bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interaction of n‐3 long‐chain polyunsaturated fatty acids with n‐6 fatty acids in suckled rat pups
Authors: Boyle Frances G. , Yuhas Rebecca J. , Goldberg Kenneth , Lien Eric L. 
Published: November 2006

AbstractThe addition of long‐chain polyunsaturated fatty acids (LCP: C20, and C22) to infant formula may permit fatty acid accretion rates similar to breast‐fed infants, and may have long‐term outcome benefits, such as improved visual acuity and cognitive development. Although fish oil may provide a source of n‐3 LCP, sources of n‐6 LCP have been more difficult to identify. The present study evaluates the effects of n‐3 and n‐6 LCP derived from single‐cell oils on liver, plasma, and brain fatty acid levels in a neonatal animal model. Newborn rat pups were suckled for 14 d by dams receiving diets containing n‐3 LCP alone or combinations of n‐3 LCP and increasing doses of linoleic acid (18∶2n−6) or arachidonic acid (20∶4n−6). Dietary groups received 2% n−3 LCP and 1, 2, or 5% of either 18∶2n−6 or 20∶4n−6. The 20∶4n−6 source also contained modest levels of 18∶2n−6. At the termination of the study, liver, plasma, and brain were obtained from the rat pups and the phospholipid fatty acid profiles determined. The results indicate complex interactions of n−3 and n−6 fatty acids. Groups receiving dietary 20∶4n−6 incorporated higher levels of n−6 LCP into tissues than did the groups receiving 18∶2n−6. The brain was relatively resistant to changes in fatty acid composition compared with the liver and plasma. As expected, tissue n−3 LCP levels were reciprocally related to n−6 levels. The present results document that single‐cell LCP oils are bioavailable in a neonatal animal model. The use of 20∶4n−6 is a more effective means of supporting n−6 status than the use of 18∶2n−6. These results may have implications for the addition of LCP to infant formula.
Absorption, excretion, and distribution of plant sterols after proximal gut resection and autotransplantation of porcine ileum
Authors: Pakarinen M. P. , Halttunen J. , Kuusanmäki P. , Lauronen J. , Miettinen T. A. 
Published: November 2006

AbstractContribution of different gut segments to plant sterol absorption, adaptation of plant sterol absorption after partial small bowel resection, and effects of gut transplantation (necessitates extrinsic autonomic denervation and lymphatic disruption) on plant sterol biodynamics are unclear. We studied the consequences of massive proximal small bowel resection and autotransplantation of the remaining ileum on the adaptive absorption and biodynamics of plant sterols. Dietary, fecal, biliary, hepatic and plasma plant sterols, fecal elimination and absorption of cholesterol, small bowel morphology, and intestinal transit were determined before (n=5) and at 4, 8, and 14 wk after resection of the proximal 75% of the jejunoileum (n=15) and autotransplantation of the remaining ileum (n=15) or transection (n=5). Proximal gut resection significantly reduced cholesterol absorption efficiency; percentage absorption and biliary secretion of plant sterols; plasma, biliary and hepatic campesterol‐to‐cholesterol proportions; and sitosterol proportions in plasma and bile. Autotransplantation of the remaining ileum further significantly decreased cholesterol absorption efficiency; percentage absorption and biliary secretion of campesterol; campesterol proportions in plasma, bile and liver; and plasma proportions of sitosterol while increasing fecal excretion of neutral and acidic steroids. Plasma proportions of the two plant sterols, but absorption of just campesterol, were gradually improved with increasing cholesterol absorption and villus height after proximal gut resection; the same result was observed to a lesser degree after ileal autotransplantation. In addition, significant positive correlations were found between percentage cholesterol and campesterol absorption and the plasma plant sterol proportions in both proximal resection groups, between campesterol absorption and ileal villus height in the resection group, and between campesterol absorption and intestinal transit time in the autotransplantation group. In conclusion, plasma campesterol and sitosterol closely reflect absorption of cholesterol and plant sterols from intact and autotransplanted ileum during adaptation to proximal gut resection. A loss of proximal gut absorptive surface impairs cholesterol and campesterol absorption more than sitosterol absorption, the later being apparently less dependent on available jejunal villus surface area.
The effect of dietary vitamin E supply and a moderately oxidized oil on activities of hepatic lipogenic enzymes in rats
Authors: Eder Klaus , Kirchgessner Manfred 
Published: November 2006

