scholarly journals Natural CLA-Enriched Lamb Meat Fat Modifies Tissue Fatty Acid Profile and Increases n-3 HUFA Score in Obese Zucker Rats

Biomolecules ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 751 ◽  
Author(s):  
Gianfranca Carta ◽  
Elisabetta Murru ◽  
Claudia Manca ◽  
Andrea Serra ◽  
Marcello Mele ◽  
...  

Ruminant fats are characterized by different levels of conjugated linoleic acid (CLA) and α-linolenic acid (18:3n-3, ALA), according to animal diet. Tissue fatty acids and their N-acylethanolamides were analyzed in male obese Zucker rats fed diets containing lamb meat fat with different fatty acid profiles: (A) enriched in CLA; (B) enriched in ALA and low in CLA; (C) low in ALA and CLA; and one containing a mixture of olive and corn oils: (D) high in linoleic acid (18:2n-6, LA) and ALA, in order to evaluate early lipid metabolism markers. No changes in body and liver weights were observed. CLA and ALA were incorporated into most tissues, mirroring the dietary content; eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) increased according to dietary ALA, which was strongly influenced by CLA. The n-3 highly-unsaturated fatty acid (HUFA) score, biomarker of the n-3/n-6 fatty acid ratio, was increased in tissues of rats fed animal fats high in CLA and/or ALA compared to those fed vegetable fat. DHA and CLA were associated with a significant increase in oleoylethanolamide and decrease in anandamide in subcutaneous fat. The results showed that meat fat nutritional values are strongly influenced by their CLA and ALA contents, modulating the tissue n-3 HUFA score.

1989 ◽  
Vol 257 (4) ◽  
pp. R822-R828 ◽  
Author(s):  
M. J. Azain ◽  
J. A. Ontko

These studies were undertaken to further characterize and explain the differences in hepatic fatty acid metabolism between lean and obese Zucker rats. It was shown that the rate of palmitate or octanoate oxidation and the inhibition of palmitate oxidation by malonyl CoA in mitochondria isolated from lean and obese Zucker rats were similar. Cytochrome oxidase activity was similar in lean and obese rat livers. It was found that the addition of cytosol from the obese rat liver inhibited palmitate oxidation by 20-30% in mitochondria isolated from lean or obese rat livers and thus reproduced the conditions observed in the intact cell. Increased concentrations of metabolites such as malonyl CoA and glycerophosphate in the liver of the obese rat are likely contributors to this inhibitory effect. These results are extrapolated to the intact cell and suggest that decreased hepatic fatty acid oxidation in the obese rat can be accounted for by cytosolic influences on the mitochondria. The decreased rate of fatty acid oxidation observed in the intact hepatocyte or perfused liver cannot be explained by a defect in the capacity of mitochondria to oxidize substrate or by a decrease in mitochondrial number in the obese rat liver.


2000 ◽  
Vol 278 (2) ◽  
pp. R453-R459 ◽  
Author(s):  
J. Anthony Peth ◽  
Tyson R. Kinnick ◽  
Erik B. Youngblood ◽  
Hans J. Tritschler ◽  
Erik J. Henriksen

The purpose of this study was to assess the individual and interactive effects of the antioxidant α-lipoic acid (LPA) and the n-6 essential fatty acid γ-linolenic acid (GLA) on insulin action in insulin-resistant obese Zucker rats. LPA, GLA, and a unique conjugate consisting of equimolar parts of LPA and GLA (LPA-GLA) were administered for 14 days at 10, 30, or 50 mg ⋅ kg body wt− 1 ⋅ day− 1. Whereas LPA was without effect at 10 mg/kg, at 30 and 50 mg/kg it elicited 23% reductions ( P < 0.05) in the glucose-insulin index (the product of glucose and insulin areas under the curve during an oral glucose tolerance test and an index of peripheral insulin action) that were associated with significant increases in insulin-mediated (2 mU/ml) glucose transport activity in isolated epitrochlearis (63–65%) and soleus (33–41%) muscles. GLA at 10 and 30 mg/kg caused 21–25% reductions in the glucose-insulin index and 23–35% improvements in insulin-mediated glucose transport in epitrochlearis muscle. The beneficial effects of GLA disappeared at 50 mg/kg. At 10 and 30 mg/kg, the LPA-GLA conjugate elicited 29 and 38% reductions in the glucose-insulin index. These LPA-GLA-induced improvements in whole body insulin action were accompanied by 28–63 and 38–57% increases in insulin-mediated glucose transport in epitrochlearis and soleus muscles and resulted from the additive effects of LPA and GLA. At 50 mg/kg, the metabolic improvements due to LPA-GLA were substantially reduced. In summary, these results indicate that the conjugate of the antioxidant LPA and the n-6 essential fatty acid GLA elicits significant dose-dependent improvements in whole body and skeletal muscle insulin action on glucose disposal in insulin-resistant obese Zucker rats. Moreover, these actions of LPA-GLA are due to the additive effects of its individual components.


