bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition of desaturation of stearic acid in livers of rats fed ethionine
Authors: Lyman R. L. , Fosmire M. A. , Giotas C. , Miljanich P. 
Published: November 2006

AbstractThe effect of ethionine on the conversion of stearic acid to oleic acid was studied. Rats were fed essential fatty acid (EFA) deficient diet for three weeks, after which time half the animals were fed 0.25% DL‐ethionine for nine additional days. Seventeen hours prior to killing, they were fed a slurry of the diet containing 18‐14C‐stearic acid. Liver triglycerides and phospholipids were extracted and separated and their fatty acid composition and the distribution of radioactivity between stearic and oleic acid was determined. In the tissues studied, oleic acid was maintained at control levels in ethionine‐fed rats, but eicosatrienoic acid was significantly depressed. Distribution of radioactivity and specific activity of oleic acid in the triglycerides and phospholipids were significantly reduced by the analogue. In vitro studies of desaturation and chain elongation reactions, with liver microsomes, using 18‐14C‐stearic and 1‐14C‐linoleic acids as substrates, showed that ethionine depressed the synthesis of oleic acid from stearic and γ‐linolenic from linoleic acid. Elongation of linoleic adie to a 20∶2 fatty acid was unaffected by ethionine. Therefore, the results showed that ethionine inhibited desaturation of stearic to oleic acid in vivo and in vitro and probably also impaired the desaturation of oleic to octadeca‐6, 9‐dienoic acid. Maintenance of control levels of oleic acid in the tissues of ethionine‐fed, EFA deficient rats suggested the presence of synthetic pathways for oleic acid other than via desaturation of stearic acid.
Fatty acid composition of the neutral lipids and individual phospholipids of muscle of cold‐stressed arctic mice
Authors: Eybel Carl E. , Simon R. Gerald 
Published: November 2006

AbstractFatty acids of the individual phospholipids and total neutral lipid fractions in skeletal muscle of three species of Arctic mice were identified and quantitated after the mice had been classified as control, cold‐sensitive or cold‐resistant. The results indicate that some species increase the percentage of unsaturated fatty acids as an apparent result of cold exposure and some species do not. A common finding for all cold‐sensitive mice was a significant increase in 14∶0 in phosphatidic acid when compared to cold‐resistant and control animals. Hypotheses are presented in an attempt to explain this finding.
Effect of culture temperature on fatty acid composition ofChlorella sorokiniana
Authors: Patterson Glenn W. 
Published: November 2006

AbstractChlorella sorokiniana was grown for extraction of fatty acids at seven temperatures ranging from 14 C to 38 C. The predominant fatty acids inC. sorokiniana grown at 38 C were saturated (46% of total); at 22 C, triunsaturated (40% of total); and at 14 C diunsaturated (47% of total). Increasing temperature resulted in an increase in the degree of unsaturation from 14 C to 22 C, but further increases in temperature always resulted in a decrease in unsaturation. At any point in the temperature range used, an increased temperature always resulted in fatty acids with a lower average chain length. Total fatty acid production was greatest at the extremes of temperature and lowest at 26 C. The chain length and degree of saturation of fatty acids increased at temperatures lower than 22 C. Therefore, the fatty acids ofC. sorokiniana do not have an increasingly lower melting point when the culture temperature is reduced at temperatures 22 C or below.
Desaturation of saturated fatty acids by rat liver microsomes
Authors: Paulsrud John R. , Stewart Sheila E. , Graff Gustav , Holman Ralph T. 
Published: November 2006

AbstractA method was developed for the rapid determination of the initial velocity of the desaturation of saturated fatty acids. In the reaction, DPNH was a more efficient electron donor than TPNH. Fatdeficient rats have a 2.5‐fold greater level of acyl desaturase per milligram of liver microsomal protein than did animals fed lab chow. Increasing the chain length of the acyl substrate from 10∶0 to 18∶0 increases the rate of monoene formation, but 19∶0 is desaturated at a rate lower than that for 15∶0. The energy of activation (Ea) for the overall desaturation reaction has been determined for 12∶0 through 19∶0. The Ea values for desaturation of 13∶0 and 16∶0 are markedly lowr than for the other acids. An interaction between the alkyl chain of the substrate and polyunsaturated acids of the microsomal membrane‐bound phospholipids is postulated to explain the recurring 3‐carbon pattern of the relative reaction rates of the various acyl substrates.
The metabolism of linoleic and arachidonic acids in rat testis
Authors: Bridges Raymond B. , Coniglio John G. 
Published: November 2006

