Fatty acids,the immune response,and autoimmunity: A question of n−6 essentiality and the balance between n−6 and n−3

The essentiality of n−6 polyunsaturated fatty acids (PUFA) is described in relation to a thymus/thymocyte accretion of arachidonic acid (20∶4n−6, AA) in early development, and the high requirement of lymphoid and other cells of the immune system for AA and linoleic acid (18∶2n−6, LA) for membrane phospholipids. Low n−6 PUFA intakes enhance whereas high intakes decrease certain immune functions. Evidence from in vitro and in vivo studies for a role of AA metabolites in immune cell development and functions shows that they can limit or regulate cellular immune reactions and can induce deviation toward a T helper (Th)2-like immune response. In contrast to the effects of the oxidative metabolites of AA, the longer-chain n−6 PUFA produced by γ-linolenic acid (18∶3n−6, GLA) feeding decreases the Th2 cytokine and immunoglobulin (Ig)G1 antibody response. The n−6 PUFA, GLA, dihomo-γ-linolenic acid (20∶3n−6, DHLA) and AA, and certain oxidative metabolites of AA can also induce T-regulatory cell activity, e.g., transforming growth factor (IGF)-β-producing T cells; GLA feeding studies also demonstrate reduced proinflammatory interleukin (IL)-1 and tumor necrosis factor (TNF)-α production. Low intakes of long-chain n−3 fatty acids (fish oils) enhance certain immune functions, whereas high intakes are inhibitory on a wide range of functions, e.g., antigen presentation, adhesion molecule expression, Th1 and th2 responses, proinflammatory cytokine and eicosanoid production, and they induce lymphocyte apoptosis. Vitamin E has a demonstrable critical role in long-chain n−3 PUFA interactions with immune functions, often reversing the effects of fish oil. The effect of dietary fatty acids on animal autoimmune disease models depends on both the autoimmune model and the amount and type of fatty acids fed. Diets low in fat, essential fatty acid deficient (EFAD), or high in long-chain n−3 PUFA from fish oils increase survival and reduce disease severity in spontaneous autoantibody-mediated disease, whereas high-fat LA-rich diets increase disease severity. In experimentally induced T cell-mediated autoimmune disease, EFAD diets or diets supplemented with long-chain n−3 PUFA augment disease, whereas n−6 PUFA prevent or reduce the severity. In contrast, in both T cell- and antibody-mediated autoimmune disease, the desaturated/elongated metabolites of LA are protective. PUFA of both the n−6 and n−3 families are clinically useful in human autoimmune-inflammatory disorders, but the precise mechanisms by which these fatty acids exert their clinical effects are not well understood. Finally, the view that all n−6 PUFA are proinflammatory requires revision, in part, and their essential regulatory and developmental role in the immune system warrants appreciation.     

The correlation between nitrogen species in coke and NOx formation during regeneration☆

Nitrogen oxides(NO x)emission during the regeneration of coked fluid catalytic cracking(FCC)catalysts is an environmental issue.In order to identify the correlations between nitrogen species in coke and different nitrogencontaining products in tail gas,three coked catalysts with multilayer structural coke molecules were prepared in a fixed bed with model compounds(o-xylene and quinoline)at first.A series of characterization methods were used to analyze coke,including elemental analysis,FT-IR,XPS,and TG–MS.XPS characterization indicates all coked catalysts present two types of nitrogen species and the type with a higher binding energy is related with the inner part nitrogen atoms interacting with acid sites.Due to the stronger adsorption ability on acid sites for basic nitrogen compounds,the multilayer structural coke has unbalanced distribution of carbon and nitrogen atoms between the inner part and the outer edge,which strongly affects gas product formation.At the early stage of regeneration,oxidation starts from the outer edge and the product NO can be reduced to N_2 in high CO concentration.At the later stage,the inner part rich in nitrogen begins to be exposed to O_2.At this period,the formation of CO decreases due to lack of carbon atoms,which is not bene ficial to the reduction of NO.Therefore,nitrogen species in the inner part of multilayer structural coke contributes more to NO X formation.Based on the multilayer structure model of coke molecule and its oxidation behavior,a possible strategy to control NO X emission was discussed merely from concept.     

