bluuebunny/crossref_metadata_2025_split huggingface dataset:
A new concept of cellular uptake and intracellular trafficking of long‐chain fatty acids
Authors: Stremmel Wolfgang , Pohl Jürgen , Ring Axel , Herrmann Thomas 
Published: November 2006

AbstractFatty acids are the main structural and energy sources of the human body. Within the organism, they are presented to cells as fatty acid: albumin complexes. Dissociation from albumin represents the first step of the cellular uptake process, involving membrane proteins with high affinity for fatty acids, e.g., fatty acid translocase (FAT/CD 36) or the membrane fatty acid‐binding protein (FABPpm). According to the thus created transmembrane concentration gradient, uncharged fatty acids can flip‐flop from the outer leaflet across the phospholipid bilayer. At the cytosolic surface of the plasma membrane, fatty acids can associate with the cytosolic FABP (FABPc) or with caveolin‐1. Caveolins are constituents of caveolae, which are proposed to serve as lipid delivery vehicles for subcellular organelles. It is not known whether protein (FABPc)‐ and lipid (caveolae)‐mediated intracellular trafficking of fatty acids operates in conjunction, or in parallel. Channeling fatty acids to the different metabolic pathways requires activation to acyl‐CoA. For this process, the family of fatty acid transport proteins (FATP 1‐5/6) might be relevant because they have been shown to possess acyl‐CoA synthetase activity. Their variable N‐terminal signaling sequences suggest that they might be targeted to specific organelles by anchoring in the phospholipid bilayer of the different subcellular membranes. At the highly conserved cytosolic AMP‐binding site of FATP, fatty acids are activated to acyl‐CoA for subsequent metabolic disposition by specific organelles. Overall, fatty acid uptake represents a continuous flow involving the following: dissociation from albumin by membrane proteins with high affinity for fatty acids; passive flip‐flop across the phospholipid bilayer; binding to FABPc and caveolin‐1 at the cytosolic plasma membrane; and intracellular trafficking via FABPc and/or caveolae to sites of metabolic disposition. The uptake process is terminated after activation to acyl‐CoA by the members of the FATP family targeted intracellularly to different organelles.
Polyunsaturated fatty acids and T‐cell function: Implications for the neonate
Authors: Field Catherine J. , Clandinin M. Thomas , Van Aerde John E. 
Published: November 2006

AbstractInfant survival depends on the ability to respond effectively and appropriately to environmental challenges. Infants are born with a degree of immunological immaturity that renders them susceptible to infection and abnormal dietary responses (allergies). T‐lymphocyte function is poorly developed at birth. The reduced ability of infants to respond to mitogens may be the result, of the low number of CD45RO+ (memory/antigen‐primed). T cells in the infant or the limited ability to produce cytokines [particularly interferon‐γ, interleukin (IL)‐4, and IL‐10]. There have been many important changes in optimizing breast milk substitutes for infants; however, few have been directed at replacing factors in breast milk that convey immune benefits. Recent research has been directed at the neurological, retinal, and membrane benefits of adding 20∶4n−6 (arachidonic acid; AA) and 22∶6n−3 (docosahexaenoic acid; DHA) to infant formula. In addults and animals, feeding DHA affects T‐cell function. However, the effect of these lipids on the development and function of the infant's immune system is not known. We recently reported the effect of adding DHA+AA to a standard infant formula on several functional indices of immune development. Compared with standard formula, feeding a formula containing DHA+AA increased the proporition of antigen mature (CD45RO+) CD4+ cells, improved IL‐10 production, and reduced IL‐2 production to levels not different from those of human milk‐fed infants. This review will briefly describe T‐cell development and the potential immune effect of feeding long‐chain polyunsaturated fatty acids to the neonate.
Polyunsaturated n−3 fatty acids and the development of atopic disease
Authors: Duchén Karel , Björkstén Bengt 
Published: November 2006

