bluuebunny/crossref_metadata_2025_split huggingface dataset:
Esterification of 8,11,14‐eicosatrienoate and arachidonate into alkylacyl‐ and diacylglycerophosphocholine by vascular endothelial cells
Authors: Rosenthal Miriam D. , Brown Morris E. , Jones Janet E. 
Published: November 2006

AbstractAgonist‐stimulated phospholipases release arachidonate, but not 8,11,14‐eicosatrienoate, from human endothelial cells. One source of the arachidonic acid is deacylation of 1‐alkyl‐2‐arachidonoyl‐glycerophosphocholine, with subsequent conversion of some of the resultant lysophospholipid to platelet‐activating factor. This study has compared the distribution of incorporated 8,11,14‐[14C]‐eicosatrienoate in alkylacyl‐GPC and diacyl‐GPC with that of [14C]arachidonate synthesized endogenously by desaturation of the 8,11,14‐[14C]eicosatrienoate. Cells were incubated for 24 or 48 hr with 8,11,14‐[14C]eicosatrienoate, and the resultant mixture of14C‐fatty acids in the cellular lipids was characterized by gas chromatography. The choline phospholipids were then separated, hydrolyzed with phospholipase C and derivatized to diradylbenzoates. Gas chromatographic analysis indicated extensive incorporation of [14C]eicosatrienoate, as well as [14C]arachidonate, into alkylacyl‐GPC. Although the ratio of esterified [14C]arachidonate to [14C]eicosatrienoate was greater in alkylacyl‐GPC than in diacyl‐GPC, the enrichment with [14C]arachidonate was far less than the ratio of arachidonate/eicosatrienoate released from these cells. These results thus support the hypothesis that the acyl specificity of polyunsaturated fatty acid release is provided by the agonist‐stimulated phospholipase A2 rather than the composition of the alkylacyl‐GPC.
Comparison of fatty acid and triacylglycerol metabolism of macrophages and smooth muscle cells
Authors: Bergstraesser Lynn M. , Bates Sandra R. 
Published: November 2006

AbstractThe response of macrophages and smooth muscle cells to culture in free fatty acid has been compared. Because oleate and linoleate promoted triacylglycerol enrichment of smooth muscle cells, whereas palmitate had little effect, oleate was used for these studies. The kinetics of the accumulation of triacylglycerol produced by oleate was comparable between smooth muscle cells and macrophages. When grown in increasing concentrations of oleic acid at various fatty acid to albumin molar ratios, the extent of triacylglycerol accumulation in both cell types was dependent on the concentration of oleate, the concentration of albumin, and the oleate to albumin molar ratio. However, macrophages contained 2.6‐fold more triacylglycerol than smooth muscle cells in the presence of oleate at 0.36 mM or greater and at levels of albumin higher than 0.15 mM. The cellular triacylglycerol content of macrophages was linearly related to the oleate to albumin molar ratio at both a constant albumin concentration and a constant oleate concentration, whereas the accumulation of triacylglycerol in smooth muscle cells showed a curvilinear relationship. When cells were preloaded with triacylglycerols, smooth muscle cells showed a greater loss of lipid when exposed to albumin than macrophages did. Over a two‐hr time period, macrophages incorporated twice as much labeled fatty acid as smooth muscle cells. Thus, while smooth muscle cells and macrophages showed similar responses to exogenous fatty acid and albumin, there were also significant quantitative distinctions.
Influence of dietary soybean and egg lecithins on lipid responses in cholesterol‐fed guinea pigs
Authors: O'Brien Barbara C. , Corrigan Sheila M. 
Published: November 2006

