bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of passive smoking on the regulation of rat aortic cholesteryl ester hydrolases by signal transduction
Authors: Maehira Fusako , Zaha Fusako , Miyagi Ikuko , Tanahara Asami , Noho Ayano
Published: November 2006

The effects of exogenous oxidative stress due to passive smoking on cholesteryl ester (CE)‐metabolizing enzymes and their regulatory kinases were examined by exposing rats to cigarette smoke (CS) for a 1‐h period twice a day for 8, 12, or 20 wk. An oxidatively modified low density lipoprotein (Ox‐LDL) with a high lipid peroxide was identified in three CS groups after all three exposure periods. The rat aortic acid and neutral CE hydrolases (ACEH and NCEH) were activated to similar extents by both cAMP‐dependent protein kinase (PKA) and protein kinase C (PKC) in the presence of their respective cofactors. The aortic PKC activity in the three CS groups exhibited significant reductions of 72, 84, and 75% as compared with the respective controls, which coincided with the reductions in the ACEH activities (86, 71, and 80%, respectively), whereas the PKA activities increased to 121, 197, and 252% in the three CS groups, respectively. Reflecting the increase of the PKA activity, the NCEH activity exhibited increases of 112% at 8 wk and 140% until 12 wk of exposure and decreased by 50% of the control value at 20 wk of exposure, suggesting inactivation of NCEH itself. The activation of acyl‐CoA:cholesterol O‐acyl‐transferase activity was associated with an increase of free cholesterol in aorta. The vitamin E diet prevented the formation of Ox‐LDL and the oxidative inactivation of most enzymes, especially PKC, until 12 wk, but was less effective by 20 wk. The oxidative inactivation of PKC, particularly its activated form that translocated to the membrane fraction, was confirmed in the in vitro exposure to active oxygen generators at an optimal concentration; this inactivation was prevented by catalase and superoxide dismutase. These results suggested that the formation of Ox‐LDL and alterations in CE‐metabolizing enzymes caused by passive smoking could contribute to a twofold increase in the aortic CE content, thereby contributing to one of the mechanisms for atherosclerosis associated with smoking.
Polyunsaturated monoglycerides and a pregnadiene in defensive glands of the water beetleAgabus affinis
Authors: Schaaf Otmar , Dettner Konrad
Published: November 2006

In addition to the C21steroid 15α‐hydroxypregna‐4,6‐dien‐3,20‐dione, four 1‐ or 2‐acylated polyunsaturated monoglycerides, 1‐ or 2‐(cis‐5,8,11,14‐eicosatetraenoyl)‐glycerol and 1‐ or 2‐(cis‐5,8,11,14,17‐eicosapentaenoyl)glycerol were identified as constituents of the prothoracic defensive gland secretion of the dytiscid beetleAgabus affinisby gas chromatography‐mass spectrometry of trimethylsilylated gland extracts. In a feeding assay with minnows, synthetic samples of the two 2‐acylated monoglycerides showed only a weak activity as a feeding deterrent. For that reason, other possible functions of the monoglycerides are discussed, such as roles as emulsifiers of cannabimimetics.
Blood fatty acid composition of pregnant and nonpregnant Korean women: Red cells may act as a reservoir of arachidonic acid and docosahexaenoic acid for utilization by the developing fetus
Authors: Ghebremeskel K. , Min Y. , Crawford M. A. , Nam Joo‐Hyun , Kim Ahm , Koo Ja‐Nam , Suzuki Hiramitsu
Published: November 2006

Relative fatty acid composition of plasma and red blood cell (RBC) choline phosphoglycerides (CPG), and RBC ethanolamine phosphoglycerides (EPG) of pregnant (n=40) and nonpregnant, nonlactating (n=40), healthy Korean women was compared. The two groups were of the same ethnic origin and comparable in age and parity. Levels of arachidonic (AA) and docosahexaenoic (DHA) acids were lower (P<0.05) and palmitic and oleic acids higher (P<0.0001) in plasma CPG of the pregnant women. Similarly, the RBC CPG and EPG of the pregnant women had lower AA and DHA (P<0.05) and higher palmitic and oleic acids (P<0.01). The reduction in DHA and total n−3 fatty acids in plasma CPG of the pregnant women was paralleled by an increase in docosatetraenoic (DTA) and docosapentaenoic (DPA) acids of the n−6 series and in DPA/DTA ratio. In the RBC phospholipids (CPG and EPG) of the pregnant women, DTA and DPA acids of the n−6 series and DPA/DTA ratio did not increase with the decrease of the n−3 metabolites (eicosapentaenoic acid, DPA, and DHA) and total n−3. Since pregnancy was the main identifiable variable between the two groups, the lower levels of AA and DHA in RBC CPG and EPG of the pregnant women suggest that the mothers were mobilizing membrane AA and DHA to meet the high fetal requirement for these nutrients. It may also suggest that RBC play a role as a potential store of AA and DHA and as a vehicle for the transport of these fatty acids from maternal circulation to the placenta to be utilized by the developing fetus.
Simultaneous derivatization of acyl and S‐alkyl moieties of acyl thioesters by using trimethylsulfonium hydroxide for gas chromatographic analysis
Authors: Klein Erika , Weber Nikolaus
Published: November 2006

The reaction of long‐chain acyl thioesters, viz. lauric acid dodecyl thioester, 1,8‐di‐S‐palmitoyl octanedithiol, and tristearoyl α‐monothioglycerol, with trimethylsulfonium hydroxide in the presence of methanol leads to simultaneous derivatization of acyl moieties and S‐alkyl moieties of acyl thioesters to the corresponding fatty acid methyl esters and methyl alkylsulfides, respectively. These derivatized products were analyzed by gas chromatographic technique.
The composition of saturated fatty acids in plasma phospholipids changes in a way to counteract changes in the mean melting point during pregnancy
Authors: De Vrieses S. R. , v. Houwelingen A. C. , Hornstra G. , Dhont M. , Christophe A. B.
Published: November 2006

