linoleic-acid and Weight-Gain

The objective of this study was to investigate the effects of dietary linoleic acid level and the ratio of linoleic acid:linolenic acid (LA:ALA) on the growth performance, expression of genes associated with lipid metabolism, and inflammatory status of grow-finish pigs. A total of 300 growing pigs (body weight [BW] = 41.1 ± 6.3 kg) were randomly assigned to either a high (30 g/kg; HLA) or low (15 g/kg; LLA) dietary linoleic acid level with a high (23:1; HR), moderate (13:1; MR) or low (4:1; LR) dietary LA:ALA in a 2 × 3 factorial design. Diets were fed across three 28-d phases and were balanced for dietary metabolizable energy. Pigs were housed five pigs per pen in single-sex pens. Blood samples were collected on days 0, 21, 42, and 84, and synovial fluid was collected from the hock joint on days 0 and 84 for inflammatory marker analysis. Data were analyzed as repeated measures using PROC MIXED (SAS 9.4) with initial BW as a covariate, pen as the experimental unit, and LA level, LA:ALA, sex, phases, and their interactions as fixed effects. Compared to HLA, LLA pigs tended to have increased BW at days 56 and 84 (P = 0.088). There was no effect of LA × LA:ALA for growth performance. For the overall days 0 to 84 growth period, pigs fed HR had increased ADG compared to MR, with pigs receiving LR performing intermediate of MR and HR. Gilts receiving HR diets had increased day 84 BW compared to gilts receiving the low and moderate LA:ALA (P = 0.006), which was a result of improved overall days 0 to 84 ADG compared to gilts receiving the MR diets (P = 0.023). Barrows fed LR had improved BW on day 56 compared to MR and HR and higher final BW compared to HR, with MR performing intermediately (P = 0.006). This was a result of greater days 0 to 84 ADG (P = 0.023). Overall, C-reactive protein (CRP), tumor necrosis factor-α (TNFα), and interleukin-6 were reduced in the plasma of pigs over time (P ≤ 0.037). Across all treatments, CRP and TNFα were reduced in the hock and carpus synovial fluid on day 84 vs. day 0 (P ≤ 0.049). In conclusion, LA:ALA ratios utilized in this study can be fed at varying linoleic acid levels without impacting growth or inflammation. Additionally, LA:ALA ratios can differentially impact the growth of gilts and barrows.. Previous research in lactating sows has reported that dietary inclusion of the essential fatty acids linoleic acid and linolenic acid is important for performance. Research in grow–finish pigs has shown an improvement in gilt growth performance when fed differing linoleic:linolenic acid ratios (LA:ALA); however, further research evaluating LA:ALA in diets with similar metabolizable energy is needed in growing pigs. In the present research, a 23:1 dietary essential fatty acid ratio increased the final body weight of gilts compared to a 13:1 or 4:1 LA:ALA, while barrows fed a 4:1 dietary essential fatty acid ratio had increased gain and final body weight compared to a 23:1 LA:ALA. Plasma and synovial fluid inflammatory markers were also reduced with time and were unaffected by dietary LA:ALA or linoleic acid inclusion. Dietary essential fatty acid ratio can differentially impact the growth of barrows and gilts, with no impact on systemic or joint inflammation.

Topics: Animal Feed; Animals; Body Composition; Body Weight; Diet; Fatty Acids; Female; Linoleic Acid; Sus scrofa; Swine; Tumor Necrosis Factor-alpha; Weight Gain

Ready-to-use therapeutic food (RUTF) is the preferred treatment for uncomplicated severe acute malnutrition. It contains large amounts of linoleic acid and little α-linolenic acid, which may reduce the availability of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) to the recovering child. A novel high-oleic RUTF (HO-RUTF) was developed with less linoleic acid to determine its effect on DHA and EPA status.. We conducted a prospective, randomized, double-blind clinical effectiveness trial treating rural Malawian children with severe acute malnutrition. Children were treated with either HO-RUTF or standard RUTF. Plasma phospholipid fatty acid status was measured on enrollment and after 4 weeks and compared between the 2 intervention groups.. Among the 141 children enrolled, 48 of 71 receiving HO-RUTF and 50 of 70 receiving RUTF recovered. Plasma phospholipid samples were analyzed from 43 children consuming HO-RUTF and 35 children consuming RUTF. The change in DHA content during the first 4 weeks was +4% and -25% in the HO-RUTF and RUTF groups, respectively (P = 0.04). For EPA, the change in content was 63% and -24% in the HO-RUTF and RUTF groups, respectively (P < 0.001). For arachidonic acid, the change in content was -3% and 13% in the HO-RUTF and RUTF groups, respectively (P < 0.009).. The changes in DHA and EPA seen in the children treated with HO-RUTF warrant further investigation because they suggest that HO-RUTF support improved polyunsaturated fatty acid status, necessary for neural development and recovery.

Topics: alpha-Linolenic Acid; Arachidonic Acid; Child, Preschool; Docosahexaenoic Acids; Double-Blind Method; Eicosapentaenoic Acid; Fast Foods; Female; Food, Formulated; Humans; Infant; Linoleic Acid; Male; Nutritional Status; Oleic Acid; Phospholipids; Prospective Studies; Protein-Energy Malnutrition; Weight Gain

Three-year-old Angus x Gelbvieh beef cows nutritionally managed to achieve a BCS of 4 +/- 0.07 (479.3 +/- 36.3 kg of BW) or 6 +/- 0.07 (579.6 +/- 53.1 kg of BW) at parturition were used in a 2-yr experiment (n = 36/yr) to determine the effects of prepartum energy balance and postpartum lipid supplementation on cow and calf performance. Beginning 3 d postpartum, cows within each BCS were assigned randomly to be fed hay and a low-fat control supplement or supplements with either high-linoleate cracked safflower seeds or high-oleate cracked safflower seeds until d 60 of lactation. Diets were formulated to be isonitrogenous and isocaloric, and safflower seed supplements were provided to achieve 5% of DMI as fat. Ultrasonic 12th rib fat and LM area were lower (P < 0.001) for cows in BCS 4 compared with BCS 6 cows throughout the study. Cows in BCS 4 at parturition maintained (P = 0.02) condition over the course of the study, whereas cows in BCS 6 lost condition. No differences (P = 0.44 to 0.71) were detected for milk yield, milk energy, milk fat percentage, or milk lactose percentage because of BCS; however, milk protein percentage was less (P = 0.03) for BCS 4 cows. First-service conception rates did not differ (P = 0.22) because of BCS at parturition, but overall pregnancy rate was greater (P = 0.02) in BCS 6 cows. No differences (P = 0.48 to 0.83) were detected in calf birth weight or ADG because of BCS at parturition. Dietary lipid supplementation did not influence (P = 0.23 to 0.96) cow BW change, BCS change, 12th rib fat, LM area, milk yield, milk energy, milk fat percentage, milk lactose percentage, first service conception, overall pregnancy rates, or calf performance. Although cows in BCS of 4 at parturition seemed capable of maintaining BCS during lactation, the overall decrease in pregnancy rate indicates cows should be managed to achieve a BCS >4 before parturition to improve reproductive success.

Topics: Adipose Tissue; Animal Feed; Animals; Body Constitution; Cattle; Diet; Dietary Supplements; Female; Lactation; Linoleic Acid; Oleic Acid; Parturition; Weight Gain

To determine whether certain nutrients and dietary factors act as modulators of the immune system and improve the nutritional status of immunocompromised patients.. Controlled, double-blind, crossover phase trials of the effects of a fortified formula in patients infected with the human immunodeficiency virus (HIV). Patients consumed a control formula for 4 months and a study formula for 4 months.. Ten men with symptomatic HIV infection who were following stable medication regimens and had no malignancies, mycobacteriosis, or additional virus infection requiring systemic treatment.. Formula fortified with alpha-linolenic acid (1.8 g/day), arginine (7.8 g/day), and RNA (0.75 g/day) and a standard formula.. Nutritional status determined by anthropometric, bioelectrical, biochemical, and dietary assessment; energy expenditure determined by indirect calorimetry; disease progression; CD4 lymphocyte counts; HIV p24 antigen plasma concentrations; tumor necrosis factor (TNF) receptor proteins; and compliance control parameters.. Student's t tests for paired and unpaired data.. Fortified nutrition resulted in a weight gain (+ 2.9 kg/4 months vs -0.5 kg/4 months with the control formula, P < .05), an incorporation of eicosaenoic acid into erythrocyte cell membranes (+ 47% of baseline values, P < .05), and increased plasma arginine concentrations (96.8 +/- 45.1 vs 51.8 +/- 20.9 mumol/L, P < .01). The serum concentrations of the soluble tumor necrosis factor receptor (sTNFR) proteins increased during the study period (sTNFR 55 = + 0.23 vs -0.40 ng/mL, P < .001; sTNFR 75 = + 0.90 vs -0.36 ng/mL, P < .01), whereas no changes in CD4+ lymphocyte counts were observed.. Increasing dietary intakes of n-3 polyunsaturated fatty acids, L-arginine, and RNA increased body weight, possibly by modulating the negative effects of TNF.

Topics: Adolescent; Adult; Aged; Anthropometry; Arginine; CD4-Positive T-Lymphocytes; Cross-Over Studies; Double-Blind Method; Energy Metabolism; Food, Formulated; Food, Fortified; HIV Antigens; HIV Infections; Humans; Immune System; Linoleic Acid; Linoleic Acids; Male; Middle Aged; Nutritional Status; Receptors, Tumor Necrosis Factor; RNA; Weight Gain

Limited information is available on the metabolic fate of medium-chain triacylglycerols (triglycerides) after intestinal absorption and on their influence on essential fatty acid metabolism. We studied in preterm infants the effect of two infant formulas, one with a high (HMCT) and one with a low (LMCT) medium-chain triacylglycerol content, on plasma fatty acids. The HMCT formula contained 46 mol% 8:0 + 10:0 and the LMCT formula (4.8 mol% 8:0 + 10:0) had approximately twice the amount of long-chain saturated and monounsaturated fatty acids as the HMCT. Both formulas had similar contents of linoleic and linolenic acids. Plasma lipids and fatty acids were determined at birth and on day 24 of life in 20 infants fed the LMCT (n = 12) or HMCT (n = 8) formula. Significant amounts of medium-chain fatty acids were found in the systemic circulation of the infants fed the HMCT formula, mainly in plasma fatty acids and triacylglycerols. Despite striking dietary differences, palmitic and stearic acids were not different between groups, indicating de novo synthesis of long-chain fatty acids with the HMCT formula. Plasma phospholipid docosahexaenoic acid was significantly lower in the HMCT group than in the LMCT infants (1.38 +/- 0.07 compared with 1.73 +/- 0.07 mol%, P = 0.002). Our data indicate that a high MCT intake in preterm infants increases lipogenesis, and dietary nonessential fatty acids interfere with the metabolism of docosahexaenoic acid.

Topics: alpha-Linolenic Acid; Fatty Acids; Fatty Acids, Essential; Humans; Infant Food; Infant, Newborn; Infant, Premature; Linoleic Acid; Linoleic Acids; Lipids; Phospholipids; Triglycerides; Weight Gain

Fatty acid-induced hypothalamic inflammation (HI) is a potential cause of the obesity epidemic. It is unclear whether saturated or n-6 polyunsaturated fat is the primary driver of these effects. Premenopausal women are protected, in part, from obesity and associated comorbidities by circulating 17β-estradiol (E2). It is unknown how HI interacts with E2, because most studies of HI do not examine females despite the involvement of E2 in hypothalamic energy homeostasis. Our objective is to determine the effects of high-fat diets with varying levels of linoleic acid (LA) and saturated fat on the energy and glucose homeostasis in female mice with and without E2. Female C57BL/6J mice were fed either a control diet or a 45% kilocalories from fat diet with varying levels of LA (1, 15, or 22.5% kilocalories from LA) with or without E2 (300 μg/kg/day orally). After 8 weeks, the oil-treated high-fat groups gained more weight than control groups regardless of fat type. E2 reduced body fat accumulation in all high-fat groups. Glucose clearance from glucose challenge was impaired by LA. Nighttime O

Topics: Adiposity; Animals; Blood Glucose; Body Composition; Body Weight; Diet; Diet, High-Fat; Dietary Fats; Estradiol; Fatty Acids; Female; Homeostasis; Hypothalamus; Interleukin-6; Leptin; Linoleic Acid; Mice; Mice, Inbred C57BL; Obesity; Oxygen Consumption; Weight Gain

Dietary fatty acids play important roles in the regulation of fat accumulation or metabolic phenotype of adipocytes, either as brown or beige fat. However, a systematic comparison of effects of diets with different composition of 18-C fatty acids on browning/beiging phenotype has not been done. In this study, we compared the effects of different dietary fats, rich in specific 18-carbon fatty acids, on thermogenesis and lipid metabolism. Male C57BL/6 mice were fed a control diet containing 5.6% kcal fat from lard and 4.4% kcal fat from soybean oil (CON) or high-fat diets (HFD) containing 25% kcal from lard and 20% kcal fat from shea butter (stearic acid-rich fat; SHB), olive oil (oleic acid-rich oil; OO), safflower oil (linoleic acid-rich oil; SFO), or soybean oil (mixed oleic, linoleic, and α-linolenic acids; SBO)

Topics: Adipocytes; Adiposity; alpha-Linolenic Acid; Animals; Blood Glucose; Cholesterol; Diet, High-Fat; Dietary Fats; Fatty Acids; Gene Expression Regulation; Insulin; Linoleic Acid; Lipid Metabolism; Male; Mice; Mice, Inbred C57BL; Norepinephrine; Oleic Acid; Olive Oil; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Safflower Oil; Soybean Oil; Thermogenesis; Uncoupling Protein 1; Up-Regulation; Weight Gain

A significant change in the Western diet, concurrent with the obesity epidemic, was a substitution of saturated fatty acids with polyunsaturated, specifically linoleic acid (LA). Despite increasing investigation on type as well as amount of fat, it is unclear which fatty acids are most obesogenic. The objective of this study was to determine the obesogenic potency of LA vs. saturated fatty acids and the involvement of hypothalamic inflammation. Forty-eight mice were divided into four groups: low-fat or three high-fat diets (HFDs, 45% kcals from fat) with LA comprising 1%, 15% and 22.5% of kilocalories, the balance being saturated fatty acids. Over 12 weeks, bodyweight, body composition, food intake, calorimetry, and glycemia assays were performed. Arcuate nucleus and blood were collected for mRNA and protein analysis. All HFD-fed mice were heavier and less glucose tolerant than control. The diet with 22.5% LA caused greater bodyweight gain, decreased activity, and insulin resistance compared to control and 1% LA. All HFDs elevated leptin and decreased ghrelin in plasma. Neuropeptides gene expression was higher in 22.5% HFD. The inflammatory gene Ikk was suppressed in 1% and 22.5% LA. No consistent pattern of inflammatory gene expression was observed, with suppression and augmentation of genes by one or all of the HFDs relative to control. These data indicate that, in male mice, LA induces obesity and insulin resistance and reduces activity more than saturated fat, supporting the hypothesis that increased LA intake may be a contributor to the obesity epidemic.