AbstractThe relationship between polyunsaturated long‐chain fatty acids and atopy has been discussed for decades. Higher levels of the essential fatty acids linoleic acid and α‐linolenic acid and lower levels of their longer metabolites in plasma phospholipids of atopic as compared to nonatopic individuals have been reported by several, but not all, studies. Largely similar findings have been reported in studies of cell membranes from immunological cells from atopics and nonatopics despite differences in methodology, study groups, and definitions of atopy. An imbalance in the metabolism of the n−6 fatty acids, particularly arachidonic acid and dihomo‐γ‐linolenic acid, leading to an inappropriate synthesis of prostaglandin (PG) E2 and PGE1 was hypothesized early on but has not been corroborated. The fatty acid composition of human milk is dependent on the time of lactation not only during a breast meal but also the time of the day and the period of lactation. This explains the discrepancies in reported findings regarding the relationship between milk fatty acids and atopic disease in the mother. Prospective studies show disturbances in both the n−6 and n−3 fatty acid composition between milk from atopic and nonatopic mothers. Only the composition of long‐chain polyunsaturated n−3 fatty acids was related to atopic development in the children, however. A relationship between lower levels of n−3 fatty acids, particularly eicosapentaenoic acid (20∶5 n−3), and early development of atopic disease is hypothesized.
The role of polyunsaturated fatty acid supplementation in intestinal inflammation and neonatal necrotizing enterocolitis
Authors: Caplan Michael S. , Jilling Tamas 
Published: November 2006

AbstractDietary polyunsaturated fatty acid (PUFA) supplementation has been shown to reduce the incidence of necrotizing enterocolitis (NEC) in a recent randomized, controlled trial. These compounds are known to modulate the inflammatory cascade and to influence intestinal health in a variety of ways. Although the pathophysiology of NEC is not well understood, recent evidence suggests that platelet‐activating factor (PAF) is a key endogenous mediator of intestinal necrosis in animals. Using a neonatal rat model of NEC that includes the key risk factors of asphyxia and formula feeding, we investigated the role of dietary PUFA supplementation on the incidence and pathophysiology of NEC. Our findings suggest that PUFA reduce the incidence of NEC by modulating PAF metabolism and endotoxin translocation.
Changes in the chemical composition of surfactant‐like particles secreted by rat small intestine in response to different dietary fats
Authors: Kalra Seema , Mahmood Safrun , Nagpaul J. P. , Mahmood Akhtar 
Published: November 2006

AbstractConsumption of dietary oil, viz., corn, fish, coconut, or olive, induced the secretion of surfactant‐like particles (SLP) in rat intestine. These lipoprotein particles differ in (i) levels of alkaline phosphatase activity, (ii) lipid composition, and (iii) FA composition in response to feeding of different oils. The secreted particles had similar buoyancy (1.07–1.08 g/mL) and cholesterol/phospholipid molar ratios (0.61–0.72) except that feeding coconut oil to rats produced SLP with a low (0.18) cholesterol/phospholipid molar ratio compared to control animals. It is concluded from these observations that feeding different oils induces the secretion of lipoprotein particles in rat intestine with different chemical compositions.
Albumin stimulates lysophosphatidic acid acyltransferase activity in T‐lymphocyte membranes
Authors: Jolly Christopher A. , Kannan Latha 
Published: November 2006

AbstractPhosphatidic acid (PtdOH) and lysophosphatidic acid (lysoPtdOH) have been shown to enhance T‐lymphocyte function. However, the FA preference and influence of acyl‐CoA binding proteins on lysoPtdOH and PtdOH biosynthesis are not known. Therefore, we determined glycerol‐3‐phosphate acyltransferase (GPAT) and lysophosphatidic acid acyltransferase (LAT) activity in rat T‐lymphocyte and liver membrane preparations in the presence of palmitoyl‐CoA and oleoyl‐CoA with or without BSA. We found two different properties of GPAT and LAT in whole T‐lymphocyte membrane preparations relative to liver. First, T‐lymphocyte basal GPAT and LAT activities were similar, whereas in liver membranes LAT activity was 10‐fold higher than GPAT. Second, T‐lymphocyte LAT, but not GPAT, activity was inducible (fivefold) by the addition of albumin in the presence of palmitoyl‐CoA but not oleoyl‐CoA. In contrast, albumin stimulated GPAT, but not LAT, activity in liver membranes in the presence of palmitoyl‐CoA. These results show, for the first time, that T‐lymphocyte LAT activity can be increased by the presence of an acyl‐CoA binding protein, which may indicate a new important control mechanism for regulating intracellular lysoPtdOH and PtdOH levels in T‐lymphocytes.
Analysis of vitamin E and its oxidation products by HPLC with electrochemical detection
Authors: Yamauchi Ryo , Noro Hiroki , Shimoyamada Makoto , Kato Koji 
Published: November 2006