It has been demonstrated that in pathological conditions with an increase in the calculated mean melting point (MMP) of phospholipid (PL) fatty acids (FA) there are changes in the composition of the saturated FA (SFA), which partially counteract this effect: shorter‐chain SFA with lower melting points are increased, while longer‐chain less fluid SFA are suppressed. The aim of this study was to determine whether there are differences in MMP during pregnancy and in the newborn and, if so, whether similar adaptive changes occur in the composition of the SFA The FA composition of plasma PL was determined in healthy women (n‐16) twice during pregnancy (15–24 wk and 29–36 wk) and at delivery and in umbilical venous blood obtained at birth. The MMP of maternal PL was significantly higher at delivery compared to mid‐gestation, due to a loss of highly unsaturated FA (HUFA) which were replaced by SFA. In addition, changes in the SFA occurred; 16∶0 with lower melting point was higher while 18∶0 with higher melting point was lower at delivery. MMP of PL FA in umbilical plasma was lower than in maternal plasma at delivery, which was due to higher HUFA content. In contrast to maternal plasma, 16∶0 was lower while 18∶0, 20∶0 and 24∶0 were higher in umbilical plasma resulting in a higher MMP of SFA, tending to raise the overall MMP. It can be concluded that, during pregnancy and in the newborn, the FA composition of SFA changes in a way to counteract changes in MMP induced by reduced and increased HUFA, respectively.
Influence of fatty alcohol and other fatty acid derivatives on fatty acid uptake into rat intestinal epithelial cells
Authors: Murota Kaeko , Matsui Noriko , Kawada Teruo , Takahashi Nobuyuki , Shintani Takafumi , Sasaki Kahori , Fushiki Tohru
Published: November 2006

We investigated the influence of various substrates on the uptake of long‐chain fatty acid into IEC‐6, rat intestinal epithelial cell line. The uptake of [3H]oleic acid into IEC‐6 cells was a saturable function of the oleic acid concentration. Long‐chain fatty acids significantly inhibited the oleic acid uptake into IEC‐6 cells and shorter‐chain fatty acids had little or no effect. Various fatty acid esters suppressed the oleic acid uptake into IEC‐6. Fatty alcohols also inhibited oleic acid uptake into IEC‐6 and the length of the carbon chain played an important role. These results suggest that long‐chain fatty acid uptake was inhibited by the substrates which had a structure similar to long‐chain fatty acids, especially those with a long carbon chain. At least two molecules, fatty acid translocase and fatty acid transport protein type 4, which are considered to be involved in the long‐chain fatty acid transport into the cell, were expressed on IEC‐6 cells, supporting the existence of the carrier‐mediated system of long‐chain fatty acid transport on IEC‐6 cells.
In vitro behavior of marine lipid‐based liposomes. Influence of pH, temperature, bile salts, and phospholipase A2
Authors: Nacka Fabienne , Cansell Maud , Entressangles Bernard
Published: November 2006

To deliver polyunsaturated fatty acids (PUFA) by the oral route, liposomes based on a natural mixture of marine lipids were prepared by filtration and characterized in media that mimic gastrointestinal fluids. First the influence of large pH variations from 1.5–2.5 (stomach) to 7.4 (intestine) at the physiological temperature (37°C) was investigated. Acidification of liposome suspensions induced instantaneous vesicle aggregation, which was partially reversible when the external medium was further neutralized. Simultaneously, complex morphological bilayer rearrangements occurred, leading to the formation of small aggregates. These pH‐ and temperature‐dependent structural changes were interpreted in terms of osmotic shock and lipid chemical alterations, i.e., oxidation and hydrolysis, especially in the first hours of storage. Besides, oxidative stability was closely related to the state of liposome aggregation and the supramolecular organization (vesicles or mixed micelles). The effects of bile salts and phospholipase A2 (PLA2) on the liposome structures were also studied. Membrane solubilization by bile salts was favored by preliminary liposome incubation in acid conditions. PLA2 showed a better activity on liposome structures than on the corresponding mixed lipid‐bile salt micelles. As a whole, in spite of slight morphological modifications, vesicle structures were preserved after an acid stress and no lipid oxidation products were detected during the first 5 h of incubation. Thus, marine lipids constituted an attractive material for the development of liposomes as potential oral PUFA supplements.
Mechanisms of dimer and trimer formation from ultraviolet‐irradiated α‐tocopherol
Authors: Krol Ed S. , Escalante Daniel D. J. , Liebler Daniel C.
Published: November 2006

α‐Tocopherol (α‐TH) undergoes ultraviolet (UV)‐induced photooxidation on the surface of mouse skin to produce a dihydroxydimer, a spirodimer, and trimers as the major products. To study the photochemistry involved, we UV‐irradiated α‐TH in a thin film on a glass petri dish. Photooxidation yielded a mixture of dihydroxydimer, spirodimer, and trimers. In the time‐course studies, the dihydroxydimer accumulated and then was further oxidized, whereas the spirodimer and trimers accumulated more gradually. Reaction of two tocopheroxyl radicals forms the dihydroxydimer, whereas the spirodimer may be formed either by photooxidation of α‐TH to an orthoquinone methide (o‐QM) followed by a Diels‐Alder reaction or by photooxidation of α‐TH to the dihydroxydimer, followed by two‐electron oxidation. Irradiation of a mixture of d10‐labeled and unlabeled (d0) dihydroxydimer produced a mixture of labeled and unlabeled spirodimers as detected by positive atmospheric pressure chemical ionization‐mass spectrometry. The absence of mixed label spirodimers among products indicated that direct oxidation of the dihydroxydimer is a facile route to the spirodimer and is probably the major spirodimer‐forming reaction in α‐TH photooxidations. Trimer formation from the dihydroxydimer and the spirodimer was observed, however, and requires an o‐QM intermediate. Photooxidation of d10‐labeled and unlabeled (d0) dihydroxydimers yielded mixed isotopomers of the trimer products, thus demonstrating that the dihydroxydimer and spirodimers underwent conversion to o‐QM intermediates. Photochemical conversion of α‐TH to UV‐absorbing dimer and trimer products may contribute to photoprotection by topically applied α‐TH.
Effects of ascorbate on membrane phospholipids and tocopherols of intact erythrocytes during peroxidation by t‐butylhydroperoxide: Comparison with effects of dithiothreitol
Authors: Mawatari Shiro , Murakami Kaori
Published: November 2006

