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

1992 ◽  
Vol 283 (2) ◽  
pp. 333-339 ◽  
Author(s):  
A C Rustan ◽  
E N Christiansen ◽  
C A Drevon

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.

2019 ◽  
Vol 20 (12) ◽  
pp. 3110 ◽  
Author(s):  
Migliaccio ◽  
Sica ◽  
Di Gregorio ◽  
Putti ◽  
Lionetti

High-fat diets rich in fish oil (HFO diet, mainly ω3-PUFAs), in contrast to high-fat diets rich in lard (HL diet, mainly saturated fatty acids) have been shown to induce improvement in mitochondrial function and fusion processes associated with a reduction in reactive oxygen species production in both liver and skeletal muscle. High-fat diets may also impair testicular function, and mitochondria represent important cellular organelles with a pivotal role in reproductive function. Mitochondria are dynamic organelles that frequently undergo fission/fusion processes. A shift toward mitochondrial fusion process has been associated with improvement of mitochondrial function, as well as with ω3-PUFAs protective effects. The present study aimed to analyze the effect of chronic overfeeding (six weeks) with HFO or HL diet on testicular tissue histology, oxidative stress, antioxidant defenses, and mitochondrial fusion (mitofusin 2) and fission (dynamic related protein 1) protein. Our results showed that HFO diet induced less testicular histology impairment, oxidative stress, and apoptosis compared to a HL diet. This finding was associated with an increase in antioxidant activities and a shift toward mitochondrial fusion processes induced by HFO diet compared to HL diet, suggesting that ω3-PUFAs may act as bioactive compound targeting mitochondria dynamics to prevent testicular impairment.


Author(s):  
Jacaline K. Parkman ◽  
Kristiana Sklioutovskaya-Lopez ◽  
Kalhara R. Menikdiwela ◽  
Logan Freeman ◽  
Naima Moustaid-Moussa ◽  
...  

2011 ◽  
Vol 32 (7) ◽  
pp. 1078-1084 ◽  
Author(s):  
Y.-R. Lou ◽  
Q.-Y. Peng ◽  
T. Li ◽  
C. M. Medvecky ◽  
Y. Lin ◽  
...  

2010 ◽  
Vol 35 (5) ◽  
pp. 598-606 ◽  
Author(s):  
Beatrice Y. Lau ◽  
Val Andrew Fajardo ◽  
Lauren McMeekin ◽  
Sandra M. Sacco ◽  
Wendy E. Ward ◽  
...  

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.


1997 ◽  
Vol 21 (11) ◽  
pp. 955-962 ◽  
Author(s):  
H Oudart ◽  
R Groscolas ◽  
C Calgari ◽  
M Nibbelink ◽  
C Leray ◽  
...  

2011 ◽  
Vol 22 (4) ◽  
pp. 366-371 ◽  
Author(s):  
Johan De Vogel-van den Bosch ◽  
Sjoerd A.A. van den Berg ◽  
Silvia Bijland ◽  
Peter J. Voshol ◽  
Louis M. Havekes ◽  
...  

2005 ◽  
Vol 98 (1) ◽  
pp. 350-355 ◽  
Author(s):  
Erin A. Turvey ◽  
George J. F. Heigenhauser ◽  
Michelle Parolin ◽  
Sandra J. Peters

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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