AbstractA sensitive HPLC procedure with postcolumn reduction and electrochemical detection was developed for the analysis of vitamin E and its oxidation products, α‐tocopherylquinone, epoxy‐α‐tocopherylquinones, and 8a‐(lipid‐dioxy)‐α‐tocopherones. After the separation on a reversed‐phase column, on‐line zinc‐catalyzed reduction allowed the detection of α‐tocopherylquinone and epoxy‐α‐tocopheryl‐quinones, whereas platinum‐catalyzed reduction allowed the detection of 8a‐(lipid‐dioxy)‐α‐tocopherones. The lowest detectable level of each compound was about 0.2 pmol at the signal‐to‐noise ratio of 3. This method was applied to the detection of α‐tocopherol products in peroxidized human plasma. When the plasma was peroxidized by the addition of a free radical initiator, peaks corresponding to α‐tocopherylquinone, epoxy‐α‐tocopherylquinones, and the addition products of α‐tocopherol with peroxyl radicals derived from cholesteryl ester hydroperoxides and PC hydroperoxides were observed. The amount of these oxidation products in the plasma increased with the depletion of endogenous α‐tocopherol. The results indicate that the method is useful to detect the oxidation products formed by the peroxyl radical‐trapping reactions of α‐tocopherol in biological systems.
Differences in Δ9 desaturase activity between jersey‐and limousin‐sired cattle
Authors: Siebert B. D. , Pitchford W. S. , Kruk Z. A. , Kuchel H. , Deland M. P. B. , Bottema C. D. K. 
Published: November 2006

AbstractAn experiment examined Δ9 desaturase activity and FA composition in subcutaneous adipose tissue in two differing breeds of cattle. Jersey‐sired cattle had significantly higher rates of desaturase activity than Limousin‐sired cattle (1.55 vs. 0.75 nmol/mg protein/min). This difference was also demonstrated by a lower concentration of individual (e.g. 18∶0) and total saturated FA (38.3 vs. 45.1 wt%), and a higher concentration of individual (e.g., 16∶1) and total monounsaturated FA (58.2 vs. 52.7 wt%) in the Jersey animals. Other indices of desaturation calculated from the FA composition showed this same difference. The slip point of adipose tissue of Jersey cattle (36.8°C) was significantly lower than that of Limousin cattle (39.2°C), but Jersey adipose tissue had a greater content of β‐carotene. The positive relationship between adipose tissue β‐carotene and desaturation opposes the negative relationship between dietary β‐carotene and desaturation determined elsewhere. These results, however, lead to the hypothesis that some cattle have a reduced capacity to metabolize β‐carotene to various forms of vitamin A, a compound that can reduce Δ9 desaturase enzyme activity. In addition, the higher level of intramuscular fat in Jersey cattle (6.97 vs. 3.82%) is possibly related to a lack of inhibition of the adipocyte differentiation genes by vitamin A.
Development of intestinal alkaline sphingomyelinase in rat fetus and newborn rat
Authors: Lillienau Jan , Cheng Yajun , Nilsson Åke , Duan Rui‐Dong 
Published: November 2006

AbstractSphingomyelin metabolism is a novel signal transduction pathway related to cell differentiation, proliferation, and apoptosis. Alkaline sphingomyelinase (alk‐SMase) is specifically present in the intestinal tract of many species. The enzyme is important in digestion of dietary sphingomyelin. Milk is the ony exogenous source of sphingomyelin for an infant, and digestion of milk sphingomyelin may be important for development of intestinal mucosa. It is unknown whether alk‐SMase is present before birth and whether it changes after birth and during the suckling period. We studied activities, expression, and distribution of alk‐SMase in rat fetus and newborn. The changes of acid and neutral SMase as well as alkaline phosphatase were analyzed for comparison. Little activity of alk‐SMase was identified up to gestation day 20, but increased 10 times during the following 2 d. After birth, the activity continused to increase during the following 4 wk. Western blot using IgY antibody against rat alk‐SMase failed to identify the enzyme at gestation day 20 but clearly showed the protein at day 22. The distribution pattern of the enzyme along the intestinal tract in fetus was largely the same as in adult animals, but became more pronounced after birth. Short‐term weaning had no effect on alk‐SMase activity. The activities of acid and neutral SMase were high at gestation day 20 and decreased significantly before birth. The changes of alk‐SMase also differed from those of alkaline phosphatase, another brush border enzyme. Thus, we conclude that alk‐SMase is rapidly expressed during the last days of gestation and that the newborn rat acquires the ability to digest milk sphingomyelin early in life.
Occurrence of a novel cis,cis,cis‐octadeca‐3,9,12‐trienoic (Z,Z,Z‐octadeca‐3,9,12‐trienoic) acid in Chrysanthemum (Tanacetum) zawadskii herb. (Compositae) seed oil
Authors: Tsevegsuren Nanzad , Fujimoto Kenshiro , Christie William W. , Endo Yasushi 
Published: November 2006

