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PubMed2006

Adiponectin, adipocyte fatty acid binding protein, and epidermal fatty acid binding protein: proteins newly identified in human breast milk.

BACKGROUND: Breastfeeding may protect children from developing metabolic syndrome and other diseases later in life. We investigated novel proteins in human breast milk that might play a role in this process. METHODS: We used ELISA to measure adiponectin, adipocyte and epidermal fatty acid binding proteins (AFABP, EFABP), and leptin concentrations in human breast milk obtained from 59 mothers 48 h after initiation of lactation. Using a questionnaire and medical records, we collected information about the mothers and newborns. RESULTS: Mean (SE) adiponectin concentrations in breast milk were 13.7 (0.8), range 3.9-30.4 microg/L; AFABP concentrations 26.7 (4.4), range 1.2-137.0 microg/L; EFABP concentrations 18.1 (1.4), range 0.8-47.0 microg/L; and leptin concentrations 0.50 (0.05), range 0-1.37 microg/L. We found a significant correlation between AFABP and EFABP concentrations (r = 0.593, P <0.0001). Maternal EFABP concentrations were significantly higher in mothers who delivered boys than in those who delivered girls [21.7 (2.3) vs 15.4 (1.7) microg/L, P = 0.028] and correlated with newborn birth weight (r = 0.266, P = 0.045). Maternal leptin correlated with body weight before pregnancy (r = 0.272, P = 0.043) and at delivery (r = 0.370, P = 0.005), body mass index before pregnancy (r = 0.397, P = 0.003) and at delivery (r = 0.498, P <0.0001), body weight gain during pregnancy (r = 0.267, P = 0.047), and newborn gestational age (r = 0.266, P = 0.048). Leptin was significantly lower in mothers who delivered preterm vs term babies [0.30 (0.09) vs 0.60 (0.05) ug/L, P = 0.026]. CONCLUSIONS: Concentrations of adiponectin, AFABP, and EFABP in human breast milk are related to nutritional variables of mothers and newborns and thus may play a role in the protective effects of breastfeeding.

Adipocytes↗
PubMed1992

Developmental changes in the fatty acids of rat uterus and the influence of dietary essential fatty acids.

The effect of age on uterine fatty acid composition was studied in rats fed diets of differing fatty acid composition. Uteri of newly weaned 23-day rats had a higher fatty acid content and a higher proportion of short-chain (less than or equal to C18) fatty acids. Higher incorporation of C less than or equal to 18 fatty acids into neutral lipid (NL) and phospholipid (PL) of young 42-day rats compared with adult 240-day rats was detected. Uterine NL incorporated predominantly C less than or equal to 18 fatty acids which may be an important metabolic energy store in developing uterine tissue. Incorporation of C less than or equal to 18 fatty acids by uterine PL and NL was relatively unselective. In contrast, there was selective retention of arachidonic acid (AA) and docosahexanoic acid (DHA) throughout uterine development. An effect of dietary EFA on uterine n-3 and n-6 EFA was detected in each age group. There was marked retention of uterine AA when dietary supplies of n-6 EFA were low, but the total AA, eicosapentaenoic acid (EPA) and DHA in uterine PL remained constant in the three diet groups, and a constant content of AA, EPA and DHA was maintained throughout uterine development, regardless of diet. The degree of n-3 substitution achieved in this study inhibited uterine release of PG and parturition in adult rats.

Aging↗
PubMed1995

Maternal essential fatty acid patterns during normal pregnancy and their relationship to the neonatal essential fatty acid status.