2009 ◽  
Vol 296 (4) ◽  
pp. E738-E747 ◽  
Author(s):  
Graham P. Holloway ◽  
Carley R. Benton ◽  
Kerry L. Mullen ◽  
Yuko Yoshida ◽  
Laelie A. Snook ◽  
...  

Intramuscular triacylglycerol (IMTG) accumulation in obesity has been attributed to increased fatty acid transport and/or to alterations in mitochondrial fatty acid oxidation. Alternatively, an imbalance in these two processes may channel fatty acids into storage. Therefore, in red and white muscles of lean and obese Zucker rats, we examined whether the increase in IMTG accumulation was attributable to an increased rate of fatty acid transport rather than alterations in subsarcolemmal (SS) or intermyofibrillar (IMF) mitochondrial fatty acid oxidation. In obese animals selected parameters were upregulated, including palmitate transport (red: +100%; white: +51%), plasmalemmal FAT/CD36 (red: +116%; white: +115%; not plasmalemmal FABPpm, FATP1, or FATP4), IMTG concentrations (red: ∼2-fold; white: ∼4-fold), and mitochondrial content (red +30%). Selected mitochondrial parameters were also greater in obese animals, namely, palmitate oxidation (SS red: +91%; SS white: +26%; not IMF mitochondria), FAT/CD36 (SS: +65%; IMF: +65%), citrate synthase (SS: +19%), and β-hydroxyacyl-CoA dehydrogenase activities (SS: +20%); carnitine palmitoyltransferase-I activity did not differ. A comparison of lean and obese rat muscles revealed that the rate of change in IMTG concentration was eightfold greater than that of fatty acid oxidation (SS mitochondria), when both parameters were expressed relative to fatty transport. Thus fatty acid transport, esterification, and oxidation (SS mitochondria) are upregulated in muscles of obese Zucker rats, with these effects being most pronounced in red muscle. The additional fatty acid taken up is channeled primarily to esterification, suggesting that upregulation in fatty acid transport as opposed to altered fatty acid oxidation is the major determinant of intramuscular lipid accumulation.


1988 ◽  
Vol 59 (2) ◽  
pp. 273-278 ◽  
Author(s):  
Stephen C. Cunnane

1. Young male rats were fed on diets containing 3·4, 36 or 411 mg zinc/kg for 10 weeks in order to determine whether effects of Zn deficiency on plasma and liver essential fatty acid composition could be distinguished from those of reduced protein and energy intake.2. Fatty acid analysis revealed that a Zn intake of 3·4 mg/kg (plasma Zn 0·80 v. 1·97 mmol/l in controls fed on 36 mg Zn/kg) resulted in a significant increase in the linoleic acid: arachidonic acid ratio in both plasma and liver phospholipids in comparison with rats fed on 36 or 411 mg Zn/kg.3. Zn supplementation (411 mg/kg) decreased the linoleic acid: arachidonic acid ratio in plasma phosphatidylserine compared with that of the controls.4. The previously reported increase in arachidonic acid (mol %) in liver triacylglycerol of Zn-deficient rats was shown to be a function of a reduced liver triacylglycerol pool size; quantitatively, triacylglycerol content of arachidonic acid in the liver was not significantly affected by Zn intake.