AbstractA new octadecatrienoic acid (6.9%), found as a component of Chrysanthemum zawadskii Herb. (Asteraceae) seed oil, was shown to be the hitherto unknown cis,cis,cis‐octadeca‐3,9,12‐trienoic acid. The oil also contained 8.6% of crepenynic acid in addition to the other common FA. The structures of the new unusual FA and other FA were confirmed by chromatographic (TLC, GC), spectroscopic (IR, UV, and NMR), and MS methods by using different chemical derivatizations (preparation of methyl ester, pyrrolidide, picolinyl esters, and dimethyloxazoline derivatives).
Quantitative characterization of phospholipids in milk fat via31P NMR using a monophasic solvent mixture
Authors: Murgia Sergio , Mele Stefania , Monduzzi Maura 
Published: November 2006

AbstractThe phospholipids (PL) occurring in both ewe and cow milk fat globule membrane were identified and quantitatively determined using 31P NMR spectroscopy with inverse gated decoupled sequences, which allowed a rigorous quantitative analysis. A strict relation between amount and distribution of PL and type of feeding was found. The method was calibrated over a mixture of PL standards. A recently introduced solvent constituted by a monophasic dimethylformamide/triethylamine/guanidinium hydrochloride solvent mixture was used. Compared to the traditional chloroform/methanol/water‐EDTA solvent, the new solvent mixture shows very similar accuracy and precision from a quantitative point of view. The monophasic solvent overcomes the partition problems related to a biphasic system, and slightly enlarges the range of 31P NMR chemical shifts, thus improving the resolution. In addition, the new solvent apparently displays a lower chemical shift dependence on the various PL concentrations. The limit of the method is mainly determined by the formation of adducts between triethylamine and some PL, namely, PE, monomethylphosphati‐dylethanolamine, phosphatidylethanolamine plasmalogens, and some lyso‐PL. However, the new 31P NMR signals arising from these adducts could be easily quantified in the determination of PE.
n−3 fatty acid enrichment of edible tissue of poultry: A review
Authors: Rymer C. , Givens D. I. 
Published: November 2006

AbstractThere is clear evidence of the nutritional benefits of consuming long‐chain n−3 PUFA, which are found predominantly in oily fish. However, oily fish consumption, particularly in the United Kingdom, is declining, as is the consumption of all meats with the exception of poultry, which has increased in consumption by 73% in the last 30 yr. This pattern, if less marked, is reflected throughout Europe, and therefore one means of increasing long‐chain n−3 PUFA consumption would be to increase the long‐chain n−3 PUFA content in the edible tissues of poultry. This review considers the feasibility of doing this, concentrating particularly on chickens and turkeys. It begins by summarizing the benefits to human health of consuming greater quantities of n−3 FA and the sources of n−3 PUFA in the human diet. The literature on altering the FA composition of poultry meat is then reviewed, and the factors affecting the incorporation of n−3 PUFA into edible tissues of poultry are investigated. The concentration of α‐linolenic acid (ALA) in the edible tissues of poultry is readily increased by increasing the concentration of ALA in the birds' diet (particularly meat with skin, and dark meat to a greater extent than white meat). The concentration of EPA in both white and dark meat is also increased when the birds' diet is supplemented with EPA, although supplementing the diet with the precursor (ALA) does not result in a noticeable increase in EPA content in the edible tissues. Although supplementing the birds' diets with relatively high concentrations of DHA does result in an increased concentration of DHA in the tissues, the relationship between dietary and tissue concentrations of DHA is much weaker than that observed with ALA and EPA. The impact that altering the FA composition of edible poultry tissue may have on the organoleptic and storage qualities of poultry products is also considered.
Triacylglycerol oxidation in pig lipoproteins after a diet rich in oxidized sunflower seed oil
Authors: Suomela Jukka‐Pekka , Ahotupa Markku , Kallio Heikki 
Published: November 2006