Peroxidation of intact human erythrocytes by t‐butylhydroperoxide (tBHP) was studied. By incubation of the erythrocytes with 1 mM tBHP, reduced glutathione (GSH) was exhausted within 1 min, and tocopherols (Toc) and phospholipids (PL) decreased to nearly their lowest levels (in this study) within 5 min. The rate of decrease of α‐Toc was faster than that of γ‐Toc, but α‐Toc was never exhausted. The rates of decrease of Toc were faster than that of PL. Malondialdehyde increased slowly to reach a maximal value at 30 min. Methemoglobin (metHB) reached a maximum at 15 min. The maximal levels of these substances were maintained until 90 min incubation, which indicated that the peroxidation by tBHP had stopped spontaneously until at least 90 min. By the incubation with tBHP for 30 min, phosphatidylethanolamine (PE) and α‐Toc decreased to about 70 and 30% of control levels, respectively, and γ‐Toc and GSH were almost exhausted. Ascorbate (0.1 mM) afforded protection of 92% to PF, 50% to α‐Toc, and 65% to γ‐Toc against peroxidation, but ascorbate had no preventive effect at all on the formation of metHB and the decrease of GSH. These results may indicate that ascorbate‐mediated protection of the membrane PL against the peroxidation depends primarily on Toc. On the other hand, dithiothreitol (DTT) (5 mM) almost completely prevented the formation of metHB, and DTT completely protected the PL and Toc against peroxidation, indicating the importance of sulfhydryl groups in erythrocytes.
Cacao liquor polyphenols reduce oxidative stress without maintaining α‐tocopherol levels in rats fed a vitamin E‐deficient diet
Authors: Yamagishi Megumi , Osakabe Naomi , Takizawa Toshio , Osawa Toshihiko
Published: November 2006

The effect of crude polyphenols (CLP) from cacao liquor on vitamin F‐deficient rats was examined. The CLP fraction contained 49.8% antioxidative polyphenols such as catechins and their oligomers. Supplementation of the vitamin E‐deficient diet with CLP for 7 wk did not prevent the decrease in α‐tocopherol levels in the liver, kidney, heart, brain, and plasma. The lipid peroxide levels in these tissues increased in the group fed the vitamin F‐deficient diet compared with the control group. However, these changes were inhibited in a dose‐dependent manner as a result of supplementation of the vitamin E‐deficient diet with 0.25, 0.5, or 1.0% CLP. The lipid peroxide levels in plasma increased in the group fed the vitamin E‐deficient diet. This change tended to be suppressed as a result of supplementation of the diet with CLP, but the difference was not significant. There was no evidence of absorption and distribution of CLP to the tissues; however, CLP intake resulted in a decrease in oxidative stress without maintaining vitamin E levels in the plasma and the tissues.
The first naturally occurring α‐methoxylated branched‐chain fatty acids from the phospholipids of Amphimedon complanata
Authors: Carballeira Néstor M. , Alicea Johanna
Published: November 2006

The phospholipid fatty acid composition of the sponge Amphimedon complanata was reinvestigated, and the 2‐methoxy‐13‐methyltetradecanoic acid, 2‐methoxy‐14‐methylpentadecanoic acid, and 2‐methoxy‐13‐methylpentadecanoic acid were identified for the first time in nature. Structure characterization was accomplished by means of gas chromatographic retention times and gas chromatography‐mass spectrometry. These acids could have originated from bacteria in symbiosis with the sponge.
A Fast and reliable spectroscopic method for the determination of membrane‐water partition coefficients of organic compounds
Authors: de Castro Baltazar , Gameiro Paula , Lima José L. F. C. , Matos Carla , Reis Salette
Published: November 2006

Partition coefficients (Kp) between egg yolk phosphatidylcholine multilamellar vesicles and water were determined for two nonsteroidal anti‐inflammatory drugs (indomethacin and acemetacin) using two independent methodologies: derivative spectrophotometry and variation of the experimental acidity constant in the presence of increasing vesicle concentration. Second‐derivative spectrophotometry allowed for total elimination of background signal effects arising from lipid vesicles, without the need for separation techniques that may disturb equilibrium states. By using a model based on a simple partition, the values of KpT can be obtained directly; furthermore, by performing determinations at two different pH values it is possible to calculate partition coefficients for the neutral and negatively charged forms of the drugs (KpAH and KpA). In the other methodology, values of apparent acidity constants (Kapp) were determined by spectrophotometry at different pH values and different lipid concentrations, and an increase in Kapp with decreasing lipid concentration was observed for both drugs, and from this dependence it was possible to calculate KpAH and KpA‐ for each drug. These values were used as a check for those obtained by derivative spectroscopy, which has proven to be a reliable and more expeditious method to obtain KpAH and KpA‐.
A novel assay method for glycosphingolipid deacylase by enzyme‐linked immunochemical detection of lysoglycosphingolipid
Authors: Izumi Kazuo , Sawada Michiko Takagi
Published: November 2006

