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PubMed1978

Stimulation of Chromobacterium lipase activity and prevention of its adsorption to palmitoyl cellulose by hydrophobic binding of fatty acids.

Fatty acids prevented adsorption of purified Chromobacterium lipase [triacylglycerol acylhydrolase, EC 3.1.1.3] onto palmitoyl cellulose (Pal-C) and also increased the activity of the purified lipase. These effects increased with increase in the concentration and chainlength (up to 16 carbon atoms) of the fatty acids, and long-chain unsaturated fatty acids, such as oleic acid, linoleic acid and erucic acid, were most effective. When the lipase was adsorbed (immobilized) on Pal-C, its activity was elevated to 20 times that of the free lipase in detergent-free reaction mixture (olive oil-buffer system). Thus lipase was adsorbed to Pal-C through a hydrophobic site distinct from its catalytic site and the binding of fatty acids to the hydrophobic site seems to result in stimulation of the lipase activity.

Adsorption↗
PubMed1993

Structural requirements for unsaturated fatty acids and fatty alcohols to induce optimal biological responses: an approach using model membranes.

The permeation induced by unsaturated fatty acids and fatty alcohols through the membrane of dihexadecyl phosphate vesicles was quantified, using [Ru(bpy)3(2+)] ions as a permeant probe. In both the free fatty acid and the free fatty alcohol series, the permeation induced by the unsaturated isomers is higher than that of the corresponding saturated analogues. Moreover the permeant effect associated with free fatty acids or free fatty alcohols is under the control of structural and conformational parameters: carbon chain length, number and position of the double bonds, and the geometry Z or E of the double bond. Optimal membrane perturbing effects are observed for compounds having a carbon chain length ranging from 18 to 20 carbon atoms, incorporating two or four Z double bonds in the center of the carbon chain. Good correlation has been found between the membrane perturbing effect quantified as PD50 values and some of the biological properties associated with these fatty lipids. The PD50 values obtained for free fatty alcohols are in fair agreement with anesthetic properties reported by different authors, (Pringle et al., 1981) while PD50 values obtained for free fatty acids show a good correlation with their activity on the superoxide respiratory burst induced by chemotactic peptides. These preliminary results led to the conclusion that as far as a biological activity directly associated with unsaturated fatty acids or alcohols, involved a membrane barrier passage, the measure of their permeant properties using a DHP vesicle model appears to be an excellent criterion for the quantification of optimal biological effects.

Anesthetics↗
PubMed1993

Skin permeation enhancement of tegafur by ethanol/panasate 800 or ethanol/water binary vehicle and combined effect of fatty acids and fatty alcohols.

The effects of vehicle and enhancer on the skin permeation of tegafur across excised hairless mouse skin were investigated. Ethanol, water, panasate 800 (tricaprylin), and their mixtures were used as vehicles, and then a series of fatty acids or fatty alcohols was employed as representative enhancers. The skin permeability of tegafur was dramatically increased by the combination of ethanol and panasate 800, whereas the combination of ethanol and water resulted in only a little increase. The greatest permeation ratio (56.8% of dose at 12 h) was obtained with the ethanol/panasate 800 (40/60) binary vehicle. Furthermore, the skin permeability of tegafur could be enhanced by the addition of fatty acids or fatty alcohols to ethanol/panasate 800 (40/60) and ethanol/water (60/40) binary vehicles. The infinite dose studies suggested that panasate 800 decreased the lag time by increasing the diffusion of tegafur, and ethanol increased the permeation rate by increasing the partition of tegafur into skin. The effects of fatty acids or fatty alcohols added to ethanol as a single vehicle were dramatic, but did not appear in the case of panasate 800 as a single vehicle. In conclusion, panasate 800 was an excellent hydrophobic vehicle in that it minimized time lag and promoted tegafur permeability combined with ethanol. This improvement was further promoted when enhancers were added.

