered at the heavier BW was redder (a*; P,0.001) and had more ( P,0.01) intramuscular fat and less thawing ( P,0.05) and cooking ( P,0.10) loss than meat from pigs slaughtered at the lighter BW. In addition, pigs slaughtered at 122 kg BW had less ( P,0.01) linoleic acid content in subcutaneous fat than pigs slaughtered at 106 kg BW. Castration of gilts and slaughtering at heavier BW are useful practices for the production of heavy pigs destined to the dry-cured industry in which a certain amount of fat in the carcass is required. In contrast, when the carcasses are destined to fresh meat production, IG slaughtered at 106 kg BW is a more efficient alternative.
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The main objetive of this Doctoral Thesis was to study the influence of female castration and pig sex on growth performance and carcass and meat quality of white pigs slaughtered at different final weights. Three experiments (Exp.) were conducted. In Exp. 1, a total of 200 (Landrace * Large White dam x Pietrain * Large White sire) gilts of 50 ± 3 days of age (23.3 ± 1.47 kg BW) was used to investigate the effects of castration (intact females, IF vs. castrated feamles, CF) and slaughter weight (106 vs. 122 kg BW) on productive performance and carcass and meat quality. There were four experimental treatments arranged as a 2 x 2 factorial and 5 replicates of 10 pigs each per treatment. Half of the gilts were ovariectomized at 58 d of age (8 days after the beginning of the trial; 29.8 ± 1.64 kg BW) whereas the other half remained intact. Meat samples were taken at m. Longissimus thoracis at the level of the last rib and subcutaneous fat samples were taken at the tail insertion. For the entire experiment period, CF had higher BW gain (P<0.05) and backfat and m. Gluteus medius (GM) fat thickness (P<0.001) than IF. However, IF had higher loin and trimmed primal cut yields (P<0.05) than CF. Meat quality was similar for IF and CF but the proportion of linoleic acid in subcutaneous fat was higher (P<0.001) for IF. Pigs slaughtered at 122 kg BW had higher (P<0.001) feed intake and poorer feed efficiency than pigs slaughtered at 106 kg BW. An increase in slaughter weight (SW) improved (P<0.001) carcass yield but decreased (P<0.05) trimmed primal cut yield. Meat from females slaughtered at the heavier BW was redder (a*; P<0.001) and had more (P<0.01) intramuscular fat and less thawing (P<0.05) and cooking (P<0.10) loss than meat from females slaughtered at the lighter BW. Also, females slaughtered at 122 kg BW had less (P<0.01) linoleic acid content in the subcutaneous fat than pigs slaughtered at 106 kg BW. Castration of gilts and slaughtering at heavier BW might be useful practices for the production of heavy pigs destined to the dry cured industry in which a certain amount of fat in the carcass is required. In contrast, when the carcasses are destined to fresh meat production, IF slaughtered at 106 kg BW are a more efficient alternative. In Exp. 2, crossbred pigs (n=240) from Pietrain*Large White sires mated to Landrace*Large White dams with an average of 100 d of age (60.5 ± 2.3 kg) were used to investigate the effects of gender and slaughter weight (SW) on growth performance and carcass and meat quality characteristics. There were 6 treatments arranged factorially with 3 genders (IF vs. CF vs.castrated males, CM) and 2 SW (114 vs. 122 kg BW). Each of the 6 combinations of treatments was replicated 4 times and the experimental unit was a pen with 10 pigs. Castrated males and CF ate more feed, grew faster and had more carcass backfat depth and fat thickness at the GM muscle, but lower loin yield than IF (P<0.05). In addition, CF and CM had more intramuscular fat (P<0.05) and less linoleic acid content in the subcutaneous fat (P<0.01) than IF. Pigs slaughtered at 122 kg BW had lower ADG (P<0.05), poor gain-to-feed ratio (P<0.05), and more GM fat than pigs slaughtered at 114 kg BW (P < 0.05). It is concluded that CF and CM had similar productive performance and meat quality characteristics when slaughtered at the same age, and that the castration of females improved daily gains and increased weight and fat content of primal cuts with respect to IF. Therefore, castration of females is recommended in pigs destined to the dry-cured industry because of the beneficial effects on the quality of the primal cuts. In Exp. 3, the effects of gender and castration of females (IF vs. CF vs. CM) on performance and carcass and meat quality were studied in crossbred pigs (Landrace x Large White dams x Duroc sires) slaughtered at 119.2 (trial 1) or 131.6 (trial 2) kg BW. Intact females had better feed conversion and less carcass fat than CF and CM. Trimmed shoulder yield was higher for CM than for CF with IF being intermediate. Primal cut yield and meat quality, however were similar for all treatments. Proportion of linoleic acid in backfat was lower for CF than for IF or CM, and the differences were significant in pigs slaughtered witn 131.6 kg BW. The higher fat content and the fatty acid profile favour the use of CF and CM over IF for the production of heavy pigs destined to the dry-cured industry.