Lysoglycosphingolipids consist of a sphingoid long‐chain base and monosaccharide or complex sugar, and they lack the fatty acyl group present in native glycosphingolipids. Less than 1 pmol of lyso‐Forssman glycolipid and lysoganglioside GM1 were detected on a thin‐layer chromatogram by an enzyme‐linked immunochemical coloration method with anti‐Forssman glycolipid antibody (FOM‐1) and cholera toxin B subunit, respectively. Each spot between 1 and 100 pmol lyso‐Forssman glycolipid was immunostained as densely as that of the same amount of native Forssman glycolipid. The density of the lyso‐Forssman glycolipid spots increased proportionally with increment in the amount of lysoglycolipid. The density of spots of 0.2–100 pmol lysoganglioside GM1 was also proportional to the amount of each lyso‐GM1 spot. These results indicated that less than 1 to 100 pmol of deacylated glycosphingolipid was quantifiable by the immunochemical coloration method with sugar chain‐specific antibodies. Glycosphingolipid deacylase, which cleaved an amide bond between the sphingoid long‐chain base and fatty acyl chain in ceramide of glycosphingolipid, was assayed by detecting the lyso‐Forssman glycolipid produced. Lipophilic compounds, recovered from an aliquot of the reaction mixture of Forssman glycolipid and crude enzyme at appropriate times, were analyzed by thin‐layer chromatography. It was found that lyso‐Forssman glycolipid was produced in the first 1–2 h by the enzyme and production increased with incubation time. This coloration method is more sensitive and specific than the visualization method with a non‐specific reagent such as orcinol‐sulfuric acid reagent.
Measurement of human chylomicron triglyceride clearance with a labeled commercial lipid emulsion
Authors: Park Yongsoon , Damron Bart D. , Miles John M. , Harris William S.
Published: November 2006

Human chylomicron triglyceride (TG) kinetics has been difficult to determine directly owing to technical limitations. This report describes a new method for studying chylomicron metabolism. Healthy volunteers (n=10) sipped a drink providing 175 mg fat·kg−1·h−1 for 7.5 h to produce a steady‐state chylomicronemia. A commercial 10% intravenous lipid emulsion was labeled with [3H]triolein, purified by high‐performance liquid chromatography, and sterilized. A trace amount of labeled emulsion was injected intravenously 30 min before (i.e., in the fasting state) and 5, 6, and 7 h after sipping began (i.e., triplicate determinations in the fed state). Chylomicron half‐lives were calculated from the monoexponential decay curves, and apparent distribution volumes were estimated by back‐extrapolation to time zero. Plasma and estimated chylomicron TG concentrations increased from 89±13 and 0.8±0.3 to 263±43 and 91±39 mg/dL (mean±SEM), respectively, with feeding. Tracer‐determined chylomicron TG half‐lives were 5.34±0.58 and 6.51±0.58 min during the fasting and fed states, respectively (P<0.01). The apparent distribution volume during the fasting state was 24% greater than plasma volume (4515±308 vs. 3630±78 mL, P<0.02), consistent with significant margination of lipid emulsion particles to endothelial binding sites. Margination was reduced during the fed state, suggesting that native chylomicrons competed with lipid emulsion particles for endothelial lipoprotein lipase. The results indicate that a radiolabeled commercial lipid emulsion is metabolized in a fashion similar to native chylomicron TG, and thus can be used to study chylomicron TG kinetics.
Low density lipoprotein receptor mRNA in rat liver is affected by resistant starch of beans
Authors: Fukushima Michihiro , Ohashi Tetsu , Kojima Michiyuki , Ohba Kiyoshi , Shimizu Hideki , Sonoyama Kei , Nakano Masuo
Published: November 2006

The effects of resistant starches of beans on serum cholesterol and hepatic low density lipoprotein (LDL) receptor mRNA in rats were investigated. Rats were fed a cholesterol‐free diet with 150 g/kg corn starch (CS), 150g/kg adzuki (Vigna angularis) starch (AS), 150 g/kg kintoki (Phaseolus vulgaris, variety) starch (KS), or 150 g/kg tebou (P. vulgaris, variety) starch (TS) for 4 wk. There were no significant differences in body weight among groups through the experimental period. The liver weight in the CS group was 1.1–1.2 times higher than that in the AS, KS, and TS groups. The cecum weight in the TS was 1.4 times higher than that in the CS group, and the cecal pH in the CS group was significantly higher than in the other groups. The serum total cholesterol, very low density lipoprotein + intermediate density lipoprotein +LDL‐cholesterol and high density lipoprotein (HDL)‐cholesterol concentrations in the bean starch groups were significantly lower than those in the CS group through the feeding period. The total cholesterol/HDL‐cholesterol ratio in the bean starch groups was also significantly lower than that in the CS group at the end of the 4‐wk feeding period. The hepatic cholesterol concentration in the TS group was significantly higher than in the CS group at the end of the 4‐wk feeding period. The relative quantity of hepatic apo B mRNA in the AS group was 1.2 times higher than that in the CS group, and the hepatic LDL receptor mRNA levels in the AS and TS groups were 1.8–2.0 times higher than that in the CS group. The results of this study demonstrate that AS, KS, and TS lowered the serum total cholesterol level by enhancing the hepatic LDL receptor mRNA level.
Cyclodehydration reactions of methyl 9,10‐; 10,12‐; and 9,12‐dioxostearates with 1,2‐diaminoethane under ultrasonic irradiation
Authors: Lie Ken Jie Marcel S. F. , Lau Maureen M. L. , Kalluri Prabhavathi
Published: November 2006

Reaction of methyl 9,10‐dioxostearate (1) and 9,12‐dioxostearate (2) with 1,2‐diaminoethane under concomitant ultrasonic irradiation (10–15 min, 60°C) in water furnished the corresponding 2,3‐dihydropyrazine (4, 79%) and 1,2,3,4‐tetrahydro‐1,4‐diazocine (5, 70%) derivatives, respectively. Reaction of methyl 10,12‐dioxostearate (3) with 1,2‐diaminoethane was successful only when glacial acetic acid was used instead of water under ultrasonic irradiation (4×10 min, 70°C) to give a 2,3‐dihydro‐1H‐1,4‐diazepine (6, 95%) derivative. The structures of these novel six‐membered (4), seven‐membered (6), and eight‐membered (5) N‐heterocyclic fatty ester derivatives were confirmed by a combination of infrared, nuclear magnetic resonance spectroscopic and mass spectral analyses.
Dialysis and gel filtration of isolated low density lipoproteins do not cause a significant loss of low density lipoprotein tocopherol and carotenoid concentration
Authors: Chopra Mridula , Fitzsimons Patricia , Hopkins Marie , Thurnham David I.
Published: November 2006

