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PubMed1994

Occurrence of 5c,8c,11c,15t-eicosatetraenoic acid and other unusual polyunsaturated fatty acids in rats fed partially hydrogenated canola oil.

Uncommon cis and trans fatty acids can be desaturated and elongated to produce unusual C18 and C20 polyunsaturated fatty acids in animal tissues. In the present study we examined the formation of such metabolites derived from cis and trans isomers of oleic and linoleic acids of partially hydrogenated vegetable oil origin in rats. For two months, adult male rats were fed a partially hydrogenated canola oil diet containing moderately high levels of trans fatty acids (9.6 energy%) and an adequate level of linoleic acid (1.46 energy%). Analysis of the phospholipid (PL) fatty acids of liver, heart, serum and brain showed no new C18 polyunsaturated fatty acids, except for those uncommon 18:2 isomers originating from the diet. However, minor levels (each < 0.3% PL fatty acids) of six unusual C20 polyunsaturated fatty acids were detected in the tissues examined, except in brain PL. Identification of their structures indicated that the dietary 9c,13t-18:2 isomer, which is the major trans polyunsaturated fatty acid in partially hydrogenated vegetable oils, was desaturated and elongated to 5c,8c,11c,15t-20:4, possibly by the same pathway that is operative for linoleic acid. Furthermore, dietary 12c-18:1 was converted to 8c,14c-20:2 and 5c,8c,14c-20:3; dietary 9c,12t-18:2 metabolized to 11c,14t-20:2 and 5c,8c,11c14t-20:4, and dietary 9t,12c to 11t,14c-20:2. These results suggested that of all the possible isomers of oleic and linoleic acids in partially hydrogenated vegetable oils, 12c-18:1, 9c,13t-18:2, 9c,12t-18:2 and 9t,12c-18:2 are the preferred substrates for desaturation and elongation in rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1982

Peripheral nerve cells in culture rich in Schwann cells incorporate and metabolize trans-unsaturated fatty acid (elaidic acid) as well as physiological dis isomer (oleic acid).

A culture of peripheral nerve cells enriched in Schwann cells was obtained from sciatic nerve in normal and demyelinating trembler mutant. These cells incorporated and metabolized a non-physiological trans fatty acid (elaidic aid) as well as the physiological cis isomer (oleic acid). Both acids were incorporated similarly in all lipids studied (phosphatidylcholine was a very potent acceptor) only cholesterol-esters' formation was slightly reduced from elaidic acid. Both acids were partially degradates into sub-units, in turn used for synthesis of new fatty acids. However elaidic acid was less degraded by the cells thus providing more C14:1, C16:1 fatty acids and less cholesterol. The sub-units were also used to provide very long chains, saturated and mono-unsaturated; only synthesis of nervonic acid was at variance when using oleic and elaidic acids. The presence of elaidic acid diminished the elongation-desaturation of essential fatty acids. No major differences were found between control and trembler cells, however cholesterol-esters' synthesis was slightly enhances in the mutant cells, when using both acids.

Animals↗
PubMed1998

Effect on plasma lipids and lipoproteins of replacing partially hydrogenated fish oil with vegetable fat in margarine.

