bluuebunny/crossref_metadata_2025 huggingface dataset:
Lipid, sterol and fatty acid composition of antarctic krill (Euphausia superba Dana)
Authors: Fricke H. , Gercken G. , Schreiber W. , Oehlenschläger J.
Published: November 2006

The lipid classes, fatty acids of total and individual lipids and sterols of Antarctic krill (Euphausia superba Dana) from two areas of the Antarctic Ocean were analyzed by thin layer chromatography (TLC), gas liquid chromatography (GLC) and gas liquid chromatography/mass spectrometry (GLC/MS). Basic differences in the lipid composition of krill from the Scotia Sea (caught in Dec. 1977) and krill from the Gerlache Strait (caught in Mar. 1981) were not observed. The main lipid classes found were: phosphatidylcholine (PC) (33–36%), phosphatidylethanolamine (PE) (5–6%), triacylglycerol (TG) (33–40%), free fatty acids (FFA) (8–16%) and sterols (1.4–1.7%). Wax esters and sterol esters were present only in traces. More than 50 fatty acids could be identified using GLC/MS, the major ones being 14∶0, 16∶0, 16∶1(n−7), 18∶1(n−9), 18∶1(n−7), 20∶5(n−3) and 22∶6(n−3). Phytanic acid was found in a concentration of 3% of total fatty acids. Short, medium‐chain and hydroxy fatty acids (C≤10) were not detectable. The sterol fraction consisted of cholesterol, desmosterol and 22‐dehydrocholesterol.
Comparative study of lipogenic enzymes in several vertebrates
Authors: Iritani Nobuko , Ikeda Yumiko , Fukuda Hitomi , Katsurada Akihiko
Published: November 2006

The liver lipogenic enzymes are compared among rats, chickens, frogs and fish. Although the apparent Km values of glucose‐6‐phosphate dehydrogenase for glucose‐6‐phosphate are not much different among all the species, those of malic enzyme for malate are much higher in chickens and fish than in rats and frogs. Glucose‐6‐phosphate dehydrogenase showed very high activities compared with malic enzyme in fish liver, and malic enzyme showed high activities in chicken liver. Although the apparent Km values of acetyl‐CoA carboxylase and fatty acid synthetase for substrates are in the same range among all the animals, the activity of acetyl‐CoA carboxylase seems to be extremely low in fish and frog livers, and that of fatty acid synthetase is low in frog livers only. In addition, the apparent Km values of α‐glycerophosphate acyltransferase of fish liver are very high, and the enzyme activity appears to be extremely low compared to the others. Therefore, the enzymes at the first steps of both fatty acid and glycerolipid syntheses of poikilothermos animals appear to be very low. On the other hand, the Ouchterlony double‐diffusion patterns showed that the lipogenic enzymes of chickens, frogs and fish are immunologically different from those of rats, with the exception of acetyl‐CoA carboxylase in chickens. Therefore, it is suggested that the fatty acid and glycerolipid forming systems of poikilothermos animals are quite different from those of homoiothermos and the lipogenesis is very low in poikilothermos.
Urinary malondialdehyde as an indicator of lipid peroxidation in the diet and in the tissues
Authors: Draper H. H. , Polensek L. , Hadley M. , McGirr L. G.
Published: November 2006

Although malondialdehyde (MDA) is extensively metabolized to CO2, small amounts are nevertheless excreted in an acid‐hydrolyzable form in rat urine. In this study, urinary MDA was evaluated as an indicator of lipid peroxidation in the diet and in the tissues. MDA was released from its bound form(s) in urine by acid treatment and determined as the TBA‐MA derivative by HPLC. MDA excretion by the rat was found to be responsive to oral administration of the Na enol salt and to peroxidation of dietary lipids. Urinary MDA also increased in response to the increased lipid peroxidation in vivo produced by vitamin E deficiency and by administration of iron nitrilotriacetate. Chronic feeding of a diet containing cod liver oil led to increases in MDA excretion which were not completely eliminated by fasting or feeding a peroxide‐free diet, indicating that there was increased lipid peroxidation in vivo. MDA excretion was not responsive to Se deficiency or CCl4 administration. DPPD, a biologically active antioxidant, but not BHA, a non‐biologically active antioxidant, prevented the increase in MDA excretion in vitamin E deficient animals. The results indicate that MDA excretion can serve as an indicator of the extent of lipid peroxidation in the diet and, under conditions which preclude a dietary effect, as an index of lipid peroxidation in vivo.
The influence of protein and carbohydrate type on serum and liver lipids and lipoprotein cholesterol in rabbits
Authors: Bauer John E. , Covert Steven J.
Published: November 2006