Although essential fatty acids (EFA) and their longer chain, more unsaturated derivatives play a major role during pregnancy, hardly any information is available with respect to the course of the maternal EFA status during an uncomplicated pregnancy and its relationship to the neonatal EFA status. Therefore, a longitudinal study was started in which 110 pregnant women gave repeated blood samples from the 10th week of gestation until delivery. After birth a blood sample from the umbilical vein and a maternal venous blood sample were collected as well, and 6 months after delivery a final blood sample from the mother was taken. The absolute (mg/l) and relative (% total fatty acids) amounts of the fatty acids in plasma phospholipids were determined. The total amounts of fatty acids increased significantly during pregnancy. This pattern was similar for the individual fatty acids and fatty acid families. The relative amount of linoleic acid (18:2n-6) did not change during pregnancy, whereas the relative amount of arachidonic acid (20:4n-6) decreased. Despite maternal mobilization of docosahexaenoic acid (22:6n-3, DHA), suggested by a temporary increase in the DHA status until 18 weeks gestation, the DHA status steadily declined thereafter. This pattern was associated with a progressive increase in the DHA deficiency index in maternal blood throughout pregnancy and resulted in a sub-optimal neonatal DHA status. The overall maternal EFA status also declined steadily during pregnancy. Therefore, the question arises whether the mother, under the prevailing dietary conditions, is able to meet the high fetal requirement for EFA.

Adult↗
PubMed1987

Interaction of (n-3) and (n-6) fatty acids in desaturation and chain elongation of essential fatty acids in cultured glioma cells.

Recent research in various biological systems has revived interest in interactions between the (n-6) and (n-3) essential fatty acids. We have utilized cultured glioma cells to show that linolenic acid, 18:3(n-3), is rapidly desaturated and chain elongated; 20:5(n-3) is the major product and accumulates almost exclusively in phospholipids. We examined effects of various (n-6), (n-3), (n-9) and (n-7) fatty acids at 40 microM concentration on desaturation and chain elongation processes using [1-14C]18:3(n-3) as substrate. In general, monoenoic fatty acids were without effect. The (n-6) fatty acids (18:2, 18:3, 20:3, 20:4 and 22:4) had little effect on total product formed. There was a shift of labeled product to triacylglycerol, and in phospholipids, slightly enhanced conversion of 20:5 to 22:5 was evident. In contrast, 22:6(n-3) was inhibitory, whereas 20:3(n-3) and 20:5(n-3) had much less effect. At concentrations less than 75 microM, all acids were inhibitory. Most products were esterified to phosphatidylcholine, but phosphatidylethanolamine also contained a major portion of 20:5 and 22:5. We provide a condensed overview of how the (n-6) and (n-3) fatty acids interact to modify relative rates of desaturation and chain elongation, depending on the essential fatty acid precursor. Thus, the balance between these dietary acids can markedly influence enzymes providing crucial membrane components and substrates for biologically active oxygenated derivatives.

Animals↗
PubMed1994

Lymphatic absorption of n - 3 polyunsaturated fatty acids from marine oils with different intramolecular fatty acid distributions.

Male Wistar rats were given 0.5 ml of either fish oil or seal oil intragastrically. The intramolecular fatty acid distributions of the triacylglycerols administered were determined by non-specific Grignard degradation followed by isolation and analysis of the 2-monoacylglycerols. The n - 3 polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (20:5(n - 3)) and docosahexaenoic acid (22:6(n - 3)), were located in outer positions (sn-1/3) in the seal oil triacylglycerols whereas the sn-2 position of fish oil triacylglycerols was enriched in 20:5(n - 3) and 22:6(n - 3). The mesenteric lymph was collected over the following 24 h and the absorption patterns of n-3 PUFAs were determined. In the lymph, the n - 3 fatty acids characteristic of the marine oils rapidly increased both with regard to mole percentage and transport (micrograms/min). There were, however, no overall significant differences in the absorption patterns over a 24 h period. The ratio between mole percentage in the oil and mole percentage in the lymph calculated at the steady-state period was significantly greater for both 20:5(n - 3) and 22:6(n - 3) following fish oil administration compared with seal oil. Initially, the recovery of n - 3 PUFAs as a percentage of the total amount transported over the experimental period was higher following injection of fish oil than seal oil but seal oil resulted in greater recovery in the last two fractions at 8 and 24 h post injection, respectively. This indicated that n - 3 PUFAs from fish oil may have been better absorbed in the initial period of digestion but overall the structure of dietary triacylglycerols had negligible effects on the assimilation of n - 3 PUFAs when these were administered as native marine oils.