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In kidney epithelial cells, an angiotensin II (Ang II) type 2 receptor subtype (AT2) is linked to a membrane-associated phospholipase A2 (PLA2) and the mitogen-activated protein kinase (MAPK) superfamily. However, the intervening steps in this linkage have not been determined. The aim of this study was to determine whether arachidonic acid mediates Ang II’s effect on p21ras and if so, to ascertain the signaling mechanism(s). We observed that Ang II activated p21ras and that mepacrine, a phospholipase A2 inhibitor, blocked this effect. This activation was also inhibited by PD123319, an AT2 receptor antagonist but not by losartan, an AT1 receptor antagonist. Furthermore, Ang II caused rapid tyrosine phosphorylation of Shc and its association with Grb2. Arachidonic acid and linoleic acid mimicked Ang II-induced tyrosine phosphorylation of Shc and activation of p21ras. Moreover, Ang II and arachidonic acid induced an association between p21ras and Shc. We demonstrate that arachidonic acid mediates linkage of a G protein-coupled receptor to p21ras via Shc tyrosine phosphorylation and association with Grb2/Sos. These observations have important implications for other G protein-coupled receptors linked to a variety of phospholipases.
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Jasmonic acid and its precursors are potent regulatory molecules in plants. We devised a method for the simultaneous extraction of these compounds from plant leaves to quantitate changes in the levels of jasmonate family members during health and on wounding. During our study, we identified a novel 16-carbon cyclopentenoic acid in leaf extracts from Arabidopsis and potato. The new compound, a member of the jasmonate family of signals, was named dinor-oxo-phytodienoic acid. Dinor-oxo-phytodienoic acid was not detected in the Arabidopsis mutant fad5, which is incapable of synthesizing 7Z,10Z,13Z-hexadecatrienoic acid (16:3), suggesting that the metabolite is derived directly from plastid 16:3 rather than by β-oxidation of the 18-carbon 12-oxo-phytodienoic acid. Simultaneous quantitation of jasmonate family members in healthy leaves of Arabidopsis and potato suggest that different plant species have different relative levels of jasmonic acid, oxo-phytodienoic acid, and dinor-oxo-phytodienoic acid. We term these profiles “oxylipin signatures.” Dinor-oxo-phytodienoic acid levels increased dramatically in Arabidopsis and potato leaves on wounding, suggesting roles in wound signaling. Treatment of Arabidopsis with micromolar levels of dinor-oxo-phytodienoic acid increased the ability of leaf extracts to transform linoleic acid into the α-ketol 13-hydroxy-12-oxo-9(Z) octadecenoic acid indicating that the compound can regulate part of its own biosynthetic pathway. Tightly regulated changes in the relative levels of biologically active jasmonates may permit sensitive control over metabolic, developmental, and defensive processes in plants.