Topics: Animals; Carbon Dioxide; Chemokine CX3CL1; Diet, Fat-Restricted; Encephalitis; Fatty Acids; Ghrelin; Glucose; Hypothalamus; Leptin; Linoleic Acid; Male; Mice, Inbred C57BL; Weight Gain

Fatty acids (FAs) are fundamental for a foetus's growth, serving as an energy source, structural constituents of cellular membranes and precursors of bioactive molecules, as well as being essential for cell signalling. Long-chain polyunsaturated FAs (LC-PUFAs) are pivotal in brain and visual development. It is of interest to investigate whether and how specific pregnancy conditions, which alter fatty acid metabolism (excessive pre-pregnancy body mass index (BMI) or gestational weight gain (GWG)), affect lipid supply to the foetus. For this purpose, we evaluated the erythrocyte FAs of mothers and offspring (cord-blood) at birth, in relation to pre-pregnancy BMI and GWG. A total of 435 mothers and their offspring (237 males, 51%) were included in the study. Distribution of linoleic acid (LA) and α-linolenic acid (ALA), and their metabolites, arachidonic acid, dihomogamma linoleic (DGLA) and ecosapentanoic acid, was significantly different in maternal and foetal erythrocytes. Pre-pregnancy BMI was significantly associated with maternal percentage of MUFAs (Coeff: -0.112; p = 0.021), LA (Coeff: -0.033; p = 0.044) and DHA (Coeff. = 0.055; p = 0.0016); inadequate GWG with DPA (Coeff: 0.637; p = 0.001); excessive GWG with docosaexahenoic acid (DHA) (Coeff. = -0.714; p = 0.004). Moreover, pre-pregnancy BMI was associated with foetus percentage of PUFAs (Coeff: -0.172; p = 0.009), omega 6 (Coeff: -0.098; p = 0.015) and DHA (Coeff: -0.0285; p = 0.036), even after adjusting for maternal lipids. Our findings show that maternal GWG affects maternal but not foetal lipid profile, differently from pre-pregnancy BMI, which influences both.

Topics: 8,11,14-Eicosatrienoic Acid; Adolescent; Adult; alpha-Linolenic Acid; Arachidonic Acid; Birth Weight; Body Mass Index; Docosahexaenoic Acids; Educational Status; Eicosapentaenoic Acid; Erythrocytes; Fatty Acids; Female; Fetal Blood; Fetus; Humans; Infant, Newborn; Linoleic Acid; Male; Middle Aged; Mothers; Obesity; Pregnancy; Weight Gain; Young Adult

The objective was to evaluate the effect of feeding increasing amounts of essential fatty acids (FA) in milk replacer (MR) during the first 60 d of life on growth, health, and immunity of Holstein calves. Calves were born from dams fed low concentrations of total and essential FA during the lasT2 mo of pregnancy. Newborn calves were blocked by sex and parity of the dam and assigned randomly to receive 1 of 4 MR treatments (T). Hydrogenated coconut oil and soybean oil were mixed with emulsifier and commercial MR powder to prepare the following 4 MR containing 0.119 and 0.007 (T1), 0.187 and 0.017 (T2), 0.321 and 0.036 (T3), and 0.593 and 0.076 (T4) g of intake per kg of metabolic body weight (BW(0.75)) of linoleic acid and α-linolenic acid, respectively. At 30 d of life, concentrations of essential FA (linoleic acid and α-linolenic acid) in liver increased, whereas concentrations of C12:0, C14:0, C16:0, and C20:3n-9 decreased linearly with increasing intake of essential FA. Body weight gain and feed efficiency were optimized when male calves consumed T2, whereas gain by female calves tended to increase linearly with increasing intake of essential FA during the first 30 d of age. However, these responses to treatment were not maintained after initiation of concentrate feeding at 31 d of life. Over the 60-d preweaning period, wither and hip heights were improved in both sexes as intake of essential FA increased up to T3. Some measures of health and immunity were affected by replacing some coconut oil with soybean oil. Severity of diarrhea tended to decrease linearly; plasma concentrations of haptoglobin during diarrhea were lower in T2, T3, and T4; phagocytosis by blood neutrophils tended to peak for calves fed T2; in vitro proliferation of stimulated blood lymphocytes was greater for calves fed T2; in vitro stimulated blood cells produced more IFN-γ (up to T3 for males and T2 for females), concentrations of serum IgG against ovalbumin injections were increased in males fed T2 or T3; and skin-fold thickness increased in response to an intradermal antigen injection of all calves fed up to T4. Across sex and under the conditions of the present study, mean daily intakes of linoleic acid between 3 to 5g/d and intakes of α-linolenic acid between 0.3 and 0.6g/d during the first 30 d of life promoted growth of preweaned Holstein calves, possibly by improving their immune status.

Topics: alpha-Linolenic Acid; Animals; Animals, Newborn; Body Weight; Cattle; Coconut Oil; Diet; Fatty Acids, Essential; Female; Linoleic Acid; Male; Milk; Neutrophils; Plant Oils; Soybean Oil; Weaning; Weight Gain

Previous studies on rats and human subjects have established that the linoleic acid (LA) requirement is 2 % of the total energy intake (en%), but is obtained in the absence of α-linolenic acid (ALA) and consequently appear to be overestimated. This raises questions since a recent study including ALA has suggested to divide the historical value by four. However, this recent study has remained inconclusive because the animals used were not totally LA-deficient animals. For the first time, the present study was especially designed using physiological and biochemical markers and performed in two steps: (1) to achieve a specific n-6 fatty acid deficiency model using growing male rats fed either a 0 en% from LA/0 en% from ALA (0LA/0ALA), 0LA/0·5ALA or 2LA/0·5ALA diet, born from female rats fed a 0LA/0·5ALA diet; and (2) to refine the required level of LA in the presence of ALA using rats fed either a 0LA/0ALA, 0·5LA/0·5ALA, 1LA/0·5ALA, 1·5LA/0·5ALA diet, born from female rats fed a 0LA/0·5ALA diet. The first step shows that the best LA deficiency model was obtained using rats fed the 0LA/0ALA diet, born from female rats fed the 0LA/0·5ALA diet. The second step demonstrates that in growing rats, LA deficiency was corrected with an intake of 1-1·5 en% from LA and 0·5 en% from ALA. These data suggest that the requirements in humans should be revisited, considering the presence of ALA to set up the recommendation for LA.

Topics: alpha-Linolenic Acid; Animals; Biomarkers; Deficiency Diseases; Disease Models, Animal; Energy Intake; Female; Fetal Development; Lactation; Linoleic Acid; Male; Maternal Nutritional Physiological Phenomena; Nutritional Requirements; Pregnancy; Random Allocation; Rats, Wistar; Skin Diseases, Metabolic; Tail; Weaning; Weight Gain

Animal and human adult studies indicate that long-term intake of trans fatty acids (TFAs) may be associated with weight gain. High intake of fast foods and snacks, which are rich in TFAs, is linked to overweight status among school-age children. However, the specific effects of TFAs in this population are unknown.. We examined whether serum TFAs, used as biomarkers of intake, are associated with faster weight gain and linear growth during school years.. We quantified TFAs by GLC in serum samples of 668 children aged 5-12 y at the time of recruitment into an ongoing cohort study performed in Bogota (Colombia) since 2006. Serum proportions of trans palmitoleic acid (16:1t), trans oleic acid (18:1t), trans linoleic acid (18:2t), and total TFAs were used as biomarkers of intake. Anthropometric characteristics were measured periodically for a median of 30 mo. Body mass index-for-age z scores (BAZs) and height-for-age z scores (HAZs) were calculated with the use of the WHO reference. We estimated mean changes in BAZs and HAZs over follow-up according to quartiles of each TFA at baseline by using mixed-effects regression models with restricted cubic splines.. Proportions of trans palmitoleic acid, trans oleic acid, trans linoleic acid, and total TFAs (mean ± SD, % of total serum FAs), were 0.22 ± 0.06, 0.91 ± 0.37, 0.96 ± 0.27, and 2.10 ± 0.59, respectively. Serum TFAs were not associated with changes in BAZs and HAZs after adjusting for sex, baseline age, and socioeconomic status. In a subgroup analysis by sex, serum trans palmitoleic acid was positively associated with the estimated change in HAZs from ages 6 to 14 y in boys (with use of the first quartile as the reference, differences in HAZs for trans palmitoleic acid quartiles were 0.73, 0.53, and 0.70, P-trend = 0.03).. Proportions of serum TFAs, used as biomarkers of TFA intake, were not associated with weight gain in children aged 6-14 y in low- and middle-income populations in Bogota. The proportion of trans palmitoleic acid was positively associated with linear growth in boys. Longer follow-up and studies in diverse cohorts with wider ranges of TFA intake are warranted.

Topics: Biomarkers; Body Mass Index; Child; Child Development; Child Nutritional Physiological Phenomena; Child, Preschool; Cohort Studies; Colombia; Fatty Acids, Monounsaturated; Female; Follow-Up Studies; Humans; Linoleic Acid; Male; Multivariate Analysis; Oleic Acid; Snacks; Socioeconomic Factors; Trans Fatty Acids; Weight Gain

Dietary intake of linoleic acid (LNA, 18:2n-6) has increased dramatically during the 20th century and is associated with greater prevalence of obesity. The endocannabinoid system is involved in regulation of energy balance and a sustained hyperactivity of the endocannabinoid system may contribute to obesity. Arachidonic acid (ARA, 20:4n-6) is the precursor for 2-AG and anandamide (AEA), and we sought to determine if low fat diets (LFD) could be made obesogenic by increasing the endocannabinoid precursor pool of ARA, causing excessive endocannabinoid signaling leading to weight gain and a metabolic profile associated with obesity. Mice (C57BL/6j, 6 weeks of age) were fed 1 en% LNA and 8 en% LNA in low fat (12.5 en%) and medium fat diets (MFD, 35 en%) for 16 weeks. We found that increasing dietary LNA from 1 to 8 en% in LFD and MFD significantly increased ARA in phospholipids (ARA-PL), elevated 2-AG and AEA in liver, elevated plasma leptin, and resulted in larger adipocytes and more macrophage infiltration in adipose tissue. In LFD, dietary LNA of 8 en% increased feed efficiency and caused greater weight gain than in an isocaloric reduction to 1 en% LNA. Increasing dietary LNA from 1 to 8 en% elevates liver endocannabinoid levels and increases the risk of developing obesity. Thus a high dietary content of LNA (8 en%) increases the adipogenic properties of a low fat diet.

Topics: Adipose Tissue; Analysis of Variance; Animals; Arachidonic Acids; Body Weight; Diet; Diet, Fat-Restricted; Endocannabinoids; Erythrocytes; Fatty Acids; Glycerides; Leptin; Linoleic Acid; Liver; Macrophages; Male; Mice; Mice, Inbred C57BL; Obesity; Phospholipids; Polyunsaturated Alkamides; Risk Factors; Weight Gain

Δ-6-fatty acid desaturase (FADS2) is the key enzyme in the biosynthesis of polyunsaturated fatty acids (PUFAs), the essential structural determinants of mammalian membrane lipid-bilayers. We developed the auxotrophic fads2(-/-) mouse mutant to assess the enigmatic role of ω3- and ω6-PUFAs in lipid homeostasis, membrane structure and function. Obesity resistance is another major phenotype of the fads2(-/-) mutant, the molecular basis of which is unknown. Phospholipidomic profiling of membrane systems of fads2(-/-)mice revealed diacylglycerol-structures, deprived of PUFAs but substituted with surrogate eicosa-5,11,14-trienoic acid. ω6-Arachidonic (AA) and ω3-docosahexaenoic acid (DHA) supplemented diets transformed fads2(-/-) into AA-fads2(-/-) and DHA-fads2(-/-) mutants. Severely altered phospholipid-bilayer structures of subcellular membranes of fads2(-/-) liver specifically interfered with maturation of transcription factor sterol-regulatory-element-binding protein, the key regulator of lipogenesis and lipid homeostasis. This study strengthens the concept that specific PUFA-substituted membrane phospholipid species are critical constituents of the structural platform operative in lipid homeostasis in normal and disease conditions.

Topics: Adipocytes, White; Adipose Tissue, White; Animals; Arachidonic Acid; Cell Size; Disease Resistance; Docosahexaenoic Acids; Fatty Liver; Female; Linoleic Acid; Linoleoyl-CoA Desaturase; Lipogenesis; Liver; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Obesity; Phospholipids; Transcriptome; Weight Gain

Dietary intake of linoleic acid (LA) has increased dramatically during the twentieth century and is associated with a greater prevalence of obesity. Vegetable oils are recognised as suitable alternatives to fish oil (FO) in feed for Atlantic salmon (Salmo salar L.) but introduce high amounts of LA in the salmon fillet. The effect on fish consumers of such a replacement remains to be elucidated. Here, we investigate the effect of excessive dietary LA from soyabean oil (SO) on endocannabinoid levels in Atlantic salmon and mice, and study the metabolic effects in mice when SO replaces FO in feed for Atlantic salmon. Atlantic salmon were fed FO and SO for 6 months, and the salmon fillet was used to produce feed for mice. Male C57BL/6J mice were fed diets of 35% of energy as fat based on FO- and SO-enriched salmon for 16 weeks. We found that replacing FO with SO in feed for Atlantic salmon increased LA, arachidonic acid (AA), decreased EPA and DHA, elevated the endocannabinoids 2-arachidonoylglycerol (2-AG) and anandamide (AEA), and increased TAG accumulation in the salmon liver. In mice, the SO salmon diet increased LA and AA and decreased EPA and DHA in the liver and erythrocyte phospholipids, and elevated 2-AG and AEA associated with increased feed efficiency, weight gain and adipose tissue inflammation compared with mice fed the FO salmon diet. In conclusion, excessive dietary LA elevates endocannabinoids in the liver of salmon and mice, and increases weight gain and counteracts the anti-inflammatory properties of EPA and DHA in mice.

