bluuebunny/crossref_metadata_2025_split huggingface dataset:
A high‐yield saponification of galactosylceramide I3‐sulfate
Authors: Koshy K. M. , Boggs J. M. 
Published: December 2006

AbstractA method for the deacylation of galactosylceramide I3‐sulphate using aqueous methanolic KOH is described. The combination of a relatively low concentration of the alkali (0.3 M) and a moderate reaction temperature (reflux point of 90% methanol) results in the formation of galactosylsphingosine I3‐sulphate in consistently high yields (61%) with a minimum of side reactions. The product was purified by column chromatography and its identity established by thin layer chromatography, infrared spectroscopy, determination of galactose content and organic sulphate assay using established methods or their modifications.
The absorption and transport of dietary cholesterol in the presence of peanut oil or randomized peanut oil
Authors: Tso Patrick , Pinkston Gene , Klurfeld David M. , Kritchevsky David 
Published: December 2006

AbstractPeanut oil has been shown to be unexpectedly atherogenic for cholesterol‐fed rats, rabbits and rhesus monkeys. However, randomization (rearrangement of fatty acids to random distribution) of peanut oil significantly reduced its atherogenicity for rabbits and monkeys. This study was conducted to investigate whether the absorption and transport of dietary cholesterol was altered in the presence of peanut oil or randomized peanut oil, thereby accounting for the difference in the atherogenicity of the two diets. Intestinal lymph fistula rats were infused intraduodenally with a lipid emulsion at a rate of 3 ml/hr. The lipid emulsion contained either peanut oil (control) or randomized peanut oil (experimental) (10 mM),14C‐cholesterol (1.3 mM) and sodium taurocholate (19 mM) in phosphate‐buffered saline, pH 6.4. Lymph triglyceride, cholesterol and phospholipid outputs were similar in both groups of rats during fasting and subsequently during lipid infusion. Comparable recovery of14C‐cholesterol from the intestinal lumen and the intestinal mucosa of the control and the experimental rats showed that the absorotion and transport of dietary cholesterol were similar in both groups of rats. Analyses of thefatty acid of both lymph and intestinal mucosal lipid again failed to reveal a difference between the 2 groups of rats. It is concluded that the difference in the atherogenicity between the peanut oil and the randomized peanut oil is probably caused by events subsequent to the release of cholesterol containing chylomicrons and very low density lipoproteins by the small intestinal epithelial cells.
The role of calcium in the regulation of prostacyclin synthesis by porcine aortic endothelial cells
Authors: Whorton A. R. , Willis C. E. , Kent R. S. , Young S. L. 
Published: December 2006

AbstractBoth bradykinin (EC50=8 ng/ml) and the ionophore A23187 (EC50=3×10−7 M) potently stimulated arachidonate release and prostaglandin synthesis in porcine aortic endothelial cells. The response to each was completely dependent on extracellular Ca2+ (EC50=3×10−7 M); no role for intracellular Ca2+ was noted. The rapid Ca2+ influx prompted by either activator was consistent with the time course for arachidonate release. Whereas the arachidonate released in response to bradykinin was trasient, that released in response to A23187 was more prolonged, and paralleled a continued influx of Ca2+. Ca2+ entry elicited by bradykinin was mediated by channels which could not be blocked by verapamil. When Mn2+ was substituted for Ca2+, no stimulation of prostacyclin synthesis was seen in response to A23187; however, the bradykinin response was unaffected. The mechanism of these effects was studied using doses of bradykinin or A23187 which resulted in increases in Ca2+ influx and prostacyclin synthesis of similar magnitude for each agonist. Under these conditions, trifluoperazine blocked elevated prostacyclin synthesis (ID50=5–6×10−6 M for each agonist). Trifluoperazine sulfoxide, however, was much less active. Pimozide inhibited bradykinin‐stimulated prostacyclin synthesis at low doses (ID50=3×10−6 M). Trifluoperazine was much less effective against high doses of A23187 (4×10−6 M). These data suggest that arachidonate release and prostacyclin synthesis are dependent on influx of extracellular calcium and subsequent activation of a Ca2+‐dependent phospholipase by a calmodulin‐mediated mechanism.
A unique lipid pattern associated with the gall bladder bile of the chick embryo
Authors: Noble R. C. , Connor K. 
Published: December 2006