AbstractDiets rich in polyunsaturated fatty acids (PUFA) are well known to suppress hepatic lipogenic enzymes compared to fat‐free diets or diets rich in saturated fatty acids. However, the mechanism underlying suppression of lipogenic enzymes is not quite clear. The present study was undertaken to investigate whether lipid peroxidation products are involved in suppression of lipogenic enzymes. Therefore, an experiment with growing male rats assigned to six groups over a period of 40 d was carried out. Rats received semisynthetic diets containing 9.5% coconut oil and 0.5% fresh soybean oil (coconut oil diet, peroxide value 5.1 meq O2/kg oil), 10% fresh soybean oil (fresh soybean oil diet, peroxide value 0.5 meq O2/kg oil), or 10% thermally treated soybean oil (oxidized soybean oil diet, peroxide value 74 meq O2/kg oil). To modify the antioxidant state of the rats, we varied the vitamin E supply (11 and 511 mg α‐tocopherol equivalents per kg of diet) according to a bi‐factorial design. Food intake and body weight gain were not influenced by dietary fat and vitamin E supply. Activities of hepatic lipogenic enzymes were markedly influenced by the dietary fat. Feeding either fresh or oxidized soybean oil diets markedly reduced activities of fatty acid synthase, (FAS), acetyl CoA‐carboxylase, (AcCX), glucose‐6‐phosphate dehydrogenase, (G6PDH), 6‐phosphogluconate dehydrogenase, and ATP citrate lyase (ACL) relative to feeding the coconut oil diet. Moreover, feeding oxidized soybean oil slightly, but significantly, lowered activities of FAS, AcCX, and ACL compared to feeding fresh soybean oil. Activities of hepatic lipogenic enzymes were reflected by concentrations of triglycerides in liver and plasma. Rats fed the coconut oil diet had markedly higher triglyceride concentrations in liver and plasma than rats consuming fresh or oxidized soybean oil diets, and rats fed oxidized soybean oil had lower concentrations than rats fed fresh soybean oil. The vitamin E supply of the rats markedly influenced concentrations of thiobarbituric acid‐reactive substances in liver, but it did not influence activities of hepatic lipogenic enzymes. Because the vitamin E supply had no effect, and ingestion of an oxidized oil had only a minor effect, on activities of hepatic lipogenic enzymes, it is strongly suggested that neither exogenous nor endogenous lipid peroxidation products play a significant role in the suppression of hepatic lipogenic enzymes by diets rich in PUFA. Therefore, we assumed that dietary PUFA themselves are involved in regulatio of hepatic lipogenic enzymes. Nevertheless, the study shows that ingestion of oxidized oils, regardless of the vitamin E supply, also affects hepatic lipogenesis, and hence influences triglyceride levels in liver and plasma.
Effects of polyunsaturated fatty acids and their n‐6 hydroperoxides on growth of five malignant cell lines and the significance of culture media
Authors: Nøding Randi , Schønberg Svanhild A. , Krokan Hans E. , Bjerve Kristian S. 
Published: November 2006

AbstractWe examined effects of polyunsaturated fatty acids (PUFA), their corresponding hydroperoxy fatty acids (hp‐PUFA), as well as various pro‐ and antioxidants on the growth of tumor cells in culture. When cultured in RPMI 1640 medium, A‐427 and WEHI clone 13 cells were both highly sensitive to hydroperoxy docosahexaenoic acid (hp‐DHA), but they were far less sensitive in minimum essential medium (MEM). In contrast, A‐427 cells were also sensitive to DHA in both culture media, while WEHI clone 13 cells, as well as other cell lines, tested in their respective media, were resistant. The lower sensitivity of the cell lines to hp‐DHA in MEM‐medium was apparently due to a more rapid reduction of hp‐DHA to the corre‐sponding hydroxy‐DHA in MEM‐medium. Addition of glutathione (GSH) to the culture medium abolished the effects of hp‐DHA, but not the effects of DHA, while depletion of intracellular GSH levels by L‐buthionine‐S,R‐sulfoximine strongly enhanced the cytotoxic effect of hp‐DHA, but not the cytotoxic effect of DHA. α‐Tocopherol protected A‐427 cells against the toxic effect of DHA and abolished the induced lipid peroxidation, while it did not protect against the toxic effects of hp‐DHA in A‐427 or WEHI clone 13 cells. Ascorbic acid reduced the cytotoxic effect of DHA, but potentiated the toxic effect of hp‐DHA while selenite essentially abolished the toxicity of both DHA and hp‐DHA. These results indicate that sensitivity of tumor cell lines to PUFA and their oxidation products depends on their antioxidant defense mechanisms, as well as culture conditions, and establishes hp‐DHA as a major, but probably not the sole, metabolite responsible for cytotoxicity of DHA.
Rapid hydrolysis of bile acid conjugates using microwaves: Retention of absolute stereochemistry in the hydrolysis of (25R) 3α,7α,12α‐trihydroxy‐5β‐cholestan‐26‐oyltaurine
Authors: Dayal Bishambar , Ertel Norman H. 
Published: November 2006