Animals↗
PubMed1984

Triglycerides, free fatty acids, free fatty acids/albumin molar ratio, and cholesterol levels in serum of neonates receiving long-term lipid infusions: controlled trial of continuous and intermittent regimens.

We compared intermittent (8 hours/day) versus continuous (24 hours/day) isocaloric lipid infusion regimens in 28 neonates. The lipid dose was increased incrementally by 0.5 gm/kg/day to either 3 gm/kg/day or until fat contributed 40% of daily calories. Serum total triglycerides, free fatty acids, free fatty acids/albumin molar ratio, and total cholesterol levels were measured prior to the daily lipid infusion, at the end of the intermittent infusion, and at 8 hours during the continuous infusion. Neonates less than 32 weeks postconception had significant fluctuation of triglycerides, free fatty acids, and free fatty acids/albumin molar ratio during the intermittent regimen at all lipid doses, but not during the continuous regimen. Neonates greater than or equal to 32 weeks postconception had significant fluctuation of serum triglycerides, free fatty acids, and free fatty acids/albumin molar ratio during the intermittent regimen with a lipid dose greater than or equal to 2 gm/kg/day, but not during the continuous regimen at all lipid doses. Serum free fatty acids correlated closely with serum triglycerides during both regimens (r = 0.89, P less than 0.001). Serum total cholesterol rose with increasing lipid doses during both regimens (f = 8.16, P less than 0.05). We conclude that neonates less than 32 weeks postconception tolerate the continuous regimen better than the intermittent regimen at all lipid doses; neonates greater than or equal to 32 weeks postconception tolerate both regimens well at lipid dose less than 2 gm/kg/day, but tolerate a continuous regimen better with lipid dose greater than or equal to 2 gm/kg/day.

Cholesterol↗
PubMed2004

Antimicrobial activity of saturated fatty acids and fatty amines against methicillin-resistant Staphylococcus aureus.

The objective of this study was to investigate the antimicrobial activities of saturated fatty acids and fatty amines against methicillin-resistant Staphylococcus aureus (MRSA). The antimicrobial activity of saturated fatty acids and fatty amines was determined by oxygen meters with multi-channels and disposable oxygen electrode sensors (DOX-96). Lauric acid, the most effective among the saturated fatty acids, showed antimicrobial activity at 400 microg/ml against methicillin-susceptible Staphylococcus aureus (MSSA) and MRSA. The minimal inhibitory concentration (MIC) of fatty amines depended on each hydrophobic chain length. The MIC of myristylamine was 1.56 microg/ml; most effective of the fatty amines. In time-kill curves, lauric acid and myristylamine produced a bactericidal effect and a bacteriostatic effect at 4-fold the MIC, respectively. The antimicrobial activities of lauric acid and myristylamine were decreased by human plasma. Cytotoxicity of 3 saturated fatty acids and 3 fatty amines was examined in cultured endothelial cells. Although cytotoxicity of fatty amines was severer than that of saturated fatty acids, myristylamine showed the highest value of apparent therapeutic index among them. DOX-96 was useful for screening antimicrobial substances, especially in the case of insoluble substances. We found that myristylamine showed anti-MRSA activity comparable to that of vancomycin and teicoplanin.

Amines↗
PubMed2006

Development and application of an analytical method for the determination of storage lipids, fatty acids and fatty alcohols in Calanus finmarchicus.

A method was developed for the determination of the major storage lipids, wax ester and triglycerides, in the copepod Calanus finmarchicus. A variation of the Folch method was used to extract the lipid. The method was scaled down to enable the extraction of either pooled (-1 mg) or individual (approximately 200 microg) copepods. The major lipid classes were identified using TLC and quantified using HPLC coupled with evaporative light scattering detection. Analysis of laboratory reference materials indicated that this method underestimated the minor triglyceride component, but gave a good estimate of the major wax ester component. The fatty acid and fatty alcohol composition of the C. finmarchicus were determined following trans-esterification of the lipid extract in methanol. Fatty acids and fatty alcohols were initially identified by comparison with authentic standard and by mass spectroscopy. Using GC with flame ionisation detection the normalised area percentage of the fatty alcohols and fatty acid methyl esters was determined simultaneously in one run for either pooled or individual copepod samples. These methods were applied to C. finmarchicus collected from the Irminger Sea, North Atlantic in 2001 and 2002.

