bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lipids of dermatophytes. III. Sterol‐induced changes in the lipid composition and functional properties ofEpidermophyton floccosum
Authors: Sanadi S. , Pandey R. , Khuller G. K. 
Published: November 2006

AbstractSterol supplementation, alone or in the presence of cerulenin, resulted in an increase in the total sterol content ofEpidermophyton floccosum. While the total phospholipid levels ofE. floccosum exhibited only marginal changes with sterol supplementation, the fatty acid profiles of these phospholipids were highly varied. In the presence or absence of cerulenin, the oleic acid content of phospholipids were increased significantly by cholesterol supplementation, whereas linoleic acid levels were enhanced by ergosterol supplementation. These variations resulted in higher unsaturated/saturated phospholipid fatty acid ratios in sterol‐supplemented cells. The uptake of labeled amino acids (aspartic acid, lysine, glycine) was influenced by sterol supplementation. Alterations in the number of binding sites for the membrane probe, 1‐anilino‐naphthalene‐8‐sulfonate (ANS), were seen based on Scatchard plot calculations. The results indicate a correlation between sterol‐induced changes in membrane lipid composition and function.
Occurrence of cholesterol as a major sterol component in leaf surface lipids
Authors: Noda Manjiro , Tanaka Mitsunobu , Seto Yukari , Aiba Takaaki , Oku Chiyo 
Published: November 2006

AbstractCholesterol has been detected as one of the major sterols in the surface lipids of higher plant leaves. It was widely distributed among the plant leaves of various species as a common main sterol component with a few exceptions. The content of cholesterol amounted to 71.5% of the total sterols in the surface lipids of rape leaves. However, the proportion of cholesterol in the intracellular lipids of rape leaves was lower than that in the surface lipids, and the seed lipids contained only a trace amount of cholesterol, as reported in the literature. In the leaf surface lipids examined, a minor amount of cholestanol associated with cholesterol often was detected by capillary gas chromatography and gas chromatography‐mass spectrometry. The related analysis for the surface lipids of fruits showed that cholesterol was one of the major component sterols also in those lipids of several species.
Premalignant alterations in the glycosphingolipids of small intestinal mucosa of rats treated with 1,2‐dimethylhydrazine
Authors: Dahiya R. , Dudeja P. K. , Brasitus T. A. 
Published: November 2006

Abstract1,2‐Dimethylhydrazine is a procarcinogen with selectivity for the colon and proximal small intestine. In weekly subcutaneous (s.c.) doses of 20 mg/kg body weight, this agent produces colonic and proximal small intestinal tumors in a high percentage of rodents with a latency period of approximately six months. To determine whether alterations in the glycosphingolipid content of rat proximal and/or distal small intestinal mucose existed before the development of dimethylhydrazine‐induced cancer, rat were given s.c. injections of this agent (20 mg/kg body weight per wk) or diluent for five wk. Animals were killed at this time, and mucosa was isolated from each small intestinal segment of both groups. Glycosphingolipids then were extracted from these tissues and analyzed by high performance thin layer chromatography and gas liquid chromatography.The results of these studies demonstrated that (1) the content of neutral and acidic glycosphingolipids was significantly decreased (approximately 20%) in the proximal small intestine of treated rats compared with their control counterparts; (2) no significant difference in the glycosphingolipid content was seen, however, in the distal small intestinal mucosa of control and treated rats; and (3) while significant differences were noted in the majority of fatty acids of GM3, glucosyl‐ and globotriaosylceramide in the proximal small intestine of control and treated animals, differences in the fatty acids of these glycosphingolipids in the distal segment of these groups were confined to stearic (18∶0) acid and/or arachidic (20∶0) acid.
Analysis of cardiac membrane phospholipid peroxidation kinetics as malondialdehyde: Nonspecificity of thiobarbituric acid‐reactivity
Authors: Janero David R. , Burghardt Barbara 
Published: November 2006