The non‐lipid portions of semi‐synthetic diets appear to be important determinants of hypercholesterolemia and atherosclerosis in the rabbit. Serum and liver lipid concentrations were determined in rabbits which had been pair‐fed various protein (casein or soy protein isolate) and carbohydrate (sucrose or dextrose) sources as part of low fat, low cholesterol, semi‐synthetic diets. It was verified that caseincontaining diets render rabbits hypercholesterolemic, while soy protein caused a degree of hypocholesterolemia. Additionally, sucrose, when fed in conjunction with casein, appears to augment this hypercholesterolemic effect. The distribution of total cholesterol among lipoprotein subclasses was increased in both the intermediate density lipoprotein (IDL) (1.006–1.019 g/ml) and low density lipoprotein (LDL) (1.019–1.063 g/ml) fractions and decreased in the high density lipoprotein (HDL) (1.063–1.21 g/ml) fraction when casein is fed. Soy protein feeding caused relatively more cholesterol to appear only in the IDL fraction when compared with commercial chow fed rabbits. Reasons for these differences may involve the saturation or suppression of endogenous lipoprotein hepatic receptors.
Lung surfactant phospholipids in different animal species
Authors: Shelley Sue A. , Paciga June E. , Balis John U.
Published: November 2006

A comparative study of adult mammalian lung surfactants was undertaken to determine which animal species might serve as appropriate models for surfactant alterations in human lung diseases. Phosphatidylcholine (PC) comprised 80–87% of the phospholipid and contained more than 65% palmitic acid in all species studied. Phosphatidylglycerol (PG) was found to vary significantly in fatty acid composition among the species. Rabbit, dog and rat surfactant PG contained 50–60% palmitic acid, while human and cat surfactant contained much lower levels of saturated fatty acids. Both the PC and PG of all species contained 2 positional isomers of fatty acids with 16 carbons and one double bond, but the relative amounts of the unusual isomer, 16∶1Δ7, and palmitoleic, acid, 16∶1Δ9, varied among the different animal species. Only cat and dog surfactant phospholipids contained 18∶1Δ5. Cat surfactant phospholipids also differed by the absence of 20∶4 and the presence of small amounts of several 20‐ and 22‐carbon fatty acids. These results explain some discrepancies found in the literature concerning surfactant composition and delineate limiting factors in extrapolating results from animal studies for the evaluation of maturation and pathological alterations in human surfactant.
Peroxidation of free and esterified fatty acids by horseradish peroxidase
Authors: Garner Charles W.
Published: November 2006

Linoleic and arachidonic acids and unsaturated esterified fatty acids of soybean lecithin liposomes were oxidized by horseradish peroxidase in the presence of hydrogen peroxide. The major products formed in the presence of oxygen were fatty acid hydroperoxides. In the absence of oxygen, other unidentified products were formed. Diene conjugation was about 5 times faster in oxygen than in nitrogen. Malondialdehyde was formed only in the presence of oxygen. Superoxide, singlet oxygen and hydroxyl radical may have been involved in the free fatty acid oxidation system but not in the liposome system. Replacement of hydrogen peroxide with the hydrogen peroxide (and superoxide) generators xanthine oxidase or galactose oxidase caused a more efficient oxidation in the presence of peroxidase than in its absence, suggesting that the in vivo toxicity of hydrogen peroxide and superoxide may be greatly increased in the presence of peroxidase.
Intestinal metabolism of plasma free fatty acids in streptozotocin diabetic rats
Authors: Renner F. , Schernthaner G. , Gangl A.
Published: November 2006