AbstractLinoleic and arachidonic acids, labeled with14C and injected intratesticularly, were used to study with time the interconversion of polyunsaturated fatty acids in rat testis and their incorporation into the major lipid classes. With both substrates14C activity was readily incorporated into longer chain, more highly unsaturated fatty acids. After the injection of 1‐14C‐linoleic acid the major portion of the14C was found in palmitic, linoleic, 8,11,14‐eicosatrienoic, 5,8,11,14‐eicosatetraenoic, 7,10,13,16‐docosatetraenoic and 4,7,10,13,16‐docosapentaenoic acids. Hydrogenation of the total fatty acids isolated from rat testes after intratesticular injection of 1‐14C‐linoleate revealed that the polyenoic acids hydrogenating to lignoceric acid (previously characterized as 9,12,15,18‐tetracosatetraenoate and 6,9,12,15,18‐tetracosapentaenoate) had a relatively high specific activity. After the injection of 1‐14C‐arachidonate significant14C activity was found in palmitate, 7,10,13,16‐docosatetraenoate, 4,7,10,13,16‐docosapentaenoate, 9,12,15,18‐tetracosatetraenoate and 6,9,12,15,18‐tetracosapentaenoate. The biosynthesis of the ω6 polyunsaturated fatty acids in rat testis is discussed in relation to these data. Investigation of the distribution of label in the complex lipid fractions demonstrated the majority of the14C activity to be present in phosphatides and triglycerides after injection of either of these14C substrates with only small quantities being present as nonesterified acids. At the time periods studied the polyenoic acids of triglycerides had a higher specific activity than the corresponding acids of phosphatides with the exception of linoleate.
The synthesis of phosphatidylethanolamine and phosphatidylserine containing acetylenic or cyclopropane fatty acids and the activity of these phosphatides in blood coagulation
Authors: Turner D. L. , Silver M. J. , Baczynski E. , Holburn R. R. , Herb S. F. , Luddy F. E. 
Published: November 2006

AbstractSix different phosphatides were made by combination of phosphorus oxychloride and eithert‐butyloxycarbonylaminoethanol or the phthalimidomethyl ester of anisyloxycarbonyl‐L‐serine with three different diglycerides. The diglycerides wererac‐1,2‐distearoloylglycerol,rac‐1‐stearoloyl‐2‐stearoylglycerol, andrac‐1,2‐di(9,10‐methyleneoctadecanoyl) glycerol. The phosphatides were freed of protective groups by methods that did not cause rupture of the cyclopropane rings. The resulting phosphatides were purified by chromatography and evaluated for their effects on blood coagulation in vitro after solubilization with sodium desoxycholate. The phosphatidyl(distearoloyl)serine and the phosphatidyl di(9,10‐methyleneoctadecanoyl) serine were as active as beef brain phosphatidylserine in the antithromboplastin test and the Hicks‐Pitney test. The phosphatidyl(stearoloyl, stearoyl)serine was slightly less active in the Hicks‐Pitney test. The phosphatidylethanolamines accelerated coagulation in the Hicks‐Pitney test. The cyclopropane phosphatidylethanolamine was also tested in a test of prothrombin conversion using all purified components and was found to be active. The high activity of the cyclopropane phosphatidylserine is specially important because of its resistance to autoxidation.
The effect of hydrogen peroxide on serum lecithin‐cholesterol acytransferase activity
Authors: Mickel Hubert S. , Foulds Emmett L. 
Published: November 2006

AbstractGlomset has reported an acyltransferase in plasma which effects the transfer of a fatty acid from the beta position of lecithin to cholesterol, forming cholesteryl esters. Peroxide is shown to have an inhibitory effect on the enzyme activity in a concentration of 0.1 M. There is a variable effect with a concentration of 0.01 M, with a stimulation of activity in some sera, while in others an inhibition. The addition of a synthetic saturated lecithin does not cause a reversal of the inhibition at 0.1 M H2O2.
Lipid alterations and their reversion in the central nervous system of growing rats deficient in essential fatty acids
Authors: Galli C. , White H. B. , Paoletti R. 
Published: November 2006