Topics: Adipose Tissue; Analysis of Variance; Animal Feed; Animals; Arachidonic Acids; Dietary Fats; Endocannabinoids; Fish Oils; Inflammation; Linoleic Acid; Liver; Male; Mice; Mice, Inbred C57BL; Salmo salar; Soybean Oil; Weight Gain

Fatty acid (FA) composition and desaturase indices are associated with obesity and related metabolic conditions. However, it is unclear to what extent desaturase activity in different lipid fractions contribute to obesity susceptibility. Our aim was to test whether desaturase activity and FA composition are linked to an obese phenotype in rats that are either obesity prone (OP) or resistant (OR) on a high-fat diet (HFD).. Two groups of Sprague-Dawley rats were given ad libitum (AL-HFD) or calorically restricted (HFD-paired; pair fed to calories consumed by chow-fed rats) access to a HFD. The AL-HFD group was categorized into OP and OR sub-groups based on weight gain over 5 weeks. Five different lipid fractions were examined in OP and OR rats with regard to proportions of essential and very long-chain polyunsaturated FAs: linoleic acid (LA), alpha-linolenic acid, eicosapentaenoic acid, docosahexaenoic acid and the stearoyl-CoA desaturase 1 (SCD-1) product 16:1n-7. FA ratios were used to estimate activities of the delta-5-desaturase (20:4n-6/20:3n-6), delta-6-desaturase (18:3n-6/18:2n-6), stearoyl-CoA desaturase 1 (SCD-1; 16:1n-7/16:0, SCD-16 and 18:1n-9/18:0, SCD-18), de novo lipogenesis (16:0/18:2n-6) and FA elongation (18:0/16:0). Fasting insulin, glucose, adiponectin and leptin concentrations were measured in plasma.. After AL-HFD access, OP rats had a significantly higher SCD-16 index and 16:1n-7 proportion, but a significantly lower LA proportion, in subcutaneous adipose tissue (SAT) triacylglycerols, as well as significantly higher insulin and leptin concentrations, compared with OR rats. No differences were found between the two phenotypes in liver (phospholipids; triacylglycerols) or plasma (cholesterol esters; phospholipids) lipid fractions or for plasma glucose or adiponectin concentrations. For the desaturase indices of the HFD-paired rats, the only significant differences compared with the OP or OR rats were higher SCD-16 and SCD-18 indices in SAT triacylglycerols in OP compared with HFD-paired rats.. The higher SCD-16 may reflect higher SCD-1 activity in SAT, which in combination with lower LA proportions may reflect higher insulin resistance and changes in SAT independent of other lipid fractions. Whether a lower SCD-16 index protects against diet-induced obesity is an interesting possibility that warrants further investigation.

Topics: Adiponectin; alpha-Linolenic Acid; Animals; Blood Glucose; Caloric Restriction; Delta-5 Fatty Acid Desaturase; Diet, High-Fat; Dietary Fats; Docosahexaenoic Acids; Eicosapentaenoic Acid; Fatty Acid Desaturases; Insulin; Leptin; Linoleic Acid; Lipogenesis; Liver; Male; Obesity; Rats; Rats, Sprague-Dawley; Stearoyl-CoA Desaturase; Subcutaneous Fat; Triglycerides; Weight Gain

Diabetes and insulin resistance increase the risk of cardiovascular disease caused by atherosclerosis through mechanisms that are poorly understood. Lipid-loaded macrophages are key contributors to all stages of atherosclerosis. We have recently shown that diabetes associated with increased plasma lipids reduces cholesterol efflux and levels of the reverse cholesterol transporter ABCA1 (ATP-binding cassette transporter A1) in mouse macrophages, which likely contributes to macrophage lipid accumulation in diabetes. Furthermore, we and others have shown that unsaturated fatty acids reduce ABCA1-mediated cholesterol efflux, and that this effect is mediated by the acyl-CoA derivatives of the fatty acids. We therefore investigated whether acyl-CoA synthetase 1 (ACSL1), a key enzyme mediating acyl-CoA synthesis in macrophages, could directly influence ABCA1 levels and cholesterol efflux in these cells. Mouse macrophages deficient in ACSL1 exhibited reduced sensitivity to oleate- and linoleate-mediated ABCA1 degradation, which resulted in increased ABCA1 levels and increased apolipoprotein A-I-dependent cholesterol efflux in the presence of these fatty acids, as compared with wildtype mouse macrophages. Conversely, overexpression of ACSL1 resulted in reduced ABCA1 levels and reduced cholesterol efflux in the presence of unsaturated fatty acids. Thus, the reduced ABCA1 and cholesterol efflux in macrophages subjected to conditions of diabetes and elevated fatty load may, at least in part, be mediated by ACSL1. These observations raise the possibility that ABCA1 levels could be increased by inhibition of acyl-CoA synthetase activity in vivo. This article is part of a Special Issue entitled Advances in High Density Lipoprotein Formation and Metabolism: A Tribute to John F. Oram (1945-2010).

Topics: Amino Acid Substitution; Animals; Apolipoproteins A; ATP Binding Cassette Transporter 1; ATP-Binding Cassette Transporters; Cell Line; Cholesterol; Coenzyme A Ligases; Diet, High-Fat; Gene Expression; Gene Expression Regulation; Linoleic Acid; Macrophages; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Mutagenesis, Site-Directed; Oleic Acid; Proteolysis; Triglycerides; Weight Gain

We hypothesized that due to the absence of a dietary source of omega-3 fatty acids, the essential fatty acid (EFA) deficiency model leads to an overestimate of linoleic acid (LA) requirements.. over 7wk, young rats consumed an EFA diet containing either 0en% linoleate (0LA) and 0en% α-linolenate (0LNA) or a diet containing 0.5en% LNA plus one of seven levels of added LA (0.12-4.0en%; n=6/group).. Rats consuming the 0LA-0LNA diet had the lowest final body weight, 34-68% lower LA and arachidonate in plasma and liver, 87% lower LA in epididymal fat, and an 8-20 fold higher eicosatrienoate in plasma, liver and muscle lipids. 0.5LNA completely prevented the lower growth and partly prevented the rise in eicosatrienoate seen in the 0LA-0LNA group.. Providing dietary LNA at 0.5 en% reduces the rat's physiological requirement for LA by an estimated factor of at least four (0.5en% instead of 2en%). Since LA requirements in humans are also based on the same flawed model of EFA deficiency, it is plausible that they too have been overestimated and should therefore be reinvestigated.

Topics: alpha-Linolenic Acid; Animals; Arachidonic Acids; Cerebral Cortex; Dietary Fats; Docosahexaenoic Acids; Fatty Acids; Fatty Acids, Essential; Fatty Acids, Unsaturated; Linoleic Acid; Liver; Male; Muscle, Skeletal; Rats; Rats, Wistar; Weight Gain

Maize shows wide differences in linoleic acid due both to total lipid content and to fatty acid profile. Therefore, diets containing the same high maize percentage (up to 55%) can differ in linoleic acid content and lead to subcutaneous fats of differing suitability for raw ham curing. Two trials were performed on heavy pigs; in the first, 60 pigs (body weight 48.7+/-5.1 kg) were fed three diets made using three maize batches differing in linoleic acid due to different total lipid content, in the second trial, 40 pigs (live weight 70.4+/-3.4 kg) were fed two diets made using two maize batches differing in linoleic acid due to their fatty acid profile. Pigs were slaughtered at 170 kg of live weight. In both trials, the growth and slaughtering performance did not differ. In the first trial the three diets lead to a different content of linoleic acid both in subcutaneous (low linoleic vs medium linoleic vs high linoleic P0.01) and intramuscular fat (low linoleic vs high linoleic P0.05). In the second trial different linoleic acid content was observed for subcutaneous fat (P0.01) but not for intramuscular fat. To formulate diets for heavy pigs, it is crucial to know the linoleic acid content of the maize used, because differences of only 0.3% can lead to significant differences in fatty acids composition of depot fats.

Topics: Animal Feed; Animals; Body Composition; Dietary Fats; Edible Grain; Fatty Acids; Female; Linoleic Acid; Male; Meat; Quality Control; Sex Characteristics; Subcutaneous Fat; Sus scrofa; Weight Gain; Zea mays

The aim of this study was to determine the effect of different dietary fatty acid profiles on the main fat depots of broiler chickens: skin including s.c. fat (SK) and abdominal fat pad (AF). One hundred forty-four female broiler chickens were fed a low-fat diet (B; 0.5% of added fat) or diets supplemented with 10% of tallow (T), sunflower oil rich in oleic acid (SOO), sunflower oil rich in linoleic acid (SOL), linseed oil rich in linolenic acid (LO), or a mix of fats (M: 55% of T + 35% of LO + 10% SOL) that contained one-third each of saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids. The animals were housed in 36 cages and were randomly distributed into 6 dietary treatments with 6 replicates each. Experimental diets were evaluated for apparent total fatty acid availability and AME. On d 42, birds were slaughtered to determine the weight of AF and SK and fatty acid profile. Regarding the diets containing 10% added fat, the highest saturated diet (T) resulted in the lowest values of apparent total fatty acid availability and percentage of AME. Animals fed the most polyunsaturated diet (LO) had a lower SK deposition than those fed the saturated diet, on both an absolute (LO: 145 vs. T: 159 and M: 168 g; P < 0.001) and a relative basis (LO: 6.94 vs. T: 7.39 and M: 7.52 g/100 g of BW; P < 0.001). Furthermore, the lowest AF depot was observed in the LO diet (LO: 26.3 g vs. T: 37.6 and M: 39.9 g; P < 0.001). The added fat treatments caused significant but similar changes in fatty acid profile of both studied tissues. In conclusion, feeding broiler chickens polyunsaturated fatty acids, in comparison to dietary saturated fatty acids, reduced the amount of both AF and SK by approximately 30 and 9%, respectively.

Topics: Abdominal Fat; Animal Nutritional Physiological Phenomena; Animals; Biological Availability; Chickens; Dietary Fats; Dietary Fats, Unsaturated; Dose-Response Relationship, Drug; Fats; Female; Linoleic Acid; Oleic Acid; Plant Oils; Subcutaneous Fat; Sunflower Oil; Weight Gain

Twenty, 1-2-day-old goat kids were used in a feeding trial to investigate the effect of linoleic acid (LA) (C18:2n-6) intake on weight gain and carcass composition. Eight animals were selected randomly and killed at the start of the trial to determine initial body composition. The other animals were assigned to the three dietary treatments and were fed milk replacers with varying LA concentrations (low: 5.5%; medium: 11.2% and high: 17.1% LA of total fatty acids) for 5 weeks. There was no systematic effect of LA intake on body composition. The average retentions of fat, protein, ash and energy were 46.3%, 61.2%, 42.2% and 37.4% respectively. Increased intakes of LA caused a significant increase in LA content of the carcass and of the weight gain, whereas there was a simultaneous decrease in fatty acids with 16 carbon atoms or less. The incorporation of LA into carcass was directly related to intake, but the percentage retention of LA remained constant. The data indicate that in goat kids the intake of extra LA raises the amount of LA in carcass but does not affect the total fat content.

Topics: Adipose Tissue; Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Animals, Newborn; Body Composition; Dietary Proteins; Dose-Response Relationship, Drug; Goats; Linoleic Acid; Male; Random Allocation; Weight Gain

The intake of linoleic acid (LA) and alpha-linolenic acid (ALA) in relation to average daily weight gain (ADG) was studied in growing-finishing pigs kept on smallholdings in Central Vietnam. Groups of three piglets each were assigned randomly to 12 farms, where they were fed on local feedstuffs according to the farmer's choice but were given a restricted amount of dry matter according to a preset feeding regimen. On arrival at the farms, the pigs weighed 10.4 +/- 0.9 kg (mean +/- SD, n = 36) and at 130 days of age they weighed 45.4 +/- 9.6 kg. Dietary LA concentration ranged from 1.34 to 2.41 g/MJ metabolizable energy (ME) and ALA from 0.06 to 0.33 g/MJ ME. On a farm level, dietary LA and ALA concentrations were significantly correlated with their concentrations in adipose tissue, both correlation coefficients being 0.63. Dietary protein concentration and protein:energy ratio were significantly correlated with ADG, the correlation coefficients being 0.68 and 0.64. For individual piglets there were significant correlations between either LA or ALA in adipose tissue and ADG, the correlation coefficients being 0.37 and 0.45. Dietary protein concentration or protein:energy ratio was correlated with the dietary contents of LA and ALA. It is uncertain whether LA and ALA intake had a causal relationship with ADG. Since dietary LA levels were above the LA requirement, LA intake may not have limited growth. It is suggested tentatively that, through enhanced disease resistance, supplementation with ALA of the diets on the farms studied might have a positive influence on ADG.