AbstractA study has been made of the lipid and fatty acid composition of the gall bladder bile of the chick embryo during the last week of incubation. The lipids and their fatty acid composition showed a unique pattern when compared to other animal species. Of the total lipid present, phospholipid accounted for less than half, and there were substantial proportions of both cholesteryl ester and triglyceride. In the cholesteryl ester, the proportion of which increased significantly over the last week of incubation, there was a very high level of oleic acid. The phospholipid contained a high level of arachidonic acid. The results are discussed in relation to observations on the biliary lipids of other animal species and the major features of the lipid metabolism of the chick embryo during the last week of incubation.
A nuclear magnetic resonance spectroscopic investigation of the headgroup motions of lysophospholipids in bilayers
Authors: Wu W. , Stephenson' F. A. , Mason J. T. , Huang C. 
Published: December 2006

AbstractFully hydrated lysophospholipids in both the gel and the liquid crystalline states have been shown to exhibit negative phosphorus chemical shift anisotropies (Δσ) by31P nuclear magnetic resonance (NMR). The magnitude of Δσ for monoacyl lysophospholipids is found to be smaller than that of the corresponding diacyl phosphospholipids in bilayers by about a factor of two. We present evidence to suggest that the reduction in Δσ can be attributed primarily to an additional motional averaging of the lysophospholipid headgroup, and the additional motion can best be explained by rapid rotational motions of the headgroup about the C(1)‐C(2) glycerol bond.
Australian fish—An excellent source of both arachidonic acid and ω‐3 polyunsaturated fatty acids
Authors: Gibson R. A. 
Published: December 2006

AbstractThe fatty acid methyl esters obtained by the esterification of total lipids extracted from 24 species of fin fish and 4 species of invertebrates caught in the rivers and coastal waters of southern Australia were analyzed by gas chromatography. The lipids of most species contained significant levels of arachidonic acid (0.7–15.8%) as well as the more common marine polyunsaturate, eicosapentaenoic acid (0.7–15.9%). The major ω6 fatty acid present in most species was 20∶4; however, other fatty acids of this series, including 18∶2, 22∶4 and 22∶5, were present. The level of total ω6 fatty acids ranged from 3.9 to 22.3% of the total lipid. In general, the level of total ω3 polyunsaturates was higher than the total ω6 fatty acids with levels of ω3 fatty acids ranging from 9.6 to 48.2%. Only 2 fish (barramundi and gurnard perch) had ω6/ω3 ratios greater than 1.0. Most of the Australian species examined contained low levels of fat (0.5–7.8% of fresh weight). Two species examined, callop (freshwater) and blue groper (marine) contained sufficient quantities of both fat (7.7 and 7.8%) and arachidonic acid (4.8 and 9.3%) to warrant consideration for commercial exploitation.
Acyl group distributions in tissue lipids of rats fed evening primrose oil (λ‐linolenic plus linoleic acid) or soybean oil (α‐linolenic plus linoleic acid)
Authors: Høy C. ‐E. , Hølmer G. , Kaur N. , Byrjalsen I. , Kirstein D. 
Published: December 2006