Moderate insulin deficiency was reported to be accompanied by an increased production of intestinal very low density lipoprotein (VLDL) triglyceride in the rat. Because plasma free fatty acids (FFA) are incorporated into triglyceride by intestinal mucosa of rats and humans and plasma FFA are increased in insulin‐deficient diabetes mellitus, we investigated several aspects of the intestinal metabolism of plasma FFA in diabetic rats. All experiments were performed on the third day following the i.v. injection of streptozotocin (45 mg/kg body weight) or buffer alone. A (14C)palmitic acid‐rat serum complex was rapidly injected intravenously and its initial uptake by small bowel mucosa, the intracellular incorporation into lipids and water soluble metabolites and the specific radioactivity of triglycerides of mucosal homogenates was determined. No significant differences could be found between diabetic and control rats at 2 and 5 min after14C‐palmitate i.v., suggesting that neither the influx of plasma free fatty acids into intestinal mucosal cells nor their initial intracellular metabolic pathways are significantly altered in moderately diabetic rats. A pronounced decrease in intestinal mucosal triglyceride at 10 min after14C‐palmitate i.v. might be interpreted as indirect evidence for an enhanced triglyceride efflux from intestinal mucosa into mesenteric lymph in diabetic rats.
Analysis of sterol esters by capillary gas chromatography‐electron impact and chemical lonization‐mass spectrometry
Authors: Lusby William R. , Thompson Malcolm J. , Kochansky Jan
Published: November 2006

Synthetic mixtures of C40 to C47 sterol esters in groups of 7 esters were effectively separated and analyzed by capillary gas chromatography‐mass spectrometry. Ammonia chemical ionization of all 20 sterol esters analyzed at a source block temperature of 120 C yielded (M+NH4)+ and (M+H‐RCO2H)+ ions of high abundance or as base peak, thereby indirectly indicating the molecular weights of the ester and the sterol and acid moieties. Ammonia CI spectra of all esters containing a Δ5‐sterol moiety exhibited in addition to the above 2 ions an M+NH4‐RCO2 H fragment. At a source block temperature of 150 C, M+H‐RCO2 H fragment was the base peak for all esters, and there was little or no indication of an (M+NH4)+ adduct ion. Protonated molecules were not observed for any esters analyzed by methane or isobutane CI. Molecular ions of 3–14% intensity were obtained for only 3 of the esters analyzed by electron impact; they contained a Δ7‐bond in the sterol nucleus, and the acid moiety was either saturated normal or branched chain or contained a single double bond. The base peak was a function of both the acid and sterol moieties of the sterol ester. The esters containing both saturated straight chain acid and saturated sterol moieties exhibited a base peak at m/z 215. The Δ5‐sterol esters with saturated branched or straight chain acid moieties exhibited base peaks at M‐RCO2 H. Other ions also were of diagnostic value.
Properties of diacylglycerol acyltransferase from spinach leaves
Authors: Martin B. A. , Wilson R. F.
Published: November 2006

Diacylglycerol‐acyltransferase (EC 2.3.1.20) was partially purified and characterized from spinach leaves. The enzyme had a pH optimum of 8.0 and activity was stimulated 2‐fold by the addition of 20 mM Mn2+ or Mg2+. Diolein and dipalmitin were examined assn‐1,2‐diacylglycerol substrates. Only diolein gave detectable triacylglycerol synthesis. In addition, the saturation kinetics of the enzyme with 16∶0‐CoA, 18∶0‐CoA and 18∶1‐CoA were examined. The highest apparent, Km was observed with 18∶1‐CoA, the lowest with 16∶0‐CoA. Endogenous spinach leaf glycerolipids were extracted and analyzed. The leaves contained 70 nmol triacylglycerol (g fresh weight)−.
Effect of environmental temperature changes on rat liver fatty acid desaturases
Authors: Gonzalez Susana , Nervi Anibal M. , Peluffo Raúl O. , Brenner Rodolfo R.
Published: November 2006