AbstractWhen exposed to xanthine oxidase (superoxide)‐dependent, iron‐promoted Fenton chemistry, purified cardiac membranes evidenced, by the thiobarbituric acid (TBA) test, a virtually instantaneous peroxidative response with a maximal linear rate of 5.8 nmol malondialdehyde (MDA)‐equivalents/mEquivalents lipid ester reacted/min. Yet when the lipids purified from these same membranes and reconstituted into liposomes were peroxidized under identical reaction conditions, the TBA test indicated that a pronounced (∼20‐min) lag period preceded a maximal peroxidation rate of only 2.1 nmol MDA‐equivalents/ mEquivalents lipid ester reacted/min. After 120 min of peroxidation, the cardiac membranes yielded some 300 nmol TBA‐reactive MDA‐equivalents/mEquivalent ester, whereas the isolated membrane lipids evidenced ∼40% less TBA‐reactivity. To verify that these quantitative and kinetic differences in membrane (phospho)‐lipid peroxidation occurred with removal of the lipids from their membrane milieu, the MDA produced during both cardiac membrane peroxidation and the peroxidation of the lipids derived therefrom was isolated as its free anion by ion‐pair high‐pressure liquid chromatography. As quantified spectrophotometrically, true MDA production during myocardial membrane peroxidation was identical in kinetics and in amount to the production of TBA‐reactive substance from the peroxidized isolated membrane lipids. These results demonstrate that significant non‐MDA. TBA‐reactive species are generated during the peroxidation of cardiac membranes, especially before the maximal rates of bona fide MDA production. As a direct consequence, artifactual levels and kinetics of membrane lipid peroxidation do result.
Lack of protein‐mediated α‐tocopherol transfer between membranes in the cytoplasm of acites hepatomas
Authors: Mowri Hiro‐omi , Nojima Shoshichi , Inoue Keizo 
Published: November 2006

AbstractTransfer‐stimulating activity for α‐tocopherol and the concentration of α‐tocopherol and peroxidized lipids in rat ascites hepatoma cells were compared with those from normal and regenerating liver.The ability of supernatants from ascites hepatomas (AH‐13, AH‐60C, AH‐109A) to enhance the transfer of α‐tocopherol was much lower than that from normal livers. The α‐tocopherol per mg protein of supernatant from ascites hepatomas was lower than that from normal liver. Regenerating liver showed almost the same values as normal liver in activity to stimulate the transfer of α‐tocopherol and α‐tocopherol content of the supernatant. By gel filtration, about 60% of α‐tocopherol in the supernatant of normal liver was detected in the fractions containing the 30 K protein, which stimulates transfer of α‐tocopherol between membranes, whereas no significant amount of α‐tocopherol was detected in 30 K protein fractions of AH‐60C supernatant. Little stimulating activity for α‐tocopherol transfer was detected in AH‐60C, AH‐109A and AH‐13.All ascites hepatomas tested contained less arachidonic acid and docosahexaenoic acid than normal and regenerating liver. An absorption peak with maximum intensity at 233 nm, which is due to conjugated dienes, was observed in UV‐absorption spectra of ascites hepatoma total lipids, indicating that peroxidized lipids accumulate in these cells. With normal and regenerating liver, no significant peak due to conjugated dienes was detected.
Effect of 7‐methylated bile acids and bile alcohols on cholesterol metabolism in hamsters
Authors: Matoba Naoyuki , Kuroki Syoji , Cohen Bertram I. , Mosbach Erwin H. , McSherry Charles K. 
Published: November 2006