AbstractIn recent years, defects of bile acid synthesis caused by disorders of peroxisome biogenesis have led to increased interest in C27 bile acids. In humans, while the majority of bile acids are C24 carboxylic acids, the presence of increased concentrations of C27 bile acids and their metabolites in hereditary diseases associated with peroxisomal dysfunction can serve as a useful marker for the intensity of the metabolic disorder. Our present studies describe an efficient method for the rapid hydrolysis of C27 and C24 bile acid conjugates using a commercial microwave oven. The advantages of this method include freedom from racemization, minimal activation, mild reaction conditions, and the highly stereocontrolled nature of the reaction, thus allowing for free bile acid recovery in high yield. For example, when (25R) 3α,7α,12α‐trihydroxy‐5β‐cholestan‐26‐oyl taurine, a major compound present in the bile of Alligator mississippiensis, was deconjugated with 4% NaOH/diethylene glycol or 1 M LiOH/propylene glycol in the microwave oven for 4–6 min, 3α,7α,12α‐trihydroxy‐5β‐cholestan‐26‐oic acid (THCA) was obtained in 81% yield with retention of configuration at C‐25. It is suggested that present studies will be helpful in delineating the absolute stereochemistry of 3α,7α,12α‐trihydroxy‐5β‐cholestanoyl‐CoA oxidase, the peroxisomal enzyme that catalyzes the first step in the oxidation of THCA.
Gas chromatography‐mass spectrometry methods for structural analysis of fatty acids
Authors: Christie William W. 
Published: November 2006

AbstractProcedures for structural analysis of fatty acids are reviewed. The emphasis is on methods that involve gas chromatography‐mass spectrometry and, in particular, the use of picolinyl ester and dimethyloxazoline derivatives. These should be considered as complementing each other, not simply as alternatives. However, additional derivatization procedures can be of value, including hydrogenation and deuteration, and preparation of dimethyl disulfide and 4‐methyl‐1,2,4‐triazoline‐3,5‐dione adducts. Sometimes complex mixtures must be separated into simpler fractions prior to analysis by gas chromatography‐mass spectrometry. Silver ion and reversed‐phase high‐performance liquid chromatography are then of special value. In particular, a novel application of the latter technique, involving a base‐deactivated stationary phase and acetonitrile as mobile phase, is described that is suited to the separation of fatty acids in the form of picolinyl ester and dimethyloxazoline derivatives, as well as methyl esters.
Effect of selenium and vitamin E supplements on tissue lipids, peroxides, and fatty acid distribution in experimental diabetes
Authors: Douillet C. , Bost M. , Accominotti M. , Borson‐Chazot F. , Ciavatti M. 
Published: November 2006

AbstractThe protective role of selenium (Se), given as a Se‐rich yeast, selenomethionine or selenomethionine+vitamin E supplement, toward changes in lipid, peroxide, and fatty acid distribution in tissues of streptozotocin‐induced diabetic rats, was investigated, after 24 wk of disease. Diabetes increased liver thiobarbituric acid‐reactive substances and conjugated dienes; Se supplement completely corrected these changes. In kidney, as in heart, the peroxide levels were not significantly changed by diabetes. In diabetic rat liver, a significant drop in triglycerides and phospholipids (P<0.05) was observed; this was modulated by Se+vitamin F supplementation. Se+vitamin E supplementation also inhibited the decrease in 18∶2n‐6 and the increase in 22∶6n‐3 observed in liver of diabetic rats, changes which reflect altered glycemic control. In kidney, heart, and aorta, diabetes produced some changes in lipid content and fatty acid distribution, especially an increase in heart triglycerides which was also corrected by the Se supplement. Se supplementation to diabetic rats also increased 18∶0 etherlinked alcohol, 20∶4 n‐6, and 22∶5 n‐3 in cardiac lipids. In aorta, Se + vitamin E significanlty increased 20∶5 n‐3. These polyunsaturated fatty acids are precursors, in situ, of prostaglandin l2 (PGl2) and PGl3 which may protect against cardiovascular dysfunction. In kidney, converrely, Se decreased 20∶4 n‐6, the precursor of thromboxane A1 implicated in diabetic glomerular injury. thus Se, and more efficiently Se + vitamin E supplementation, in experimental diabetes could play a role in controlling oxidative status and altered lipid metabolism in liver, thereby maintaining favorable fatty acid distribution in the major tissues affected by diabetic complications.
Chronic dietary n‐3 polyunsaturated fatty acids deficiency affects the fatty acid composition of plasmenylethanolamine and phosphatidylethanolamine differently in rat frontal cortex, striatum, and cerebellum
Authors: Favrelière S. , Barrier L. , Durand G. , Chalon S. , Tallineau C. 
Published: November 2006