We have compared the effects on lipoproteins and haemostatic variables of two hard margarines with similar functional properties, one traditional margarine containing partially hydrogenated fish oil (PHFO), and one experimental margarine based on vegetable oil (VO). Both were all-purpose cooking margarines with nearly identical functional properties. Trans fatty acids from PHFO in the traditional margarine were replaced mostly by saturated, monounsaturated and trans fatty acids of vegetable origin in the new formulation. Both test margarines contained approximately the same amount of cis polyunsaturated fatty acids. Sixteen female normolipidaemic students consumed each diet with the two test margarines for 14 d in random order (crossover design). The amount of fat was 31% energy in the PHFO diet and 32% energy in the VO diet. The test margarines provided approximately 26% energy in both diets. In the PHFO diet 7.8% of the energy was derived from trans fatty acids and 9.2% from saturated fatty acids (12:0, 14:0 and 16:0) while in the VO diet, 1.1% energy was derived from trans fatty acids and 13.3% from saturated fatty acids (12:0, 14:0 and 16:0). The natural content of cholesterol in PHFO was deliberately not balanced by addition of cholesterol to the VO diet, thus the PHFO diet contained 215 mg and the VO diet 86 mg cholesterol per 8.5 MJ. LDL-cholesterol concentration was 19% higher in subjects on the PHFO diet compared with the VO diet (P < 0.01). The ratio LDL-cholesterol:HDL-cholesterol was 12.6% higher in subjects on the PHFO diet compared with the VO diet (P < 0.01). The level of apolipoprotein (apo)A-I was 6% lower in subjects on the PHFO diet compared with the VO diet (P < 0.01). The ratio apoB:apoA-I was 10.4% higher in subjects on the PHFO diet than on the VO diet (P < 0.01). There were no significant differences in total cholesterol, HDL-cholesterol, triacylglycerols, apoB, lipoprotein(a) and haemostatic variables between the diets. Our results demonstrate that PHFO, with its unfavourable effects on plasma lipids, can be replaced by vegetable oils in margarine without appreciable loss of functional properties but with significant improvement in the effects on plasma lipoproteins.

Adult↗
PubMed2001

Dietary fat intake and risk of type 2 diabetes in women.

BACKGROUND: The long-term relations between specific types of dietary fat and risk of type 2 diabetes remain unclear. OBJECTIVE: Our objective was to examine the relations between dietary fat intakes and the risk of type 2 diabetes. DESIGN: We prospectively followed 84204 women aged 34-59 y with no diabetes, cardiovascular disease, or cancer in 1980. Detailed dietary information was assessed at baseline and updated in 1984, 1986, and 1990 by using validated questionnaires. Relative risks of type 2 diabetes were obtained from pooled logistic models adjusted for nondietary and dietary covariates. RESULTS: During 14 y of follow-up, 2507 incident cases of type 2 diabetes were documented. Total fat intake, compared with equivalent energy intake from carbohydrates, was not associated with risk of type 2 diabetes; for a 5% increase in total energy from fat, the relative risk (RR) was 0.98 (95% CI: 0.94, 1.02). Intakes of saturated or monounsaturated fatty acids were also not significantly associated with the risk of diabetes. However, for a 5% increase in energy from polyunsaturated fat, the RR was 0.63 (0.53, 0.76; P < 0.0001) and for a 2% increase in energy from trans fatty acids the RR was 1.39 (1.15, 1.67; P = 0.0006). We estimated that replacing 2% of energy from trans fatty acids isoenergetically with polyunsaturated fat would lead to a 40% lower risk (RR: 0.60; 95% CI: 0.48, 0.75). CONCLUSIONS: These data suggest that total fat and saturated and monounsaturated fatty acid intakes are not associated with risk of type 2 diabetes in women, but that trans fatty acids increase and polyunsaturated fatty acids reduce risk. Substituting nonhydrogenated polyunsaturated fatty acids for trans fatty acids would likely reduce the risk of type 2 diabetes substantially.

Adult↗
PubMed2004

Dietary fatty acids regulate acyl-CoA:cholesterol acyltransferase and cytosolic cholesteryl ester hydrolase in hamsters.