AbstractThe effects of two sunflower seed oil diets differing in oxidation levels (PV in oils 1 and 190 mequiv O2/kg) on lipoprotein TAG and total lipid oxidation were investigated in growing pigs. For 2 wk, two groups of 10 pigs were fed either of the diets, after which blood samples were collected. A method based on RP‐HPLC and electrospray ionization‐MS was used for the analysis of oxidized TAG molecules in chylomicrons and VLDL. The baseline diene conjugation method was used for the estimation of in vivo levels of lipoprotein lipid oxidation. TAG molecules with a hydroxy, an epoxy, or a keto group attached to a FA, as well as TAG core aldehydes were detected in the samples. Typically, lipoprotein TAG and total lipids were more oxidized in the pigs fed on the oxidized oil compared with those fed on nonoxidized oil. Oxidation of dietary fat was thus reflected in the lipoprotein oxidation, which confirmed our earlier findings.
Dietary fatty acids regulate cholesterol induction of liver CYP7α1 expression and bile acid production
Authors: Li Yan , Hou Meng Jun , Ma Jing , Tang Zhi Hong , Zhu Hui Lian , Ling Wen Hua 
Published: November 2006

AbstractIn the present study we investigated the effects of dietary fats containing predominantly PUFA, monounsaturated FA (MUFA), or saturated FA (SFA) on lipid profile and liver cholesterol 7α‐hydroxylase (CYP7α1) mRNA expression and bile acid production in C57BL/6J mice. The animals (n=75) were randomly divided into five groups and fed a basic chow diet (AIN‐93G) (BC diet), a chow diet with 1g/100g of cholesterol (Chol diet), a chow diet with 1g/100g of cholesterol and 14g/100g of safflower oil (Chol+PUFA diet), a chow diet with 1g/100g of cholesterol and olive oil (Chol+MUFA diet), or a chow diet with 1g/100g of cholesterol and myristic acid (Chol+SFA diet) for 6 wk. The results showed that the Chol+SFA diet decreased CYP7α1 gene expression and bile acid pool size, resulting in increased blood and liver cholesterol levels. Addition of PUFA and MUFA to a 1% cholesterol diet increased the bile acid pool production or bile acid excretion and simultaneously decreased liver cholesterol accumulation despite decreased CYP7α1 mRNA expression. The results indicate that the decreased bile acid pool size induced by the SFA diet is related to inhibition of the liver CYP7α1 gene expression, but an increased bile acid pool size and improved cholesterol homeostasis are disassociated from the liver CYP7α1 gene expression.
Regulation of palmitoyl‐CoA chain elongation by clofibric acid in the liver of Zucker fa/fa rats
Authors: Toyama Tomoaki , Kudo Naomi , Mitsumoto Atsushi , Kawashima Yoichi 
Published: November 2006

AbstractThe regulation of palmitoyl‐CoA chain elongation (PCE) by clofibric acid [2‐(4‐chlorophenoxy)‐2‐methylpropionic acid] was investigated in comparison with stearoyl‐CoA desaturase (SCD) in the liver of obese Zucker fa/fa rats. The proportion of oleic acid in the hepatic lipids of Zucker obese rats is 2.7 times higher than that of lean littermates. The activities of PCE and SCD in the liver of Zucker obese rats were markedly higher than in lean rats, and the hepatic uptake of 2‐deoxyglucose (2‐DG) was also higher in Zucker obese rats compared with lean rats. The increased activities of SCD and PCE in Zucker obese rats were due to the enhanced expression of mRNA of rELO1. The proportion of oleic acid in the liver was significantly increased by the administration of clofibric acid to Zucker obese rats, and the hepatic PCE activity and rELO2 mRNA expression, but not the SCD activity or SCD1 mRNA expression, were increased in response to clofibric acid treatment. By contrast, the activities of both PCE and SCD and the mRNA expression of SCD1 and rELO2 in the liver were increased by the treatment of Zucker lean rats with clofibric acid. Multiple regression analysis, which was performed to determine the relationships involving PCE activity, SCD activity, and the proportion of oleic acid, revealed that the three parameters were significantly correlated and that the standardized partial regression coefficient of PCE was higher than that of SCD. These results indicate that oleic acid is synthesized by the concerted action of PCE and SCD and that PCE plays a crucial role in the formation of oleic acid when Zucker fa/fa rats are given clofibric acid.