AbstractThree groups of rats were fed diets with either 10 weight percent (wt%) of evening primrose oil, safflower oil or soybean oil for 11 weeks. Diets contained 7.1 wt% linoleic acid +0.8 wt% γ‐linolenic acid, 7.6 wt% linoleic acid, or 5.3 wt% linoleic acid +0.7 wt% α‐linolenic acid, respectively. In liver mitochondria as well as in heart, dietary γ‐linolenic acid did not affect the fatty acid profiles of phosphatidylcholnes (PC), phosphatidylethanolamines (PE) or cardiolipins (CL), whereas dietary α‐linolenic acid caused an increased formation of (n−3) polyunsaturated fatty acids (PUFA). The liver Δ6− and Δ5‐desaturase activities determined in vitro were not affected by the dietary fats. In brain PE, which are rich in C22− and C20‐(n−3) PUFA, as well as in testes PC and PE, which are rich in (n−6) PUFA, no effects were found from a partial replacement of dietary linoleic acid with γ‐linolenic acid or α‐linolenic acid. In kidney PC, PE, phosphatidylinositol (PI) and CL, 20∶3(n−6) was moderately elevated to ca. 1% following intake of γ‐linolenic acid, whereas partial replacement of linoleic acid with α‐linolenic acid was followed by increased deposition of 22∶6(n−3) in PC and PE of testes and kidney. Thus, no general effect of evening primrose oil on the content of (n−6) PUFA in rat tissue phospholipids was observed, wheras a significant incorporation of γ‐linolenic acid into liver and adipose tissue triglycerides was found.
Oleic acid transfer from microsomes to egg lecithin liposomes: Participation of fatty acid binding protein
Authors: Catala Angel , Avanzati Beatriz 
Published: December 2006

AbstractOleic acid transfer from microsomes or mitochondria to egg lecithin liposomes was stimulated by fatty acid binding protein. By gel filtration, it could be demonstrated that this protein incorporates oleic acid into liposomes. Fatty acid binding protein transfer activity was higher using microsomes rather than mitochondria, which suggests a selective interaction with different kinds of membranes. Transfer of oleic acid by this soluble protein is greater than that of stearic acid. The results indicate that fatty acid binding protein may participate in the intracellular transport of fatty acids.
1‐O‐alkyl‐linked phosphoglycerides of human platelets: Distribution of arachidonate and other acyl residues in the ether‐linked and diacyl species
Authors: Mueller Howard W. , Purdon A. David , Smith J. Bryan , Wykle Robert L. 
Published: December 2006

AbstractIn this study, the 1‐O‐alkyl‐2‐acyl‐sn‐glycero‐3‐phosphocholine content of human platelets was determined. The distribution of arachidonate among the 1,2‐diacyl, 1‐O‐alkyl‐2‐acyl, and 1‐O‐alk‐l′‐enyl‐2‐acyl classes of choline‐ and ethanolamine‐containing phosphoglycerides was also assessed. The major platelet phospholipids were choline‐containing phosphoglycerides (38%), ethanolamine‐containing phosphoglycerides (25%) and sphingomyelin (18%), with smaller amounts of phosphatidylserine (11%) and phosphatidylinositol (4%). In addition to the diacyl class, the choline‐linked fraction was found to contain both 1‐O‐alkyl‐2‐acyl (10%) and 1‐O‐alk‐l′‐enyl‐2‐acyl (9%) species. The ethanolamine‐linked fraction, on the other hand, had an elevated level of the 1‐O‐alk‐l′‐enyl‐2‐acyl (60%) species and a small amount of the 1‐O‐alkyl‐2‐acyl component (4%). The major fatty acyl residues found in all classes of the choline and ethanolamine phospholipids were 16∶0, 18∶0, (Δ9), 18∶2(n−6) and 20∶4(n−6). The 1‐O‐alk‐l and 1‐O‐alk‐l′‐enyl fraction of the ethanolamine‐linked phospholipids also contained substantial amounts of 22∶4(n−6), 22∶5(n−3) and 22∶6(n−3) acyl chains. Arachidonate comprised 44% of the acyl residues in thesn‐2 position of 1‐O‐alkyl‐2‐acyl‐sn‐glycero‐3‐phosphocholine. Corresponding values for the diacyl and 1‐O‐alk‐l′‐enyl‐2‐acyl species were 23% and 25%, respectively, based on all 20∶4(n−6) being linked to thesn‐2 position of all classes. In the ethanolamine‐linked phosphoglycerides, arachidonate constituted 60%, 20% and 68% of the acyl groups in thesn‐2 position of the 1,2‐diacyl, 1‐O‐alkyl‐2‐acyl and 1‐O‐alk‐l′‐enyl‐2‐acyl classes, respectively. The content of 1‐O‐alkyl‐2‐acyl‐sn‐glycero‐3‐phosphocholine appears sufficient to support the synthesis of platelet activating factor by a deacylation‐reacylation pathway in platelets. Our findings also demonstrate that human platelets contain a significant amount of 1‐O‐alkyl‐2‐arachidonyl‐sn‐glycero‐3‐phosphocholine that could possibly serve as a precursor of both platelet activating factor and bioactive arachidonate metabolites.
A comparison of the positional distribution of fatty acids in milk triglycerides of the extant monotremes platypus (Ornithorhynchus anatinus) and echidna (Tachyglossus aculeatus)
Authors: Parodi Peter W. , Griffiths Mervyn 
Published: December 2006

