PEROXISOMAL ?T-OXIDATION OF LONG FATTY ACIDS: EFFECTS OF HIGH FAT DIETS

Previous studies have suggested that high-fat diets adversely affect bone development. However, these studies included other dietary manipulations, including low calcium, folic acid, and fibre, and (or) high sucrose or cholesterol, and did not directly compare several common sources of dietary fat. Thus, the overall objective of this study was to investigate the effect of high-fat diets that differ in fat quality, representing diets high in saturated fatty acids (SFA), n-3 polyunsaturated fatty acids (PUFA), or n-6 PUFA, on femur bone mineral density (BMD), strength, and fatty acid composition. Forty-day-old male Sprague–Dawley rats were maintained for 65 days on high-fat diets (20% by weight), containing coconut oil (SFA; n = 10), flaxseed oil (n-3 PUFA; n = 10), or safflower oil (n-6 PUFA; n = 11). Chow-fed rats (n = 10), at 105 days of age, were included to represent animals on a control diet. Rats fed high-fat diets had higher body weights than the chow-fed rats (p < 0.001). Among all high-fat groups, there were no differences in femur BMD (p > 0.05) or biomechanical strength properties (p > 0.05). Femurs of groups fed either the high n-3 or high n-6 PUFA diets were stronger (as measured by peak load) than those of the chow-fed group, after adjustment for significant differences in body weight (p = 0.001). As expected, the femur fatty acid profile reflected the fatty acid composition of the diet consumed. These results suggest that high-fat diets, containing high levels of PUFA in the form of flaxseed or safflower oil, have a positive effect on bone strength when fed to male rats 6 to 15 weeks of age.

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Brown fat thermogenesis in rats fed high-fat diets enriched with n-3 polyunsaturated fatty acids

International Journal of Obesity ◽

10.1038/sj.ijo.0800500 ◽

1997 ◽

Vol 21 (11) ◽

pp. 955-962 ◽

Cited By ~ 72

Author(s):

H Oudart ◽

R Groscolas ◽

C Calgari ◽

M Nibbelink ◽

C Leray ◽

...

Keyword(s):

Fatty Acids ◽

Polyunsaturated Fatty Acids ◽

Brown Fat ◽

High Fat ◽

High Fat Diets ◽

Fat Diets

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Serum lipids, hepatic glycerolipid metabolism and peroxisomal fatty acid oxidation in rats fed ω-3 and ω-6 fatty acids

Biochemical Journal ◽

10.1042/bj2830333 ◽

1992 ◽

Vol 283 (2) ◽

pp. 333-339 ◽

Cited By ~ 89

Author(s):

A C Rustan ◽

E N Christiansen ◽

C A Drevon

Keyword(s):

Fatty Acids ◽

Fish Oil ◽

Linseed Oil ◽

The Other ◽

Acid Oxidation ◽

High Fat ◽

High Fat Diets ◽

Peroxisomal Fatty Acid Oxidation ◽

Fat Diets ◽

Peroxisomal Fatty Acid

Rats were fed, for 3 weeks, high-fat (20% w/w) diets containing sunflower-seed oil, linseed oil or fish oil. Chow-fed rats were used as a low-fat reference. The high-fat diets markedly reduced non-fasting-rat serum triacylglycerol as compared with the low-fat reference, and the highest reduction (85%) was observed with the fish-oil group, which was significantly lower than that of the other high-fat diets. The serum concentration of phospholipids was significantly reduced (30%) only in the fish-oil-fed animals, whereas serum non-esterified fatty acids were reduced 40-50% by both the fish-oil- and linseed-oil-fed groups. The liver content of triacylglycerol showed a 1.7-fold increase with the fish-oil diet and 2-2.5-fold with the other dietary groups when compared with rats fed a low-fat diet, whereas the hepatic content of phospholipids was unchanged. Peroxisomal fatty acid oxidation (acyl-CoA oxidase) was 2-fold increased for the rats fed fish oil; however this was not significantly higher when comparison was made with rats fed the linseed-oil diet. There was no difference in phosphatidate hydrolysis (microsomal and cytosolic fractions) among animals fed the various diets. Acyl-CoA:diacylglycerol acyltransferase activity was increased by all high-fat diets, but the fish-oil-diet-fed group showed a significantly lower enzyme activity than did rats fed the other high-fat diets. A linear correlation between acyl-CoA:diacylglycerol acyltransferase activity and liver triacylglycerol was observed, and the microsomal enzyme activity was decreased 40-50% by incubation in the presence of eicosapentaenoyl-CoA. CoA derivatives of arachidonic, linolenic and linoleic acid had no inhibitory effect when compared with the control. These results indicate that dietary fish oil may have greater triacylglycerol-lowering effect than other polyunsaturated diets, owing to decreased triacylglycerol synthesis caused by inhibition of acyl-CoA:diacylglycerol acyltransferase. In addition, increased peroxisomal fatty acid oxidation and decreased availability of non-esterified fatty acids could also contribute by decreasing the amounts of fatty acids as substrates for triacylglycerol synthesis and secretion.