Bonding phase formation in eco-friendly periclase−spinel−Al bricks used in RH degassing process

Mere unburnt periclase–spinel–Al bricks have been accepted by steel mills in the chromium-free campaign of the lining materials for Ruhrstahl ?Heraeus (RH) degassers, in terms of comparable/optimistic performance to traditional material, low carbon emission due to unburnt manufacturing process and chromium-free material for eco-friendly steel-making process. Investigations are made on the used periclase–spinel–Al bricks for the thermal evolution of their components and the formation of novel phase and bonding structure. Under the working atmosphere of RH degasser, metallic Al particles got molten above its melting point, leaving Al rim around their circumference, and AlN formed in the gaseous state dispersing into overall matrix of periclase–spinel–Al bricks with rising temperature. AlN formed and Mg reduced in their gaseous state germinated MgAlON whisker initially in the original space of metallic Al particles, and MgAlON whisker grew further all over the matrix. A whisker-interwoven network has been full of the matrix behind the hot face and toward the cold face of the used bricks, which is a completely novel type of bond and distinguished from traditional ceramic one. The whisker-interwoven network is somewhat like the stripe graphite containing microstructure of magnesia–carbon brick, which results in low wettability and high flexibility. The superior performance of periclase–spinel–Al bricks is attributed to such a bonding structure of whisker-interwoven network, which could reduce slag penetration and facilitate thermomechanical stress resistance.     

Dietary intakes and food sources of n−6 and n−3 PUFA in french adult men and women

The intake of individual n−6 and n−3 PUFA has been estimated in 4,884 adult subjects (2,099 men and 2,785 women), volunteers from the French SU.VI.MAX intervention trial. The food intakes of each subject were recorded in at least ten 24-h record questionnaires completed over a period of 2.5 yr, allowing the estimation of the daily intake of energy; total fat; and linoleic, α-linolenic, arachidonic, eicosapentaenoic (EPA), n−3 docosapentaenoic (DPA), and docosahexaenoic (DHA) acids. The mean total fat intake corresponded to 94.1 g/d (36.3% of total energy intake) in men and 73.4 g/d (38.1% of energy) in women. The intake of linoleic acid was 10.6 g/d in men and 8.1 g/d in women, representing 4.2% of energy intake; that of α-linolenic acid was 0.94 g/d in men and 0.74 g/d in women, representing 0.37% of energy intake, with a mean linoleic/α-linolenic acid ratio of 11.3. The mean intakes of long-chain PUFA were: arachidonic acid, 204 mg/d in men and 152 mg/d in women; EPA, 150 mg/d in men and 118 mg/d in women; DPA, 75 mg/d in men and 56 mg/d in women; DHA, 273 mg/d in men and 226 mg/d in women; long-chain n−3 PUFA, 497 mg/d in men and 400 mg/d in women. Ninety-five percent of the sample consumed less than 0.5% of energy as α-linolenic acid, which is well below the current French recommendation for adults (0.8% of energy). In contrast, the mean intakes of long-chain n−6 and n−3 PUFA appear fairly high and fit the current French recommendations (total long-chain PUFA: 500 mg/d in men and 400 mg/d in women; DHA: 120 mg/d in men and 100 mg/d in women). The intakes of α-linolenic acid, and to a lesser extent of linoleic acid, were highly correlated with that of lipids. Whereas the main source of linoleic acid was vegetable oils, all food types contributed to α-linolenic acid intake, the main ones being animal products (meat, poultry, and dairy products). The main source of EPA and DHA (and of total long-chain n−3 PUFA) was fish and seafood, but the major source of DPA was meat, poultry, and eggs. Fish and seafood consumption showed very large interindividual variations, the low consumers being at risk of insufficient n−3 PUFA intake.     