AbstractEssential fatty acid (EFA) deficiency modifies several biological parameters, i.e., growth, metabolic rate and water balance and induces functional changes in liver, kidney and lung tissues. The brain fatty acid changes reported in the literature are generally smaller than those observed in other tissues. However, EFA deficiency initiated in rats prior to birth and continued for a prolonged period of time results in decreased brain weight, brain lipid and phospholipid content and in considerable changes in polyunsaturated fatty acid distribution, especially in the ethanolamine phosphoglyceride fraction. The unsaturation level of this phospholipid is maintained at a constant level in spite of the fatty acid distribution changes. Brain lipid analyses, carried out at various time intervals in EFA deficient animals, indicate that brain weights are already reduced in 10‐day‐old deficient rats, that brain phospholipids decrease, especially in the males after three months, and that fatty acid distribution changes begin rather early. The latter consist of a decrease of tetraenes and increase of trienes and of the triene‐tetraene ratios as early as at 10 days, a decrease of hexaenes after six months, and after six months, an increase of pentaenes, which are elevated at birth but usually disappear after three months of age. Similar changes are observed in myelin. The induced changes are not completely reversed upon return to normal diet.
Effect of EFA deficiency on lipid transport from liver
Authors: Fukazawa Toshio , Privett O. S. , Takahashi Yoshiyata 
Published: November 2006

AbstractStudies are reported of the effect of an essential fatty acid (EFA) deficiency on synthesis of triglycerides (TG) and phospholipids (PL) and secretion of these compounds by livers of male Sprague‐Dawley rats. Animals were fed a semipurified diet containing corn oil or hydrogenated coconut oil (HCO) as the sole source of fat or no fat from weaning to 20 weeks of age. Liver function of the animals in each group was compared by an isolated liver perfusion technique with perfusates containing erythrocytes and linoleate, and in vivo experiments via tail vein injection of palmitate‐3H. Perfusion experiments showed that an EFA deficiency reduced the ability of the liver to secrete TG and PL. Accumulation of TG in the liver and its diminished secretion into the blood of EFA deficient animals were demonstrated by in vivo experiments with palmitate‐3H. The rate of conversion of linoleate to arachidonate and synthesis of PL was greater in livers of EFA deficient rats than in the control, corn oil fed animals. The results suggest a relationship of EFA metabolism to lipid transport.
Deposition of cyclopropenoids in the tissue lipids of rainbow trout fed methyl sterculate
Authors: Roehm J. N. , Lee D. J. , Sinnhuber R. O. , Polityka S. D. 
Published: November 2006

AbstractGroups of young rainbow trout were fed diets containing 0, 100 and 200 ppm methyl sterculate. Their tissue lipids were analyzed for cyclopropene content using the modified Halphen test. Halphenpositive compounds, calculated as sterculic acid, accumulated in all tissues analyzed and reached concentrations approximately equal to those of the dietary lipid. Gas liquid chromatography used in conjuction with mild hydrogenation of the cyclopropene ring revealed that these Halphen‐positive compounds were predominantly, if not entirely, sterculic acid which was esterified in the triglycerides. To facilitate analysis of cyclopropenes in liver tissue, a method was developed whereby interfering pigments were removed prior to the Halphen test.
Renal cerebroside in globoid cell leukodystrophy (Krabbées disease)
Authors: Suzuki Kunihiko 
Published: November 2006

AbstractThe kidney tissues of five patients with globoid cell leukodystrophy (Krabbées disease) and of seven agematched normal individuals were analyzed for the content of galacto‐and glucocerebrosides. There was a statistically significant increase of galactocerebroside (+25%) in the pathological specimens. However, glucocerebroside was also similarly increased (+30%). Therefore, despite the genetic defect of the degradative enzyme, galactocerebroside β‐galactosidase, there is no specific accumulation of galactocerebroside in the kidneys of patients with globoid cell leukodystrophy.
The incorporation of phosphorylethanolamine into the phospholipids of brain microsomes in vitro
Authors: Porcellati G. , Biasion M. G. , Arienti G. 
Published: November 2006

AbstractSynthesis of ethanolamine phosphoglycerides (EPG) from labeled14C‐phosphorylethanolamine (PE) and cytidine triphosphate (CTP) has been studied in vitro in particles and in soluble fractions of chicken brain. The microsomal membranes can carry out this conversion, but supplementing the microsomes with an enzymic fraction derived from the particle‐free supernatant results in a noticeable increase of the rate of EPG synthesis. Mitochondria are almost inactive, in this connection. The conversion of PE to lipid is very low, in no case exceeding 0.5–0.6%, even in the presence of diacyl glycerols or 1‐alkenyl 2‐acyl glycerol. No stimulation occurs by supplementing the incubation system with natural lipid acceptors, intermediates of lipid synthesis, energy‐producing cofactors or monoacylsn‐glycero‐3‐phosphorylethanolamine (GPE), monoacylsn‐glycero‐3‐phosphorylcholine (GPC) and other lipid material. From these and other results, the conclusion is made that the PE:CTP cytidylyltransferase (E.C. 2.7.7.14) must display very low activity in vitro, thus limiting the overall rate of synthesis from PE. Diacyl GPE is the only lipid which has been found labeled after incubation with PE of the brain preparations. A small synthesis of alkenyl acyl GPE takes place, only when PE is incubated with suitable concentrations of a plasmalogenic diglyceride.
Fatty acid composition of human and rat adrenal lipids: Occurrence of ω6 docosatrienoic acid in human adrenal cholesterol ester
Authors: Takayasu Ken , Okuda Kunihiko , Yoshikawa Iwao 
Published: November 2006