The resistance of isolated low density lipoprotein (LDL) to copper‐initiated oxidation is often used as a measure of effectiveness of an antioxidant intervention. Prior to oxidation excess salt and EDTA are removed via dialysis or gel filtration of the LDL sample. However, there is concern over whether the antioxidant content of dialyzed or gel‐filtered LDL is truly representative of native LDL extracted from a blood sample. Previously, the experiments done after the storage of native and dialyzed LDL at −80°C showed that the dialysis step can cause a loss of up to 60% in the tocopherol and carotenoid content of LDL. In the present study, a comparison of the micronutrient concentration in freshly prepared dialyzed and native LDL from 35 subjects showed that after the correction for cholesterol, only lycopene (13%, P<0.001) and to a lesser extent α‐carotene (8%, P<0.02) were significantly decreased, and the absolute fall in concentration was far smaller than previously reported. Other experiments done with smaller numbers of samples suggested that there were minimal micronutrient losses following gel filtration and that it was important to include 10 μmol/L EDTA in the dialysis and elution buffer; otherwise micronutrient losses did occur. In summary, immediate dialysis of freshly isolated LDL in the presence of 10 μmol/L. EDTA does not cause any major loss in the concentration of tocopherol and most carotenoids.
Peripheral differential leukocyte counts in humans vary with hyperlipidemia, smoking, and body mass index
Authors: Huang Zei‐Shung , Chien Kuo‐Liong , Yang Chi‐Yu , Tsai Keh‐Sung , Wang Chiu‐Hwa
Published: November 2006

Reports of diverse relationships between blood concentrations of different lipids and peripheral total leukocyte count, and a unique lower peripheral monocyte count in hypercholesterolemia, have driven us to think that in humans, peripheral differential leukocyte counts may be influenced differently by different types of hyperlipidemia. Our subjects were Taipei residents who attended a regular health check program in our hospital in 1998. A total of 3,282 subjects was enrolled, including 1,677 normolipidemic, 960 untreated borderline hyperlipidemic, and 645 untreated hyperlipidemic subjects. By one‐way analysis of variance (ANOVA), we found that different types of hyperlipidemia were associated with significant differences in differential leukocyte counts. In hypertriglyceridemia, the total leukocyte count and counts of all leukocyte subtypes were significantly higher than those in normolipidemia. Pure hypercholesterolemia, by contrast, was associated with a significantly lower monocyte count and no significant difference in other leukocyte counts. By two‐way ANOVA adjusted for presence and degree of hyperlipidemia, we found significantly higher counts of total leukocytes and of all leukocyte subtypes in smokers, and significantly positive trends in relationships between body mass index (BMI) and counts of all leukocytes, neutrophils, lymphocytes, and monocytes. By multivariate regression analysis including all subjects, the serum triglyceride (TG) level was positively correlated with total leukocyte count and counts of all subtypes except eosinophils. On the contrary, serum high density lipoprotein‐cholesterol had a negative correlation with total leukocyte count and with counts of neutrophils, monocytes, and basophils. In these multivariate regression analyses, there was no significant correlation between lipid levels and eosinophil count, whereas smoking was consistently associated with significantly higher counts of all leukocyte subtypes, including eosinophils. BMI had a significantly positive correlation with counts of all leukocytes, neutrophils, lymphocytes, and monocytes.
Incorporation and distribution of saturated and unsaturated fatty acids into nuclear lipids of hepatic cells
Authors: Ves‐Losada Ana , Maté Sabina M. , Brenner Rodolfo R.
Published: November 2006

Liver nuclear incorporation of stearic (18∶0), linoleic (18∶2n−6), and arachidonic (20∶4n−6) acids was studied by incubation in vitro of the [1‐14C] fatty acids with nuclei, with or without the cytosol fraction at different times. The [1‐14C] fatty acids were incorporated into the nuclei as free fatty acids in the following order: 18∶0>20∶4n−6≫18∶2n−6, and esterified into nuclear lipids by an acyl‐CoA pathway. All [1‐14C] fatty acids were esterified mainly to phospholipids and triacylglycerols and in a minor proportion to diacylglycerols. Only [1‐14C] 18∶2n−6‐CoA was incorporated into cholesterol esters. The incorporation was not modified by cytosol addition. The incorporation of 20∶4n−6 into nuclear phosphatidylcholine (PC) pools was also studied by incubation of liver nuclei in vitro with [1‐14C]20∶4n−6‐CoA, and nuclear labeled PC molecular species were determined. From the 15 PC nuclear molecular species determined, five were labeled with [1‐14C]20∶4n−6‐CoA: 18∶0–20∶4, 16∶0–20∶4, 18∶1–20∶4, 18∶2–20∶4, and 20∶4–20∶4. The highest specific radioactivity was found in 20∶4–20∶4 PC, which is a minor species. In conclusion, liver cell nuclei possess the necessary enzymes to incorporate exogenous saturated and unsaturated fatty acids into lipids by an acyl‐CoA pathway, showing specificity for each fatty acid. Liver cell nuclei also utilize exogenous 20∶4n−6‐CoA to synthesize the major molecular species of PC with 20∶4n−6 at the sn‐2 position. However, the most actively synthesized is 20∶4–20∶4 PC, which is a quantitatively minor component. The labeling pattern of 20∶4–20∶4 PC would indicate that this molecular species is synthesized mainly by the de novo pathway.
Bovine milk gangliosides: Changes in ceramide moiety with stage of lactation
Authors: Martín María‐Jesús , Martín‐Sosa Samuel , Hueso Pablo
Published: November 2006