Phase formation,dielectric and ferroelectric properties of CaxBa1−xNb2O6 ceramics

Lead-free Ca_xBa_1?xNb₂O₆ (CBN, 0.20≤x≤0.35) ceramics were prepared by the conventional solid state method. Effects of Ca content on the phase formation, microstructure, dielectric and ferroelectric properties for the prepared CBN ceramics were systematically studied. XRD results showed that pure CBN phase with tungsten bronze structure could be obtained from the solid solutions of BaNb₂O₆ and CaNb₂O₆ in all ceramics. Higher Ca contents favored the occurrence of grains with anisometric morphology, but no abnormal grain growth could be found in all compositions. With the increase of x, Curie temperature T_c shifted downward, whereas the maximum dielectric constant ε_m increased initially and then decreased. All the ceramics showed an intermediate relaxor-like behavior between normal and ideal relaxor ferroelectrics according to the modified Curie–Weiss law. Normal ferroelectric hysteresis loops were observed in all compositions. Both remnant polarization P_r and coercive field E_c increased initially and then decreased with the increase of x. The ceramics with homogeneous microstructure, high density and better properties were obtained at x=0.28 with ε_m=2998, T_c=234 °C, P_r=3.98 μC cm^?2 and E_c=14.03 kV cm^?1.     

Vibrations of the S–S bond in elemental sulfur and organic polysulfides: a structural guide

This review summarizes and analyzes in comparative manner the S–S bond vibrations in IR and Raman spectra of elemental sulfur and organosulfur compounds containing disulfide and polysulfide moieties. It is intentionally biased toward application of the experimental S–S bond frequencies for structural elucidation of sulfur compounds. It was shown that the S–S bond frequencies are a useful tool for identification of the elemental sulfur modifications, organic disufides and polysulfides. Particular attention is paid to the correlation between the S–S bond frequencies and the molecular structure.     

Synthesis and in vitro bioactivity assessment of injectable bioglass−organic pastes for bone tissue repair

The aim of this work was to study the bioactivity of systems based on a clinically tested bioactive glass (BG) particulates (mol%: 4.33 Na₂O−30.30 CaO−12.99 MgO−45.45 SiO₂−2.60 P₂O₅−4.33 CaF₂) and organic carriers. The cohesiveness of injectable bone graft products is of high relevance when filling complex volumetric bone defects. With this motivation behind, BG particulates with mean sizes within 11−14 μm were mixed in different proportions with glycerol (G) and polyethylene glycol (PEG) as organic carriers and the mixtures were fully injectable exhibiting Newtonian flow behaviors. The apatite forming ability was investigated using X-ray diffraction and field emission scanning electron microscopy under secondary electron mode after immersion of samples in simulated body fluid (SBF) for time durations varying between 12 h and 7 days. The results obtained revealed that in spite of the good adhesion of glycerol and PEG carriers to glass particles during preparation stage, they did not hinder the exposure of bioactive glass particulates to the direct contact with SBF solution. The results confirmed the excellent bioactivity in vitro for all compositions expressed by high biomineralization rates with the formation of crystalline hydroxyapatite being identified by XRD after 12 h of immersion in SBF solution.     

Complex permittivity and relaxation processes in CaCu3Ti(4−x)MnxO12

The effects of Mn-doping on CaCu₃Ti₄O₁₂ (CCTO), i.e. the electrical properties of CaCu₃Ti_(4−x)Mn_xO₁₂ were studied in order to get a deep insight into the origin of the colossal dielectric constant of CCTO. It was found that 1 mol% substitution of Mn for Ti decreases the dielectric constant largely to a factor of 1/100, supporting the point of view that the native defects are responsible for the dielectric response of CCTO.     