AbstractThe comparative influence on plasma and tissue lipids of dietary soybean and egg lecithins, which have contrasting fatty acid compositions, was studied in the hypercholesterolemic guine apig. The polyunsaturated to saturated fatty acid (P/S) ratios of the soybean and egg lecithins were 3.4 and 0.38, respectively. Hypercholesterolemia was induced by feeding guinea pigs a purified diet that contained 15% lard enriched with 0.5% cholesterol. Subsequently, guinea pigs were fed for six wk the same diet supplemented with either soybean or egg lecithin as 7.5% of the diet. A control group continued to be fed the lecithin‐free diet. Parameters measured included body weight and relative liver weight; in plasma, total cholesterol, high density lipoprotein cholesterol (HDLC), phospholipid, and nonesterified cholesterol; in liver, total fat, cholesterol, and the specific activity of the catabolic enzyme cholesterol 7α‐hydroxylase; (EC 1.14.13.17); and in the aorta, cholesterol. Among the most noteworthy observations were the 49% decrease in total plasma cholesterol of the soybean lecithin group without decreasing HDLC and the 177% increase in HDLC of the egg lecithin group without a significant increase in total cholesterol compared with those values in the control group. These data suggest that dietary lecithin is particularly effective in increasing the HDLC/total cholesterol ratio in plasma. However, the absolute concentrations of those plasma lipids seem to depend upon the fatty acid composition of the lecithin.
Malondialdehyde‐containing proteins and their relationship to vitamin E
Authors: Manwaring John D. , Csallany A. Saari 
Published: November 2006

AbstractA high molecular weight (Sephadex G‐15 void volume), water‐soluble, fluorescent material that was found to increase significantly in the mouse liver in response to vitamin E deficiency was separated into six proteins by high performance liquid chromatography (HPLC) using a TSK G2000 SW column. One of these proteins increased significantly in concentration due to vitamin E deficiency and had a molecular weight of 20,000 daltons. This protein was found to contain malondialdehyde, an end product of lipid peroxidation, attached to it presumably in a Schiff‐base type structure with amino groups. This appears to be the first report in the literature of direct evidence that malondialdehyde is attached to protein in vivo.
Effects of dietary corn oil and salmon oil on lipids and prostaglandin E2 in rat gastric mucosa
Authors: Grataroli Renée , Léonardi Jeannie , Charbonnier Monique , Lafont Raymond , Lafont Huguette , Nalbone Gilles 
Published: November 2006

AbstractThree groups of male rats were fed either a corn oilenriched diet (17%, w/w), a salmon oil‐enriched diet (12.5%) supplemented with corn oil (4.5%) or a low‐fat diet (4.4%) for eight wk to investigate the possible relationships between dietary fatty acids and lipid composition, and prostaglandin E2 level and phospholipase A2 activity in the rat gastric mucosa.High‐fat diets induced no important variation in total protein, phospholipid and cholesterol contents of gastric mucosa.Compared with a low‐fat diet, corn oil produced a higher n−6/n−3 ratio in mucosal lipids, whereas this ratio was markedly lowered by a fish oil diet.In comparison with the low‐fat diet, the production of prostaglandin E2(PGE2) in gastric mucosa of rats fed salmon oil was significantly, decreased by a factor of 2.8. In the corn oil group, PGE2 production tended to decrease, but not significantly.In comparison with the low‐fat diet, both specific and total gastric mucosal phospholipase A2 activities were increased (+18 and 23%, respectively) in the salmon oil group; they were unchanged in the corn oil group.It is suggested that the decrease of gastric PGE2 in rats fed fish oil is not provoked by a decrease in phospholipase A2 activity but may be the result of the substitution of arachidonic acid by n−3 PUFA or activation of PGE2 catabolism.
Perfluorodecanoic acid and lipid metabolism in the rat
Authors: Van Rafelghem Marc J. , Vanden Heuvel John P. , Menahan Lawrence A. , Peterson Richard E. 
Published: November 2006