AbstractAs chronic consumption of a diet devoid of n‐3 fatty acid induced modification of neurotransmission pathways in the frontal cortex of rats, plasmalogen alteration could occur in this area. Because of the propensity to facilitate membrane fusion, plasmenylethanolamine (PmE), a major plasmalogen of brain, may be involved in synaptic transmission. Female rats were fed diet containing peanut oil [(n‐3)‐deficient diet] through two generations. Two weeks before mating, half of the female rats of the second generation received a diet containing peanut oil and rapeseed oil (control group). The distribution and acyl composition of major phospholipids, phosphatidylethanolamine and PmE, were measured in the frontal cortex, striatum, and cerebellum of the male progeny of the two groups at 60 d of age. The n‐3 polyunsaturated fatty acid (PUFA) deficiency had no effect on the distribution of phospholipids in all brain regions but affected their acyl composition differently. The level of 22∶6n‐3 was significantly lower and compensated for by higher levels of n‐6 fatty acids in all regions and phospholipids studied. However, docosahexaenoic acid, being more concentrated in the PmE of frontal cortex, is also more decreased in the n‐3‐deficient rats compared to the striatum. By contrast, striatum PmE has retained more 22∶6n‐3 than PmE of the other regions. In addition, the increase of n‐6 PUFA was significantly lower in frontal cortex PmE compared to the striatum and cerebellum PmE. In association with altered neurotransmission observed in frontal cortex of n‐3‐deficient rats, our results suggest that frontal cortex PmE might be more affected in chronically α‐linolenic‐deficient rats. However, by retaining 22∶6n‐3, striatum PmE could be most resilient.
Inhibitory effect of linoleic acid on chain elongation and desaturation of 18∶2 c,t isomers in lactating and neonatal rats
Authors: Kwan Kwok Yiu , Wang Li‐Ya , Chan Kwok Pan , Chen Zhen Yu 
Published: November 2006

AbstractThe previous studies showed that dietary 18∶2 c,t isomers could be chain‐elongated and desaturated to produce unusual 20∶4 isomers. The present study was undertaken to determine the minimal amount of 18∶2n−6 required to suppress the chain elongation and desaturation of 18∶2 c,t isomers in the lactating and neonatal rats when animals were fed 15% partially hydrogenated canola oil diet containing 1.72% energy as 18∶2 c,t isomers and varying amounts of free 18∶2n−6. These diets induced marginal essential fatty acid (EFA) deficiency states (0.56% energy 18∶2n−6) to EFA adequacy (2.56% energy 18∶2n−6). After feeding for 50 d, the female animals were mated with males by overnight pairing. After conception, the lactating rats were killed, together with one pup from each dam, at term and day 26 of lactation. Two unusual 20∶4 isomers in both maternal and neonatal liver phospholipids were identified as 20∶4Δ5c,8c,11c,14t and 20∶4Δ5c,8c,11c,15t, which were derived from 18∶2Δ9c,12t, and 18∶2Δ9c,13t, respectively. The results showed that 18∶2n−6 at about 2.0% of total energy in maternal diet was required to block the production of 20∶4Δ5c,8c,11c,14t and 20∶4Δ5c,8c,11c,15t in the maternal liver, whereas 18∶2n−6 at about 2.5% of total energy in maternal diet was required to suppress production of these unusual 20∶4 isomers in the neonatal liver.
Effects of dietary marine oils and olive oil on fatty acid composition, platelet membrane fluidity, platelet responses, and serum lipids in healthy humans
Authors: Vognild Eva , Elvevoll Edel O. , Brox Jan , Olsen Ragnar L. , Barstad Harald , Aursand Marit , Østerud Bjarne 
Published: November 2006