Animals↗
PubMed1990

Phospholipase A activity of cultured rat ventricular myocyte is affected by the nature of cellular polyunsaturated fatty acids.

Fatty acid composition of membrane phospholipids of cultured cardiomyocytes can be modified by the type of polyunsaturated fatty acids (n-3 or n-6 PUFA) constituting the culture medium. In this study, we investigated the effect of fatty acid modification on the activities of the key enzymes involved in the deacylation-reacylation cycle of membrane phospholipids. Results showed that cardiomyocytes grown in the presence of n-6 PUFA exhibited a higher specific alkaline phospholipase A (mainly A2) activity (+34%) and a moderately lower lysophospholipase activity (-17%) than when incubated with n-3 PUFA. AcylCoA:lysophosphatidylcholine acyltransferase, acid lysosomal phospholipase A1 and acylCoA synthetase activities were not significantly altered by changes in cellular PUFA composition. It was demonstrated that the differences between phospholipase A activities of the two types of cultured cells were linked neither to a differential leakage of enzyme nor to oxidative injury to the enzyme through blockage of essential sulfhydryl groups. One likely explanation is that the PUFA-induced changes in membrane composition alter membrane physical properties which, in turn, affect membrane-bound phospholipase A activity. Possible beneficial effects of the n-3 PUFA-induced changes on membrane stability are discussed.

Animals↗
PubMed1984

Activities of fatty acid desaturases and fatty acid composition of liver microsomes in rats fed beta-carotene and 13-cis-retinoic acid.

The fatty acid composition of microsomal lipids and the activities of delta 9- and delta 6-desaturases in liver microsomes of rats fed diets supplemented with beta-carotene and two levels of 13-cis-retinoic acid were studied. Four groups of male, weanling rats were fed semipurified diets containing 0 or 100 mg beta-carotene per kg diet, and 20 or 100 mg 13-cis-retinoic acid per kg diet. After 11 weeks of feeding, the rats were killed, liver microsomes were prepared and assayed for delta 9-desaturase and delta 6-desaturase activities. The activity of delta 9-desaturase was lower in liver microsomes of rats fed beta-carotene-supplemented diet or the diet supplemented with the higher level of 13-cis-retinoic acid. Microsomal delta 6-desaturase activity was, however, higher in liver of rats fed 13-cis retinoic acid; there was no effect of beta-carotene on delta 6-desaturase activity. The fatty acid compositional data on total lipids of liver microsomes were consistent with the diet-induced changes in fatty acid desaturases. Phospholipid composition of liver microsomes was also altered as a result of feeding beta-carotene or 13-cis-retinoic acid-containing diets. The proportions of phosphatidylethanolamine were generally higher, whereas those of phosphatidylcholine were lower in the experimental groups as compared with the control.

Animals↗
PubMed1980

Cholesterol reduces the effects of dihydroxy bile acids and fatty acids on water and solute transport in the human jejunum.