AbstractAlterations in lipid metabolism were axamined in adult male Sprague‐Dawley rats seven days after a single intraperitoneal injection of perfluorodecanoic acid (PFDA; 20, 40 or 80 mg/kg). Because PFDA treatment caused a dose‐related reduction in feed intake, the response of vehicle‐treated rats pair‐fed to those receiving PFDA was monitored to distinguish direct effects of the perfluorinated fatty acid from those secondary to hypophagia. Carcass content of lipid phosphorus and free cholesterol decreased in dose‐dependent fashion in both PFDA‐treated and pair‐fed rats. Carcass triacylglycerols diminished in a similar manner, yet PFDA‐treated rats at each dose had a higher concentration of neutral acylglycerols than their vehicle‐treated, pair‐fed counterparts. In vehicle‐treated, pair‐fed rats at the 80 mg/kg dose level, lipid phosphorus and free cholesterol as a proportion of carcass fat increased, whereas the share of the triacyl‐glycerols declined. Because of the higher concentration of triacylglycerols in the carcass of rats treated with 80 mg/kg PFDA, enrichment of lipid phosphorus and free cholesterol in carcass fat was less than in their pair‐fed partners. The amount of lipid phosphorus and free cholesterol per hepatocyte was similar in both PFDA‐treated rats and their pair‐fed partners. Liver triacyl‐glycerols were markedly increased in PFDA‐treated rats. A similar but less extensive augmentary effect of PFDA on hepatic esterified cholesterol was found. Concentration of triacylglycerols in plasma was not elevated in PFDA‐treated rats, in spite of hepatic accumulation of esterified compounds. Also, the plasma level of free fatty acids and 3‐hydroxybutyrate was similar in all treatment groups, including those receiving PFDA. Thus, the administration of PFDA appears to divert fatty acids from oxidation toward esterification in the liver.
The phospholipid fatty acids of the marine spongeXestospongia muta
Authors: Carballeira Néstor M. , Maldonado Lilliam 
Published: November 2006

AbstractThe rare phospholipid fatty acids 3,7,11‐trimethyldodecanoic (1), 5,9‐hexadecadienoic (2) and 12‐methyl‐hexadecanoic (3) were identified in the marine spongeXestospongia muta. Branched fatty acids inX. muta accounted for 35% of the total fatty acid mixture. It was observed that the occurrence of the 5,9‐hexadecadienoic acid (2) coincides with the complete absence of the very long chain fatty acid 5,9‐hexacosadienoic. The acid 5,9,19‐octacosatrienoic seems to be found in mostXestospongia species.
The composition of furan fatty acids in the crayfish
Authors: Ishii Kazuo , Okajima Haruo , Koyamatsu Tsuyoshi , Okada Youji , Watanabe Hiroshi 
Published: November 2006

AbstractCapillary gas chromatography‐mass spectrometry (GC‐MS) analysis of the sterol ester fatty acid methyl esters of the crayfish hepatopancreas revealed the presence of at least 30 kinds of unusual furan fatty acids (F acids), which accounted for 28.49% of the total sterol ester fatty acids. On the other hand, only small amounts were found in triacylglycerols (0.5%) and phospholipids (0.7%). Among the F acids, 17 acids were the hitherto unknown ones, the major component being 12,15‐epoxy‐13,14‐dimethyleicosa‐12,14‐dienoic acid (F6) (41.83% of the total F acids). These novel acids possessed chain lengths of C12 to C22, with the largest concentration at C20 (45.38%), C18 (41.97%) and C16 (10.35%). Odd‐numbered F acids also were found, though in a very small amount (0.4%). In the living things other than the crayfish, the longest chain F acid (C24) was detected in the sterol ester of the carp hepatopancreas. The bullfrog, an amphibian, and the turtle, a reptilian, were found to have F acids as well in their livers.Olefinic furan fatty acids, which were detected by GC‐MS, were found to have resulted during the analytical process from cyclodehydration of the diketo‐ene formed by autoxidation of the F acids.
Trans fatty acids. 2. Fatty acid composition of the brain and other organs in the mature female pig
Authors: Pettersen Jan , Opstvedt Johannes 
Published: November 2006