The stage of lactation is one of the most important factors that influence milk composition. Changes in fatty acids from triacylglycerols and phospholipids have already been reported. In this study, we looked for a lactational change in the ganglioside lipid moeity since ganglioside contents and patterns vary strongly with stage of lactation. Individual gangliosides from four stages were isolated, methanolyzed to cleave the bonds between individual constituents, and derivatized for gas‐liquid chromatography and gas chromatography/mass spectrometry analyses. Ceramide components, both fatty acids (as methyl esters derivatives) and long‐chain bases, were identified and quantified. The results pointed to a marked change in ceramide from colostrum to milk that was characterized by a dramatic decrease in saturated and the longest‐chain fatty acids as well as an increase in 18∶1 and 18∶2. The major long‐chain base along lactation was a recently described structure, 3‐ethoxy‐15∶0 sphinganine. Other new long‐chain base structures appeared in these gangliosides. All these changes suggest differences in the fluidity of the fat globule membrane, reflecting physiological variations in cows with respect to milk production.
Optimization of methods and treatment conditions for studying effects of fatty acids on cell growth
Authors: Tronstad Karl Johan , Berge Kjetil , Flindt Esben N. , Kristiansen Karsten , Berge Rolf Kristian
Published: November 2006

Antiproliferative properties of molecular regulators of lipid metabolism have been increasingly studied during recent years. Discussion is ongoing concerning optimal treatment conditions and assays used for monitoring proliferation and cytotoxicity. The objective of the present work was to optimize methods and treatment conditions used for studying antiproliferative effects of fatty acids and analogs, represented by palmitic acid (PA) and the β‐oxidation‐restricted fatty acid analog tetradecylthioacetic acid (TTA), in rat (BT4Cn) and human (D54Mg and GaMg) glioma cell lines. Changes in [3H]thymidine incorporation preceded changes in cell number in TTA‐treated glioma cell cultures, and the growth inhibition was more significantly expressed by [3H]thymidine incorporation than cell number. Addition of bovine serum albumin decreased cellular fatty acid uptake and reduced the effects of TTA and PA on [3H]thymidine incorporation. Determination of the antiproliferative effect of TTA in BT4Cn cells by MTT conversion and [3H]thymidine incorporation yielded concordant results. TTA‐mediated reduction in cell number corresponded to reduction in cellular protein and total DNA content in BT4Cn cells. Reduced growth potential in TTA‐treated multicellular D54Mg and GaMg spheroids supported the findings from monolayer cultures. In conclusion, cell density, treatment period, fatty acid administration, and methods for growth determination may profoundly influence the outcome of cell growth experiments. Thus, experimental conditions should be carefully controlled when performing cell growth experiments, and effects on cell growth should preferably be confirmed by different methods.
Dietary supplementation with conjugated linoleic acid increased its concentration in human peripheral blood mononuclear cells, but did not alter their function
Authors: Kelley D. S. , Simon V. A. , Taylor P. C. , Rudolph I. L. , Benito P. , Nelson G. J. , Mackey B. E. , Erickson K. L.
Published: November 2006

The purpose of this study was to examine if conjugated linoleic acid (CLA) supplementation of diets would alter fatty acid (FA) composition and function of peripheral blood mononuclear cells (PBMC). Seventeen women, 20–41 yr, participated in a 93‐d study conducted at the Metabolic Research Unit. The same diet (19, 30, and 51% energy from protein, fat, and carbohydrate, respectively) was fed to all subjects throughout the study. Seven subjects (control group) supplemented their diet with six daily capsules (1 g each) of placebo oil (sunflower) for 93 d. For the other 10 subjects (CLA group), the supplement was changed to an equivalent amount of Tonalin capsules for the last 63 d of the study. Tonalin provided 3.9 g/d of a mixture of CLA isomers (trans‐10,cis‐12, 22.6%; cis‐11,trans‐13, 23.6%; cis‐9,trans‐11, 17.6%; trans‐8,cis‐10, 16.6%; other isomers 19.6%), and 2.1 g/d of other FA. PBMC isolated on study days 30 and 90 were used to assess intracellular cytokines by flow cytometry, secreted cytokines, and eicosanoid by enzyme‐linked immonosorbent assay, and FA composition by gas‐liquid chromatography. After supplementation, total CLA concentration increased from 0.012 to 0.97% (P<0.0001) in PBMC lipids, but it did not significantly alter the concentration of other FA. CLA supplementation did not alter the in vitro secretion of prostaglandin E2, leukotriene B4, interleukin‐1β (IL‐1β), or tumor necrosis factor α (TNFα) by PBMC simulated with lipopolysaccharide, and the secretion of IL‐2 by PBMC stimulated with phytohemagglutinin. Nor did it alter the percentage T cells producing IL‐2, interferon γ, and percentage of monocytes producing TNFα. The intracellular concentration of these cytokines was also not altered. None of the variables tested changed in the control group. Our results show that CLA supplementation increased its concentration in PBMC lipids, but did not alte their functions.
Incorporation of α‐linolenic acid and linoleic acid into human respiratory epithelial cell lines
Authors: Bryan Dani‐Louise , Hart Prue , Forsyth Kevin , Gibson Robert
Published: November 2006