Animals↗
PubMed1997

Human fatty acid synthase: assembling recombinant halves of the fatty acid synthase subunit protein reconstitutes enzyme activity.

Our model of the native fatty acid synthase (FAS) depicts it as a dimer of two identical multifunctional proteins (Mr approximately 272,000) arranged in an antiparallel configuration so that the active Cys-SH of the beta-ketoacyl synthase of one subunit (where the acyl group is attached) is juxtaposed within 2 A of the pantetheinyl-SH of the second subunit (where the malonyl group is bound). This arrangement generates two active centers for fatty acid synthesis and predicts that if we have two appropriate halves of the monomer, we should be able to reconstitute an active fatty acid-synthesizing site. We cloned, expressed, and purified catalytically active thioredoxin (TRX) fusion proteins of the NH2-terminal half of the human FAS subunit protein (TRX-hFAS-dI; residues 1-1,297; Mr approximately 166) and of the C-terminal half (TRX-hFAS-dII-III; residues 1,296-2,504; Mr approximately 155). Adding equivalent amounts of TRX-hFAS-dI and TRX-hFAS-dII-III to a reaction mixture containing acetyl-CoA, malonyl-CoA, and NADPH resulted in the synthesis of long-chain fatty acids. The rate of synthesis was dependent upon the presence of both recombinant proteins and reached a constant level when they were present in equivalent amounts, indicating that the reconstitution of an active fatty acid-synthesizing site required the presence of every partial activity associated with the subunit protein. Analyses of the product acids revealed myristate to be the most abundant with small amounts of palmitate and stearate, possibly because of the way the fused recombinant proteins interacted with each other so that the thioesterase hydrolyzed the acyl group in its myristoyl state. The successful reconstitution of the human FAS activity from its domain I and domains II and III fully supports our model for the structure-function relationship of FAS in animal tissues.

Enzyme Activation↗
PubMed2005

The effect of bio-converted polyunsaturated fatty acids on the oxidation of TAG containing highly unsaturated fatty acids.

Microbial modification of vegetable fatty acids can often lead to special changes in their structure and in biological function. A bacterial strain, Pseudomonas aeruginosa PR3, is known to carry out multiple hydroxylations on polyunsaturated fatty acids containing 1,4-cis, cis diene structural units, resulting in antibacterial activity. In this paper, in an effort to understand the overall mechanism involved in the varied biological functions of the complicated metabolites of bio-converted polyunsaturated fatty acids, we performed bioconversion of several polyunsaturated fatty acids using PR3, and determined their oxidative activities against fish oil. Bio-converted linoleic acid, eicosapentanoic acid, and docosahexanoic acid promoted effectively oxidation of fish oil. It is assumed that this oxidative effect could plausibly play an important role in the antimicrobial function of these bio-converted fatty acids.

Fatty Acids, Unsaturated↗
PubMed2006

Chemical C2-elongation of polyunsaturated fatty acids.

Three fatty acids were synthesized from commercially available alpha-linolenic, stearidonic and eicosapentaenoic acids by C2-elongation using a four step preparative technique. The parent fatty acid methyl esters were reduced to alcohols with LiAlH(4), converted to bromides by treatment with triphenylphosphine dibromide, coupled with a lithiated C2-elongation block--2,4,4-trimethyl-2-oxazoline--to form the corresponding 2,2-dimethyloxazolines of C2-elongated fatty acids, and finally, converted to the target polyunsaturated fatty acids by acidic alcoholysis. Yields of more than 60% were achieved on a gram scale. The resulting 11Z,14Z,17Z-eicosatrienoic, 8Z,11Z,14Z,17Z-eicosatetraenoic and 7Z,10Z,13Z,16Z,19Z-docosapentaenoic acids were obtained as colorless oils with >98% purity and could be used for biochemical investigations without additional purification. The elongated fatty acids were free of byproducts that could result from Z-E isomerization or migration of double bonds.