Topics: Adipose Tissue; alpha-Linolenic Acid; Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Dietary Proteins; Dose-Response Relationship, Drug; Energy Intake; Fatty Acids, Essential; Linoleic Acid; Male; Random Allocation; Swine; Vietnam; Weight Gain

The interaction of dietary protein type and fat level on the body fat-reducing activity of conjugated linoleic acid (CLA) was studied in male rats fed diets containing casein (CAS) or soy protein (SOY) as a protein source with low fat (LF, 6.0% soybean oil) or high fat (HF, 13.0% soybean oil) combinations for 4 weeks. CLA was added at the 1.0% level to all diets. The weight of perirenal adipose tissue tended to be lower in the SOY groups than in the corresponding CAS groups, and the difference between the LF diets was significant. The weight of epididymal adipose tissue showed a similar but insignificant trend. The weight of brown adipose tissue was heaviest on the SOY-HF diet and lowest on two CAS diets, the SOY-LF diet being intermediate. The concentration of serum leptin was lowest on the SOY-LF diet and was significantly lower than that of the corresponding CAS group, but this difference disappeared when the dietary fat level increased. The serum cholesterol-lowering activity of SOY in relation to CAS was reproduced even when CLA was given. Thus the body fat-reducing activity of CLA was most marked when rats were fed the SOY-LF diet. Although the CAS-HF diet increased body fat deposition, the magnitude of the reduction by lowering dietary fat level was more marked than in the case of SOY. These results indicate a complicated interaction of dietary manipulations with the body fat-reducing effect of CLA, but the combination of CLA with the SOY-LF diet appears to be an appropriate approach.

Topics: Adipose Tissue; Animals; Anti-Obesity Agents; Body Weight; Caseins; Cytokines; Diet; Dietary Fats; Dietary Proteins; Epididymis; Fatty Acids; Leptin; Linoleic Acid; Lipid Metabolism; Lipids; Liver; Male; Organ Size; Oxidation-Reduction; Rats; Rats, Sprague-Dawley; Soybean Proteins; Weight Gain

The role of enteral or parenteral long-chain triacylglycerol (LCT) in the complex process of intestinal adaptation is poorly defined and may involve alterations in eicosanoid synthesis. Our objective was to determine whether provision of parenteral LCT stimulates eicosanoid synthesis and resection-induced intestinal adaptation. We assessed small bowel structural adaptation, the fatty acid profiles of liver, plasma and jejunal mucosa, and the profile of 11 eicosanoids derived from (n-6) PUFA of the jejunal mucosa in rats maintained with total parenteral nutrition (TPN) with 0 or 32% of nonprotein energy from Intralipid for 7 d after mid-small bowel resection or transection control surgery. There was no evidence of biochemical essential fatty acid (EFA) deficiency in the absence of parenteral fat. Resection-induced gut growth occurred independently of parenteral LCT based on significant mucosal hyperplasia in the jejunum and ileum. The mucosal profile of linoleic acid in the total lipid extract of jejunum increased with the presence of parenteral LCT, but decreased with resection without differences in arachidonic acid. There were no differences in the jejunal profile of 11 (n-6)-derived eicosanoids among the four TPN groups as determined by tandem MS. In summary, small bowel resection-induced adaptation occurs independently of parenteral LCT, and fat-free TPN without EFA deficiency does not alter the profile of jejunal (n-6)-derived eicosanoids. Thus, parenteral administration of LCT does not appear to alter jejunal eicosanoid synthesis nor is it beneficial in stimulating intestinal adaptation.

Topics: Adaptation, Physiological; Dietary Fats; Dinoprost; Dinoprostone; Eicosanoids; Fatty Acids; Hyperplasia; Ileum; Intestinal Mucosa; Intestine, Small; Intestines; Jejunum; Linoleic Acid; Lipids; Liver; Oleic Acid; Palmitic Acid; Parenteral Nutrition, Total; Triglycerides; Weight Gain

Iron deficiency (ID) is among the most common nutritional diseases, causing deleterious effects that include decreases in cognitive function and weight loss. The ID also induces a reduction in the number and affinity of dopaminergic D2 receptors. The new finding that ID induces an increase in the pancreas cells, leads to the hypothesis that cholecystokinin-8 (CCK-8) is involved in the ID effects. The level of CCK-8 was higher among ID rats, compared with normal rats. The ID rats in our study were anorectic and performed poorly in learning tests (Morris water maze and passive avoidance learning). Essential fatty acids (EFA) mediate dopamine activity and have been found to rehabilitate learning deficits. Treatment with a fatty acid compound blocked both the learning deficits and the anorexia, while a CCK-8 antagonist was successful only against the anorectic effects.

Topics: Animal Feed; Animals; Avoidance Learning; Cholecystokinin; Energy Intake; Hormone Antagonists; Iron Deficiencies; Islets of Langerhans; Linoleic Acid; Male; Motor Activity; Peptide Fragments; Proglumide; Rats; Rats, Long-Evans; Swimming; Weight Gain

In this study, we examined the effect of dietary conjugated linoleic acid (CLA) on body fat levels in Sprague-Dawley rats.. Rats were fed AIN-93G type diets containing 4%, 7%, and 10% fats with or without 1.5% CLA.. Three weeks after the onset of the experimental period, the weights of perirenal white adipose tissue were lower in CLA-fed rats. The weights of epididymal white adipose tissue also were lower in CLA-fed rats than in control rats, but this effect disappeared with increased dietary fat level. Serum leptin levels tended to be lower in the CLA group, especially the low-fat diet group, than in the control group. There were significant positive correlations between serum leptin level and weights of perirenal and epididymal white adipose tissues in control groups, but these correlations were weaker in the CLA groups. Serum tumor necrosis factor-alpha levels also tended to be lower in CLA-fed rats, and this tendency was most remarkable in the rats fed 7% fat diets.. In conclusion, dietary CLA, especially the low-fat diet, reduced body fat without hepatic injury to Sprague-Dawley rats.

Topics: Adipose Tissue; Animals; Body Composition; Dietary Fats; Dose-Response Relationship, Drug; Leptin; Linoleic Acid; Liver; Male; Random Allocation; Rats; Rats, Sprague-Dawley; Tumor Necrosis Factor-alpha; Weight Gain

Thirty female Large White x Landrace pigs (average weight 57.2 (sd 1.9) kg) were allocated to one of six dietary treatments containing 0, 1.25, 2.5, 5.0, 7.5 or 10.0 g 55 % conjugated linoleic acids (CLA) isomers (CLA-55)/kg diet and fed for 8 weeks. Each pig was scanned at 0, 28 and 56 d and again at post slaughter using dual-energy X-ray absorptiometry (DXA) to determine the temporal pattern of body composition responses. Values determined by DXA were adjusted using regression equations generated from validation experiments between chemically and DXA-predicted values. Overall, there was a significant linear reduction in fat content with the increasing levels of CLA in the diet (P=0.007, P=0.011, P=0.008 at week 4, week 8 and for the carcass, respectively). The greatest improvement was recorded at the early stages of CLA supplementation and for the highest dose of CLA (week 4, -19.2 % compared with week 8, -13.7 %). In the first 4 weeks of feeding CLA, pigs receiving 10 g CLA-55/kg diet deposited 93 g less fat/d than pigs fed basal diets (P=0.002) compared with only 6 g less fat than control animals in the final 4 weeks. Lean content and lean deposition rate were maximised at 5 and 2.5 g CLA-55/kg diet for the first 4 weeks (P=0.016) and the final 4 weeks of treatment respectively. DXA estimates of bone mineral content and bone mineral density were not affected by CLA supplementation throughout the experiment. These data demonstrate that dietary CLA decreases body fat in a dose-dependent manner and that the response is greatest over the initial 4 weeks of treatment.

Topics: Absorptiometry, Photon; Animal Feed; Animals; Body Composition; Female; Linoleic Acid; Random Allocation; Sus scrofa; Weight Gain

We examined the effect of dietary conjugated linoleic acid (CLA) on growth performance and liver composition in broiler chickens. Day-old male broiler chicks were assigned to receive a diet supplemented with corn oil (5%; n = 48) or CLA (5%; n = 48) for 21 d. Broilers fed CLA weighed less and grew at slower rates than broilers fed corn oil. Feed intake and feed conversion were higher for the corn-oil group than for the CLA dietary group. Hepatic lipid and triacylglycerol concentrations were significantly reduced by dietary CLA. The proportions of saturated fatty acids (SFA) in liver lipids increased, whereas those of monounsaturated fatty acids (MUFA) decreased with CLA supplementation. Although the total concentration of polyunsaturated fatty acids (PUFA) did not change with dietary treatment, the concentration of linoleic acid as a percentage of total methylated fatty acids decreased, and that of linolenic add increased in broilers fed CLA. The concentration of CLA isomers in liver lipids increased substantially with CLA feeding. The relative proportion of the c9,t11 CLA isomer in hepatic lipids was much higher than that of the t10,c12 or t9,t11 CLA isomers. These studies provide evidence that feeding CLA to broilers results in substantial reduction in liver fat accumulation and promotes CLA incorporation into hepatic lipid pools.

Topics: Animal Nutritional Physiological Phenomena; Animals; Chickens; Diet; Eating; Fatty Acids; Linoleic Acid; Lipids; Liver; Male; Organ Size; Triglycerides; Weight Gain

Dietary soy protein, in comparison with casein, generally lowers the serum cholesterol concentration in rats fed on a cholesterol-enriched diet, while mixed results were observed in rats fed on a diet free of cholesterol. Soy protein also suppresses the conversion of linoleic acid to arachidonic acid in the rat liver. The present study examines whether phytate, a minor component of a soy protein isolate, is responsible for these beneficial effects of soy protein. Weanling male rats were fed for 4 weeks on a purified diet containing a 20% level of protein (either casein (CAS), soy protein (SOY), phytate-depleted SOY (PDSOY) or phytate-replenished PDSOY (PRSOY)) and cholesterol (0 or 0.5%). The dietary protein source and phytate level only affected the serum and liver cholesterol concentrations when the animals were fed on the cholesterol-enriched diet, being significantly lower in those rats fed on the SOY and PRSOY diets than in those fed on the CAS diet, while the concentrations in the rats fed on the PDSOY diet were intermediate. When the animals were fed on the cholesterol-free diet, the ratio of (20:3n-6 + 20:4n-6)/18:2n-6 in liver phosphatidylcholine, a delta6 desaturation index, was significantly lower in the SOY diet group than in the CAS, PDSOY and PRSOY diet groups. Dietary cholesterol significantly depressed the ratio, but neither depletion nor replenishment of phytate affected the ratio. These results suggest that phytate in soy protein played a limited role in the cholesterol-lowering effect of soy protein and was not involved in the metabolism of linoleic acid.

Topics: Animals; Cholesterol; Cholesterol, Dietary; Diet; Fatty Acids; Growth; Linoleic Acid; Lipid Metabolism; Liver; Male; Organ Size; Phytic Acid; Rats; Rats, Sprague-Dawley; Soybean Proteins; Weight Gain

The objective of this study was to evaluate the effect of feeding prepubertal heifers a diet containing a high level of polyunsaturated fatty acids on mammary development and milk production. A total of 116 Holstein heifers were either fed a conventionally formulated concentrate or a high oil (HO) concentrate, using the same formulation but including 20% soybean oil, from birth to 6 mo of age. After 6 mo of age, all heifers were managed identically. Mammary gland development was evaluated on heifers slaughtered at 4 mo (n = 10) and 12 mo (n = 30) of age. Other heifers were bred when they reached 15 mo of age and milk production and feed intake were recorded every day from wk 4 to 18 of lactation. Feeding the high oil concentrate increased the concentration of linoleic acid in blood plasma (176%) and mammary fat pad (78%) at 4 mo of age and mammary fat pad (93%) at 12 mo of age. At 4 mo of age, mammary development was similar in both treatments. At 12 mo of age, total, parenchyma, and stroma weights of the mammary gland were not affected by treatments. However, lipid content was lower and concentration of DNA was higher in the parenchyma of heifers fed the high oil diet. Nevertheless, total parenchymal DNA and dry fat free tissue content did not reach statistical significance despite the fact that they were, respectively, 15 and 21% higher in HO heifers. Milk production and composition was not affected by treatments. In conclusion, feeding prepubertal heifers with a high oil concentrate slightly improved the mammary development but effects were too small to be translated into better lactating performances.

Topics: Aging; Animal Nutritional Physiological Phenomena; Animals; Cattle; Dietary Fats, Unsaturated; DNA; Eating; Female; Lactation; Linoleic Acid; Lipids; Mammary Glands, Animal; Milk; Sexual Maturation; Soybean Oil; Weight Gain

Primiparous Angus x Gelbvieh (n = 36) rotationally crossed beef cows (initial BW = 487.9 +/- 10.5 kg, body condition score = 5.5 +/- 0.02) were utilized to determine effects of supplemental safflower seeds high in linoleic (76% 18:2) or oleic (72% 18:1) acid on cow BW change, body condition score, milk production and composition, calf weight gain, cow serum metabolites, and metabolic hormones. On d 3 postpartum, cows were randomly assigned to one of three isonitrogenous dietary supplements with equal total quantity of TDN: corn-soybean control supplement (n = 12); high-linoleate safflower seeds (n = 12); or high-oleate safflower seeds (n = 12). Safflower-seed supplements were formulated to provide 5% DMI as fat. Supplements were individually fed from d 3 postpartum through 90 d postpartum. Cows had ad libitum access to native grass hay (7.8% CP), trace-mineralized salt, and water. Date of parturition was evenly distributed across treatments with all cows calving within 14 +/- 0.8 d. There were no differences (P = 0.65) in total OM intake among treatments. Although cow BW change did not differ (P = 0.33) by treatment, supplementation influenced cow body condition score (P = 0.02) with linoleate-supple-mented cows in higher (P = 0.005) condition overall than oleate-supplemented cows (5.1 +/- 0.06 vs 4.9 +/- 0.06). Twenty-four-hour milk production did not differ (P = 0.68) among treatments. Percentage milk fat was not different at d 30; however, at d 60 and d 90 percentage milk fat was greater (P ( 0.05) in control and oleate-supplemented cows than in linoleate-supplemented cows. Calf BW gains (P = 0.27) and adjusted 205-d weights (P = 0.48) were not affected by supplement treatment. Supplementation did not influence serum concentrations of glucose (P = 0.38), NEFA (P = 0.61), GH (P = 0.29), IGF-I (P = 0.81), insulin (P = 0.26), or IGF-I binding proteins (P > or = 0.11). Days to conception did not differ (P = 0.40) among treatments. Although overall productivity of the primiparous cows and their calves was not altered by safflower-seed supplementation, differential effects were noted between supplements. Oleate supplementation increased percentage milk fat at d 60, and cow body condition score was lower than in linoleate-supplemented cows. Linoleate-supplemented cows had greater body condition scores by 90 d postpartum than either corn-soybean- or oleatesupplemented cows.