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High-fat diets rich in medium- versus long-chain fatty acids induce distinct patterns of tissue specific insulin resistance

The Journal of Nutritional Biochemistry ◽

10.1016/j.jnutbio.2010.03.004 ◽

2011 ◽

Vol 22 (4) ◽

pp. 366-371 ◽

Cited By ~ 18

Author(s):

Johan De Vogel-van den Bosch ◽

Sjoerd A.A. van den Berg ◽

Silvia Bijland ◽

Peter J. Voshol ◽

Louis M. Havekes ◽

...

Keyword(s):

Insulin Resistance ◽

Fatty Acids ◽

Long Chain Fatty Acids ◽

High Fat ◽

Tissue Specific ◽

High Fat Diets ◽

Fat Diets ◽

Specific Insulin ◽

Long Chain ◽

Chain Fatty Acids

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Elevated n-3 fatty acids in a high-fat diet attenuate the increase in PDH kinase activity but not PDH activity in human skeletal muscle

Journal of Applied Physiology ◽

10.1152/japplphysiol.00604.2004 ◽

2005 ◽

Vol 98 (1) ◽

pp. 350-355 ◽

Cited By ~ 11

Author(s):

Erin A. Turvey ◽

George J. F. Heigenhauser ◽

Michelle Parolin ◽

Sandra J. Peters

Keyword(s):

Skeletal Muscle ◽

Fatty Acids ◽

Pyruvate Dehydrogenase ◽

High Fat Diet ◽

Human Skeletal Muscle ◽

Fat Content ◽

Pyruvate Dehydrogenase Kinase ◽

High Fat ◽

High Fat Diets ◽

Fat Diets

We tested the hypothesis that a high-fat diet (75% fat; 5% carbohydrates; 20% protein), for which 15% of the fat content was substituted with n-3 fatty acids, would not exhibit the diet-induced increase in pyruvate dehydrogenase kinase (PDK) activity, which is normally observed in human skeletal muscle. The fat content was the same in both the regular high-fat diet (HF) and in the n-3-substituted diet (N3). PDK activity increased after both high-fat diets, but the increase was attenuated after the N3 diet (0.051 ± 0.007 and 0.218 ± 0.047 min−1 for pre- and post-HF, respectively; vs. 0.073 ± 0.016 and 0.133 ± 0.032 min−1 for pre- and post-N3, respectively). However, the active form of pyruvate dehydrogenase (PDHa) activity decreased to a similar extent in both conditions (0.93 ± 0.17 and 0.43 ± 0.09 mmol/kg wet wt pre- and post-HF; vs. 0.87 ± 0.19 and 0.39 ± 0.05 mmol/kg wet wt pre- and post-N3, respectively). This suggested that the difference in PDK activity did not affect PDHa activation in the basal state, and it was regulated by intramitochondrial effectors, primarily muscle pyruvate concentration. Muscle glycogen content was consistent throughout the study, before and after both diet conditions, whereas muscle glucose-6-phosphate, glycerol-3-phosphate, lactate, and pyruvate were decreased after the high-fat diets. Plasma triglycerides decreased after both high-fat diets but decreased to a greater extent after the N3, whereas plasma free fatty acids increased after both diets, but to a lesser extent after the N3. In summary, PDK activity is decreased after a high-fat diet that is rich in n-3 fatty acids, although PDHa activity was unaltered. In addition, our data demonstrated that the hypolipidemic effect of n-3 fatty acids occurs earlier (3 days) than previously reported and is evident even when the diet has 75% of its total energy derived from fat.