AbstractThe effect of 7‐methyl substituted bile acid and bile alcohol analogues on cholesterol metabolism was studied in the hamster. Animals were fed chow plus 0.1% cholesterol supplemented with 0.1% of one of the following steroids: chenodeoxycholic acid, 7‐methyl‐chenodeoxy‐cholic acid, 7β‐methyl‐24‐nor‐5β‐cholestane‐3α,7α,25‐triol, cholic acid, 7‐methyl‐cholic acid, or 7β‐methyl‐24‐nor‐5β‐cholestane‐3α,7α,12α,25‐tetrol. Cholesterol absorption was determined from fecal analysis after feeding of radiolabeled cholesterol and β‐sitosterol.Of the six compounds studied, chenodeoxycholic acid and 7‐methyl‐chenodeoxycholic acid decreased intestinal cholesterol absorption (17% and 31% decrease, respectively). Only 7‐methyl‐chenodeoxycholic acid decreased serum cholesterol concentration (29% decrease), but there were no analogous changes of liver and biliary cholesterol concentration and cholesterol saturation of bile. Total fecal neutral sterol excretion was increased in the groups fed chenodeoxycholic acid and 7‐methyl‐chenodeoxycholic acid. In addition, the production of coprostanol was increased in both groups. These data suggest that 7‐methyl‐chenodeoxycholic acid resembles chenodeoxycholic acid in its effect on cholesterol metabolism and may be a potential candidate for further studies of its gallstone‐dissolving properties.
Compensatory mechanisms in erythrocyte lipids in patients with atherosclerosis
Authors: Michalak Jerzy , Kadziolka Adam , Pruszkowska Romualda , Ledwozyw Andrzej , Madejczyk Andrej 
Published: November 2006

AbstractThe quantitative coposition of phospholipids and fatty acids of erythrocytes was investigated in patients with atherosclerosis. It was stated that the erythrocyte lipids of atherosclerotic patients contained smaller quantitities of phosphatidylcholine and phosphatidylinositol, a significantly larger quantity of sphingomyelin, and higher sphingomyelin/phosphatidylcholine and cholesterol/phospholipid ratios. The existence of compensatory changes was stated, which was evident in the reduction of palmitic and stearic acids and the increase of linoleic and eicosatrienoic acids in erythrocyte phospholipids. These changes in fatty acid composition probably cause minimal changes in the membrane fluidity indiced by an increased cholesterol/phospholipid and sphingomyelin/phosphatidylcholine ratios. This paper was the first evidence of occurrence of those changes in erythrocytes during spontaneous atherosclerosis in human
Determination of individual long‐chain fatty acyl‐CoA esters in heart and skeletal muscle
Authors: Molaparast‐Saless F. , Shrago E. , Spennetta T. L. , Donatello S. , Kneeland L. M. , Nellis S. H. , Liedtke A. J. 
Published: November 2006

AbstractA method has been developed for determination of individual long‐chain fatty acyl‐CoA esters from heart and skeletal muscle using high performance liquid chromatography (HPLC). The esters were extracted from freezeclamped tissue of pig and rat hearts and rat skeletal muscle for analysis on a radially compressed C18 5μ reversephase column. Nine peaks in the extract with carbon chain lengths from C12 to C20 that subsequently disappeared on alkaline hydrolysis were identified. The major acyl‐CoA peaks were 14∶1, 18∶2, 16∶0 and 18∶1 and additionally in rat heart 18∶0. Total long‐chain acyl‐CoA esters obtained by summation of the individual molecular species was 11.34±1.48 nmol/g wet wt. pig heart; 14.51±2.11 nmol/g wet wt. in rat heart, and 4.35±0.71 nmol/g wet wt. in rat skeletal muscle. These values were approximately 132% of those obtained using a separate procedure that measured total CoA by HPLC after alkaline hydrolysis of the esters. The described method demonstrates the quantitation of individual acyl‐CoA species in muscle tissue. Therefore, it has a number of advantages in that it permits information to be obtained on the individual molecular species under various nutritional and metabolic conditions.
Influence of diet on (n−3) and (n−6) fatty acids in monkey erythrocytes
Authors: Carman Martha A. , Beare‐Rogers Joyce L. 
Published: November 2006