Topics: Animal Nutritional Physiological Phenomena; Animals; Body Composition; Body Weight; Cattle; Dietary Supplements; Fats; Female; Lactation; Linoleic Acid; Milk; Oleic Acid; Parity; Postpartum Period; Random Allocation; Reproduction; Safflower Oil; Seeds; Time Factors; Weight Gain

CLA has a range of biological properties, including effects on lipid metabolism and body composition in experimental animals. The prevalent isomer of CLA found in the human diet is 9c,11 t-CLA, and it is predominantly found in products containing fat from ruminant animals. This study investigated the effect of dietary CLA on energy balance in mice. Synthetic CLA reduced body fat in growing male BALB/c mice in a dose-dependent manner over the range 0.25-1.0% w/w CLA in the diet. Weight gain was also reduced at the highest levels of dietary CLA, being only 5.88 +/- 2.68 g/4 mice (mean +/- 1 SD) after 4 wk of 2.0% CLA in the diet, compared with weight gains of 7.51 +/- 2.22 to 8.17 +/- 2.34 g/4 mice in the 0-0.5% CLA groups. There was no significant effect on weight gain if diets contained 0.5% synthetic CLA or less. These results suggest that high levels of a synthetic mixture of CLA isomers modify energy metabolism and body composition and that high levels of synthetic CLA impair weight gain and reduce body fat pad mass in growing mice.

Topics: Adipose Tissue; Animals; Body Composition; Body Weight; Diet; Dietary Fats; Dose-Response Relationship, Drug; Energy Metabolism; Linoleic Acid; Male; Mice; Mice, Inbred BALB C; Motor Activity; Weight Gain

Seventy-two 8-week-old ram lambs from three breeds, Suffolk, Soay and Friesland, were offered one of four diets based on dried grass and formulated to have a similar fatty acid content (60 g/kg DM) and containing: Megalac (high in 16 : 0, control; Volac Ltd, Royston, Herts., UK), whole linseed (18 : 3n-3), fish oil (20 : 5n-3 and 22 : 6n-3) or whole linseed plus fish oil. The lambs were slaughtered at approximately half of their mature live weight (43, 21 and 43 kg for Suffolk, Soay and Friesland lambs, respectively). Fish oil reduced DM intake and lamb live-weight gain (P<0.001), while DM intake, live-weight gain and subcutaneous fat content were highest in Suffolk and lowest in Soay lambs. Linseed feeding doubled the proportion (x100) of 18 : 3n-3 in the longissimus dorsi from 1.4 to 3.1 and in the subcutaneous adipose tissue from 1.2 to 2.6 (P<0.001). Suffolk and particularly Soay lambs contained higher proportions of 18 : 3n-3 than Friesland lambs in the longissimus dorsi, while in the adipose tissue, Suffolk lambs had the highest level. Feeding fish oil increased the muscle proportion (x100) of 20 : 5n-3 from 0.7 to 2.3 and 22 : 6n-3 from 0.3 to 0.8 (P<0.001). By contrast, the proportions of the longer-chain n-3 polyunsaturated fatty acids were similar across all three breeds. All three lipid supplements containing n-3 polyunsaturated fatty acids increased the content of muscle trans-18 : 1 relative to the control values, but conjugated linoleic acid (cis-9,trans-11-18 : 2) only increased in the muscle of lambs fed linseed. Feeding linseed or fish oil lowered the n-6 : n-3 ratio in sheep meat, but neither diet nor breed had much effect on the polyunsaturated fatty acid: saturated fatty acid ratio.

Topics: Adipose Tissue; Analysis of Variance; Animals; Body Composition; Breeding; Dietary Fats; Energy Intake; Fatty Acids, Omega-3; Fish Oils; Linoleic Acid; Linseed Oil; Male; Meat; Sheep; Weight Gain

The effects of a combination of dietary conjugated linoleic acid (CLA) supplemented with sesamin on hepatic ketogenesis and triacylglycerol secretion were compared using the livers of rats fed diets containing 1% CLA or linoleic acid (LA) in combination with 0.2% sesamin for 14 d, respectively. The feeding of CLA, as compared to LA, caused a significant reduction in the weight of perirenal adipose tissue but not that of epididymal adipose tissue, and affected neither growth parameters nor hepatic lipid concentration. Hepatic production of ketone bodies was consistently higher in rats fed CLA than in those fed LA, while triacylglycerol secretion was reversed. No significant difference was noted in the hepatic secretion of cholesterol among the groups. Although there was no effect of the dietary combination of CLA with sesamin on adipose tissue weight, hepatic lipid parameters and ketone body production were observed: i.e., triacylglycerol secretion tended to be reduced. These results suggest that the dietary combination of CLA with sesamin may be an effective approach for lowering serum triacylglycerol levels. The decreased hepatic secretion of triacylglycerol is, in part, due to enhanced fatty acid oxidation in the liver.

Topics: Animals; Anticholesteremic Agents; Body Composition; Diet; Dioxoles; Ketone Bodies; Lignans; Linoleic Acid; Lipid Metabolism; Liver; Male; Perfusion; Rats; Rats, Sprague-Dawley; Time Factors; Triglycerides; Weight Gain

Conjugated linoleic acid (CLA) was fed to growing-finishing barrows (n = 92) at 0.75% of the diet. A commercial CLA preparation (CLA 60) containing 60% CLA isomers was included at 1.25% to provide 0.75% CLA in the diet. The inclusion of CLA in diets was initiated at various BW and fed until slaughter. Growth, carcass, meat quality, physical, chemical, and sensory data were collected and analyzed. Treatments T1, T2, T3, and T4 included the last 0, 29, 56 and 87 kg, respectively, of weight gain before slaughter. Average daily gain and feed intake were not affected (P > or = 0.06) by CLA, but gain:feed responded quadratically (P = 0.05), over the entire BW gain (28 to 115 kg) with pigs of T2 and T3 having the greatest gain:feed. Loin muscle area increased (P = 0.01) linearly with increasing weight gain while fed CLA, and 10th rib, first rib, and last rib fat depth decreased (P < or = 0.05) linearly. Subjective quality measures on loin muscles increased linearly for marbling (P < 0.05) and tended to increase for firmness (P = 0.07) with increasing weight gain while barrows were fed CLA. Objective Hunter color values for loin chops from T1 and T4 were not different for L* (P = 0.12) or a* (P = 0.08) values but were higher (P < 0.05) for b* values with CLA feeding. Lipid oxidation values of loin muscle tissue were lower (P < 0.05) for pigs fed CLA (T1 vs T4). Increasing the period of weight gain while feeding CLA linearly increased (P < 0.01) saturated fatty acids and CLA isomers in loin tissue and linearly increased (P < 0.01) saturated fatty acids and CLA isomers in subcutaneous adipose tissue. Sensory panel characteristics of loin chops were not changed (P > 0.05) by feeding CLA. Increased gain:feed, increased loin muscle area, decreased fat depth, and improvements in marbling and firmness with CLA feeding could result in improved profitability of pork production systems.

Topics: Animal Feed; Animals; Body Composition; Energy Intake; Energy Metabolism; Isomerism; Linoleic Acid; Male; Meat; Swine; Time Factors; Weight Gain

We investigated the effects of conjugated linoleic acid (CLA) supplementation on growth, feed efficiency, carcass characteristics, meat quality, lipogenesis, and lipid metabolism in rabbits. One hundred forty-four New Zealand White rabbits, half males, half females, age 55 d, mean 1.8 kg BW, were randomly assigned to three weight- and sex-balanced feeding groups in which conventional pelleted diets were supplemented with 0, 0.25, or 0.5% of a CLA preparation. The CLA preparation contained 65% CLA isomers. Twelve rabbits (six males and six females from each group) were slaughtered at each of three slaughtering trials (2.5, 2.8, and 3.1 kg BW, or 76, 90, and 104 d of age). Conjugated linoleic acid supplementation did not influence growth performance (P > or = 0.05) or carcass characteristics but reduced perirenal fat at heavier slaughtering weights (P = 0.09 at 2.8 kg BW; P < 0.01 at 3.1 kg BW). Conjugated linoleic acid reduced acetyl-CoA-carboxylase (CBX) activity in liver (P < 0.05) and adipose tissues (P < 0.01) but did not influence malic enzyme (ME) or glucose-6-phosphate dehydrogenase activity. Significant differences were found between sex in interscapular fat (P < 0.05) for CBX, in perirenal (P < 0.01) and interscapular (P < 0.05) fat for ME, and a tendency (P = 0.070) in liver for glucose-6-phosphate dehydrogenase. The oxidative stability of longissimus lumborum muscle was increased at the higher level of supplementation (P < 0.05). Conjugated linoleic acid reduced (P < 0.05) triglycerides and total cholesterol in plasma with a trend to increased serum leptin (P = 0.06). Plasma triglycerides were higher in males than females (P < 0.01) and plasma leptin tended to be higher in females (2.57 vs. 2.13 ng/ml, P = 0.06). It is concluded that dietary CLA reduced carcass fat in rabbits slaughtered at 2.8 kg or above and altered lipid metabolism to produce lower concentrations of serum triglycerides and total cholesterol and higher concentrations of leptin.

Topics: Animal Feed; Animals; Body Composition; Dietary Supplements; Energy Intake; Female; Isomerism; Leptin; Linoleic Acid; Lipid Metabolism; Lipid Peroxidation; Lipids; Liver; Male; Meat; Rabbits; Sex Factors; Thiobarbituric Acid Reactive Substances; Weight Gain

Fatty acid profiles with emphasis on linoleic, linolenic, oleic, and conjugated linoleic acid (CLA) were compared in milk from dairy cows fed diets containing 3.25% supplemental fat and a control diet containing no supplemented fat. The fat was supplied by either whole ground solin, flax, or canola oilseed. Solin (linola) is a new cultivar of flax that contains 28% linoleic acid in the seed, Twelve multiparous Holstein cows were assigned to one of four dietary treatments. The experimental design was a 4 x 4 Latin square with each period consisting of 16 d for adjustment to the diet followed by a 5-d sampling period. Feed intake, milk yield, milk fat yield, and milk fat percentage were not affected by treatment. Adding solin, flax, or canola oilseed to lactation diets produced the highest proportions of linoleic (C18:2), linolenic (C18:3), and oleic (C18:1) acids, respectively, in the lipid fraction of the milk of the cows consuming these diets. The proportions of C6:0 to C16:1 were depressed in the milk fat of cows fed the oilseed diets, compared with the control diet. Increasing the lactation diet levels of C18:2, by using different oilseeds, increased CLA to 1.5% of milk fatty acids. The content of CLA in milk fatty acids, however, did not increase with the solin-supplemented diet compared with the canola-supplemented diet even though the C18:2 level was higher in the former diet.

Topics: alpha-Linolenic Acid; Animals; Cattle; Diet; Eating; Fatty Acids; Fatty Acids, Monounsaturated; Female; Flax; Lactation; Linoleic Acid; Lipids; Milk; Milk Proteins; Oleic Acid; Parity; Rapeseed Oil; Weight Gain

Conjugated linoleic acid (CLA) has been shown to enhance immune reactions such as lymphocyte blastogenesis and delayed-type hypersensitivity. We investigated the role of CLA in type I (immediate) hypersensitivity, using a guinea pig tracheal superfusion model for measuring antigen-induced airway smooth muscle contraction and inflammatory mediator release. Female Hartley guinea pigs were fed a diet supplemented with 0.25 g corn oil or linoleic acid/100 g of diet (control) or 0.25 g CLA/100 g of diet for at least 1 wk before and during active sensitization to ovalbumin antigen. Tracheae from sensitized guinea pigs were suspended in air-filled water-jacketed (37 degrees C) tissue chambers in a superfusion apparatus. Tracheae were superfused with buffer containing antigen, and tissue contraction was recorded. Superfusate was collected at 90-s intervals for evaluation of histamine and PGE(2) release. CLA did not affect antigen-induced tracheal contractions when expressed as gram contraction per gram tissue. CLA significantly reduced antigen-induced histamine and PGE(2) release. CLA appears to decrease release of some inflammatory mediators during type I hypersensitivity reactions.

Topics: Animals; Antigens; Carbachol; Dietary Fats; Dinoprostone; Eating; Female; Guinea Pigs; Histamine Release; Hypersensitivity, Immediate; Linoleic Acid; Muscle Contraction; Ovalbumin; Trachea; Weight Gain

We investigated the efficacy of a 4-wk supplementation of conjugated linoleic acid (CLA) as free fatty acid (FFA) or triacylglycerol (TG) on serum leptin concentration, body-fat accumulation, and mitochondrial beta-oxidation in Otsuka Long-Evans Tokushima Fatty (OLETF) rats. A significant reduction of serum leptin concentration (42%) and a decrease in the wet weights of perirenal, epididymal, and omental/visceral-adipose tissue in TG-CLA and FFA-CLA groups were found in comparison with the OLETF control group. Both forms of CLA supplementation produced a 5.2% decrease in body weight compared with the control even though food intake was similar in the OLETF groups. Moreover, both forms of CLA enhanced carnitine-palmitoyltransferase activity in brown adipose tissue, perirenal adipose tissue, red gastrocnemius muscle, and liver in comparison with the OLETF control group. Serum concentrations of non-esterified fatty acid and TG also were reduced in rats fed diets supplemented with TG-CLA and FFA-CLA.