To investigate the effects of dietary fatty acids on acyl-CoA:cholesterol acyltransferase (ACAT) and cytosolic cholesteryl ester hydrolase (cCEH), male Syrian hamsters (F(1)B hybrid) were fed a modified version of the NIH-07 open formula, cereal-based rodent diet enriched with one of the following 4 dietary fatty acids: palmitic acid (16:0), trans fatty acids (18:1t), oleic acid (18:1c), or linoleic acid (18:2). Hamsters fed 16:0 and 18:1t had significantly higher plasma non-HDL cholesterol concentrations compared with those fed 18:1c and 18:2. However, differences in plasma apolipoprotein (apo)B(100) concentration, hepatic cCEH mRNA abundance, and hepatic ACAT activity between 16:0- and 18:1t-fed hamsters suggest that the hypercholesterolemic effects are achieved by different mechanisms. Specifically, an increase in ACAT activity by 16:0 may induce enrichment of cholesteryl esters in apoB(100)-containing particles, whereas 18:1t may increase the number of the particles. Hepatic cholesteryl esters accumulated in the 18:1c- and 18:2-fed groups with no differences in hepatic ACAT activity and cCEH mRNA abundance among hamsters fed unsaturated fatty acids (i.e., 18:1t, 18:1c, and 18:2). Considering the lack of change in free cholesterol concentration and increased cholesteryl esters in the liver, the hypocholesterolemic effect of 18:1c and 18:2 compared with 18:1t may be attributed to decreased production of apoB(100)-containing particles. ACAT-1 was expressed in all the tissues examined; in contrast, ACAT-2 was highly expressed in the liver and small intestine. Hepatic ACAT activity was disproportionate to the levels of ACAT-1 and ACAT-2 mRNA and protein, indicating post-transcriptional regulation of ACAT by dietary fatty acids. The data suggest that cholesterolemic effects of individual dietary fatty acids can be achieved through their independent modulation of pathways regulating assembly and secretion of apoB(100)-containing particles.

Animals↗
PubMed1985

Effects of dietary fats and butylated hydroxytoluene on mutagen activation in rats.

The effects of hydrogenated fats and butylated hydroxytoluene (BHT) in the diets of rats on the hepatic activation of benzo(a)pyrene, 2-acetylaminofluorene (AAF), and 2-aminofluorene by liver homogenates (S-9 fraction) were evaluated. The Salmonella/microsomal mutagenicity assay (Strain TA 98) was utilized to determine the mutagenic potential of the activated compounds. The S-9 fraction was obtained from animals fed a 15% fat diet consisting of hydrogenated fats (43% trans-fatty acids) or unsaturated fats (0% trans-fatty acids). BHT was administered orally (0.5%) 6 days prior to sacrifice in both groups. The incorporation of BHT in the diet of rats enhanced the mutagenic potential of AAF and 2-aminofluorene but not of benzo(a)pyrene. This effect was independent of the lipid composition of the diet. The most significant increment in the production of mutagenic metabolites was observed with AAF when BHT and hydrogenated fats were included in the diet of rats. Dietary hydrogenated fats appeared to potentiate the effects of BHT on AAF mutagenicity. Further studies to elucidate the mechanisms by which BHT and hydrogenated fats enhance AAF mutagenicity are warranted.

2-Acetylaminofluorene↗
PubMedDate not supplied

Overview of infrared methodologies for trans fat determination.

trans Fatty acids are present in a variety of foods like dairy products, but the major sources are products that contain commercially hydrogenated fats. Some studies have shown that trans fatty acids elevate levels of serum low-density lipoprotein (LDL)-cholesterol and lower high-density lipoprotein (HDL)-cholesterol. The quantitation and identification of trans fatty acid isomers is difficult because of the wide range of positional monoene, diene, and triene fatty acid isomers present in hydrogenated oils. This is complicated by the cis positional isomers that are also present, as well as the lack of commercial chromatographic standards for many fatty acid isomers. In this review, infrared methodologies for the determination of total trans fat are presented. Using an attenuated total reflection (ATR) infrared cell, a novel Fourier transform infrared (FTIR) spectroscopic method that was developed for the rapid (5 min) quantitation of the total trans fatty acid levels in neat (without solvent) fats and oils measured as triacylglycerols (TAG) is discussed. TAG required no derivatization, but had to be melted prior to measurement. The lower limit of trans quantitation was 5% of total fat. The precision of this ATR method was found to be superior to that of transmission infrared official methods. Accuracy was enhanced by generating a symmetric absorption trans infrared band at 966 cm(-1) on a horizontal background. This was achieved by "ratioing" the single-beam spectrum of the trans-containing fat or oil against that of a reference oil or standard having only cis double bonds. Attempts to apply this ATR-FTIR method to food matrixes with low trans fat and/or low total fat content were not satisfactory due to interfering infrared absorptions in the trans region. To overcome this interference, the method was modified by applying the standard addition technique to the ATR-FTIR determination. The modified procedure required more time, but eliminated any adverse impact on accuracy arising from interfering minor food components having absorption bands near 966 cm(-1).