Jejunal perfusion studies were performed in 16 healthy volunteers to test the hypothesis that intraluminal cholesterol can mitigate the fluid secretion induced by dihydroxy bile acids and fatty acids. Fluid secretion in the presence of 5 mM taurodeoxycholate was somewhat reduced by 4 mM mono-olein which was used for the solubilization of cholesterol. Addition of 0.8 mM cholesterol reduced fluid secretion further (P less than 0.05). Fluid secretion induced by 4 mM oleic acid was changed to net absorption in a linear fashion with increasing cholesterol concentration in the perfusion solutions. 1 mM cholesterol reduced fluid secretion induced by 6 mM oleic acid (P less than 0.005), but had no effect on fluid secretion induced by 6 mM linolenic acid. Glucose absorption was generally affected in a similar manner as water transport. In vitro, 1 mM cholesterol reduced monomer activity of 6 mM oleic acid to 72.3 +/- 0.9% of control and that of linolenic acid to 81.1 +/- 1.7% of control. Although statistically significant (P less than 0.001), the difference in the effects of cholesterol on monomer activities of the two fatty acids was rather small and it is unlikely that changes in monomer concentration of fatty acids and bile acids account for the protective effect of cholesterol. The in vivo observations point to a new physiological role for biliary cholesterol: the modification of the response of the small intestine to the effects of dihydroxy bile acids and fatty acids.

Bile Acids and Salts↗
PubMed1978

Comparison of C18-, C20- and C22-unsaturated fatty acids in reducing fatty acid synthesis in isolated rat hepatocytes.

C18-, C20- and C22-unsaturated acids were tested for inhibition of fatty acid synthesis in hepatocytes isolated from essential fatty acid-deficient rats. Fatty acid synthesis was measured by incorporation of radioactivity from [1-14C-A1-acetate or 3H2O into fatty acids. C20-polyunsaturated fatty acids included arachidonic acid (20 : 4 (n-6)) and 4 other fatty acids formed from linoleic acid (18 : 2 (n-6)) or linolenic acid (18 : 3 (n-3)). These were (11,14)-icosadienoic acid (20 : 2 (n-6)), (8,11,14)-icosatrienoic acid (20 : 3 (n-6)), (11,14,17)-icosatrienoic acid (20 : 3 (n-3)) and (5,8,11,14,17)-icosapentaenoic acid (20 : 5 (n-3). All of these have essential fatty acid activity. The fatty acid (5,8,11)-icosatrienoic acid (20 : 3 (n-9)) was also tested. This fatty acid is formed from oleic acid (18 : 1 (n-9)) and is not an essential fatty acid or a prostaglandin precursor. C20-unsaturated fatty acids and (22 : 6 (n-3)) were as effective as stearic acid in inhibiting fatty acid synthesis and were more inhibitory than their precursor C18-unsaturated fatty acids. These results are evidence that C20-unsaturated fatty acids of the linoleic and linolenic acid series can act in short-term inhibition as well as in adaptive inhibition of fatty acid synthesis (Bloch, K. and Vance, D. (1977) Annu. Rev. Biochem. 46, 263--298). The effectiveness of (5,8,11)-icosatrienoic acid indicates that short-term inhibition by C20-unsaturated fatty acids is not limited to those fatty acids which have essential fatty acid activity.

Animals↗
PubMedDate not supplied

[Fatty acid metabolic and perfusion abnormalities in hypertrophied myocardium assessed by dual tracer tomography using thallium-201 and iodine-123-beta-methylpentadecanoic acid].

Fatty acid metabolic and perfusion abnormalities associated with cardiac hypertrophy were investigated using dual tracer tomography with thallium and a cardiac metabolic tracer, 15-(p-iodophenyl)-3-R, S-methylpentadecanoic acid (BMIPP), in eight patients with hypertrophic cardiomyopathy (HCM) and in three with hypertension (HT). Thallium and BMIPP uptakes were scored and analyzed in 143 segments (13/heart) by comparison with the left ventricular wall thickness measured by two-dimensional echocardiography. Complete agreement of both scores in HT patients was significantly higher than that in HCM patients (64% vs 24%, p < 0.001), while a lower BMIPP uptake compared to that of thallium (mismatching) was observed more frequently in HCM than in HT patients (65% vs 31%, p < 0.001). The wall thickness significantly (p < 0.005) correlated with BMIPP uptake score. HCM patients showed a low BMIPP uptake in 22 hypertrophic segments (59%) and 15 non-hypertrophic segments (41%), and reduced BMIPP uptake in 29% hypertrophic segments, while HT patients showed just five segments with decreased BMIPP uptake of which 4 were non-hypertrophic and only one hypertrophic. The left ventricular ejection fraction assessed by radionuclide ventriculography was normal and no regional wall motion abnormality was detected in any patient by echocardiographic and scintigraphic studies. Metabolic abnormalities detected by the iodine-123-beta-methyl fatty acid analog in hypertrophic cardiomyopathy may be independent of thallium myocardial perfusion, regional wall motion, or the magnitude of cardiac hypertrophy, suggesting that fatty acid imaging may be useful in investigating the pathogenesis and subclinical abnormality of hypertrophic cardiomyopathy, and differentiation from secondary, induced cardiac hypertrophy.