AbstractFatty acids in human and rat adrenal lipids were analyzed by AgNO3‐impregnated silica gel, thin layer chromatography and gas liquid chromatography (GLC). In human adrenal cholesterol ester, 26 kinds of fatty acids were estimated. The percentage of 18∶1 was highest, and 20∶3ω6 and 22∶4ω6 represented high percentages in polyenoic acids. Docosatrienoate was found in all the five men, representing from 1.0% to 2.8%. Its retention time on GLC was different from that of 22∶3ω9 found in the adrenal cholesterol ester of fat deficient rats. The methyl esters of dicarboxylic acids produced by KMnO4‐oxidation of the docosatrienoate had a chain of 10 carbon atoms. These results elucidate that the docosatrienoate from human adrenal cholesterol ester belongs to the linoleate family. In the adrenal cholesterol ester of 10‐week fat free rats, the percentages of 22∶4ω6 and 22∶5ω6 did not decrease, compared with control rats, though arachidonate apparently decreased. The adrenal phospholipid contained about 20% of arachidonate in four of five men and about 40% of arachidonate in rats. Much more polyenoic acids were found in the triglyceride of an adrenal adenoma of primary aldosteronism than in the adjacent adrenal tissue, shereas the fatty acid compositions of phospholipid and cholesterol ester in the adenoma resembled those in the adjacent tissue.
Fatty acid and long chain base composition of adrenal medulla gangliosides
Authors: Ledeen Robert , Salsman Kenneth 
Published: November 2006

AbstractFive ganglioside fractions from bovine adrenal medulla were analyzed with respect to their fatty acid and long chain base compositions. The five fractions included two hematosides and three hexasamine‐containing species, the latter having chromatographic properties comparable to the major gangliosides of brain. The fatty acid compositions of all five were similar: 22∶0 was the most abundant, but significant amounts of 16∶0, 18∶0, 24∶0 and 24∶1 were also present. No hydroxy fatty acids were detected. The principal long chain base in each fraction was 4‐sphingenine (sphingosine), with lesser amounts of the C16 and C17 homologues. Minor quantities of the corresponding saturated bases were also detected. These were identified by two gas liquid chromatography methods: (a) trimethylsilyl ether derivatives, (b) aldehydes formed by periodate oxidation of the long chain bases. No 4‐eicosasphingenine (C20‐sphingosine), characteristic of brain gangliosides, was found in any of the fractions. The results demonstrate that gangliosides of the adrenal medulla show tissue specificity in fatty acid and long chain base composition which is independent of carbohydrate structure.
Blood α‐tocopherol: Erythrocyte and plasma relationships in vitro and in vivo
Authors: Poukka R. K. H. , Bieri J. G. 
Published: November 2006

AbstractWhen rat plasma labeled with3H‐α‐tocopherol was incubated with tocopherol‐deficient red cells, uptake of radioactivity by cells was rapid with a maximum being reached in 6–8 hr. The equilibrium ratio of red cell‐plasma α‐tocopherol, from 0.3–0.6, was independent of the initial plasma concentration. When labeled red cells were incubated with tocopherol‐deficient plasma, radioactivity in plasma became maximal in 11.5 hr. When both plasma and cells had normal α‐tocopherol concentrations initially, the rate of exchange was similar in either direction with equilibrium of specific activity being attained in 6 hr. After a single oral dose of3H‐α‐tocopherol the activity in both plasma and cells reached a maximum in 8 hr and then fell rapidly during the next four days. The ratio of red cell‐plasma radioactivity at all intervals after 8 hr was 0.5.
Biosynthesis of triglycerides from triose phosphates by microsomes of intestinal mucosa
Authors: Ananda Rao G. , Sorrels M. F. , Reiser Raymond 
Published: November 2006