1-Propanol↗
PubMed1981

Effect of exogenous fatty acids on growth, membrane fluidity, and phospholipid fatty acid composition in yeast.

The growth response of a double-mutant fatty acid auxotroph of yeast Saccharomyces cerevisiae to exogenous saturated fatty acids of a homologous series from 12:0 to 16:0, each supplied with oleate, linoleate, linolenate, or cis-delta 11-eicosenoate, cannot be explained in terms of the efficiency of incorporation of the fatty acids into phospholipids or alteration of membrane fluidity. There is, however, a negative correlation between growth and levels of 12:0 plus 13:0 in phospholipids, as well as a positive correlation between growth and levels of 14:0, 15:0, and 16:0. We, therefore, conclude that the predominant factor in these phospholipid fatty acyl chain modifications is maintenance of an optimal concentration of C14:0 through C16:0 in phospholipids of this organism.

Electron Spin Resonance Spectroscopy↗
PubMed2000

Effects of dietary conjugated linoleic acid and linoleic:linolenic acid ratio on polyunsaturated fatty acid status in laying hens.

A study was conducted to determine the effects of dietary conjugated linoleic acid (CLA) and the ratio of linoleic:linolenic acid on long-chain polyunsaturated fatty acid status. Thirty-two 31-wk-old White Leghorn hens were randomly assigned to four diets containing 8.2% soy oil, 4.1% soy oil + 2.5% CLA (4.1% CLA source), 4.1% flax oil + 2.5% CLA, or 4.1% soy oil + 4.1% flax oil. Hens were fed the diets for 3 wk before eggs and tissues were collected for the study. Lipids were extracted from egg yolk and tissues, classes of egg yolk lipids were separated, and fatty acid concentrations of total lipids, triglyceride, phosphatidylethanolamine, and phosphatidylcholine were analyzed by gas chromatography. The concentrations of monounsaturated fatty acids and non-CLA polyunsaturated fatty acids were reduced after CLA feeding. The amount of arachidonic acid was decreased after CLA feeding in linoleic acid- and linolenic acid-rich diets, but amounts of eicosapentaenoic acid and docosahexaenoic acid were increased in the linolenic-rich diet, indicating that the synthesis or deposition of long-chain n-3 fatty acids was accelerated after CLA feeding. The increased docosahexaenoic acid and eicosapentaenoic acid contents in lipid may be compensation for the decreased arachidonic acid content. Dietary supplementation of linoleic acid increased n-6 fatty acid levels in lipids, whereas linolenic acid increased n-3 fatty acid levels. Results also suggest that CLA might not be elongated to synthesize long-chain fatty acids in significant amounts. The effect of CLA in reducing the level of n-6 fatty acids and promoting the level of n-3 fatty acids could be related to the biological effects of CLA.

Animal Nutritional Physiological Phenomena↗
PubMed1993

Cytoplasmic fatty acid binding protein: significance for intracellular transport of fatty acids and putative role on signal transduction pathways.

The cellular transport of long-chain fatty acid moieties is thought to be mediated by a plasmalemmal and a cytoplasmic fatty acid binding protein (FABPPM and FABPC, respectively) and a cytoplasmic acyl-coenzyme A binding protein (ACBP). Their putative main physiological significance is the assurance that long-chain fatty acids and derivatives, either in transit through membranes or present in intracellular compartments, are largely complexed to proteins. FABPC distinguishes from the other proteins in that distinct types of FABPC exist and that these are found in a variety of tissues in remarkable abundance, with some cells containing more than one type In addition, liver type FABPC binds not only fatty acids, but also several other hydrophobic ligands, including heme, bilirubin, prostaglandin E1 and lipoxygenase metabolites of arachidonic acid. Calculations made for rat cardiomyocytes reveal that the presence of FABPC substantially enhances the cytoplasmic solubility as well as the maximal diffusional flux of fatty acids in these cells. Apart from this putative function in the bulk transport of ligands, FABPC may also function in the fine-tuning of cellular events by modulating the metabolism of hydrophobic compounds implicated in the regulation of cell growth and differentiation.