Adult↗
PubMed1999

Stability of cyclopropane and conjugated linoleic acids during fatty acid quantification in lactic acid bacteria.

Seven methods commonly used for fatty acid analysis of microorganisms and foods were compared to establish the best for the analysis of lyophilized lactic acid bacteria. One of these methods involves fat extraction followed by methylation of fatty acids, while the other methods use a direct methylation of the samples, under different operating conditions (e.g., reaction temperature and time, reagents, and pH). Fatty acid methyl esters were identified by gas chromatography-mass spectrometry and quantified by on-column capillary gas chromatography. Two reliable methods for the analysis of fatty acids in bacteria were selected and further improved. They guarantee high recovery of classes of fragile fatty acids, such as cyclopropane and conjugated acids, and a high degree of methylation for all types of fatty acid esters. These two direct methylation methods have already been successfully applied to the analysis of fatty acids in foods. They represent a rapid and highly reliable alternative to classical time- and solvent-consuming methods and they give the fatty acid profile and the amount of each fatty acid. Using these methods, conjugated linoleic acids were identified and quantified in lactic acid bacteria.

Bacteria↗
PubMed1998

Postprandial decrease in plasma unesterified fatty acids during n-3 fatty acid feeding is not caused by accumulation of fatty acids in adipose tissue.

Dietary supplementation of very long-chain n-3 fatty acids to rats reduces postprandial plasma concentrations of triacylglycerol, unesterified fatty acids and glycerol after long-term feeding by unknown mechanisms [Rustan et al., J. Lipid Res. 34 (1993) 1299-1309]. In the present study we examine the role of adipose tissues in metabolism of fatty acids. Postprandial plasma concentrations of triacylglycerol, unesterified fatty acids and glycerol were reduced by 75%, 50% and 30%, respectively, during 49 days of feeding high-fat diets containing n-3 fatty acids (6.5% n-3 fatty acid concentrate, 13% lard) as compared to lard (19.5% lard). These differences were observed already after two days of feeding. Plasma concentration of unesterified very long-chain n-3 fatty acids increased to 50 microM in n-3 fatty acid-supplemented rats, whereas these fatty acids were undetectable in lard-fed animals. The n-3 fatty acid-enriched diet limited cell volumes of perirenal and epididymal adipocytes by 40% and 30%, respectively, after 49 days, as compared to lard feeding. This reduction in cell volume was not due to reduced synthesis of glycerolipids in epididymal adipocytes. Acute incubation of perirenal and epididymal adipocytes with oleic acid or eicosapentaenoic acid, caused similar increase in synthesis of triacylglycerol. Dietary supplementation with n-3 fatty acids decreased basal and total lipolysis (isoprenalin-stimulated) in perirenal adipocytes. Basal lipolysis in epididymal adipocytes was reduced by n-3 fatty acids only after 49 days. n-3 fatty acids increased total lipolysis in mesenteric and subcutaneous fat cells compared to adipocytes derived from lard-fed animals, whereas basal lipolysis was unchanged. These results suggest that the reduced postprandial plasma concentration of unesterified fatty acids after n-3 fatty acid-supplementation is not caused by accumulation of fatty acids in adipose tissue. The reduced trophic growth of adipocytes might be due to decreased supply of unesterified fatty acids for triacylglycerol storage. (c) 1998 Elsevier Science B.V.