Spectroscopy, Fourier Transform Infrared↗
PubMed1999

Both (n-3) and (n-6) fatty acids stimulate wound healing in the rat intestinal epithelial cell line, IEC-6.

The control of proliferation and epithelial restitution are processes that are poorly understood. The effects of (n-3), (n-6) and trans fatty acids on proliferation of subconfluent IEC-6 cultures and restitution of wounded IEC-6 monolayers were investigated. Incorporation of supplemented fatty acids into cellular phospholipid was also assessed. Sulforhodamine B protein dye binding assay was utilized to assess the proliferative effects of fatty acids on growth of IEC-6 cultures. Incorporation of supplemental fatty acids into cellular phospholipid was examined by thin-layer chromatography combined with gas chromatography. The modulation of epithelial restitution was examined by razor blade wounding confluent IEC-6 monolayers grown in media supplemented with various fatty acids. Inhibition of eicosanoid synthesis by indomethacin during the wounding assay was also assessed. Both (n-3) and (n-6) fatty acids significantly inhibited growth of this intestinal epithelial cell model at concentrations above 125 micromol/L. The trans fatty acid, linoelaidate 18:2(n-6)trans, inhibited growth of IEC-6 cells at concentrations above 250 micromol/L. Another trans fatty acid, elaidate 18:1(n-9)trans, was well-tolerated at concentrations as high as 500 micromol/L. Eicosapentanoic 20:5(n-3), linoleic 18:2(n-6), alpha-linolenic 18:3(n-3), gamma-linolenic 18:3(n-6) and arachidonic 20:4(n-6) acids all significantly enhanced cellular migration in the IEC-6 model of wound healing. Eicosapentanoate, linoleate, alpha-linolenate, gamma-linolenate and arachidonate are all capable of improving reconstitution of epithelial integrity following mucosal injury. Inhibition of eicosanoid synthesis reduced the enhancement of restitution by n-6 fatty acids back to control levels.

Animals↗
PubMed1990

Cis- and trans-isomeric fatty acids in plasma lipids of newborn infants and their mothers.

The proportionate fatty acid composition of plasma lipids was determined by high-resolution gas-liquid chromatography in 30 pairs of mothers and their term infants at the time of birth. Trans-fatty acids were found at similar percentage levels in maternal and infantile plasma, evidence for the first time of their placental permeability. In umbilical plasma, linoleic and alpha-linolenic acids contributed markedly smaller portions to total fatty acids, in contrast to clearly higher proportions of their long-chain polyunsaturated metabolites (LCP). Significantly larger percentage values in cord than in maternal plasma were found for those LCP that are structural components of brain lipids, which may reflect a discriminating placental transport mechanism for certain physiologically important LCP.

Adult↗
PubMedDate not supplied

Transdermal drug delivery of tricyclic antidepressants: effect of fatty acids.

The aim of the present study was to investigate the effects of fatty acids on the permeation of tricyclic antidepressants, e.g., imipramine hydrochloride (IMH) and amitriptyline hydrochloride (AMH). Five percent w/v of saturated (lauric acid) and unsaturated (oleic acid, linoleic acid, linolenic acid, trans-elaidic acid and trans-vaccenic acid) fatty acids in an ethanol (EtOH):water (2:1) system were used in this study. Flux and lag-time of tricyclic antidepressants were significantly increased and reduced, respectively, compared with control (p < 0.05). There were no significant differences between the effects of lauric and unsaturated fatty acids, both cis and trans, on the permeation of IMH and AMH (except vaccenic acid in case of IMH). The formation of 'grain boundaries' by straight chain fatty acids (saturated and trans-unsaturated fatty acids) could not be observed by Fourier-transform infrared spectroscopy (FT-IR). However, perturbation or increased bilayer fluidity of Stratum corneum (SC) induced by cis-unsaturated fatty acid was observed by FT-IR.