Effect of dietary n−6 and n−3 polyunsaturated fatty acids on peroxidizability of lipoproteins in steers

The susceptibility of major plasma lipoproteins to lipoperoxidation was studied in relation to the FA composition of their neutral and polar lipids in steers given PUFA-rich diets. Two trials used, respectively, 18 (“sunflower” experiment, S) or 24 (“linseed” experiment, L) crossbred Salers x Charolais steers. Each involved three dietary treatments over a 70-d period: a control diet (CS or CL diets) consisting of hay and concentrate, or the same diet supplemented with oilseeds (4% diet dry matter) fed either as seeds (SS or LS diets) or continuously infused into the duodenum (ISO or ILO diets). Compared with control diets, ISO and ILO treatments tended to decrease the resistance time of LDL and HDL classes to peroxidation, mainly owing to the enrichment of their polar and neutral lipids with PUFA. With diets SS and LS, sensitivity of major lipoprotein classes (LDL, light and heavy HDL) was not affected because ruminal hydrogenation of dietary PUFA decreased their incorporation into lipoparticles. ISO and ILO treatments induced a more important production of conjugated dienes and hydroperoxides generated by peroxidation in the three lipoprotein classes due to the higher amounts of PUFA esterified in lipids of the core and the hydrophilic envelope of particles. The production of malondialdehyde (MDA) increased in steers fed linseed supplements, indicating that MDA production did not occur with linoleic acid provided by sunflower oil supplements. Thus, plasma peroxidation of PUFA generates toxic products in steers fed diets supplemented with PUFA and can be deleterious for the health of the animal during long-term treatment.     

Whole-body utilization of n−3 PUFA in n−6 PUFA-deficient rats

We evaluated the utilization of α-linolenic acid (18∶3n−3) in growing rats consuming a diet deficient in n−6 PUFA. After 90 d, whole-body 18∶3n−3 accumulation was 55% lower, total n−3 PUFA accumulation was 21% lower, and 18∶3n−3 disappearance was 14% higher in n−6 PUFA-deficient rats. Part of the reduction of whole-body 18∶3n−3 in n−6 PUFA-deficient rats was due to the 25% increase in net conversion of 18∶3n−3 to long-chain n−3 PUFA. Despite adequate 18∶3n−3 intake, n−6 PUFA deficiency decreased the accumulation of 18∶3n−3 and total n−3 PUFA.     

Positive association between plasma antioxidant capacity and n−3 PUFA in red blood cells from women

PUFA are susceptible to oxidation. However, the chain-reaction of lipid peroxidation can be interrupted by antioxidants. Whether an increased concentration of PUFA in the body leads to decreased antioxidant capacity and/or increased consumption of antioxidants is not known. To elucidate the relationship between plasma total antioxidant capacity (TAC), the concentration of antioxidant vitamins, and the proportion of PUFA in red blood cells (RBC), plasma TAC was measured by a Trolox equivalent antioxidant capacity assay in blood samples from 99 Icelandic women. Concentrations of tocopherols and carotenoids in the plasma were determined by HPLC, and the FA composition of RBC total lipids was analyzed by GC. Plasma TAC and the plasma concentration of α-tocopherol correlated positively with the proportion of total n−3 PUFA, 20∶5n−3, and 22∶6n−3 in RBC, whereas the plasma lycopene concentration correlated negatively with the proportion of total n−3 PUFA and 20∶5n−3. On the other hand, plasma TAC correlated negatively with the proportion of n−6 PUFA in RBC. Plasma TAC also correlated positively with the plasma concentration of α-tocopherol, alcohol consumption, and age. Both the plasma concentration of α-tocopherol and age correlated positively with the proportion of n−3 PUFA in RBC; however, n−3 PUFA contributed independently to the correlation with plasma TAC. Because the proportion of n−3 PUFA in RBC reflects the consumption of n−3 PUFA, these results suggest that dietary n−3 PUFA do not have adverse effects on plasma TAC or the plasma concentration of most antioxidant vitamins.     