Adipose Tissue↗
PubMed1994

Equilibrium constants for the binding of fatty acids with fatty acid-binding proteins from adipocyte, intestine, heart, and liver measured with the fluorescent probe ADIFAB.

Affinities of long chain fatty acids (FA) for fatty acid-binding proteins (FABPs) have been measured by monitoring the concentrations of the unbound or free fatty acids (FFA) in equilibrium with the FABPs using the fluorescent probe ADIFAB. This probe allows the measurement of the concentration of FFA in equilibrium with FABPs, without physical separation of any of the reactants. Equilibrium characteristics were measured at 37 degrees C for palmitate, stearate, oleate, linoleate, linolenate, and arachidonate binding to six FABPs from intestine, heart, adipose, and liver from different species. Equilibrium constants for each FA were found to be extremely sensitive to the tissue origin of the FABP but largely independent of species differences. The measured values of the dissociation constants (Kd) ranged from about 2 to 1000 nM, depending upon the tissue origin of the FABP and the FA. Binding constants for some FABPs varied considerably with different FA, as much as 80-fold in the case of the intestinal FABP. In contrast, Kd values for adipocyte FABPs exhibited less than 4-fold variation with FA type and are generally larger (lower affinities) than for the other FABPs. For all FABPs, Kd values for fatty acids with the same chain length were considerably lower for saturated as compared to polyunsaturated FA. This characteristic likely reflects the lower aqueous solubilities of the saturated fatty acids. In contrast to the other FABPs, rat liver FABP was found to have two FA-binding sites/monomer. Each of these two sites had similar high affinities for the saturated FA, while for the unsaturated FA the two sites exhibited affinities that differ by more than 7-fold. This study disagrees with earlier investigations in finding that equilibrium binding of FA to FABPs is a sensitive function of FA type and FABP tissue origin and that FA-FABP dissociation constants are submicromolar. These results provide a framework with which to understand better the biological function of FABPs and the FA-FABP interaction.

Adipocytes↗
PubMed1998

Risk of preeclampsia in relation to elaidic acid (trans fatty acid) in maternal erythrocytes.

OBJECTIVE: Trans fatty acids, formed by the partial hydrogenation of vegetable oils, are associated with increases in plasma concentrations of cholesterol, triglyceride, lipoprotein (a), and coronary heart disease risk. Trans fatty acids may also increase platelet aggregation and alter eicosanoid biosynthesis. We studied the relation between maternal dietary intake of trans fatty acids and risk of preeclampsia. METHODS: Maternal intake of elaidic acid, one of the most abundant dietary trans fatty acids and other fatty acids were estimated using gas-liquid chromatography on erythrocytes from 22 women with preeclampsia and 40 normotensive controls. Fatty acids were expressed as the percentage of total fatty acids in erythrocytes. Logistic regression procedures were used to estimate odds ratios and 95% confidence intervals. RESULTS: Mean levels of elaidic acid were 28% higher among preeclamptics (0.43 +/- 0.12) as compared with controls (0.31 +/- 0.12; p < 0.001). After adjusting for confounding factors, women with the highest levels of elaidic acid (median = 0.47) were 7.4 times (odds ratio = 7.4; 95% confidence interval 1.4-39.7) more likely to have had their pregnancy complicated by preeclampsia as compared with those women with the lowest levels (median 0.24). Risk of preeclampsia appeared to increase with increasing levels of elaidic acid (p value for linear trend = 0.05). CONCLUSION: These cross-sectional data suggest that diets high in elaidic acid may be associated with an increased risk of preeclampsia. This hypothesis should be examined in larger longitudinal studies.

Cross-Sectional Studies↗