Administration, Cutaneous↗
PubMed1980

Effects of feeding oleic acid or hydrogenated vegetable oils to lactating cows.

In feeding trials to clarify the mechanism by which unsaturated oils depress milk fat percentage, oleic acid at 250 or 500 ml per cow per day did not reduce milk fat percentage significantly. At 500 ml these changes were significant (control, oleic): rumen acetate 61.6, 60.3%; rumen propionate 19.4, 21.0%; milk fat content of 18:1 trans fatty acid 3.0, 8.0%; and of 18:2 cis fatty acid 2.2, 1.4%. Feeding hydrogenated vegetable oil containing 13% trans acid at 454 g per cow per day decreased slightly milk fat percentage and elevated plasma cholesterol 190 to 245 mg/100 ml and 18:1 trans fatty acid in milk fat 4.2 to 6.2%. Hydrogenated vegetable oil containing 49% 18:1 trans acid at 454 g daily decreased milk fat 3.9 to 3.1%. Milk fat triglycerides decreased in short chain fatty acids and increased in 18:1 trans 2.6 to 11.2%, 18:1 cis 22.9 to 29.0%, and 18:2 trans .2 to 1.8%. Milk phospholipids decreased 14.1 to 9.6% in 14:0 fatty acid and increased .3 to 3.1% in 18:1 trans and 20.5 to 31.4% in 18:1 cis. Blood cholesterol esters were increased 152 to 195 mg/100 ml. The data lend support to the concept that trans acids or compounds produced in the rumen during their formation from polyunsaturated fatty acids are responsible for the milk fat depression from unsaturated oils.

Animals↗
PubMed1986

Temperature-dependent specificity of cis-trans isomeric fatty acid interaction with the erythrocyte membrane.

Stabilization of red cells against hypotonic haemolysis by cis-trans isomeric free C18 fatty acids occurs with pronounced specificity which is strongly temperature-dependent, but in a distinctly different manner for the two configurational isomers. Oleic acid (cis-18:1) stabilizes very efficiently at 0 degrees C, even at the highest concentrations. Elaidic acid (trans-18:1) causes neither stabilization nor haemolysis at this temperature. At room temperature (23 degrees C), elaidic acid acquires the ability to protect, without turning haemolytic at high concentrations. At 37 degrees C elaidic acid also becomes haemolytic. The protecting effect of oleic acid at 0 degrees C is the result of a rapid reaction. The characteristic, temperature-dependent specificity of cis-trans isomeric C18 fatty acid interaction with the red cell membrane appears to be a general phenomenon, since it was observed alike with erythrocytes of different species.

Animals↗
PubMed1984

Oxidation and esterification of cis- and trans-isomers of octadecenoic and octadecadienoic acids in isolated rat liver.

The metabolism of 9-octadecenoic and 9,12-octadecadienoic acids with different geometrical configurations was compared in isolated perfused rat liver. More ketone bodies were produced when the trans-isomers were infused. In contrast, only the cis-isomer augmented the triacylglycerol secretion almost entirely as very-low-density lipoprotein (VLDL). Although these responses were independent of the difference in the degree of unsaturation in both the cis- and trans-isomers, the trans-monoenic acid compared to the trans-dienic acid was incorporated more readily into perfusate and hepatic lipids. Quantitative information was obtained with radioactive tracer experiments. The hepatic uptakes of 9-[10-14C]octadecenoic acids were comparable in the cis- and trans-isomers. The trans-octadecenoic acid compared to the cis counterpart was oxidized more readily and incorporated more into liver phospholipid but less into perfusate and liver triacylglycerol. These reciprocal responses counterbalanced each other. The lower rates of triacylglycerol synthesis and secretion in the liver perfused with the trans-octadecenoic acid was confirmed using [2- 3H]glycerol as a tracer. The marked difference in the channelling of cis- and trans-fatty acids in the pathways of oxidation and esterification seems to modify the VLDL secretion in perfused rat liver. Present observations indicate a considerable difference in the fate of unsaturated fatty acids with different configurations. trans-Fatty acids are expected to be an efficient energy source in animal tissues and may not be hyperlipidemic.