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EFFECT OF COMMON CARP AND AFRICAN CATFISH OILS ON RATS FED ON HIGH-FAT DIET

International Journal of Pharmacy and Pharmaceutical Sciences ◽

10.22159/ijpps.2018v10i2.23452 ◽

2018 ◽

Vol 10 (2) ◽

pp. 96

Author(s):

Medhat Mostafa Abozid ◽

Hossam Zein ◽

Amer Abd El-halem

Keyword(s):

Fatty Acids ◽

Common Carp ◽

Positive Control ◽

Positive Control Group ◽

Control Group ◽

African Catfish ◽

High Fat ◽

High Fat Diets ◽

Liver Functions ◽

Fat Diets

Objective: The present study was designed to study the effect of common carp and African catfish oils on the lipid profiles and liver functions in rats fed on high-fat diets, also fatty acids were assessed in both oils by gas-liquid chromatography (GLC).Methods: A biological experiment on rats was designed to raise fat in the diet and to study the effect of treatment with common carp and African catfish oils for 6 w (by the stomach tube) and then evaluate their impact on blood lipid profile and liver functions (Alanine transaminase [ALT], aspartate transaminase [AST] total protein and albumin).Results: GLC analysis of fatty acids (FAs) revealed the presence of oleic, palmitic, palmitolic, and linoleic acids more than 70% from total fatty acids in two oils. High-fat diet resulted in a significant increase in plasma lipid profile as well as liver functions. The treatment of rats fed high fat diets with common carp and African catfish oils resulted in a significant decrease in levels of triglycerides (TGs), total cholesterol (TC), low-denisty lipioprotein cholesterol (LDL-c), total cholesterol (TC)/high-denisty lipoprotein cholesterol (HDL-c) and TGs/HDL-c ratios compared with positive control group, while the same treatment with these oils resulted in a significant increase in HDL-c levels compared with positive control group. The intake of common carp and African catfish oils also significantly reduced ALT and AST activities compared with positive control group. Common carp and African catfish oils showed an anti-hyperlipidemic effect in rats feeding on hypercholesterolemic diets.Conclusion: It could be concluded that these fish oils have a promising role in reducing the harmful effects of high-fat diets.

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Differential effects of saturated and unsaturated fatty acid diets on cardiomyocyte apoptosis, adipose distribution, and serum leptin

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.01295.2005 ◽

2006 ◽

Vol 291 (1) ◽

pp. H38-H44 ◽

Cited By ~ 95

Author(s):

Isidore C. Okere ◽

Margaret P. Chandler ◽

Tracy A. McElfresh ◽

Julie H. Rennison ◽

Victor Sharov ◽

...

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Cardiac Function ◽

Pyruvate Dehydrogenase Kinase ◽

Cardiomyocyte Apoptosis ◽

High Fat ◽

High Fat Diets ◽

Genes Encoding ◽

Ceramide Content ◽

Fat Diets

Fatty acids are the primary fuel for the heart and are ligands for peroxisome proliferator-activated receptors (PPARs), which regulate the expression of genes encoding proteins involved in fatty acid metabolism. Saturated fatty acids, particularly palmitate, can be converted to the proapoptotic lipid intermediate ceramide. This study assessed cardiac function, expression of PPAR-regulated genes, and cardiomyocyte apoptosis in rats after 8 wk on either a low-fat diet [normal chow control (NC); 10% fat calories] or high-fat diets composed mainly of either saturated (Sat) or unsaturated fatty acids (Unsat) (60% fat calories) ( n = 10/group). The Sat group had lower plasma insulin and leptin concentrations compared with the NC or Unsat groups. Cardiac function and mass and body mass were not different. Cardiac triglyceride content was increased in the Sat and Unsat groups compared with NC ( P < 0.05); however, ceramide content was higher in the Sat group compared with the Unsat group (2.9 ± 0.2 vs. 1.4 ± 0.2 nmol/g; P < 0.05), whereas the NC group was intermediate (2.3 ± 0.3 nmol/g). The number of apoptotic myocytes, assessed by terminal deoxynucleotide transferase-mediated dUTP nick-end labeling staining, was higher in the Sat group compared with the Unsat group (0.28 ± 0.05 vs. 0.17 ± 0.04 apoptotic cells/1,000 nuclei; P < 0.04) and was positively correlated to ceramide content ( P < 0.02). Both high-fat diets increased the myocardial mRNA expression of the PPAR-regulated genes encoding uncoupling protein-3 and pyruvate dehydrogenase kinase-4, but only the Sat diet upregulated medium-chain acyl-CoA dehydrogenase. In conclusion, dietary fatty acid composition affects cardiac ceramide accumulation, cardiomyocyte apoptosis, and expression of PPAR-regulated genes independent of cardiac mass or function.

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