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The best mating strategy for males differs from that of females, because females gain from mating with several males (polyandry), but males gain from monopolizing the females. As a consequence, males have evolved a variety of methods, such as the transfer of inhibitory substances from their accessory glands, to ensure exclusive paternity of the female's offspring, generally with detrimental effects on female fitness. Inhibitory substances have been identified as peptides or other specific molecules. Unfortunately, in social insects male-mating traits are investigated only poorly, although male social insects might have the same fundamental influence on female-mating behavior as found in other species. A recently developed technique for the artificial insemination of bumblebee queens allowed us to investigate which chemical compound in the mating plug of male bumblebees, Bombus terrestris L., prevents females (queens) from further mating. Surprisingly, we found that the active substance is linoleic acid, a ubiquitous and rather unspecific fatty acid. Contrary to mating plugs in other insect species, the bumblebee mating plug is highly efficient and allows the males to determine queen-mating frequencies.
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Microsomal ω-3 fatty acid desaturase catalyzes the conversion of 18:2 (linoleic acid) to 18:3 (α-linolenic acid) in phospholipids, which are the main constituents of extrachloroplast membranes. Transgenic tobacco (Nicotiana tabacum) plants with increased 18:3 contents (designated SIIn plants) were produced through the introduction of a construct with the tobacco microsomal ω-3 fatty acid desaturase gene under the control of the highly efficient promoter containing the E12Ω sequence. 18:3 contents in the SIIn plants were increased by about 40% in roots and by about 10% in leaves compared with the control plants. With regard to growth at 15°C and 25°C and the ability to tolerate chilling at 1°C and 5°C, there were no discernible differences between the SIIn and the control plants. Freezing tolerance in leaves and roots, which was assessed by electrolyte leakage, was almost the same between the SIIn and the control plants. The fluidity of plasma membrane from the SIIn plants was almost the same as that of the control plants. These results indicate that an increase in the 18:3 level in phospholipids is not directly involved in compensation for the diminishment in growth or membrane properties observed under low temperatures.
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A number of acute wasting conditions are associated with an upregulation of the ubiquitin-proteasome system in skeletal muscle. Eicosapentaenoic acid (EPA) is effective in attenuating the increased protein catabolism in muscle in cancer cachexia, possibly due to inhibition of 15-hydroxyeicosatetraenoic acid (15-HETE) formation. To determine if a similar pathway is involved in other catabolic conditions, the effect of EPA on muscle protein degradation and activation of the ubiquitin-proteasome pathway has been determined during acute fasting in mice. When compared with a vehicle control group (olive oil) there was a significant decrease in proteolysis of the soleus muscles of mice treated with EPA after starvation for 24 h, together with an attenuation of the proteasome 'chymotryptic-like' enzyme activity and the induction of the expression of the 20S proteasome α-subunits, the 19S regulator and p42, an ATPase subunit of the 19S regulator in gastrocnemius muscle, and the ubiquitin-conjugating enzyme E214k. The effect was not shown with the related (n-3) fatty acid docosahexaenoic acid (DHA) or with linoleic acid. However, 2,3,5trimethyl-6-(3-pyridylmethyl)1,4-benzoquinone (CV-6504), an inhibitor of 5-, 12- and 15-lipoxygenases also attenuated muscle protein catabolism, proteasome 'chymotryptic-like' enzyme activity and expression of proteasome 20S α-subunits in soleus muscles from acute fasted mice. These results suggest that protein catabolism in starvation and cancer cachexia is mediated through a common pathway, which is inhibited by EPA and is likely to involve a lipoxygenase metabolite as a signal transducer. © 2001 Academic Press.