Relationships between Very Low-Density Lipoproteins–Ceramides, −Diacylglycerols,and –Triacylglycerols in Insulin-Resistant Men

This short report describes the relationships between concentrations of ceramides (CER), diacylglycerols (DAG), triacylglycerols (TAG) in very low-density lipoproteins (VLDL) particles, and hepatic lipid accumulation. VLDL particles were isolated from male subjects (n = 12, mean ± SD, age 42.1 ± 5.4 years, BMI 37.4 ± 4.1 kg/m², ALT 45 ± 21 U/L) and apolipoprotein B100 (apoB100), VLDL-TAG, -CER, and -DAG quantified. The contents of all three lipids were highly correlated with VLDL particle number (r ≥ 0.768, p ≤ 0.003). The molar quantity of VLDL-TAG was 3× that of DAG and 137× that of CER (14,053 ± 5714, 5004 ± 2714, and 105 ± 49 mol/mol apoB100, respectively). Reduced VLDL-CER concentrations were associated with both higher insulin levels (r = −0.645, p = 0.024) and intrahepatic-TAG (r = −0.670, p = 0.017). In fatty liver, the secretion of hepatic TAG, CER, and DAG may be suppressed and contribute to intrahepatic lipotoxicity. The mechanisms by which hepatic-CER and -DAG synthesis and assembly into VLDL is coordinately controlled with TAG will be important in understanding the emerging role of elevated CER contributing to cardiometabolic disease.     

The metabolism and distribution of docosapentaenoic acid (n−6) in rats and rat hepatocytes

In this study, a new marine oil that contains 45% docosahexaenoic acid (DHA, 22∶6n−3) and 13% docosapentaenoic acid (DPA, 22∶5n−6) was administered to rats. The metabolism and distribution of DPA in rats was investigated. In experiment 1, the effects of DHA and n−6 fatty acids (linoleic acid, I A; arachidonic acid, AA; and DPA) on AA contents were investigated in vivo. LA group: LA 25%, DHA 30%; LA-DPA group: LA 15%, DPA 10%, DHA 35%; LA-AA-DPA group: LA 10%, AA 5%, DPA 10%, DHA 35% were administered to rats for 4 wk. In the liver, the AA content in the LA-DPA and LA-AA-DPA groups was significantly higher than in the LA group. The decreased AA contents in the LA group might be caused by DHA administration. Although DHA also was administered in the LA-DPA and LA-AA-DPA groups, the AA contents in these two groups did not decrease. These results suggested that DPA retroconverted to AA, blunting the decrease in AA content caused by DHA administration. To conduct a detailed investigation on DPA metabolism and its relation with AA and DHA, rat hepatocytes were cultured with pruified DPA and DHA for 24 h. We discovered the retroconversion of DPA to AA occurred only when AA content was decreased by a high DHA administration; it did not occur when AA content was maintained at a normal level.     

Induction of apoptosis and apoptotic mediators in balb/C splenic lymphocytes by dietary n−3 and n−6 fatty acids

The present study was designed to investigate the effect of diatery n−6 and n−3 polyunsaturated fatty acids (PUFA) on anti-CD3 and anti-Fas antibody-induced apoptosis and its mediators in mouse spleen cells. Nutritionally adequate semipurified diets containing either 5% w/w corn oil (n−6 PUFA) or fish oil (n−3 PUFA) were fed to weanling female Balb/C mice, and 24 wk later mice were sacrificed. In n−3 PUFA-fed mice, serum and splenocyte lipid peroxides were increased by 20 and 28.3% respectively, compared to n−6 PUFA-fed mice. Further, serum vitamin F levels were decreased by 50% in the n−3 PUFA-fed group, whereas higher anti0Fas- and anti-CD3-induced apoptosis (65 and 66%) and necrosis (17 and 25%), compared to the n−6 PUFA-fed group, were found when measured with Annexin V and propidium iodide staining, respectively. In addition, decreased Bcl-2 and increased Fas-ligand (Fas-L) also were observed in the n−3 PUFA-fed group compared to the n−6 PUFA-fed group. No difference in the ratio of splenocyte subsets nor their Fas expression was observed between the n−3 PUFA-fed and n−6 PUFA-fed groups, whereas decreased proliferation of splenocytes was found in n−3 PUFA-fed mice compared to n−6 PUFA-fed mice. In conclusion, our results indicate that dietary n−3 PUFA induces higher apoptosis by increasing the generation of lipid peroxides and elevating Fas-L expression along with decreasing Bcl-2 expression. A reduced proliferative response of immune cells also was observed in n−3 PUFA-fed mice.     