AbstractCynomolgus monkeys were fed oils high in linoleic acid or with half of the linoleic acid replaced by either (n−3) linolenic acid or marine fatty acids. When the diet contained similar quantities of linoleic and (n−3) linolenic acid, erythrocyte fatty acids maintained a ratio of (n−6) to (n−3) fatty acids of approximately 2∶4. Fatty acids from menhaden oil enhanced the incorporation of eicosapentaenoic and docosahexaenoic acids into the monkey erythrocytes, the composition of which was not altered by additional α‐tocopherol.
Stimulation of liver growth and DNA synthesis by glucosylceramide
Authors: Datta Subhash C. , Radin Norman S. 
Published: November 2006

AbstractThe nature of the growth‐stimulating effect of glucosylceramide was studied. Mice were injected intraperitoneally with emulsified glucosylceramide and conduritol B epoxide, an inhibitor of cerebroside glucosidase. Within one or two days, the liver grew 18–24%, as reported. Two enzymes involved in DNA synthesis also increased more than the weight. The total liver activity of thymidine kinase increased 46–73%, and the total activity of ornithine decarboxylase increased as much as 101%. It is suggested that elevated liver levels of glucocerebroside stimulate cell proliferation through a relatively direct mechanism.
Adipose hormone‐sensitive lipase preferentially releases polyunsaturated fatty acids from triglycerides
Authors: Gavino Victor C. , Gavino Grace R. 
Published: November 2006

AbstractRat adipose hormone‐sensitive lipase‐mediated release of fatty acids from triglycerides was studied in three model systems: i) cultured preadipocytes containing polyunsaturated fatty acid‐enriched triglyceride; ii) perfused epididymal fat pads; and iii)in vitro incubations of crude preparations of hormone‐sensitive lipase with synthetic triglyceride‐analogues as substrates. We found that cultured preadipocytes challenged with 10μM norepinephrine tended to release more ω6 and ω3 polyunsaturated fatty acids than saturated fatty acids. Fat pads perfused with 10 μM norepinephrine preferentially released arachidonate and α‐linolenate but tended to retain oleate and linoleate. Finally, crude preparations of hormonesensitive lipase released from the triglyceride‐analogue substrates α‐linolenate twice as fast as oleate. We conclude that rat adipose hormone‐sensitive lipase preferentially releases polyunsaturated fatty acids from triglycerides. We suggest that this may be a mechanism by which these fatty acids are kept from being trapped in fat depots and maintained in the circulation.
Production of the criegee ozonide during the ozonation of 1‐Palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phosphocholine liposomes
Authors: Squadrito Giuseppe L. , Uppu Rao M. , Cueto Rafael , Pryor William A. 
Published: November 2006

AbstractIt is likely that Criegee ozonides are formed in small amounts in the lungs of animals breathing ozone‐containing air. This makes these compounds potential candidates to act as secondary toxins which relay the toxic effects of ozone deeper into lung tissue than ozone itself could penetrate. Therefore, we have determined the yields of Criegee ozonides from unsaturated lipids in liposomal systems as a model of the types of yields of Criegee ozonides that might be expected both in the lung lining fluid layer and in biological membranes. Ozonation of 1‐palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phosphocholine liposomes produced bothcis‐ andtrans‐Criegee ozonides. These ozonides have been isolated by solid phase extraction and high‐performance liquid chromatography of the ozonized lipid, and the products have been identified by two‐dimensional1H nuclear magnetic resonance. The combined yield of thecis‐ andtrans‐Criegee ozonides is 10.7±2.8% (avg. ±SD, n=7) with small unilamellar liposomes and 10.6±2.7% (n=3) with large multilamellar liposomes. We had previously reported (Chem. Res. Toxicol. 5 505–511, 1992) that ozonation of methyl oleate in sodium dodecylsulfate micelles also produces an 11% yield of the Criegee ozonides. Thus, ozonation in a variety of models gives about 11% of the Criegee ozonide, suggesting that these products also would be formed in small but significant amounts in the lungs of animals breathing polluted air. Further research on the pharmacokinetics and possible toxicity of the Criegee ozonides of fatty acids is suggested.
Eicosapentaenoic acid at hypotriglyceridemic dose enhances the hepatic antioxidant defense in mice
Authors: Demoz Abraham , Willumsen Nina , Berge Rolf Kristian 
Published: November 2006