AbstractMilk triglycerides from the platypus were subjected to fatty acid and stereospecific analysis to determine the positional distribution of fatty acids in the triglycerides. Of the major fatty acids, 12∶0 was preferentially esterified at thesn‐3 position, 14∶0 and 16∶0 were selectively associated with thesn‐2 position, and 18∶0 was located predominantly at thesn‐1 position. The unsaturated fatty acids, 14∶1, 16∶1, 18∶1, 18∶2 and 18∶3, were preferentially esterified at thesn‐3 position. The fatty acid distribution pattern of the platypus, a monotreme, is similar to that of marsupials and eutherians but is in contrast to the only other extant monotreme, the echidna.
Biphasic action of platelet‐activating factor on isolated guinea‐pig ileum
Authors: Tokumura A. , Harada K. , Fukuzawa K. , Tsukatani H. 
Published: December 2006

Abstract1‐0‐Hexadecyl‐2‐0‐acetyl‐sn‐glycero‐3‐phosphocholine (platelet‐activating factor) at 10−10‐10−9 M induced slow contraction of isolated guinea‐pig ilcal muscles and the contraction persisted for a long time. At a higher concentration of 10−7 M, this phospholipid induced more rapid, but not greater, contraction. At higher concentrations (10−6‐10−5 M), this phospholipid induced a biphasic response: rapid contraction followed by relaxation. At high concentrations, this compound inhibited acetylcholine‐induced contractions. The stimulatory effect of this phospholipid was ca. 300 times that of 1‐palmitoyl‐2‐0‐acetyl‐sn‐glycero‐3‐phosphocholine, while its inhibitory potency on induced contraction was similar to those of 1‐palmitoyl‐2‐0‐acetyl‐sn‐glycero‐3‐phosphocholine and its lyso derivative. It was suggested that the differences in effects on contraction of different concentrations of 1‐0‐hexadecyl‐ and 1‐palmitoyl‐2‐0‐acetyl‐sn‐glycero‐3‐phosphocholine were due to the dual effects of these compounds on the ileum: a strong stimulatory effect and a moderate inhibitory effect on contraction.
Effect of chlorpromazine on rat arterial lipid synthesis, in vitro
Authors: Bell Frank P. , Hubert Edna V. 
Published: December 2006