Relationship between the Bond Valence and the Temperature Coefficient of the Resonant Frequency in the Complex Perovskite (Pb1−xCax)[Fe0.5(Nb1−yTay)0.5]O3

The temperature coefficient of the resonant frequency (TCF) of complex perovskite (Pb_1−xCa_x)[Fe_0.5(Nb_1−yTa_y)_0.5]O₃ ceramics (x= 0.5, 0.55; 0.0 ≤y≤ 1.0) was investigated, relative to the bond valence of the A- and B-site ions in the ABO₃ perovskite structure (such as the barium-, strontium-, and calcium-based complex perovskites). The TCF of these complex perovskite compounds varied with the bond valence of the A- and B-sites and the tolerance factor (t) in the perovskite structure. In the tilted region (t < 1.0), the tilting of the oxygen octahedra increased and the TCF decreased, because of the increased bond valence of the B-site. Also, the dependence of TCF on the bond valence of the A-site was similar to its dependence on t.     

Scale formation in coal liquefaction reactor using FeS catalysts

The origin and formation behavior of scale in a coal liquefaction reactor, in which disposable catalysts such as red mud-sulfur were used, has been investigated by means of model experiments. The scale formed in the continuous coal liquefaction reactor which operated at a throughput of 0.1 t/d was analyzed with an electron probe microanalyzer (EPMA), scanning electron microscope (SEM), X-ray and scanning Auger electron microscope (SAM) techniques. It was observed in the model experiments that the scale formed on the surface of stainless steel (SUS-316) at temperatures higher than 250°C. The amount of scale formed was found to depend on the reaction temperature, the exposure time and the sulfur content of the catalyst. The scale formed in the continuous reactor collected on the walls of the tube, preheater and reactor. It was found that the scale was derived from two sources, the coal paste (catalyst, inorganic components in coal and unreacted coal) and the sulfidation of reactor materials.     

n−3 and n−6 fatty acid enrichment by dietary fish oil and phospholipid sources in brain cortical areas and nonneural tissues of formula-fed piglets

Sufficient availability of both n-3 and n-6 long-chain polyunsaturated fatty acids (LCPUFA) is required for optimal structural and functional development in infancy. The question has been raised as to whether infant formulae would benefit from enrichment with 20 and 22 carbon fatty acids. To address this issue, we determined the effect of fish oil and phospholipid (LCPUFA) sources on the fatty acid composition of brain cortical areas and nonneural tissues of newborn piglets fed artificially for 2 wk. They were fed sow milk, a control formula, or the formula enriched with n-3 fatty acids from a low-20:5n-3 fish oil added at a high or a low concentration, or the formula enriched with n-3 and n-6 fatty acids from either egg yolk- or pig brain-phospholipids. Both the fish oil- and the phospholipid-enriched formula produced significantly higher plasma phospholipid 22:6n-3 concentrations than did the control formula. The 22:6n-3 levels in the brain, hepatic, and intestinal phospholipids were significantly correlated with plasma values, whereas cardiac 22:6n-3 content appeared to follow a saturable dose-response. Feeding sow milk resulted in a much higher 20:4n-6 content in nonneural tissues than did feeding formula. Supplementation with egg phospholipid increased the 20:4n-6 content in the heart, red blood cells, plasma, and intestine in comparison to the control formula, while pig brain phospholipids exerted this effect in the heart only. The addition of 4.5% fish oil in the formula was associated with a decline in 20:4n-6 in the cortex, cerebellum, heart, liver, and plasma phospholipids, whereas using this source at 1.5% limited the decline to the cerebellum, liver, and plasma. Whatever the dietary treatment, the phosphatidylethanolamine 20:4n-6 level was 10–20% higher in the brain temporal lobe than in the parietal, frontal, and occipital lobes in the temporal lobe by administering the formula enriched with egg or brain phospholipids. In conclusion, feeding egg phospholipids to neonatal pigs increased both the 22:6n-3 content in the brain and the 20:4n-6 content in the temporal lobe cortex. This source also increased the 22:6n-3 levels in nonneural tissues with only minor alterations of 20:4n-6. These data support the notion that infant formulae should be supplemented with both 22:6n-3 and 20:4n-6 rather than with 22:6n-3 alone.     