AbstractThe influence of various dietary marine oils and olive oil on fatty acid composition of serum and platelets and effects on platelets and serum lipids were investigated as part of an extensive study of the effects of these oils on parameters associated with cardiovascular/thrombotic diseases. Healthy volunteers (266) consumed 15 mL/d of cod liver oil (CLO); whale blubber oil (refined or unrefined); mixtures of seal blubber oil and CLO; or olive oil/CLO for 12 wk. In the CLO, seal oil/CLO, and whale oil groups, serum levels of eicosapentaenoic acid (EPA) were increased. In platelets, EPA was increased in the CLO, seal/CLO, and olive oil/CLO groups. The localization of n‐3 polyunsaturated fatty acids in the triacylglycerols did not seem to influence their absorption. Intake of oleic acid is poorly reflected in serum and platelets. No significant differences in triacylglycerols (IG), total cholesterol, or high density lipoprotein cholesterol were observed, even though TG were reduced in the CLO, CLO/seal oil, and whale oil groups. Mean platelet volume increased significantly in both whale oil groups and the CLO/olive oil group. Platelet count was significantly reduced in the refined whale oil group only. Lipopolysaccharide‐stimulated blood tended to generate less thromboxane B2 in CLO, CLO/seal, and CLO/olive groups. The whale oils tended to reduce in vivo release of β‐thromboglobulin. In conclusion, intake of various marine oils causes changes in platelet membranes that are favorably antithrombotic. The combination of CLO and olive oil may produce better effects than these oils given separately. The changes in platelet function are directly associated with alterations of fatty acid composition in platelet membranes.
Contribution of meat fat to dietary arachidonic acid
Authors: Li Duo , Ng Alice , Mann Neil J. , Sinclair Andrew J. 
Published: November 2006

AbstractArachidonic acid (AA) in the diet can be efficiently absorbed and incorporated into tissue membranes, resulting in an increased production of thromboxane A2 by platelets and increased ex vivo platelet aggregability. Results from previous studies have shown that AA is concentrated in the membrane phospholipids of lean meats. However, the concentration of AA in the visible fat portion of meats also may be significant despite being ignored in most studies. The aim of this study was to accurately quantitate the AA content of visible fat and the lean portion of beef, lamb, pork, chicken, duck, and turkey. The visible fat of meat contained a significant quantity of AA, ranging from 20 to 180 mg/100 g fat, whereas the AA content of the lean portion of meat was lower, ranging from 30 to 99 mg/100 g lean meat. Beef and lamb meats contained lower levels of AA in both the visible fat and lean portion than that from the other species. The highest level of AA in lean meat was in duck (99 mg/100 g), whereas pork fat had the highest concentration for the visible fats (180 mg/100 g). The lean portions of beef and lamb contained the higher levels of n‐3 polyunsaturated fatty acids (PUFA) compared with white meats which were high in AA and low in n‐3 PUFA. The present data indicate that the visible meat fat can make a contribution to dietary intake of AA, particularly for consumers with high intakes of fat from pork or poultry meat.
Effects of caffeine on lipoprotein lipase gene expression during the adipocyte differentiation process
Authors: Couturier Cyril , Janyier Brigitte , Girlich Delphine , Béréziat Gilbert , Andréani‐Mangeney Marise 
Published: November 2006

AbstractIn this study, the effects of caffeine on lipoprotein lipase (LPL) gene expression were investigated in the 3T3‐F442A preadipocyte cell line during the adipocyte differentiation process by determining LPL enzymatic activity and its messenger RNA (mRNA) level. The results demonstrate that caffeine acts on the gene expression of LPL, an early marker of adipocyte differentiation. It has a biphasic action: it increases gene expression in terms of mRNA when it is added to preadipocytes during the early stage of differentiation, but this is accompanied by a reduction of enzymatic activity. On the other hand, when caffeine is added for long periods during differentiation and/or when it is added to mature adipocytes, it induces marked inhibition of mRNA levels, correlated with a marked reduction of secreted enzymatic activity. The inhibitory effect of caffeine on LPL mRNA level can be reproduced by theophylline, a phosphodiesterase inhibitor, and by dibutyryl cyclic AMP, a non‐metabolizable analog of cyclic AMP. However, the effect of caffeine and theophylline lasts longer than that of cyclic AMP, suggesting that a mechanism other than inhibition of cyclic AMP hydrolysis may be involved in the action of caffeine.