AbstractThe effect of chlorpromazine, a major tranquilizer, on arterial lipid metabolism was studied in vitro in rat aortas incubated with [14C] acetate and [14C] mevalonate as lipid precursors. Chlorpromazine at a level of 0.25 mM in the incubation medium significantly reduced the incorporation of [14C] acetate into free fatty acids (p<0.01) and total phospholipids (p<0.001) but not triglycerides. Chlorpromazine also altered the pattern of arterial phospholipids synthesized from [14C] acetate by significantly increasing the relative proportion of phosphatidylinositol plus phosphatidylserine (p<0.02) and reducing the relative proportion of sphingomyelin (p<0.001). [14C] Acetate incorporation into the combined fractions of steryl esters plus hydrocarbons and sterols plus diglycerides was also significantly reduced (p<0.001) by 0.25 mM chlorpromazine. Studies with [14C] mevalonate showed that chlorpromazine is also an inhibitor of sterol biosynthesis in arterial tissues as evidenced by 35–40% reductions (p<0.05) in the formation of14C‐labeled squalene and C27 sterols.
The effects of phosphate on the biosynthesis of cholesterol in rat liver homogenates
Authors: Hotta S. Steven 
Published: December 2006

AbstractThe biosyntheses of cholesterol from acetate and mevalonate were determined in rat liver homogenates that were prepared and incubated in buffers containing varying concentrations of phosphate. Relatively little acetate or mevalonate was incorporated into cholesterol in the absence of added phosphate. When phosphate was added, there was an increase in incorporation of both substrates. The addition of phosphate resulted in an increase in the incorporation of mevalonate to a maximum, whereas phosphate appeared to increase the incorporation of acetate at low phosphate levels and decrease the incorporation at higher phosphate levels. The results appear to be consistent with the possibility that, at low phosphate levels, the biosynthesis of cholesterol is limited by some phosphaterequiring reaction(s) in the pathway after mevalonate, and at higher phosphate levels, the biosynthesis is limited by the 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase‐catalyzed step.
Effect of vitamin E on pentane exhaled by rats treated with methyl ethyl ketone peroxide
Authors: Herschberger L. A. , Tappel Al L. 
Published: December 2006

AbstractOne useful method to monitor in vivo lipid peroxidation is the measurement of volatile hydrocarbons, mainly pentane and ethane, that derive from unsaturated fatty acid hydroperoxides. Vitamin E, the biological antioxidant, inhibits lipid peroxidation and the production of pentane and ethane. The rates of pentane production by male Sprague‐Dawley rats fed a diet that contained 10% vitamin E‐stripped corn oil and 0, 1, 3, 5 or 10 IU dl‐α‐tocopherol acetate/kg were monitored over a 12‐wk period. During the eleventh and twelfth weeks, the rats were injected intraperitoneally with 3.3 and 13 mg of methyl ethyl ketone peroxide (MEKP)/kg body wt, respectively. Pentane production was then measured at intervals over a 50‐min period, and the total amount of pentane produced over this time interval was estimated. An asymptotic function was found to describe the relationship between exhaled pentane and the low levels of dietary vitamin E that were fed to the rats. As measured by pentane production, rats had a higher minimal vitamin E requirement after they were treated with the potent peroxidation initiator MEKP than they did prior to treatment. The level of pentane exhaled by rats injected with 13 mg MEKP/kg body wt was significantly correlated with kidney and spleen tocopherol levels.
Hydrolysis of triglycerides in the isolated perfused rat lung
Authors: Compton Suzanne K. , Hamosh Margit , Hamosh Paul 
Published: December 2006