Animals↗
PubMed2005

Dilution rate and pH effects on the conversion of oleic acid to trans C18:1 positional isomers in continuous culture.

In a previous in vitro study, mixed ruminal microorganisms converted oleic acid to a variety of trans monenes when grown in batch cultures under constant environmental conditions. To determine whether a similar conversion occurs under environmental conditions more typical of the rumen, conversion of 13C-labeled oleic acid to biohydrogenation intermediates was determined in ruminal microorganisms grown in continuous culture at two pH (5.5 and 6.5) and liquid dilution rates (0.05 and 0.10/h) arranged factorially. After each morning feeding of the dual-flow continuous cultures, 250 mg of oleic acid in 5 mL of ethanol were injected into each culture. On d 10, 250 mg of oleic-1-(13C) replaced the unlabelled oleic acid in ethanol. Trans fatty acids were isolated from culture samples by solid phase extraction, and 13C enrichment and identity of double bond position was determined by gas chromatography-mass spectroscopy. At pH 6.5 and 0.10/h dilution rate, 13C enrichment was detected in all trans-C18:1 isomers having double bond positions from C6 through C16 in the acyl chain. However, when pH or dilution rate in fermentors was lowered, no 13C enrichment was detected in any trans isomer with a double bond position beyond C10. Enrichment in stearic acid increased by reducing culture pH from 6.5 to 5.5, but decreased when dilution rate dropped from 0.10 to 0.05/h. The stearic acid carbons that originated from oleic acid biohydrogenation increased from 30 to 72% when pH dropped from 6.5 to 5.5. The 13C enrichment of trans-10 was reduced under low pH and dilution rate conditions. The results of this study confirm that ruminal microorganisms are capable of converting oleic acid to a wide variety of trans-C18:1 positional isomers when ruminal conditions are favorable (such as the pH 6.5 and 0.10/h dilution rate treatment). However, at low pH and dilution rate, the conversion of oleic acid to trans-C18:1 still occurs, but positional isomers produced are restricted to double bond positions from C6 to C10. Low pH conditions also increased the conversion of oleic acid to stearic acid.

Animals↗
PubMed2004

Determination of trans-arachidonic acid isomers in human blood plasma.

Endogenous trans fatty acids originate from diet, but recent studies also suggest that cis-trans isomerization of fatty acids is possible by nitrogen dioxide radical, a product of NO and nitrite oxidation. We developed a method for quantitative analysis of four trans-arachidonic acids (TAA) in human plasma using isotopic dilution gas chromatography/mass spectrometry (GC/MS) with deuterium-labeled internal standard. Esterification of the plasma fatty acid extract with pentafluorobenzyl (PFB) bromide followed by high-performance liquid chromatography purification yielded a fairly pure fraction containing TAA-PFB esters that was analyzed by GC/MS. Partial separation of the TAA isomers was obtained on various GC columns. Comparison of the retention time with the synthetic standards revealed that all four TAA isomers are present in human plasma. The mean concentration of TAA in human plasma was 20.2ng/ml. The levels of isomers were 12.48+/-1.28, 2.75+/-0.39, and 4.99+/-0.74ng/ml for 5E-AA + 11E-AA, 8E-AA, and 14E-AA, respectively. The identification of TAA in plasma suggests that isomerization of arachidonic acid occurs in vivo. Our method allows distinguishing between the dietary and the NO(2)-dependent mechanisms of trans fatty acid formation and will be useful in defining the role of TAA as an in vivo marker of nitrooxidative stress in clinical and experimental settings.

Adult↗
PubMed1999

C18:1, C18:2 and C18:3 trans and cis fatty acid isomers including conjugated cis delta 9, trans delta 11 linoleic acid (CLA) as well as total fat composition of German human milk lipids.