AbstractFemale pigs were fed from three wk of age and up to two years a diet containing partially hydrogenated fish oil (PHFO, 28%trans monoenoic fatty acids), partially hydrogenated soybean oils (PHSBO, 36%trans fatty acids) or lard. No consistent differences were found between PHFO and PHSBO with regard to incorporation oftrans fatty acids in organ lipids, buttrans incorporations were highly organ‐specific. Notrans fatty acids were detected in brain phosphatidylethanolamine (PE). The incorporation of monoenoictrans isomers, as a percentage of totalcis + trans, in other organs was highest in subcutaneous adipose tissue and liver mitochondria PE, followed by blood lipids with the lowest level in heart PE. The percentage oftrans isomers compared with that of dietary lipids was consistently lower for 20∶1, compared with 18∶1 in organs from PHFO‐fed pigs. The only effect of dietarytrans fatty acids on the fatty acid pattern of brain PE was an increased level of 22∶5n−6. Heart PE and total serum lipids of pigs fed the hydrogenated fats contained higher levels of 18∶2n−6, and these lipids of the PHFO‐fed group also contained slightly elevated amounts of 20∶3n−6, 18∶3n−3 and 20∶5n−3. Liver mitochondria PE of the PHFO group also contained higher levels of 20∶3n−6 and 22∶5n−6. Dietarytrans fatty acids caused a consistent decrease of saturated fatty acids compensated by increased levels of monoenes. Thus, it may be concluded that dietary long‐chaintrans fatty acids in PHFO behaved similarly metabolically to 18∶1‐trans in PHSBO in pigs, without noticeable influence on brain PE composition and with moderate to slight effects on the fatty acid profile of the other organs.
Distal small bowel resection does not modify the intestinal 3‐hydroxy‐3‐methylglutaryl CoA reductase activity
Authors: Molina M. T. , Vazquez C. M. 
Published: November 2006

AbstractThe activity of 3‐hydroxy‐3‐methylglutaryl coenzyme‐A reductase (HMG‐CoA red.) has been evaluated in rat jejunal, caecal and colonic mucosa adapting to 50% or 75% distal small bowel resection (SBR). Six wk after surgery, the total activity and the activity state (active form) of the enzyme were determined. The results show that HMG‐CoA red. activity was stimulated per organ but not per unit mass in the mucosa adapting to SBR. As a side result, we noted regional differences in the active/total reductase ratio (RA/RT) for HMG‐CoA red. that was lower in small intestine compared with that of the large intestine.
Effect of dietary menhaden oil and vitamin E onin vivo lipid peroxidation induced by iron
Authors: Hu Miao‐Lin , Frankel Edwin N. , Tappel Al L. 
Published: November 2006

AbstractWeanling rats were fed diets containing 10% menhaden oil (MO) or 10% corn oil‐lard (1∶1, COL) with low (≤5 IU/kg) or supplementary (35 IU/kg) vitamin E for six weeks. The rats were killed 30 min after injection with 24 mg iron/kg as ferrous chloride because thiobarbituric acid‐reactive substances (TBARS) in liver homogenates were highest at 30 min after injection of iron into rats fed a standard diet. Tissue homogenates were used either without incubation (zero‐time) or after incubation at 37°C for 1 hr. In addition to TBARS and conjugated dienes, headspace hexanal and total volatiles (TOV) determined by capillary gas chromatography were useful indices of lipid peroxidation since they were decreased by vitamin E supplementation and were increased with increasing iron dose. Regardless of the dietary lipid used, vitamin E supplementation decreased headspace hexanal, TOV, TBARS and conjugated dienes in both zero‐time and incubated homogenates of liver and kidney. Dietary MO increased TBARS in both zero‐time and incubated homogenates of tissue from rats injected with iron. In contrast, dietary MO decreased hexanal and TOV in incubated tissue homogenates. The study demonstrated the usefulness and limitations of using hexanal and TOV as indices of lipid peroxidation.
Biokinetics of dietaryRRR‐α‐tocopherol in the male guinea pig at three dietary levels of vitamin C and two levels of vitamin E. Evidence that vitamin C does not “spare” vitamin Ein vivo
Authors: Burton G. W. , Wronska U. , Stone L. , Foster D. O. , Ingold K. U. 
Published: November 2006