2002 ◽  
Vol 34 (7) ◽  
pp. 1106-1114 ◽  
Author(s):  
RUSSELL G. FIEBIG ◽  
JOHN M. HOLLANDER ◽  
DENISE NEY ◽  
RICHARD BOILEAU ◽  
ELIZABETH JEFFERY ◽  
...  

2012 ◽  
Vol 52 (10) ◽  
pp. 911 ◽  
Author(s):  
Y. L. Yuan ◽  
J. L. Li ◽  
W. H. Zhang ◽  
C. Li ◽  
F. Gao ◽  
...  

The objective of this study was to evaluate the effect of vaccination against gonadotropin-releasing factor (GnRF) on carcass characteristics and meat quality and back fat quality. In total, 400 healthy male pigs were randomly assigned into two treatment groups: physically castrated males (CM) and vaccinated males (IM). CM pigs were physically castrated within 3 days of age. IM pigs received the GnRF vaccine twice, at 14 and 21 weeks of age. At the end of the experiment, 20 pigs of each treatment were weighed individually and slaughtered at 25 weeks of age. The longissimus muscle was collected to evaluate the meat quality including pH, drip loss, shear force, cooking loss, intramuscular fat, fatty acid composition and inosine monophosphate. Subcutaneous fat was sampled to evaluate fatty acid composition. IM pigs had a lower dressing percentage and were leaner (P < 0.01). The inosine monophosphate content was higher in pork from IM pigs than from CM pigs (P < 0.05). IM pigs had a higher content of polyunsaturated fatty acids in longissimus muscles than CM pigs (P < 0.01), mostly because of the higher linoleic acid content (P < 0.01). IM pigs had higher levels of unsaturated fatty acids in subcutaneous fat than CM pigs (P < 0.01), mostly because of the higher linoleic acid and linolenic acid (P < 0.01) and the lower myristic acid content (P < 0.01). There were no adverse effects of the GnRF vaccine on slaughter performance and meat quality of pigs. These results suggest that GnRF vaccine administered to pigs increases the inosine monophosphate content in longissimus muscles and the content of polyunsaturated fatty acids in longissimus muscles and back fat. Consequently, vaccination with Improvac for boar taint control will provide a good alternative to physical castration of male pigs.


2003 ◽  
Vol 83 (4) ◽  
pp. 713-720 ◽  
Author(s):  
M. E. R. Dugan ◽  
J. L. Aalhus ◽  
D. C. Rolland ◽  
L. E. Jeremiah

The objective of the present study was to compare pork quality, composition and palatability of pigs fed different levels of conjugated linoleic acid (CLA) and total oil (TO). A 3 × 2 factorial design was used feeding three levels of CLA (0, 0.25, and 0. 5%) and two levels of TO (2 and 5% made up with canola oil). Thirty-six pigs were allotted per diet and diets were fed from 35 to 115 kg liveweight. TO had no effect on longissimus thoracis (LT) moisture or intramuscular fat contents, but feeding CLA decreased LT moisture (P = 0.04) and increased LT intramuscular fat (P = 0.04). CLA and TO had no effect on LT subjective color, structure or marbling scores. Post-mortem LT temperature was also unaffected by feeding CLA or TO. Pigs fed 0.5% CLA had a marginally higher muscle pH (P = 0.01), a tendency toward lower post-mortem lactate levels (P = 0.06) and had higher glycogen concentrations (P = 0.03) at 30 min post mortem. Feeding CLA may thus offer limited protection against rapid post-mortem pH decline. Adding CLA to the diet increased subcutaneous fat hardness (P = 0.01), which was related to increased saturated (P = 0.01) and reduced monounsaturated fatty acid levels (P = 0.01). Increasing TO had an opposite effect resulting in softer fat with lower saturated and higher mono- and polyunsaturated fatty acid levels (P = 0.01). Supplementing diets with CLA in combination with canola oil did not have any detrimental effect on pork quality, composition or palatability. Feeding CLA does, however, have the potential to improve pork quality by increasing intramuscular fat levels, reducing post-mortem glycogen utilization rates and increasing subcutaneous fat hardness. Key words: Conjugated linoleic acid, canola oil, pork quality, palatability, marbling, fat composition


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