Topics: Adipose Tissue; Animals; Body Weight; Carnitine O-Palmitoyltransferase; Eating; Fatty Acids; Fatty Acids, Nonesterified; Leptin; Linoleic Acid; Liver; Male; Oxidation-Reduction; Rats; Rats, Inbred OLETF; Treatment Outcome; Triglycerides; Weight Gain

Effects of four levels of dietary linoleic acid (LA), an n-6 fatty acid, and four levels of alpha-linolenic acid (LNA), an n-3 fatty acid, and their interactions on immune responses in growing layer hens were studied. Immune responses were induced by injection with keyhole limpet hemocyanin (KLH) or Mycobacterium butyricum particles at 35 d of age. Antibody (Ab) responses were measured until 21 d after immunization. In addition, delayed-type hypersensitivity, lymphocyte proliferation, weekly feed intake, and BW gain were studied. At Day 7 after immunization, anti-M. butyricum titers in the M. butyricum-immunized hens were decreased by the increase of dietary LA (P < 0.05). In the period from 10 to 14 d after immunization, anti-KLH Ab titers in KLH-immunized animals were affected by the interaction of dietary LA with LNA (P < 0.01). High dietary levels of LA or LNA increased the anti-KLH Ab response. However, at high levels of dietary LA and LNA, anti-KLH Ab titers were not increased. In the same period, anti-M. butyricum Ab titers of M. butyricum-immunized hens were affected by the interaction of dietary LA with LNA (P < 0.05). At low levels of LA and LNA, increased LA levels decreased the Ab response, whereas increased LNA levels at low LA levels hardly affected the anti-M. butyricum response. At a high level of LA, increased dietary LNA increased the anti-M. butyricum response. In vitro proliferation of peripheral blood leukocytes after stimulation with concanavalin A (ConA) was higher in chickens with a high level of dietary LNA. Feed intake decreased when the dietary levels of LA or LNA increased. However, BW gain was not affected by dietary treatments. Feed conversion was more efficient in birds fed high levels of LA and LNA. The present study indicates that various factors affect the Ab responses. First, the interaction of n-6 and n-3 polyunsaturated fatty acids (PUFA) is more important than the separate effects of n-3 or n-6. Second, the actions of dietary PUFA were different between antigens of a different nature. Third was the nature of the antigen affects when dietary PUFA exert their actions and the persistence of these effects. The presence of these multiple factors affecting immune responses should be considered when comparing effects of dietary PUFA on immune responses.

Topics: alpha-Linolenic Acid; Animals; Antibodies; Antibodies, Bacterial; Antibody Formation; Antigens; Chickens; Concanavalin A; Dietary Fats, Unsaturated; Eating; Fatty Acids, Omega-3; Fatty Acids, Omega-6; Fatty Acids, Unsaturated; Female; Hemocyanins; Hypersensitivity, Delayed; Immunization; Linoleic Acid; Lymphocyte Activation; Mycobacterium; Weight Gain

Sprague-Dawley rats were fed either a control diet (7 g/100 g soybean oil) or a conjugated linoleic acid (CLA) diet (6.5 g/100 g soybean oil and 0.5 g/100 g CLA) beginning on d 7 of gestation to determine whether pre- and postnatal CLA affects short- and long-term growth and adiposity. At weaning (d 21), progeny were assigned control or CLA diet and fed until 11 wk of age. At birth, litter size and weight were not different between treatments. There were age- and sex-dependent changes in inguinal adipose fatty acid composition at birth and weaning, whereas there were no differences in lipid accretion or adipocyte proliferation. At weaning, CLA did not alter inguinal adipocyte proliferation but increased (P < 0.01) CCAAT/enhancer binding protein alpha expression in inguinal adipose tissue from females, whereas there was no difference in expression in males. Significant differences in size distribution of inguinal adipocytes at weaning and retroperitoneal adipocytes at 11 wk of age were observed. In general, CLA increased the proportion of smaller cells and decreased the proportion of larger cells. The main long-term effect of the dams' diet was the significantly heavier gastrocnemius and soleus muscles, and significantly longer tail lengths, an indication of skeletal growth, of male pups whose dams were fed CLA. Postweaning diet reduced fat pad weights in female but not male pups fed CLA. This response was due to differences in cell size rather than number. Response to CLA treatment may depend on the sex and age of the animal as well as duration of feeding.

Topics: Adipose Tissue; Animals; Body Composition; Dietary Fats; Embryonic and Fetal Development; Female; Growth; Linoleic Acid; Male; Pregnancy; Rats; Rats, Sprague-Dawley; Weight Gain

There is evidence that manganese (Mn) metabolism may be altered by the form and amount of dietary fat. Also, iron (Fe) absorption is greater with saturated fats, as compared to polyunsaturated fatty acids (PUFAs). The absorption of Fe and Mn are interrelated in many aspects; therefore, the form of dietary fat may indirectly alter Mn absorption. The reported studies were conducted to determine whether saturated fat, as compared to unsaturated fat, affected Mn absorption, retention, and metabolism. In experiment I, adult rats were fed diets containing either 0.7 or 100.4 microg/g Mn with the fat source as high-linoleic safflower oil or stearic acid. After 2 wk of equilibration, the animals were fed a test meal of 54Mn followed by whole-body counting for 10 d. Manganese absorption was significantly (p < 0.05) lower in the stearic acid group (0.9-4.8%) than in the safflower oil group (20-33.8%); however, the biological half-life was shorter in the safflower oil group. Retention of 54Mn and total Mn was always significantly (p < 0.05) greater in the safflower oil group when dietary Mn was low, but it was the same when dietary Mn was high. In experiment II, weanling rats were fed 1.3, 39.3, or 174.6 microg Mn/g and either stearate, high-oleic safflower oil or high-linoleic safflower oil for 8 wk. Long-term feeding of the stearate and low Mn-containing diet resulted in a significant (p < 0.0001) reduction in heart superoxide dismutase activity and kidney and liver Mn concentrations compared to the other diets. These data show that stearic acid inhibitits Mn absorption, but it may not inhibit Mn retention when dietary Mn is high.

Topics: Animals; Blood Glucose; Cholesterol; Dietary Fats; Dietary Fats, Unsaturated; Eating; Half-Life; Intestinal Absorption; Iron; Linoleic Acid; Male; Manganese; Radioisotopes; Rats; Rats, Sprague-Dawley; Safflower Oil; Stearic Acids; Triglycerides; Weight Gain

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a potent mutagen and suspected human carcinogen present in cooked protein-rich food. It preferentially induced colon tumors in male rats and mammary tumors in female rats. In the present study, the in vivo antimutagenic efficacy of two dietary compounds, conjugated linoleic acid (CLA) and 1,2-dithiole-3-thione (DTT), against PhIP was explored using 1acI transgenic Big Blue rats. Five- or six-week-old male Big Blue rats were fed a diet containing CLA (0.5%, wt/wt) or DTT (0.005%, wt/wt) starting one week before exposure to 200 ppm PhIP for 61 days. PhIP treatment induced a approximately 8- to 16-fold increase in the mutation frequency (MF) in the colon. The induced MF was significantly lower in the cecum than in the proximal and distal colon (approximately 52 x 10(-5) vs. 100 x 10(-5), p < 0.008). CLA and DTT significantly reduced the PhIP-induced MF in the distal colon (p < 0.05) by 14% and 24%, respectively. The frequency of -1 frameshift mutations was lower in the distal colon of CLA- or DTT-treated rats. This protective effect was not observed in the cecum or in the proximal colon. In contrast, the PhIP-induced MF in the cecum (specifically, the frequency of -1 frameshifts and GC-->TA transversions) was elevated by 43% after treatment with CLA. In conclusion, CLA and DTT modulate PhIP-induced mutagenesis in a tissue-specific manner, and different modulation pathways are employed by CLA and DTT.

Topics: Animals; Animals, Genetically Modified; Anticarcinogenic Agents; Antimutagenic Agents; Bacterial Proteins; Cecum; Colon; Diet; Eating; Escherichia coli Proteins; Frameshift Mutation; Imidazoles; Lac Repressors; Linoleic Acid; Male; Mutagens; Rats; Rats, Inbred F344; Repressor Proteins; Thiones; Thiophenes; Weight Gain

We investigated the composition of fatty acids in adipose tissue, serum, and liver of cows that were fed at restricted energy intake or were overfed during the dry period. Overfed cows had higher concentrations of serum nonesterified fatty acids and consequently accumulated greater amounts of triacylglycerols in the liver than did cows that were fed at restricted energy intake. The percentages of the different fatty acids present in adipose tissue were similar for both groups and did not change during sampling intervals. Before parturition, concentrations of the individual fatty acids present in serum were similar between groups. After parturition, concentrations of major fatty acids in serum, including palmitic, stearic, oleic, and linoleic acids significantly increased in both groups and were higher in overfed cows than in cows that were fed at restricted energy intake. The shift of concentrations of the different fatty acids present in the liver--as a result of increased lipolysis-was observed in palmitic, oleic, and linoleic acids but not stearic acid, suggesting that stearic acid is used by the liver (i.e., oxidation) or is considerably secreted through the milk, thereby not increasing in accumulation in the liver. In conclusion, different feeding regimens during the dry period do not influence the composition of fatty acids in adipose tissue. More intensive lipolysis results in increased concentrations of palmitic, stearic, oleic, and linoleic acids in the blood; subsequently, these fatty acids, excluding stearic acid, greatly accumulated in the liver.

Topics: Adipose Tissue; Animals; Cattle; Cattle Diseases; Diet; Energy Intake; Fatty Acids; Fatty Acids, Nonesterified; Fatty Liver; Female; Linoleic Acid; Lipolysis; Liver; Oleic Acid; Palmitic Acid; Puerperal Disorders; Stearic Acids; Triglycerides; Weight Gain

The effect of dietary docosahexaenoic acid (DHA) on T cell states in peripheral blood was investigated. Weanling male C57Bl/6N mice were kept on one of three 10% fat diets containing various amounts of DHA and linoleic acid for 4 weeks. Changing the concentration of dietary DHA did not alter the proportion of T cells expressing CD4 or CD8. However, increasing the concentration of dietary DHA lowered the expression of CD4 and CD8 on the cell surface. The decreased expression of these surface molecules involved in T cell proliferation has serious implications in the role of DHA as an immunosuppressant.

Topics: Animals; CD4 Antigens; CD8 Antigens; Dietary Fats, Unsaturated; Docosahexaenoic Acids; Linoleic Acid; Male; Mice; Mice, Inbred C57BL; T-Lymphocytes; Weight Gain

Ligation of the coronary artery in rats produces severe ventricular fibrillation (VF) and malignant cardiac arrhythmia. Mortality increases with the age of the animal. Diets rich in saturated fatty acids (SF) but low in linoleic acid (LA) increase, but diets high in LA and low in SF decrease the severity of VF and mortality in older animals. The effects of an LA enriched diet can be blocked by inhibition of cyclooxygenase suggesting that conversion of LA to eicosanoids is central to the development of VF. Conversion of LA to gamma-linolenic acid (GLA) via delta-6 desaturase is the first step in the process. The activity of delta-6 desaturase declines with age. Thus inclusion of GLA in the diet of older animals may provide an additional benefit over LA alone. Dietary supplements of evening primrose oil (EPO) to one year old rats reduced ischaemic VF more than a supplement of sunflower seed oil (SSO) without GLA. Substitution of borage oil (more GLA than EPO but less LA than either EPO or SSO) was without additional benefit.

Topics: Aging; alpha-Linolenic Acid; Animals; Coronary Vessels; Cyclooxygenase Inhibitors; Dietary Fats; Dietary Fats, Unsaturated; Fatty Acid Desaturases; Fatty Acids, Essential; gamma-Linolenic Acid; Ligation; Linoleic Acid; Linoleic Acids; Linoleoyl-CoA Desaturase; Male; Oenothera biennis; Oleic Acid; Plant Oils; Rats; Rats, Wistar; Ventricular Fibrillation; Vitamin E; Weight Gain

The effects of diets containing fats and oils or fatty acids on the lipid metabolism were investigated in male rats of the Wistar strain fed hypercholesterolemic diets, especially focusing our attention on the correlation between dietary oleic acid (OLE) contents and the levels of plasma and liver total cholesterol (T-CHOL) or the fatty acid profiles in plasma and liver CHOL-ester. In the rats fed the free (FR)-type fatty acids, the concentrations of plasma and liver T-CHOL were high and the amounts of neutral steroids excreted into the feces were low when compared with those of rats given the triacylglycerol (TG)-type fatty acids, showing that TG-type fatty acids suppress the intestinal CHOL absorption more than the FR-type fatty acids do. The concentrations of plasma T-CHOL were highest in rats fed the oleic acid (OLE)-rich diets, followed in order by rats supplied with the palmitic acid (PAL)-rich diets, the hydrogenated coconut oil (HCO) diet, and the linoleic acid (LIN)-rich diets; the lowest was in rats given tristearin (TSTE) and linseed oil (LIS) diets. A positive correlation was obtained between the dietary OLE contents and the levels of plasma and liver T-CHOL or OLE in the plasma and liver CHOL-ester, and an inverse correlation between dietary OLE contents and the amounts of excreted neutral steroids. These results suggest that the dietary OLE contents regulate the levels of plasma and liver T-CHOL in CHOL-loaded rats.

Topics: Animals; Cholesterol; Cholesterol, Dietary; Coconut Oil; Dietary Fats; Eating; Feces; Intestinal Absorption; Linoleic Acid; Linseed Oil; Lipid Metabolism; Lipids; Liver; Male; Oleic Acid; Organ Size; Palmitic Acid; Plant Oils; Rats; Rats, Wistar; Triglycerides; Weight Gain

alpha-Amino-beta-carboxymuconate-epsilon-semialdehyde decarboxylase (ACMSD) [EC 4.1.1.45] is a key enzyme of niacin synthesis from tryptophan. In this study, we examined whether dietary linoleic acid alters the protein expression of ACMSD in rat liver. Antibody against rat liver ACMSD was prepared by injecting mice with the purified enzyme. With the use of this polyclonal antibody and analysis by two-dimensional electrophoresis, we studied the mechanism by which the level of liver ACMSD activity was varied in rats fed a linoleic acid diet. In the rats fed a dietary linoleic acid (L), ACMSD protein levels in the liver were strongly suppressed as compared with the rats fed a fat-free diet (FF). These results suggest that the expression level of ACMSD might be modulated by linoleic acid or their metabolites.