AbstractThe net rates of uptake of “new” and loss of “old”2R,4′ R,8′ R‐α‐tocopherol (RRR‐α‐TOH, which is natural vitamin E) have been measured in the blood and in nine tissues of male guinea pigs over an eight week period by feeding diets containing deuterium‐labelled α‐tocopheryl acetate (d6‐RRR‐α‐TOAc). There was an initial two week “lead‐in” period during which 24 animals [the “high” vitamin E (HE) group] received diets containing 36 mg of unlabelled (d0)RRR‐α‐TOAc and 250 mg of ascorbic acid per kg diet, while another 24 animals [the “low” vitamin E (LE) group] received diets containing 5 mgd0‐RRR‐α‐TOAc and 250 mg ascorbic acid per kg diet. The HE group was then tivided into three equal subgroups, which were fed diets containing 36 mgd6‐RRR‐α‐TOAc and 5000 mg [the “high” vitamin C (HEHC) subgroup], 250 mg [the “normal” vitamin C (HENC) subgroup] and 50 mg [the “low” vitamin C (HELC) subgroup] ascorbic acid per kg diet. One animal from each group was sacrificed each week and the blood and tissues were analyzed ford0‐ andd6‐RRR‐α‐TOH by gas chromatography‐mass spectrometry. The LE group was similarly divided into three equal subgroups with animals receiving diets containing 5 mgd6‐RRR‐α‐TOAc and 5,000 mg (LEHC), 250 mg (LENC) and 50 mg (LELC) ascorbic acid per kg diet with a similar protocol being followed for sacrifice and analyses. In the HE group the totald0‐+d6‐)RRR‐α‐TOH concentrations in blood and tissues remained essentially constant over the eight week experiment, whereas in the LE group the totalRRR‐α‐TOH concentrations declined noticeably (except in the brain, an organ with a particularly slow turnover of vitamin E). There were no significant differences in the concentrations of “old”d0‐RRR‐α‐TOH nor in the concentrations of “new”d6‐RRR‐α‐TOH found in any tissue at a particular time between the HEHC, HENC and HELC subgroups, nor between the LEHC, LENC and LELC subgroups. We conclude that the long‐postulated “spring” action of vitamin C on vitamin E, which is well documentedin vitro, is of negligible importancein vivo in guinea pigs that are not oxidatively stressed in comparison with the normal metabolic processes which consume vitamin E (e.g., by oxidizing it irreversibly) or elminate it from the body. This is true both for guinea pigs with an adequate, well‐maintained vitamin E status and for guinea pigs which are receiving insufficient vitamin E to maintain their body stores.The biokinetics of vitamin E uptake and loss in the HE guinea pigs are compared with analogous data for rats reported previously (Lipids 22, 163–172, 1987). For most guinea pig tissues the uptake of vitamin E under “steadystate” conditions was faster than for the comparable rat tissues. However, the brain was an exception with the turnover of vitamin E occurring at only one‐third of the rate for the rat.
Chain elongation of polyunsaturated fatty acids by vascular endothelial cells: Studies with arachidonate analogues
Authors: Garcia Martha C. , Sprecher Howard , Rosenthal Miriam D. 
Published: November 2006