Animal and human studies designed to examine the effects of α‐linolenic acid (ALA) and linoleic acid (LA) supplementation on the fatty acid composition of plasma and tissues have demonstrated a marked difference in incorporation into phospholipids of these 18‐carbon precursors of the long‐chain polyunsaturates. Whereas tissue phospholipid levels are linearly related to dietary ALA and LA, the levels of tissue LA can be 10‐fold higher than tissue ALA even when dietary levels are equivalent. There is some dispute whether this disparity is due to ALA being more rapidly metabolized to its products or substantially oxidized by the liver, or whether LA but not ALA is readily incorporated into cellular phospholipids. We examined the level of incorporation of polyunsaturated fatty acids into human respiratory epithelial cell lines (A549, 16HBE) by determining the dose‐dependent incorporation of ALA and LA as free fatty acid (5–150 μg FFA/mL). Cell membrane phospholipid ALA and LA were both increased up to ∼20–30% total fatty acids, with a concomitant decrease predominantly in monounsaturated membrane fatty acids, before significant toxicity was observed (50 μg/mL). Our data support the concept that rather than any inherent inability by human cells to incorporate ALA into membrane phospholipids, the lack of ALA content in human and animal tissues in vivo is due to the rapid metabolism or oxidation of this fatty acid in the liver.
The occurrence of geometric polyprenol isomers in the rubber‐producing plant, Eucommia ulmoides oliver
Authors: Bamba Takeshi , Fukusaki Ei‐ichiro , Kajivama Shin‐ichiro , Ute Koichi , Kitayama Tatsuki , Kobayashi Akio
Published: November 2006

The chain length and geometric isomerism of polyprenols from Eucommia ulmoides Oliver were analyzed using supercritical fluid chromatography. After intensive effort to establish separation conditions for geometric isomers, a phenyl‐bonded silica gel‐packed column was found that cleanly separated poly‐trans and‐cis prenols. The presence of longchain poly‐trans prenols (>9 mers) was confirmed for the first time in plants. Trans isomers were found in the leaf, seed coat, and root, but not in the bark and seed. Poly‐trans prenols in this plant may act as intermediates for trans‐polyisoprene biosynthesis.
Quantification of key odorants formed by autoxidation of arachidonic acid using isotope dilution assay
Authors: Lin Jianming , Fay Laurent B. , Welti Dieter H. , Blank Imre
Published: November 2006

Six odor‐active compounds generated by autoxidation of arachidonic acid (AA) were quantified by isotope dilution assay (IDA), i.e., hexanal (1), 1‐octen‐3‐one (2), (E,Z)‐2,4‐decadienal (3), (E,E)‐2,4‐decadienal (4), trans‐4,5‐epoxy‐(E)‐2‐decenal (5), and (E,Z,Z)‐2,4,7‐tridecatrienal (6). Compound 1 was the most abundant odorant with about 700 mg/100 g autoxidized AA, which corresponds to 2.2 mol% yield. Based on the odor activity values (ratio of concentration to odor threshold), odorants 3 (fatty) and 5 (metallic) showed the highest sensory contribution followed by 1 (green), 2 (mushroom‐like), 6 (egg white‐like), and 4 (fatty). For the first time, reliable quantitative results are reported for odorants 1–6 in autoxidized AA, in particular odorant 6, which is a characteristic compound found in autoxidized AA. Synthesis of deuterated 6, required for IDA, is described in detail. The formation of odorants 1–6 by autoxidation of AA is discussed with respect to the quantitative data.
Hyperthyroidism affects lipid metabolism in lactating and suckling rats
Authors: Varas Silvia Mabel , Jahn Graciela Alma , Giménez María Sofía
Published: November 2006

Two per thousand pregnant women have hyperthyroidism (HT), and although the symptoms are attenuated during pregnancy, they rebound after delivery, affecting infant development. To examine the effects of hyperthyroidism on lactation, we studied lipid metabolism in maternal mammary glands and livers of hyperthyroid rats and their pups. Thyroxine (10 μg/100 g body weight/d) or vehicle‐treated rats were made pregnant 2 wk after commencement of treatment and sacrificed on days 7, 14, and 21 of lactation with the litters. Circulating triiodothyronine and tetraiodothyronine concentratins in the HT mothers were increased on all days. Hepatic esterified cholesterol (EC) and free cholesterol (FC) and triglyceride (TG) concentrations were diminished on days 14 and 21. Lipid synthesis, measured by incorporation of [3H]H2O into EC, FC, and TG, fatty acid synthase, and acetyl CoA carboxylase activities increased at day 14, while incorporation into FC and EC decreased at days 7 and 21, respectively. Mammary FC and TG concentrations were diminished at day 14. Incorporation of [3H]H2O into TG decreased at days 7 and 21, and incorporation of [3H]H2O into FC increased at day 14. In the HT pups, growth rate was diminished, tetraiodothyronine concentration rose at days 7 and 14 of lactation, and triiodothyronine increased only at day 14, Liver TG concentrations increased at day 7 and fell at day 14, while FC increased at day 14 and only acetyl CoA carboxylase activity fell at day 14. Thus, hyperthyroidism changed maternal liver and mammary lipid metabolism, with decreased lipid concentration in spite of increased liver rate of synthesis and decreased in mammary synthesis. These changes, along with the mild hyperthyroidism of the litters, may have contributed to their reduced growth rate.
Docosahexaenoic acid modulates phorbol ester‐induced activation of extracellular signal‐regulated kinases 1 and 2 in NIH/3T3 cells
Authors: Denys Anne , Hichami Aziz , Maume Bernard , Khan Naim Akhtar
Published: November 2006

Phosphorylation of extracellular signal‐regulated kinases (ERK1/ERK2) has been implicated in cell proliferation of mammalian cells. In the present study, we investigated the role of docosahexaenoic acid (DHA) in the modulation of ERK1/ERK2 phosphorylation, stimulated either with phorbol 12‐myristate 13‐acetate (PMA) or transforming growth factor‐alpha (TGFα) in NIH/3T3 cells. We observed that both PMA and TGFα induced ERK1/ERK2 phosphorylation within 5 min of stimulation. PMA acts upstream of MEK and via activation of protein kinase C (PKC), as GF109203X, a potent PKC inhibitor, and U0126, a MEK inhibitor, abolished its actions on ERK1/ERK2 phosphorylation. TGFα did not act via PKC because GF109203X failed to curtail the degree of ERK1/ERK2 phosphorylation in these cells. DHA alone failed to induce the phosphorylation of these mitogen‐activated protein (MAP) kinases; however, this fatty acid significantly curtailed the PMA‐but not TGFα‐induced MAP kinase enzyme activity and phosphorylation in NIH/3T3 cells. Furthermore, we observed that DHA significantly inhibited PMA‐induced translocation of two PKC isoforms, PKCα and PKCε, from cytosol to plasma membrane. Interestingly, DHA failed to inhibit the PMA‐induced translocation PKCδ isoform in these cells. Furthermore, DHA decreased PMA‐induced proliferation of NIH/3T3 cells. In this study, we show for the first time that DHA inhibits MAP kinase (ERK1/ERK2) activation and proliferation of NIH/3T3 cells via its inhibitory action on PKCα and ε isoforms.
The genus Thapsia as a source of petroselinic acid
Authors: Avato Pinarosa , Fanizzi Francesco Paolo , Rosito Isabella
Published: November 2006