Topics: Animals; Carboxy-Lyases; Dietary Fats; Dietary Fats, Unsaturated; Electrophoresis, Gel, Two-Dimensional; Linoleic Acid; Liver; Male; Mice; Mice, Inbred BALB C; Niacin; Rats; Rats, Sprague-Dawley; Swine; Tryptophan; Weight Gain

Conjugated linoleic acid (CLA) is a naturally occurring group of dienoic derivatives of linoleic acid found in the fat of beef and other ruminants. CLA is reported to have effects on both tumor development and body fat in animal models. To further characterize the metabolic effects of CLA, male AKR/J mice were fed a high-fat (45 kcal%) or low-fat (15 kcal%) diet with or without CLA (2.46 mg/kcal; 1.2 and 1.0% by weight in high- and low-fat diets, respectively) for 6 wk. CLA significantly reduced energy intake, growth rate, adipose depot weight, and carcass lipid and protein content independent of diet composition. Overall, the reduction of adipose depot weight ranged from 43 to 88%, with the retroperitoneal depot most sensitive to CLA. CLA significantly increased metabolic rate and decreased the nighttime respiratory quotient. These findings demonstrate that CLA reduces body fat by several mechanisms, including a reduced energy intake, increased metabolic rate, and a shift in the nocturnal fuel mix.

Topics: Adipose Tissue; Animals; Body Composition; Calorimetry, Indirect; Circadian Rhythm; Dietary Fats; Energy Intake; Energy Metabolism; Linoleic Acid; Lipids; Male; Mice; Mice, Inbred AKR; Organ Size; Oxidation-Reduction; Proteins; Weight Gain

Essential fatty acid deficiency has been widely studied but the extent to which its effects are attributable specifically to deficiency of linoleate as opposed to deficiency of all unsaturated fatty acids is unknown. Our objective was to evaluate the effect of pure linoleate deficiency on growth as well as changes in the metabolism and oxidation of n-6 polyunsaturates. The diets contained 20 energy % fat blended from 3 energy % pure oleate, 2 energy % linoleate (0.01 energy % in the linoleate-deficient group), 0.3 energy % pure alpha-linolenate, and the balance as palmitate and stearate from fully hydrogenated soybean oil. Thirty-five-day-old rats consumed the two diets for 84 days, after which the linoleate-deficient rats weighed 15% less than the controls (P < 0.05), had mild scaling on the paws, and visible hair loss (in a few rats). Compared with the controls, the ratio of eicosatrienoate to arachidonate after 84 days was elevated in liver (170-fold) and serum (520-fold) phospholipids of the linoleate-deficient group. In total, linoleate-deficient rats consumed 122 mg of linoleate and had a net whole body loss of 479 mg n-6 polyunsaturates compared with an intake of 24,130 mg and a net whole body gain of 7206 mg n-6 polyunsaturates in the control group. Linoleate-deficient rats oxidized 1% of an oral bolus of [1-14C]linoleate over 8 h compared with 34% in the control rats (P < 0.05). We conclude that pure linoleate deficiency has marked effects on accumulation of n-6 polyunsaturates but induces milder gross symptoms, particularly growth retardation, than classical essential fatty acid deficiency. alpha-Linolenate and possibly oleate may have a sparing effect on linoleate oxidation from body stores during linoleate deficiency.

Topics: Adipose Tissue; Animals; Arachidonic Acid; Arachidonic Acids; Breath Tests; Carbon Dioxide; Carbon Radioisotopes; Cohort Studies; Diet; Dietary Fats, Unsaturated; Fatty Acids, Omega-6; Fatty Acids, Unsaturated; Linoleic Acid; Linoleic Acids; Liver; Male; Oxidation-Reduction; Phospholipids; Rats; Rats, Sprague-Dawley; Time Factors; Triglycerides; Weight Gain

The effect of linoleic and linolenic acid on antibody (Ab) responses to SRBC and BSA and on growth performance were studied in pullets of three genetically different laying lines. Pullets were fed one of three diets: a control diet, a linoleic acid-enriched diet, or a linolenic acid enriched-diet. The linoleic and linolenic acid enriched-diets were the control diet enriched with either sunflower oil or linseed oil. Two chicken lines divergently selected for high (H) and low (L) Ab responses to SRBC, and a randombred control (C) line were used. Total Ab responses to SRBC were not affected by diet, but in the H line a tendency for higher IgG titers to SRBC after primary immunization were found when birds were fed the linoleic diet. The humoral response to BSA was significantly affected by a line by immunization by diet interaction. In the H line birds, the linoleic diet significantly enhanced Ab titers to BSA as compared to the normal diet and linolenic acid-enriched diet. The linolenic acid-enriched diet significantly decreased Ab titers to BSA in the C line birds. No dietary effects on the titer to BSA were found in the L line birds. During the first 3 wk of life, the linolenic acid-enriched diet resulted in reduced BW gain of H line birds. After that period, no effects of diet on BW gain was found. It is concluded that modulation of Ab responses of poultry to T cell-dependent antigens by essential fatty acids is affected by genotype. The relationship between magnitude of Ab responsiveness, BW, and essential fatty acids is discussed.

Topics: alpha-Linolenic Acid; Animals; Antibody Formation; Body Weight; Chickens; Dietary Fats, Unsaturated; Erythrocytes; Fatty Acids, Unsaturated; Female; Genotype; Linoleic Acid; Selection, Genetic; Serum Albumin, Bovine; Sheep; Weight Gain

The hypocholesterolemic efficacies of various polyunsaturated fatty acids were compared in rats given cholesterol-enriched diets. Oenothera biennis Linn oil (OBLO, linoleic + gamma-linolenic), sunflower oil (linoleic), palm oil (PLO, oleic + linoleic), soybean oil (linoleic + alpha-linolenic), high-oleic safflower oil (oleic + linoleic), or mixed oil (linoleic + alpha-linolenic) was added to the diet at 200 g/kg (20% groups). OBLO was also added at 100 g/kg diet (10% group). The serum total and very low density lipoprotein + intermediate lipoprotein + low density lipoprotein cholesterol concentrations of the 10 and 20% OBLO groups were consistently lower than those in the other groups. The liver cholesterol concentration in the PLO group was lower in all groups. The liver cholesterol concentrations in the 10 and 20% OBLO groups were also lower than in the other groups. There were no significant differences in the fecal neutral sterol and bile acid extraction among groups.

Topics: alpha-Linolenic Acid; Animals; Anticholesteremic Agents; Cholesterol; Cholesterol, Dietary; Cholesterol, HDL; Cholesterol, LDL; Cholesterol, VLDL; Fatty Acids; Fatty Acids, Unsaturated; Feces; gamma-Linolenic Acid; Linoleic Acid; Linoleic Acids; Lipoproteins; Liver; Male; Organ Size; Palm Oil; Phosphatidylcholines; Plant Oils; Rats; Rats, Inbred F344; Soybean Oil; Steroids; Sunflower Oil; Time Factors; Triglycerides; Weight Gain

The effect of chronic heat exposure on carcass quality of broilers: proportion of lean and fat tissues, fat content, and fatty acid composition, was investigated. One hundred and eight 4-wk-old male chickens were brooded in individual battery cages in two controlled-environment rooms at constant ambient temperature (22 or 32 C) until 7 wk of age. They were equally distributed into three treatments: 22 C, ad libitum feeding (22AL); 32 C, ad libitum feeding (32AL); and 22 C, pair-feeding on the daily feed intake of heat-exposed chickens (22PF). At 7 wk of age, heat-exposed chickens (32AL) had a lower body weight gain than the other birds: -47% compared to 22AL and -31% compared to 22PF. At 32 C, broilers exhibited a lower breast to body weight proportion: 11.9 vs 13.4% for 22AL. Abdominal, subcutaneous, and intermuscular fat deposits were enhanced in hot conditions, respectively, 15, 21, and 22% compared to 22AL and 58, 64, and 33% compared to 22PF. However, lipid contents of abdominal, subcutaneous, intermuscular, and intramuscular tissues were not affected by heat exposure but were significantly reduced in the 22PF birds. In heat-exposed birds, although saturated fatty acid proportions, particularly palmitic acid (C16:0), were increased, unsaturated fatty acids as a percentage of total fatty acids were decreased, especially oleic (C18:1) and linoleic (C18:2) acids in fat tissues. Consequently, under ad libitum feeding conditions, heat exposure significantly decreased the unsaturated to saturated fatty acid ratio in the abdominal and subcutaneous fat tissues, but not in intermuscular and intramuscular fats.

Topics: Adipose Tissue; Animals; Body Composition; Chickens; Fatty Acids; Hot Temperature; Linoleic Acid; Linoleic Acids; Lipid Metabolism; Lipids; Male; Meat; Muscle Development; Muscle, Skeletal; Oleic Acid; Oleic Acids; Palmitic Acid; Palmitic Acids; Weight Gain

Recent studies with rats force-fed zinc-deficient diets containing various types of fat failed to demonstrate a role of zinc in desaturation of linoleic acid. The present study was conducted to investigate the effect of zinc deficiency on desaturation of linoleic acid in rats that were initially force-fed fat-free diets to stimulate activity of desaturases. Therefore, rats were fed zinc-adequate and zinc-deficient fat-free diets for 6 d. After that period, the groups were divided and half of the rats continued feeding the fat-free diet for another 3.5 d whereas the other half was switched to a fat diet by supplementing the fat-free diet with 5% safflower oil. In order to assess desaturation of linoleic acid, fatty acid compositions of liver phosphatidylcholine, -ethanolamine, and -serine were considered, particularly levels of individual (n-6) polyunsaturated fatty acids (PUFA). Levels of total and individual (n-6) PUFA were similar in zinc-adequate and zinc-deficient rats fed the fat-free diet throughout the experiment. Addition of 5% safflower oil increased levels of total and individual (n-6) PUFA in both zinc-adequate and zinc-deficient rats. However, total (n-6) PUFA in all types of phospholipids were higher in zinc-adequate rats than in zinc-deficient rats. Additionally, in zinc-deficient rats there were changes of (n-6) PUFA levels typical for impaired delta 5 and delta 6 desaturation: linoleic acid and dihomo-gamma-linolenic acid were elevated; arachidonic acid, docosatetraenoic acid, and docosapentaenoic were lowered by zinc deficiency. Therefore, the study shows that zinc deficiency impairs desaturation of linoleic acid in rats force-fed fat-free diets and therefore supports results from former convential zinc deficiency experiments suggesting a role of zinc for desaturation of linoleic acid.

Topics: Analysis of Variance; Animals; Chromatography, Gas; Diet, Fat-Restricted; Dietary Fats, Unsaturated; Enteral Nutrition; Linoleic Acid; Linoleic Acids; Liver; Male; Osmolar Concentration; Phosphatidylcholines; Phosphatidylethanolamines; Phosphatidylserines; Plant Oils; Rats; Rats, Sprague-Dawley; Sunflower Oil; Weight Gain; Zinc

We investigated the effects of dietary fat saturation on very low density lipoprotein (VLDL) production in guinea pigs fed semipurified diets containing 15% (w/w) fat, either corn oil (CO, 58% linoleic acid), lard (LA, 42% oleic and 24% palmitic acids) or palm kernel oil (PK, 52% lauric and 18% myristic acids) for 4 weeks. Animals were given an intravenous injection of Triton WR 1339 to block VLDL catabolism and rates of VLDL triacylglycerol (TAG) and apolipoprotein (apo) B secretion were measured over time. Plasma TAG concentrations increased linearly for 8 h (r = 0.99) and VLDL-TAG secretion rates were significantly higher (P < 0.01) in guinea pigs fed LA (72.7 +/- 14.7 mg/kg-h, n = 12) compared to animals fed PK (55.4 +/- 13.4 mg/kg-h, n = 12) or CO (48.6 +/- 17.5 mg/kg-h, n = 15). VLDL apoB secretion rates were highest in PK-fed animals (3.1 +/- 1.8 mg/kg-h) compared to guinea pigs fed LA (1.5 +/- 0.8 mg/kg-h) or CO (1.1 +/- 0.6 mg/kg-h) diets (P < 0.005). Concurrent with analysis of VLDL secretion, turnover of 125I-labeled LDL was measured. Low density lipoprotein (LDL) fractional catabolic rates were not altered by Triton treatment and LDL apoB specific radioactivity (cpm/microgram) did not change over time indicating that: a) the Triton blockage of VLDL catabolism was complete, and b) there was no direct secretion of LDL by the liver. These data demonstrate that intake of lard increases the rate of VLDL-triacylglycerol secretion and that nascent VLDL particles from the lard and corn oil diet groups have the same relative triacylglycerol content, whereas palm kernel oil intake increases secretion of VLDL particles which have a reduced triacylglycerol content. These results demonstrate that dietary fat chain length and saturation have specific effects on VLDL secretion rates affecting both particle number and composition.

Topics: Animals; Apolipoproteins B; Corn Oil; Dietary Fats; Guinea Pigs; Lauric Acids; Linoleic Acid; Linoleic Acids; Lipoproteins, VLDL; Male; Myristic Acid; Myristic Acids; Oleic Acid; Oleic Acids; Polyethylene Glycols; Triglycerides; Weight Gain

1. The importance of linoleic acid (18:2n-6) itself and of dietary gamma-linolenic acid (18:3n-6) as essential fatty acids (EFA) in Japanese quail were investigated with regard to liver lipid metabolism. Experimental diets were made by adding of 0, 2 or 4 g gamma-linolenic acid/kg, or 20 g linoleic acid/kg to an n-6 EFA-free diet. From 3 to 6 weeks of age, birds were fed equal amounts of experimental diets. 2. Liver weight and lipid content in birds fed the 2 and 4 g gamma-linolenic acid/kg diet were significantly lower than those in birds fed the gamma-linolenic acid-free diet. However, no significant difference was observed between the gamma-linolenic acid- and linoleic acid-supplemented diets. 3. In birds fed the 4 g gamma-linolenic acid/kg diet, the proportion of arachidonic acid in the liver lipid was similar to that in quail fed the 20 g linoleic acid/kg diet, implying a conversion rate from linoleic acid to gamma-linolenic acid of approximately 20% of whole body content. 4. It is concluded that linoleic acid itself is not essential for Japanese quail and that at least 2 g/kg of gamma-linolenic acid in the diet completely prevents liver enlargement accompanied by lipid accumulation.