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A series of antioxidants was used to explore the cytotoxicity of one particularly toxic antimycobacterial 2-pyridylcarboxamidrazone anti-tuberculosis agent against human mononuclear leucocytes (MNL), in comparison with isoniazid (INH) to aid future compound design. INH caused a significant reduction of nearly 40% in cell recovery compared with control (P < 0.0001), although the co-incubation with either glutathione (GSH, 1 mM) or (NAC, 1 mM) showed abolition of INH toxicity. In contrast, the addition of GSH or NAC 1 h after INH failed to protect the cells from INH toxicity (P < 0.0001). The 2-pyridyl-carboxamidrazone 'Compound 1' caused a 50% reduction in cell recovery compared with control (P < 0.001), although this was abolished by the presence of either GSH or NAC. A 1 h post incubation with either NAC or GSH after Compound 1 addition failed to protect the cells from toxicity (P < 0.001). Co-administration of lipoic acid (LA) abolished Compound 1-mediated toxicity, although again, this effect did not occur after LA addition 1 h post incubation with Compound 1 (P < 0.001). However, co-administration of dihydrolipoic acid (DHLA) prevented Compound 1-mediated cell death when incubated with the compound and also after 1 h of Compound 1 alone. Pre-treatment with GSH, then removal of the antioxidant resulted in abolition of Compound 1 toxicity (vehicle control, 63.6 ± 16.7 versus Compound 1 alone 26.1 ± 13.6% versus GSH pre-treatment, 65.7 ± 7.3%). In a cell-free incubation, NMR analysis revealed that GSH does not react with Compound 1, indicating that this agent is not likely to directly deplete membrane thiols. Compound 1's MNL toxicity is more likely to be linked with changes in cell membrane conformation, which may induce consequent thiol depletion that is reversible by exogenous thiols. © 2004 Elsevier B.V. All rights reserved.
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Introduction: Preeclampsia is the main complication of pregnancy in developing countries. Calcium starting at 14 weeks of pregnancy is indicated to prevent the disease. Recent advances in prevention of preeclampsia endorse the addition of conjugated linoleic acid. Objective: To estimate the protective effect from calcium alone, compared to calcium plus conjugated linoleic acid in nulliparous women at risk of preeclampsia. Methods: A case-control design nested in the cohort of nulliparous women attending antenatal care from 2010 to 2014. The clinical histories of 387 cases of preeclampsia were compared with 1,054 normotensive controls. The exposure was prescriptions for calcium alone, the first period, or calcium plus conjugated linoleic acid, the second period, from 12 to 16 weeks of gestational age to labor. Confounding variables were controlled, allowing only nulliparous women into the study and stratifying by age, education and ethnic group. Results: The average age was 26.4 yrs old (range= 13-45), 85% from mixed ethnic backgrounds and with high school education. There were no differences between women who received calcium carbonate and those who did not (OR= 0.96; 95% CI= 0.73–1.27). The group of adolescents (13 to 18 yrs old) in the calcium plus conjugated linoleic acid was protected for preeclampsia (OR= 0.00; 95% CI= 0.00–0.44) independent of the confounder variables. Conclusions: 1. Calcium supplementation during pregnancy did not have preventive effects on preeclampsia. 2. Calcium plus Conjugated Linoleic acid provided to adolescents was observed to have preventive effect on Preeclampsia.
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Introduction: Preeclampsia is the main complication of pregnancy in developing countries. Calcium starting at 14 weeks of pregnancy is indicated to prevent the disease. Recent advances in prevention of preeclampsia endorse the addition of conjugated linoleic acid. Objective: To estimate the protective effect from calcium alone, compared to calcium plus conjugated linoleic acid in nulliparous women at risk of preeclampsia. Methods: A case-control design nested in the cohort of nulliparous women attending antenatal care from 2010 to 2014. The clinical histories of 387 cases of preeclampsia were compared with 1,054 normotensive controls. The exposure was prescriptions for calcium alone, the first period, or calcium plus conjugated linoleic acid, the second period, from 12 to 16 weeks of gestational age to labor. Confounding variables were controlled, allowing only nulliparous women into the study and stratifying by age, education and ethnic group. Results: The average age was 26.4 yrs old (range= 13-45), 85% from mixed ethnic backgrounds and with high school education. There were no differences between women who received calcium carbonate and those who did not (OR= 0.96; 95% IC= 0.73–1.27). The group of adolescents (13 to 18 yrs old) in the calcium plus conjugated linoleic acid was protected for preeclampsia (OR= 0.00; 95% CI= 0.00–0.44) independent of the confounder variables. Conclusions: 1. Calcium supplementation during pregnancy did not have preventive effects on preeclampsia. 2. Calcium plus Conjugated Linoleic acid provided to adolescents was observed to have preventive effect on Preeclampsia.