AbstractThis study has utilized radiolabeled analogues of arachidonic acid to study the substrate specificity of elongation of long‐chain polyunsaturated fatty acids. Human umbilical vein endothelial cells were incubated for 2–72 hr in medium supplemented with 0.9–2.6 μM [14C]fatty acid, and cellular glycerolipids were analyzed by gas‐liquid chromatography with radioactivity detection. Elongation of naturally occurring C20 polyunsaturated fatty acids occurred with eicosapentaenoate (20∶5(n−3))>Mead acid (20∶3(n−9))>arachidonate (20∶4(n−6)). Chain length markedly influenced the extent of elongation of 5,8,11,14‐tetraenoates (18∶4>19∶4>20∶4>21∶4); effects of initial double bond position were also observed (6,9,12,15–20∶4>4,7,10,13–20∶4. Neither 5,8,14‐ nor 5,11,14–20∶3 was elongated to the extent of 5,8,11–20∶3. Differences between polyunsaturated fatty acids were observed both in the initial rates and in the maximal percentages of elongation, suggesting that the content of cellular C20 and C22 fatty acids may represent a balance between chain elongation and retroconversion.Umbilical vein endothelial cells do not exhibit significant desaturation of either 22∶4(n−6) or 22∶5(n−3). By contrast, incubation with 5,8,11,14‐[14C]18∶4(n−4) resulted in formation of both [14C]20∶5(n−4) and [14C]22∶5(n−4). The respective time courses for the appearances of [14C]22∶5(n−4) and [14C]20∶5(n−5) suggests Δ6 desaturation of [14C]22∶4(n−4) rather than Δ4 desaturation of [14C]20∶4(n−4).
Cholesteryl ester analogs inhibit cholesteryl ester but not triglyceride transfer catalyzed by the plasma cholesteryl ester‐triglyceride transfer protein
Authors: Busch Steven J. , Harmony Judith A. K. 
Published: November 2006

AbstractA lipid transfer protein complex (LTC), purified from human plasma by immunoaffinity chromatography, catalyzed the interlipoprotein transfer of cholesteryl esters (CE) and triglycerides (TG). The CE transfer activity of LTC was governed by the strucutre of the CE. Incubation of LTC with long chain CE both activated and stabilized LTC. Short chain CE also enhanced the CE and TG transfer activity of LTC during the initial time of incubation. However, LTC's incubation with short chain CE induced a subsequent and time‐dependent loss of CE transfer activity without concomitant loss of TG transfer activity. The data indicate that the CE and TG transfer activity of LTC can be reglated independently.
Measurement of malondialdehyde by high performance liquid chromatography with fluorescence detection
Authors: Tatum Vickie L. , Changchit Charus , Chow Ching K. 
Published: November 2006

AbstractA method has been developed to measure malondial‐dehyde (MDA) in biological systems. MDA was reacted with 2‐thiobarbituric acid (TBA) in the presence of butylated hydroxytoluene (BHT) to minimize formation of artifacts. Initial separation of the TBA‐MDA adduct was accomplished by isobutanol extraction. Further elimination and separation of interfering substances was achieved by high performance liquid chromatography. The mobile phase consisted of a 1∶1 (v/v) mixture of methanol and water with 0.05% (w/v) tetrabutyl ammonium dihydrogen phosphate added as an ion pairing reagent. At a flow rate of 1 ml/min, the TBA‐MDA adduct was eluted from a 15‐cm, c‐18, reversed phase column in approximately 4.9 min. The TBA‐MDA adduct was quantitated with a fluorescence detector set at 515 nm excitation and 550 nm emission. Using this method, picomole quantities of MDA can be easily detected in plasma and liver samples.
Sterol composition of the phytolaccaceae and closely related families
Authors: Xu Shihua , Patterson Glenn W. 
Published: November 2006

AbstractTotal sterols were analyzed from 28 species of Phytolaccaceae and from 29 species of closely related families—Basellaceae, Portulaccaceae, Molluginaceae, and Stegnospermataceae. Eighteen of twenty‐eight species of Phytolaccaceae contained dominant Δ7‐sterols while six species had dominant Δ5‐sterols. Three species had dominant Δ0‐sterols. Sterol composition strongly reflected taxonomic position. Nineteen of twenty‐nine species from Basellaceae, Portulaccaceae, Molluginaceae, and Stegnospermataceae contained dominant Δ7‐sterols while ten species contained dominant Δ5‐sterols. Until recently Δ7‐sterols were considered rare in higher plants. It appears that a large number of species in the order Caryophyllales contain primarily Δ7‐sterols.