Animals↗
PubMed1988

Uptake of fatty acids by jejunal mucosal cells is mediated by a fatty acid binding membrane protein.

The previous identification of a membrane fatty acid binding protein (MFABP) in brush border plasma membranes of the jejunum suggested that mucosal cell uptake of fatty acids might represent a carrier-mediated transport system. For evaluation of this hypothesis cellular influx kinetics (V0) of [3H]-oleate were examined in isolated rat jejunal mucosal cells. With increasing unbound oleate concentration in the medium V0 was saturable (Km = 93 nM; Vmax = 2.1 nmol X min-1 per 10(6) cells) and temperature dependent with an optimum at 37 degrees C. Pretreatment of the cells with a monospecific antibody to MFABP significantly inhibited V0 of oleate, other long-chain fatty acids, and D-monopalmitin, but not of L-alanine. Moreover, in the in vivo system of isolated perfused jejunal segments the physiologic significance of MFABP in the directed overall intestinal absorption process of fatty acids was documented. In the presence of the anti-MFABP oleate absorption was markedly reduced, whereas uptake of L-alanine remained unaltered. By antibody inhibition studies it was suggested that this membrane carrier also reveals transport competence for various other long-chain fatty acids, D-monopalmitin, L-lysophosphatidylcholine, and cholesterol. These data support the hypothesis that absorption of fatty acids is mediated by a fatty acid binding membrane protein.

Animals↗
PubMed1997

Evaluating acid and base catalysts in the methylation of milk and rumen fatty acids with special emphasis on conjugated dienes and total trans fatty acids.

Milk analysis is receiving increased attention. Milk contains conjugated octadecadienoic acids (18:2) purported to be anticarcinogenic, low levels of essential fatty acids, and trans fatty acids that increase when essential fatty acids are increased in dairy rations. Milk and rumen fatty acid methyl esters (FAME) were prepared using several acid- (HCl, BF3, acetyl chloride, H2SO4) or base-catalysts (NaOCH3, tetramethylguanidine, diazomethane), or combinations thereof. All acid-catalyzed procedures resulted in decreased cis/trans (delta 9c,11t-18:2) and increased trans/trans (delta 9t,11t-18:2) conjugated dienes and the production of allylic methoxy artifacts. The methoxy artifacts were identified by gas-liquid chromatography (Gl.C)-mass spectroscopy. The base-catalyzed procedures gave no isomerization of conjugated dienes and no methoxy artifacts, but they did not transesterify N-acyl lipids such as sphingomyelin, and NaOCH3 did not methylate free fatty acids. In addition, reaction with tetramethylguanidine coextracted material with hexane that interfered with the determination of the short-chain FAME by GLC. Acid-catalyzed methylation resulted in the loss of about 12% total conjugated dienes, 42% recovery of the delta 9c,11t-18:2 isomer, a fourfold increase in delta 9t,11t-18:2, and the formation of methoxy artifacts, compared with the base-catalyzed reactions. Total milk FAME showed significant infrared (IR) absorption due to conjugated dienes at 985 and 948 cm-1. The IR determination of total trans content of milk FAME was not fully satisfactory because the 966 cm-1 trans band overlapped with the conjugated diene bands. IR accuracy was limited by the fact that the absorptivity of methyl elaidate, used as calibration standard, was different from those of the other minor trans fatty acids (e.g., dienes) found in milk. In addition, acid-catalyzed reactions produced interfering material that absorbed extensively in the trans IR region. No single method or combination of methods could adequately prepare FAME from all lipid classes in milk or rumen lipids, and not affect the conjugated dienes. The best compromise for milk fatty acids was obtained with NaOCH3 followed by HCl or BF3, or diazomethane followed by NaOCH3, being aware that sphingomyelins are ignored. For rumen samples, the best method was diazomethane followed by NaOCH3.