AbstractMicrosomes of hamster intestinal mucosa synthesize triglycerides from dihydroxyacetone phosphate or DL‐glyceraldehyde 3‐phosphate in the presence of palmitate, ATP, CoASH and NADPH or NADH but in the absence of soluble enzymes. An inhibitor of triose phosphate isomerase, 1‐hydroxy‐3‐chloro‐2‐propanone phosphate, completely inhibits glyceride synthesis from glyceraldehyde 3‐phosphate. This compound does not inhibit glyceride synthesis from dihydroxyacetone phosphate. These reactions confirm the conversion of glyceraldehyde 3‐phosphate to dihydroxyacetone phosphate prior to glyceride synthesis.
Effect of bound gossypol in cottonseed meal on enzymic degradation
Authors: Cater Carl M. , Lyman Carl M. 
Published: November 2006

AbstractThe nutritive value of cottonseed protein is lowered by the presence of bound gossypol. Samples of cottonseed protein containing from 0.003% to 1.03% bound gossypol were hydrolyzed enzymically and the amounts of free amino acids released were determined. The amounts of amino acids contained in peptides not precipitated by 1% picric acid were also determined. The proportionate reduction in the release of free and peptide amino acids in the presence of bound gossypol was noted. Although the amount of lysine released is reduced in the presence of bound gossypol as expected, there is a markedly larger reduction in the release of a number of other amino acids.
Triose phosphates as precursors of glyceride biosynthesis by rat liver microsomes
Authors: Puleo L. E. , Ananda Rao G. , Reiser R. 
Published: November 2006

AbstractWashed rat liver microsomes synthesize phosphatidate and di‐ and triglycerides from dihydroxyacetone phosphate (DHAP) or DL‐glyceraldehyde 3‐phosphate (DL‐GAP) and fatty acids. The cofactors required in either case are ATP, CoASH, Mg++, and either NADH or NADPH. NADH is twice as active as NADPH. In the presence of γ‐32P‐ATP, 1‐14C‐palmitate, CoASH and NADH, the combined actions of glycerol kinase (ATP‐glycerol phosphotransferase EC 2.7.1.30), and microsomes convert dihydroxyacetone to phosphatidate with the molar ratio of14C∶32P approximately 2∶1. Since glycerol 3‐phosphate dehydrogenase (L‐glycerol 3‐phosphate: NAD oxidoreductase EC 1.1.1.8) is not present in microsomes, the synthesis of glycerides from either DHAP or GAP need not occur via their conversion to glycerol 3‐phosphate (GP). However, the presence of triose phosphate isomerase (D‐glyceraldehyde 3‐phosphate:ketol‐isomerase EC 5.3.1.1) in microsomes, suggests the conversion of GAP to DHAP during glyceride synthesis. The requirement for this conversion was confirmed by the use of 1‐hydroxy‐3‐chloro‐2‐propanone phosphate (HCPP), an irreversible inhibitor of triose phosphate isomerase. The synthesis of glycerides from DL‐GAP was completely inhibited by HCPP, whereas that from DHAP was not.
A simple preparative procedure for the rapid isolation of phytosphingosine from the yeastHansenula ciferrii
Authors: Weiss Benjamin , Stiller Richard L. 
Published: November 2006

AbstractPhytosphingosine and dihydrosphingosine were isolated as a mixture of their N‐acetyl derivatives from the cells of the yeastHansenula ciferrii. After alkaline hydrolysis of the N‐acetyl compounds, the free base mixture was reacted with either acetone orp‐nitrobenzaldehyde. The reaction products consisting of the carbonyl derivative of phytosphingosine and free dihydrosphingosine were separated on an acetyl cellulose column. The acetone orp‐nitrobenzaldehyde derivative of phytosphingosine recovered from the benzene eluate contained no dihydrosphingosine as determined by thin layer and gas liquid chromatography. The operating time from preparation of the derivative through column purification was less than 3 hrs. Mass spectrometry of the acetone andp‐nitrobenzaldehyde derivatives disclosed in each case that ring closure with the carbonyl reagent involved the amino and primary hydroxyl groups to giveD‐ribo‐2‐dimethyl‐4‐(2,3‐dihydroxyhexadecyl) oxazolidine andD‐ribo‐2‐p‐nitrophenyl‐4‐(2,3‐dihydroxyhexadecyl) oxazolidene, respectively.
Interaction of detergents with transfusion gelatin
Authors: Malik W. U. , Ashraf S. M. 
Published: November 2006

AbstractBinding of sodium dodecyl and octyl sulphate to transfusion gelatin has been studied at pH 7.7 by equilibrium dialysis. At lower detergent concentration the binding is statistical, whereas at higher concentrations the binding increases apparently without limit. This may be explained by assuming unfolding of the protein molecule with formation of detergent micelles around the binding sites.