We describe the results from the isolation and structural identification of the acylglycerol constituents of fruits from wild plants belonging to different species of Thapsia (Apiaceae). The isolated lipid fractions were analyzed and characterized by chemical, chromatographic, and spectroscopic means. In particular, 13C nuclear magnetic resonance data allowed the identification of petroselinic acid as the major fatty acid esterified to glycerol in the fruit oils from all the plant samples. This was also confirmed by gas chromatography (GC) and GC‐mass spectrometry analyses of fatty acid methyl and butyl esters derivatives from Thapsia oil. The genus Thapsia should be regarded as a useful source for the extraction of petroselinic acid, which represents an important oleochemical raw material.
Absorption and effects of 3‐(N‐phenylamino)‐1,2‐propanediol esters in relation to toxic oil syndrome
Authors: Closa Daniel , Folch Emma , Calaf Rosa Elena , Abián Joaquin , Roselló‐Catafau Joan , Gelpí Emilio
Published: November 2006

Toxic Oil Syndrome (TOS) was an epidemic disease related to the consumption of rapessed oil denatured with aniline that made its sudden appearance in Spain in 1981. The fatty acid esters of 3‐(N‐phenylamino)‐1,2‐propanediol (PAP), which is a chemical class of by‐products resulting from the reaction of aniline with oil components, have shown a strong association with TOS‐related oils. These compounds also show some structural similarities to platelet‐activating factor (PAE). In search of a toxic agent that could explain the widespread systemic effects observed in TOS patients, we investigated the intestinal absorption and biotransformation of the different PAP esters found in TOS‐related oil samples and the possible pathophysiological effect of these mediators and their metabolic products if acting as PAF analogs. Results indicate that PAP esters are absorbed in the gastrointestinal tract and are distributed and stored in different organs, particularly in the liver and brown adipose tissue. PAP in these organs showed different patterns of fatty acids, indicating the ability of the gastrointestinal tract to modify the fatty acid composition of the parent PAP. Thus, the fatty acid profile of the PAP esters found in intestine appears to be related to the type of oil used as vehicle. Some of these PAP esters, when a long acyl chain was present in the sn‐1 position of the molecule, showed an inhibitory effect on the PAF synthesis. This is an important observation in line with the systemic nature of the disease.
Modulation of arachidonic acid distribution by conjugated linoleic acid isomers and linoleic acid in MCF‐7 and SW480 cancer cells
Authors: Miller Aine , Stanton Catherine , Devery Rosaleen
Published: November 2006

The relationship between growth and alterations in arachidonic acid (AA) metabolism in human breast (MCF‐7) and colon (SW480) cancer cells was studied. Four different fatty acid preparations were evaluated: a mixture of conjugated linoleic acid (CLA) isomers (c9,t11, t10,c12,c11,t13, and minor amounts of other isomers), the pure c9,t11‐CLA isomer, the pure t10,c12‐CLA isomer, and linoleic acid (LA) (all at a lipid concentration of 16 μg/mL). 14C‐AA uptake into the monoglyceride fraction of MCF‐7 cells was significantly increased following 24 h incubation with the CLA mixture (P<0.05) and c9,t11‐CLA (P<0.02). In contrast to the MCF‐7 cells, 14C‐AA uptake into the triglyceride fraction of the SW480 cells was increased while uptake into the phospholipids was reduced following treatment with the CLA mixture (P<0.02) and c9,t11‐CLA (P<0.05). Distribution of 14C‐AA among phospholipid classes was altered by CLA treatments in both cell lines. The c9,t11‐CLA isomer decreased (P<0.05) uptake of 14C‐AA into phosphatidylcholine while increasing (P<0.05) uptake into phosphatidylethanolamine in both cell lines. Both the CLA mixture and the t10,c12‐CLA isomer increased (P<0.01) uptake of 14C‐AA into phosphatidylserine in the SW480 cells but had no effect on this phospholipid in the MCF‐7 cells. Release of 14C‐AA derivatives was not altered by CLA treatments but was increased (P<0.05) by LA in the SW480 cell line. The CLA mixture of isomers and c9,t11‐CLA isomer inhibited 14C‐AA conversion to 14C‐prostaglandin E2 (PGE2) by 20–30% (P<0.05) while increasing 14C‐PGF2α by 17–44% relative to controls in both cell lines. LA significantly (P<0.05) increased 14C‐PGD2 by 13–19% in both cell lines and increased 14C‐PGE2 by 20% in the SW480 cell line only. LA significantly (P<0.05) increased 5‐hydroperoxyeicosatetraenoate by 27% in the MCF‐7 cell line. Lipid peroxidation, as determined by increased levels of 8‐epi‐prostaglandin F2α (8‐epi‐PGF2α), was observed following treatment with c9,t11‐CLA isomer in both cell lines (P<0.02) and with t10,c12‐CLA isomer in the MCF‐7 cell line only (P<0.05). These data indicate that the growth‐promoting effects of LA in the SW480 cell line may be associated with enhanced conversion of AA to PGE2 but that the growth‐suppressing effects of CLA isomers in both cell lines may be due to changes in AA distribution among cellular lipids and an altered prostaglandin profile.