In particular with respect to infant nutrition knowledge of the current contents of trans fatty acids (TFA) and of conjugated linoleic acid (CLA in human milk lipids is of interest. After pre-separation by Ag-TLC 11 trans-C18:1 isomers could be quantified by GC with a mean total content of 2.40 +/- 0.60 wt% in samples from 40 German women. For the positional isomers t4, t5, t6-8, t9, t10, t11, t12, t13, t14, t15 and t16 contents of 0.02, 0.02, 0.21, 0.37, 0.32, 0.68, 0.23, 0.15, 0.18, 0.09 and 0.14 wt% were established, with vaccenic acid being the predominant isomer. Further, small trans-C14:1 and trans-C16:1 contents of 0.08% and 0.15% on average were found. As the trans-C18:1 isomers also the trans-C16:1 isomers of human milk lipids could for the first time be baseline-resolved by GC to a great extent. Moreover, besides a mean CLA (c9,t11) content of 0.40 +/- 0.09% further 6 cis/trans isomers of linoleic acid with a total content of 1.07 +/- 0.56% on average (w/o CLA) were determined. Further, 4 trans isomers of alpha-linolenic acid could be baseline-resolved exhibiting a total content of 0.11%. Altogether German human milk lipids on average were found to contain 3.81 +/- 0.97% TFA with a range of 2.38-6.03%. Direct connections between the dietary intake of trans-C18:1 isomers and the composition of human milk lipids could be established. The major fatty acids exhibited the following contents (wt%): C4: 0.16, C6: 0.18, C8: 0.06, C10: 0.58, C12: 3.12, C14: 6.43, C16: 25.28, C18: 7.41, C18: 1 (total): 33.67, C18: 2 (total): 10.63 and alpha-C18: 3:0.87.

Adult↗
PubMed1981

[Studies of the effects of cis, cis and trans, trans-octadecadienoic acids on lipid metabolism in essential fatty acid deficient rats (author's transl)].

The effect of an essential fatty acid [EFA] deficiency in male Sprague-Dawley rats and its excerbation by inclusion of trans fatty acids in the diet were observed from the level and composition of serum lipoproteins. Male Sprague-Dawley rats were fed from weaning diet containing all essential nutrients and 10% of a fat supplement as safflower oil (SAFF] or hydrogenated coconut oil [HCO] for 28 weeks. At the end of 28 weeks, the blood was withdrawn from the retro-ocular plexes of 4 animals of each group, and lipoprotein lipid and fatty acids were analyzed. Another 5 animals of each group were switched to a 5% supplement of ethyl linolelaidate [TRANS]. In addition, the remaining 5 animals of HCO group were switched to SAFF diet. Lipoprotein lipid and fatty acid analyses were performed on the pooled serum in each group at 3, 7 and 14 days after switching the diet, and after 21 days serum was analyzed on the individual animal of each group. The results obtained were as follows: [1] With the development of an EFA deficiency in HCO group, there was a decrease in the high density lipoprotein [HDL] and increase in the very low density lipoprotein [VLDL] plus low density lipoprotein [LDL] fraction. [2] In a switching group from the SAFF to the TRANS supplement, the level of arachidonate in the serum lipid was decreased with a corresponding decrease in HDL, whereas linoleate, at least for the initial 3 weeks, decreased only in triglyceride fraction. [3] In a EFA deficient rat [HCO group] after switched to the TRANS supplement, HDL was further decreased and increase o VLDL-LDL was progressed. Consequently, the HDL: VLDL-LDL ratio was lowered strikingly. These changes in the EFA deficiency were accompanied by a large increase in monoenoic acids and a decrease in eicosatrienoic acid converted from oleic acid. [4] The administration of SAFF diet to the EFA deficient group induced a rapid increase in arachidonate in HDL, and decrease in eicosatrienoic acid and oleic acid. These changes were accompanied by a marked decrease in VLDL-LDL. It is suggested that the normal HDL might play an important role on catabolism of VLDL-LDL. These results suggest that polyunsaturated fatty acid, especially arachidonic acid rather than linoleic acid is essential to the formation and the function of HDL in the rats.

Animals↗