β-Keto sulfones: preparation and application in organic synthesis

The review summarizes a survey of recent advances and contributions to the methods of synthesis, chemical properties and application of β-keto sulfones with the main focus on the their increasingly growing demand as starting substrates and intermediates incorporated in the syntheses of various classes of organic compounds.     

Alteration of 20∶5n−3 and 22∶6n−3 fat contents and liver peroxisomal activities in fenofibrate-treated rainbow trout

Fish easily accumulate n−3 PUFA of exogenous origin, but the underlying mechanisms are not well established in the whole animal. This study was undertaken to investigate whether this feature was physiologically associated with mitochondrial and peroxisomal capacities that differentially affect FA oxidation. For this purpose, peroxisomal FA oxidation was increased by treating rainbow trout with fenofibrate, which strongly stimulates the peroxisome proliferator-activated receptor-α in rodents. Diets containing EPA and DHA, with or without fenofibrate added, were administered to male trout for 12 d. After treatment, neither liver hypertrophy nor accumulation of fat was apparent within the liver and muscle cells. However, fenofibrate treatment decreased the contents of EPA and DHA in the liver, white muscle, and intraperitoneal fat tissue, which represented (per whole body) at least 280 mg less than in controls. Carnitine-dependent palmitate oxidation rates, expressed per gram of liver, were slightly increased by fenofibrate when measured from tissue homogenates and were unchanged when calculated from isolated mitochondria, relative to control fish. The treatment altered neither carnitine palmitoyltransferase I activity rates, expressed per gram of liver, nor the sensitivity of the enzyme to malonyl-CoA inhibition, but did increase the malonyl-CoA content (+45%). Meanwhile, fenofibrate increased (by about 30%) the peroxisome-related activities, i.e, catalase, carnitine-independent palmitate oxidation, acyl-CoA oxidase, and the peroxisomal FA-oxidizing system, relative to the control group. The data strongly suggest that the induction of peroxisomal activities, some of which being able to oxidize very long chain FA, was responsible for the lower contents of EPA and DHA in the body lipids of fenofibrate-treated trout.     

Intramuscular injection of antigens and adjuvant preferentially decreases 18∶2n−6 and 18∶3n−3 in pig neck muscle

Linoleic (18∶2n−6) and α-linolenic acids (18∶3n−3) have many important physiological functions including immunomodulation. We tested how immunization influences the metabolism of 18∶2n−6 and 18∶3n−3 in the neck muscle of pigs. At 35 d old, pigs received either an intramuscular neck injection containing hen egg white lysozyme (HEWL), killed Mycobacterium tuberculosis, and Freund’s complete adjuvant (immunized) or PBS (control). At 49 d old, immunized pigs received a booster injection of HFWI and Freund’s incomplete adjuvant, and the control pigs received PBS into the neck. At 56 d old, all pigs received an intradermal injection of Mycobacterium bovis into the hind leg to induce a delayed-type hypersensitivity (DTH) reaction. At 57 d old, immunized pigs had a twofold increase in serum haptoglobin, a 10-fold increase in antibodies to HEWL, and the skinfold at the DTH reaction site was 10 times thicker than the controls. Both 18∶2n−6 and 18∶3n−3 (% composition) were approximately 25% lower in muscle IG, 40% lower in FFA, 50% lower in phospholipids, but not different in cholesteryl esters of the neck muscle of immunized pigs. The antigens in this model induce an increased response in the innate (haptoglobin), humoral (antibodies), and cellular (DTH) immune systems as well as a preferential decrease of 18∶2n−6 and 18∶3n−3 in the inflamed neck muscle. It appears that 18∶2n−6 and 18∶3n−3 are preferentially metabolized (possibly β-oxidized) in response to antigens.