Topics: Analysis of Variance; Animals; Body Weight; Chromatography, Gas; Coturnix; Dietary Fats, Unsaturated; Fatty Acids; Fatty Acids, Essential; Female; gamma-Linolenic Acid; Linoleic Acid; Linoleic Acids; Lipid Metabolism; Lipids; Liver; Organ Size; Safflower Oil; Weight Gain

Previous studies showed that zinc deficiency influences the fatty acid composition of rat tissues, but the influence of dietary fat on the effects of zinc deficiency was not considered at that time. The present study was therefore conducted to investigate the effect of zinc deficiency on lipid concentrations in the liver and on fatty acid composition of liver phospholipids in rats fed diets containing coconut oil or fish oil, using a bifactorial experimental design. To ensure an adequate food intake all rats were force-fed. The zinc-deficient rats fed the coconut oil diet developed fatty livers, whereas zinc-deficient animals fed the fish oil diet did not. The zinc-deficient rats in both dietary fat groups had lower levels of linoleic acid, arachidonic acid and total (n-6) fatty acids in the liver phospholipids, especially in the phosphatidylcholine, but greater concentrations of (n-3) fatty acids compared with zinc-adequate controls. We conjecture that zinc deficiency influences incorporation of polyunsaturated fatty acids into phosphatidylcholine. The lower levels of arachidonic acid are replaced in the zinc-deficient animals fed a coconut oil diet by docosapentaenoic and docosahexaenoic acids and in the zinc-deficient animals fed a fish oil diet by eicosapentaenoic acid. The replacement of arachidonic acid by other fatty acids in the phospholipids is likely to have implications for prostaglandin synthesis. The study shows that the type of dietary fat influences the effects of zinc deficiency on fatty acid composition and especially on lipid concentrations in the liver.

Topics: Animals; Arachidonic Acid; Coconut Oil; Dietary Fats; Fatty Acids; Fatty Acids, Omega-3; Fatty Acids, Omega-6; Fatty Acids, Unsaturated; Fish Oils; Linoleic Acid; Linoleic Acids; Lipid Metabolism; Liver; Male; Phosphatidylcholines; Phospholipids; Plant Oils; Rats; Rats, Sprague-Dawley; Weight Gain; Zinc

Topics: Animals; Food, Fortified; Linoleic Acid; Linoleic Acids; Lipid Peroxidation; Male; Rats; Rats, Wistar; Selenium; Weight Gain

Obese Zucker rats (fa/fa) have low levels of arachidonic acid (AA) in liver phospholipids (PL). We have previously shown that a 70% gamma-linolenate concentrate (GLA; an AA intermediate) fed at a fixed dose (0.07 g/day) normalized hepatic PL AA and reduced weight gain selectively in the obese animals. In a follow-up study, 16 obese (fa/fa) and 16 lean (Fa/Fa) 4-week-old male rats were randomized into 4 groups of 8 each and gavaged daily with soybean oil (SOY) containing 55% 18:2omega6 (an AA precursor) or GLA, using a progressive dose (< or = 5% of total calories) based on body weight. A defined diet with 11% of energy as SOY was fed ad libitum for 60 days. GLA obese had lower body weight (p<0.0001) and 60-day cumulative food intake (p<0.05) compared to SOY obese, but neither parameter differed between the lean groups. For the last twenty days cumulative food intake was identical for GLA obese and SOY lean, whereas SOY obese consumed 18% more (p<0.05). Thus the progressive dose of GLA selectively suppressed hyperphagia in obese Zucker rats. Erythrocytes collected at 15-day intervals showed parallel increases in AA in both genotypes over time, suggesting normal AA availability during rapid growth. Thus, the reduced PL AA in the livers from the obese rats probably reflects impaired distribution in selected tissues rather than reduced hepatic production. Due to the potential health risks of enriching tissue lipids with AA, great caution is advised in considering GLA as therapy for human obesity.

Topics: Adipose Tissue; Animals; Anti-Obesity Agents; Body Composition; Body Weight; Dietary Supplements; Disease Models, Animal; Eating; Energy Metabolism; Erythrocytes; Fatty Acids; gamma-Linolenic Acid; Genotype; Glycine max; Growth; Hyperphagia; Linoleic Acid; Lipid Metabolism; Lipids; Liver; Male; Obesity; Phospholipids; Rats; Rats, Zucker; Time Factors; Weight Gain

Three experiments were carried out with male broiler chickens reared from day- old to 6 weeks of age on semi-purified diets containing 10% fresh (Expt. 1 and 3) or oxidized (Expt. 2) re-esterified triglycerides with a fatty acid composition similar to that of soya bean oil containing increasing concentrations of either a mixture of d-alpha-, gamma-, delta-tocopherylacetate (d-tocopherols) of natural source or dl-alpha- tocopheryl acetate (dl-tocopherol). In Expt. 1 and 2 the mixture of d-tocopherols consisted of 35.7% d-alpha-, 45.3% d-gamma- and 19.0% d-delta-, while in Expt. 3 the distribution was 25.3% d-alpha-, 28.1% d-gamma- and 10.8% d-gamma- in 35.8% re-esterified triglycerides. The relative biopotency of d-alpha-: gamma-: delta-tocopherol was anticipated to be 100:25:1, whereas that of dl-alpha-tocopherol was 74% relative to d-alpha-tocopherol. The experiments demonstrate that the results obtained for the biological activity depend on the response parameters chosen. With respect to gain in weight, feed conversion, relative organ weight, packed cell volume (PCV), ELP (erythrocyte lipid peroxidation), plasma activities of glutamate-oxaloacetate-transaminase (GOT), creatine kinase (CK) and glutathione peroxidase (GSH-Px) and plasma Na+ concentration, the mixture of natural source tocopherols was identical to that of dl-alpha-tocopheryl acetate, although the concentration of alpha-tocopherol was only about one third of that of dl-alpha-tocopherol. Differences between natural source and synthetic tocopherols were expectedly observed with respect to plasma concentrations of alpha-, gamma-, delta-tocopherol. Differences between the two forms as to muscular dystrophy, in vitro haemolysis and potassium concentration in plasma were ambiguous. It is suggested that the function of d-alpha-, gamma-, delta-tocopherol in erythrocyte fragility and skeletal muscle structure should be compared to that of dl-alpha-tocopherol in future investigations.

Topics: Animals; Aspartate Aminotransferases; Cerebellar Diseases; Cerebral Hemorrhage; Chickens; Creatine Kinase; Dietary Fats; Eating; Encephalomalacia; Glutathione Peroxidase; Hematocrit; Linoleic Acid; Linoleic Acids; Liver; Male; Muscular Dystrophy, Animal; Organ Size; Oxidation-Reduction; Poultry Diseases; Vitamin E; Weight Gain

Responses of the activities of liver microsomal mixed-function oxidases (MFOs) induced by phenobarbital (PB) to dietary linoleic acid (LA) levels were investigated in rats. Diets varied in LA content (0, 1.8, 4.1, 7.0, or 13.8 energy%) were fed to rats for 16 days. The activities of MFOs did not change significantly with increasing the dietary LA level, where they reached a plateau even at 1.8 energy %, although the fatty acid composition of liver microsomal lipids reflected well that of dietary lipids. Accordingly, 2 energy % of LA as essential fatty acid seemed to be sufficient to supply the dietary requirement as assessed by the activities of PB-induced MFOs.

Topics: Animals; Dietary Fats, Unsaturated; Enzyme Induction; Fatty Acids; Linoleic Acid; Linoleic Acids; Liver; Male; Membrane Lipids; Microsomes, Liver; Mixed Function Oxygenases; Organ Size; Phenobarbital; Rats; Rats, Sprague-Dawley; Weight Gain

The effect of dietary protein, casein (CAS) and soybean protein (SOY), on linoleic acid desaturation in liver microsomes was studied in rats. The activity of delta 6 desaturase in total and rough endoplasmic reticula (ER and RER) was significantly higher in the CAS group than in the SOY group. In ER and smooth endoplasmic reticulum, the steady-state fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene, when incorporated into the membrane, was decreased in the SOY group and accompanied by a reduction in the cholesterol/phospholipid (CHOL/PL) ratio, consistent with an increase in membrane fluidity. In a separate study, the effect of varying dietary proteins, CAS, milk whey protein, egg albumin, SOY, potato protein and wheat gluten, on the relationship between the delta 6 desaturase activity and microsomal membrane fluidity was also examined. The results indicated that the dietary protein-dependent change in the liver microsomal CHOL/PL ratio affected membrane fluidity, and subsequently the activity of delta 6 desaturase in liver microsomes. However, since dietary protein influenced the delta 6 desaturase activity in RER without influencing membrane fluidity, it is possible that some regulation might have taken place at the level of enzyme synthesis.

Topics: Animals; Caseins; Cholesterol; Dietary Proteins; Diphenylhexatriene; Endoplasmic Reticulum; Fatty Acid Desaturases; Fatty Acids; Fluorescence Polarization; Linoleic Acid; Linoleic Acids; Linoleoyl-CoA Desaturase; Male; Membrane Fluidity; Microsomes, Liver; Phospholipids; Plant Proteins, Dietary; Rats; Rats, Sprague-Dawley; Soybean Proteins; Weight Gain

Peritoneal cells (PEC) and splenocytes were obtained from Listeria monocytogene (LM)-infected or noninfected mice fed a 20% fat diet rich in either (n-3) polyunsaturated fatty acids [(n-3) PUFA diet], linoleate [(n-6) PUFA diet], oleate (MONO diet), or saturated fatty acids (SAT diet) for 6 wk and were assessed for T cells, B cells, macrophages and Ia expression by flow cytometric analysis. In the peritoneum of noninfected mice, dietary fat did not affect total cell yield or the percentage of B cells, macrophages or Ia+ cells, but the (n-3) PUFA-fed group had a greater percentage of T cells than did the other groups. Among the LM-infected mice, the (n-3) PUFA-fed group generally had the highest percentage of B cells and the lowest percentages of T cells, macrophages and Ia+ cells in the peritoneum. Listeria monocytogene infection elevated peritoneal T cell numbers in all mice except the (n-3) PUFA-fed group. The density of Ia molecules on PEC was 40% lower in mice fed the (n-3) PUFA diet. In the spleen, dietary fat also influenced the immune cell populations and Ia+ cells. Two-color staining of spleen cells revealed that Ia+ splenocytes were predominately B cells. These data demonstrate that dietary fats influence Ia expression and immune cell populations and that the effects observed in one immune tissue or cell type may not be readily extrapolated to others.

Topics: Animals; Ascitic Fluid; B-Lymphocytes; Cell Membrane; Dietary Fats; Fatty Acids; Female; Histocompatibility Antigens Class II; Leukocyte Count; Linoleic Acid; Linoleic Acids; Lymphocytes; Macrophages; Mice; Mice, Inbred C3H; Oleic Acid; Oleic Acids; Organ Size; Prostaglandins E; Spleen; T-Lymphocytes; Weight Gain

Sows that had had 3 previous litters were fed either a diet with no added fat (low fat) which was rich in linoleic acid (56.7% 18:2n-6), or a high fat diet containing lard, high in total saturates (28.9%) and oleic acid (37.8% 18:1n-9) during gestation. Backfat build-up in the sows on the high fat diet was accelerated compared to the low fat group. On day 110 of gestation, fetuses were removed. The fat content of the diet had no significant effect on sow weight gain during gestation, and the number or body weight of fetuses. Activities of sow liver and adipose and fetal liver malic enzyme, glucose-6-phosphate dehydrogenase (G-6-P) and acetyl-CoA-carboxylase (ACoABx) were measured. Only fetal liver ACoABx and sow adipose G-6-P were significantly affected by the sow's diet.

Topics: Acetyl-CoA Carboxylase; Adipose Tissue; Animals; Dietary Fats; Female; Fetus; Glucosephosphate Dehydrogenase; Linoleic Acid; Linoleic Acids; Lipids; Liver; Malate Dehydrogenase; Maternal-Fetal Exchange; Oleic Acid; Oleic Acids; Pregnancy; Pregnancy, Animal; Swine; Weight Gain

The influence of dietary fats on azoxymethane-induced colorectal carcinogenesis and erythrocyte, adipose, colon mucosa and tumour tissue fatty acids was investigated in 228 Wistar rats. The two main diets compared were beef suet rich in saturated fatty acids and corn oil rich in a linoleic acid, an N-6 polyunsaturated fatty acid. The animals were placed in one of four dietary groups: A = 5% saturated fat, B = 20% saturated fat, C = 5% N-6 fat and D = 20% N-6 fat. There was no difference in the number of adenomas between any of the dietary groups. The mean (+/- SEM) carcinoma yield per rat was A = 0.93 +/- 0.28, B = 1.93 +/- 0.50, C = 0.70 +/- 0.07, D = 0.13 +/- 0.04; the tumour yields in rats fed the saturated fat diets were significantly different from each other and from those fed the N-6 fat diets. The fatty acid profiles in all tissues were dependent upon the type and level of dietary fat and the tissue type. Arachidonate was higher in tumours compared to normal mucosa. Significant correlations were found between adipose linoleate (reflecting dietary intake) and tumour oleate and tumour arachidonate but not with the colorectal mucosa of control animals. This is the first in vivo study to show reduced colorectal carcinogenesis by N-6 polyunsaturated fatty acids.

Topics: Adenoma; Adipose Tissue; Animals; Arachidonic Acid; Arachidonic Acids; Azoxymethane; Carcinoma; Cell Membrane; Colorectal Neoplasms; Fats, Unsaturated; Fatty Acids; Intestinal Mucosa; Linoleic Acid; Linoleic Acids; Male; Oleic Acid; Oleic Acids; Palmitic Acid; Palmitic Acids; Rats; Rats, Inbred Strains; Stearic Acids; Weight Gain

Topics: Animals; Body Weight; Body Weights and Measures; Fatty Acids; Linoleic Acid; Rats; Saponins; Sterols; Weight Gain