Acetates↗
PubMedDate not supplied

[Effect of fatty acid triglycerides on lipogenesis and the makeup of plasma, fatty tissue and erythocyte membrane fatty acids in rats].

The fatty acids middle-chain triglycerides (FAMCT) may be considered as a possible component of alimentary mixtures intended to lower the energy-giving efficiency of the nutritional ration. They do not join the tissue lipids, whereas their reconstruction into long-chain fatty acids requires an additional expenditure of energy. These facts were confirmed by the results obtained in tests on rats. Feeding of growing rats for 5 weeks on a ration containing 12 per cent of the FAMCT on condition of a sufficient administration of polyunsaturated fatty acids (PUFA) through addition of sunflower seed oil led to a significant fall of the body mass gain by comparison with that in rats receiving a ration whose main source of fat was lard. An increased tryglycerides synthesis in the liver was not accompanied by their accumulation in the organ. The triglycerides level in the serum was up. An analysis of the fatty acids composition in the epididymitic fatty tissue, plasma and erythrocytes confirmed that the FAMCT C2-fragments developing during metabolization are used up chiefly in lipogenesis, one of the basic products of which is palmitic acid. The metabolization of FAMC with sufficient PUFA proportion in the ration does not derange the plastic function of fat in the organism, i.e, securing biosynthesis of lipid components of the membranes.

Adipose Tissue↗
PubMed1987

Role of bacterial toxins, bile acids, and free fatty acids in colonic water malabsorption in tropical sprue.

Colonic perfusion studies in 10 southern Indian patients with tropical sprue and nine matched healthy adults revealed a defect of water and sodium absorption from the colon in sprue. Heat-labile and heat-stable enterotoxin production was not detected in coliforms cultured from the feces of any of the 19 subjects. The 24-hr fecal bile acid output was increased in patients with sprue, but fecal aqueous bile acid concentrations remained within normal limits, and these did not correlate with defects in colonic water and sodium absorption. Fecal free fatty acid excretion was markedly increased in sprue. There was a negative correlation between fecal excretion of unsaturated free fatty acids and colonic water and sodium absorption.

Adult↗
PubMed1977

Studies of effects of trans fatty acids in the diet on lipid metabolism in essential fatty acid deficient rats.

Effects of diets containing mixtures of safflower oil, hydrogenated coconut oil with elaidate of linolelaidate on growth, fatty acid composition, serum lecithin: cholesterol acyl transferase (LCAT) and postheparin plasma lipoprotein lipase activities in essential fatty acid (EFA) deficient rats were determined. Addition of trans fatty acids to the diet lowered the growth response to linoleic acid. Both elaidate and linolelaidate accumulated in the serum and liver, imparied the conversion of oleic acid to eicosatrienoic acid and linoleic acid to arachidonic acid, and the incorporation of eicosatrienoic acid into cholesteryl esters. Trans fatty acids also influenced the fatty acid composition of testicular lipids, but much lower amounts of these acids accumlated in tests than in liver or serum. Serum lecithin:cholesterol acyl transferase activity was elevated by an EFA deficiency, was unaffected by dietary elaidate, but was significantly decreased by linolelaidate. These effects were nullified by the addition of safflower oil to the diet. Postheparin plasma extrahepatic and hepatic lipase activities were also affected by an EFA deficiency, and by the addition of elaidate or linolelaidate alone or in combination with safflower oil to the diets of EFA deficient rats. It is suggested that trans fatty acids exhibit particular effects on the metabolism of lipids in addition to aggravation of an EFA deficiency.

Animals↗