AbstractThe effect of oral administration of purified (95%) eicosapentaenoic acid on serum lipids, hepatic peroxisomal enzymes, antioxidant enzymes and lipid peroxidation was compared with that of palmitic acid fed mice and corresponding controls. After 10 d, a dose of 1000 mg eicosapentaenoic acid per day/kg body weight lowered serum triglycerides by 45%, while no significant change in serum cholesterol level was noted in comparison to palmitic acid fed mice and controls. Hepatic acyl‐CoA oxidase and catalase activities increased by 50% and 30%, respectively, in the eicosapentaenoic acid fed group. In addition, the hepatic reduced glutathione content and the activities of glutathione transferase, glutathione peroxidase and glutathione reductase, increased significantly during eicosapentaenoic acid treatment. The levels of hepatic lipid peroxides were lower after eicosapentaenoic acid feeding, while no significant change was noted in the palmitic acid fed mice when compared to the controls. Taken together, the present data demonstrate for the first time that at hypolipidemic doses eicosapentaenoic acid feeding i) enhances the hepatic antioxidant defense, and ii) does not cause a significant differential induction of the two peroxisomal enzymes, acyl‐CoA oxidase and catalase, as was noted after administration of hypolipidemic peroxisome proliferating compounds, such as clofibrate in rodents.
Zinc deficiency in the rat alters the lipid composition of the erythrocyte membrane triton shell
Authors: Driscoll Eric R. , Bettger William J. 
Published: November 2006

AbstractThe effect of dietary zinc deficiency on the lipid composition of the erythrocyte membrane Triton shell was determined. Weanling male Wistar rats were fed an egg white‐based diet containing <1.0 mg Zn/kg dietad libitum. Control rats were either pair‐fed orad libitum‐fed the basal diet supplemented with 100 mg Zn/kg diet. A Zn refed group was fed the −Zn diet until day 18 and then pairfed the +Zn diet until day 21. Dietary, Zn deficiency caused an increased cholesterol/phospholipid ratio in Triton shells compared to those from pair‐fed controls. Zn deficiency caused a decreased double bond index of fatty acids in phosphatidylinositol (PI) and phosphatidylcholine (PC); there was a decreased proportion of 18∶2n−6 and 22∶4n−6 in PC and 20∶4n−6 in PI as compared to that found in pair‐fed controls. All glycerophospholipids that were retained in the shell had a lower double bond index and increased content of 16∶0 and/or 18∶0 relative to the phospholipid in the intact membrane.
Lipid composition of subcellular membranes from larvae and prepupae ofDrosophila melanogaster
Authors: Jones Helen E. , Harwood John L. , Bowen Ivor D. , Griffiths Gareth 
Published: November 2006

AbstractSubcellular membranes were analyzed for their lipid composition and protein content at two developmental points representing the third instar wandering larvae and prepupal stages ofDrosophila. At both stages, phosphatidylethanolamine (PE) and phosphatidylcholine (PC) were the major constituents with phosphatidylinositol (PI), phosphatidylserine (PS), diphosphatidylglycerol (DPG) and phosphatidic acid (PA) being relatively minor components. In total homogenates and in the nuclear‐enriched fraction there was no significant difference in the phospholipid composition of the wandering larvae and prepupae. In mitochondria only a significant increase in the minor component PS was observed in the prepupae. In lysosomal membranes on the other hand, the relative abundance of the major components PE and PC increased in the prepupae although the molar ratios of the two lipids remained almost constant. The fatty acid composition of the phospholipids remained virtually unchanged in all of the fractions examined, including the lysosomes, and there was no evidence of lipid peroxidation. With regard to cellular degeneration and the involvement of lysosomes, we conclude that mechanisms other than gross modification of the lipid and/or lipid/protein ratio of their membranes are involved in the liberation of the acid phosphatase contents.
Free fatty acids inducing mouse lethal toxicity in lipid extracts ofEngraulis japonica, the Japanese anchovy
Authors: Sajiki Junko , Takahashi Katsuhiro 
Published: November 2006