AbstractThe purpose of this study was to investigate the hydrolysis of saturated and unsaturated triglycerides by lung lipoprotein lipase and to measure the incorporation of triglyceride fatty acids into lung tissue lipids. Lipolytic activity was studied in the isolated ventilated rat lung, perfused for 100 min in a recycling system with Krebs Ringer bicarbonate containing bovine serum albumin, 5.6 mM glucose, and 1.5 or 10 mM triglyceride. Saturated triglycerides were hydrolyzed at significantly (p<0.05) lower rates than unsaturated triglycerides; tricaprylin, trimyristin and tripalmitin were hydrolyzed at 8.1+1.8, 5.4+1.5 and 9.5+1.8 μmol free fatty acids/g dry wt/100 min, respectively, whereas triolein and trilinolein were hydrolyzed at 20.2+1.8 and 20.6+0.3 μmol free fatty acids/g dry wt/100 min, respectively. The polyunsaturated triglycerides, trilinolein and triarachidonin were hydrolyzed at even higher rates (44.3+3.0 and 50.9+5.4 μmol free fatty acids/g dry wt/100 min, respectively). Intralipid infused at a concentration of 10 mM triglyceride was hydrolyzed at a significantly higher rate than at 1.5 mM triglyceride (58+6.3 μmol free fatty acids/g dry wt/100 min vs 16.6+1.7 μmol free fatty acids/g dry wt/100 min, respectively). Labeled unsaturated triglycerides were broken down at significantly higher rates than labeled saturated triglycerides. Incorporation of triglyceride‐fatty acid into lung lipid was greater into neutral lipids than into phospholipids. The data suggest that (a) the factors that appear to affect lung lipoprotein lipase activity are composition and concentration of circulating triglyceride, (b) uptake of fatty acids into the tissue was proportional to the rate of hydrolysis of the emulsion, and (c) triglyceride‐fatty acids could therefore be used by the lung for metabolic needs.
cis‐5‐olefinic unusual fatty acids in seed lipids of gymnospermae and their distribution in triacylglycerols
Authors: Takagi Toru , Itabashi Yutaka 
Published: December 2006

AbstractOpen‐tubular gas chromatographic analysis of fatty acids in the lipids from the seeds of 20 species of Gymnospermae showed that they all contained nonmethylene‐interrupted polyenoic (NMIP) acids as minor components and palmitic, oleic, linoleic and α‐linolenic acids as major components. The NMIP acids have an additional 5,6‐ethylenic bond in ordinary plant unsaturated fatty acids and the following C2 elongation acids:cis‐5,cis‐9‐octadecadienoic acid (5,9–18∶2) (I); 5,9,12–18∶3 (II); 5,9,12,15–18∶4, 5,11–20∶2, 5,11,14–20∶3 (III); and 5,11,14,17–20∶4 (IV). The main NMIP acids found in neutral lipids are I in two species ofTaxus, II in seven species of Pinaceae, III in two species of Podocarpaceae,Torreya nucifera, Cycas revoluta, andGinkgo biloba, and III and IV in each of three species of Taxodiaceae, and Cupressaceae. The polar lipids constitute the minor fraction of seed lipids in general. The content and composition of NMIP acids in these lipids differe considerably from those in neutral lipids. Analysis of the partial cleavage products of triacylglycerols showed that the NMIP acids distribute mainly in the 1,3‐position.
Preferential oxidation of linolenic acid compared to linoleic acid in the liver of catfish (Heteropneustes fossilis andClarias batrachus)
Authors: Bandyopadhyay Gautam K. , Dutta Jyotirmoy , Ghosh Sudhamoy 
Published: December 2006

AbstractThe fate of [1‐14C] linoleic acid and [1‐14C] linolenic acid in the liver slices and also in the liver tissues of live carnivorous catfish,Heteropneustes fossilis andClarias batrachus, was studied. Incorporation of the fatty acids into different lipid classes in the live fish differed greatly from the tissue slices, indicating certain physiological control operative in vivo. The extent of desaturation and chain elongation of linoleic and linolenic acids into long‐chain polyunsaturated fatty acids was low. Linolenic acid was oxidized (thus labeling the saturated fatty acid with liberated14C‐acetyl‐CoA) in preference to linoleic acid, and this oxidation also seemed to be under physiological control since both of the fatty acids were poorly oxidized in the tissue slices and in the killed fish. These fish can therefore recognize the difference in the acyl chain structures of linoleate and linolenate. The higher oxidation of liolenic acid and poor capacity for its conversion to longer chain, highly unsaturated derivatives indicates a higher demand for the dietary supply of these essential fatty acids in these two species.