AbstractMouse lethal toxicity was detected in the ether extract ofEngraulis japonica (anchovy). The mouse toxicity of extracts was more potent from viscera than from other organs. Okadaic acid (C44H68O13) and dinophysistoxin (C45H70O13), lipophilic toxins derived from phytoplankton, which are usually considered to be the diarrhetic shellfish toxins, were not detected in the ether extract of ancovy. There occurred, however, two prominent peaks in high‐performance liquid chromatography, which were identified as free eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The mouse toxicity observed correlated with the intensity of these two peaks. Toxicity was reduced considerably by pretreatment with Na2CO3. By quantitating EPA toxicity, it was concluded that the toxicity was not due to EPA only but also to DHA. The results indicate that substances in Japanese anchovy associated with mouse lethal toxicity include free polyunsaturated fatty acids, mainly EPA and DHA.
Palmitic acid enhances cholesterol gallstone incidence in sasco hamsters fed cholesterol enriched diets
Authors: Ayyad Nariman , Cohen Bertram I. , Mosbach Erwin H. , Miki Shigeo 
Published: November 2006

AbstractIn an established hamster model of cholesterol cholelithiasis, a semipurified lithogenic diet containing 4% butterfat and 0.3% cholesterol leads to the production of cholesterol gallstones in only 50–60% of animals after a 6‐wk feeding period. The purpose of this study was to investigate whether gallstone incidence could be increased while feeding a nutritionally adequate diet of moderate cholesterol content. The semipurified lithogenic diet was modified as follows: (i) substitution of 1.2% palmitic acid for 4% butterfat, and (ii) varying the amount of dietary cholesterol from 0.0 to 0.3% with either butterfat or palmitic acid as the lipid component of the diet. Substitution of palmitic acid for butterfat produced a significantly higher incidence of cholesterol gallstones (94%vs. 53%). Palmitic acid also raised the incidence of gallstones when added to the 0.1% and 0.2% cholesterol diets as compared to butterfat: 0%vs. 44% and 50%vs. 81%, respectively. Gallstone incidence increased from 0% to nearly 100% when the cholesterol content of the palmitic acid diets was raised from 0.0% to 0.3%, indicating a dose response effect with respect to dietary cholesterol. Hamsters fed cholesterol‐free diets did not form gallstones. Increased dietary cholesterol led to increased liver weight associated with a significant increase in liver cholesterol concentration. However, the palmitic acid groups had significantly lower liver cholesterol values than the corresponding butterfat groups. Serum and biliary cholesterol concentrations increased with increasing dietary cholesterol intake, but there were no differences between the butterfat and palmitic acid groups. The cholesterol saturation index increased from 0.56 to 1.32 in the butterfat groups and from 0.56 to 1.30 in the palmitic acid groups upon raising the dietary cholesterol from 0.0 to 0.3%. Biliary total bile acid concentration did not vary significantly within all groups; however, the addition of cholesterol produced an increase in the ratio of chenodeoxycholic acid to cholic acid. It is concluded that in Sasco hamsters the saturated fatty acid, palmitic acid, when substituted for butterfat in a nutritionally adequate lithogenic diet, is capable of increasing gallstone incidence to almost 100% during a 6‐wk feeding period.