Female rats warm‐adapted at 30–32 C for 20–25 days and then shifted to 13–15 C for 12, 24, 48, 72 and 120 hr showed that Δ9 desaturase and fatty acid synthetase activity decay after 24 hr of cold exposure, while Δ6 and Δ5 desaturases were increased after this period of time. These results were confirmed by an increase of arachidonic acid of heart and liver microsomes phosphatidylcholine and a decrease of oleic acid. Neither NADH‐cyt b5 reductase nor NADH‐cyt c reductase activity of liver microsomes were significantly affected. Male rats warm‐adapted under the same conditions and then shifted to 13–15 C for 120 hr did not show significant changes in fatty acid synthetase, Δ9 and Δ6 desaturases and enzymes of the microsomal electron transport chain. Therefore, the desaturase response to environmental temperature changes could be plausibly linked to female hormones.
Cholesterol esterifying capacity of various organs in cholesterol‐fed guinea pigs
Authors: Heller F. R.
Published: November 2006

In guinea pigs fed a diet enriched with 1% cholesterol, the liver, adrenals, spleen, and small intestine accumulated cholesterol much more than the lungs and kidneys. The cholesterol content of the aorta, stomach and colon was not increased by the diet. Cholesteryl ester was the predominant form of cholesterol deposited in the organs richest in this sterol and the total cholesterol content of a tissue tended to increase with the proportion of cholesteryl ester. Cholesterol esterifying activity (ACAT) was found in most tissues and paralleled the cholesteryl ester content of these tissues, being highest in the adrenals, liver, spleen and the proximal part of the small intestine. ACAT activity was enhanced by the cholesterol diet and its elevation was fairly well correlated with the increase in the cholesterol content of the organs. However, the liver and adrenals tended to accumulate more cholesterol than anticipated from their cholesteryl ester content and their ACAT activity. Cholesterol esterification may play a major role in the ability of organs to accumulate cholesterol.
Dietary squalene increases tissue sterols and fecal bile acids in the rat
Authors: Tilvis Reijo S. , Miettinen Tatu A.
Published: November 2006

Feeding 1% squalene increased markedly the concentrations of squalene and methyl sterols in each serum lipoprotein class, intestinal mucosa, liver and also in adipose tissue. It also increased cholesterol concentration of the liver and serum VLDL, and esterified cholesterol in serum LDL as well as fecal bile acids. The results suggest that absorbed dietary squalene contributes to some extent to the squalene content of adipose tissue, effectively increases the overall cholesterol synthesis and enhances cholesterol elimination preferentially as fecal bile acids.
Peroxidative formation of C3‐hydrocarbons from an ω‐4 polyunsaturated fatty acid(16∶3ω4) in the algaBumilleriopsis
Authors: Sandmann Gerhard , Böger Peter
Published: November 2006

Under peroxidative conditions (i.e., illumination in the presence of Cu2+ or ap‐nitro diphenylether herbicide), the xanthophycean microalga,Bumilleriopsis filiformis, evolves C2 and C5 hydrocarbons besides substantial amounts of propane and propene. Fatty acids were separated as methyl esters by argentation and reversed‐phase thin layer chromatography and the fractions subsequently peroxidized by illuminated and copper‐supplementedAnacystis thylakoids. These membranes do not contain polyunsaturated fatty acids and are, therefore, unable to evolve volatile hydrocarbons by itself. The C2 and C5 hydrocarbons formed by the fractions added match with their content of ω‐3 and ω‐6 fattyacid species having 2–4 double bonds. The fractions yielding C3 hydrocarbons contain a fatty acid hitherto unknown forBumilleriopsis, which was isolated and identified as 16∶3ω4.
Unsaturated fatty acids in the postnatally developing rat lung
Authors: Kehrer James P. , Autor Anne P.
Published: November 2006

Fatty acid desaturase activity specific for the C‐9 position is present in lung microsomes prepared from rats of all ages. This activity is significantly lower in neonatal rat lung compared with adult lung. A rapid increase in C‐9 fatty acid desaturase activity seen at the approximate time of weaning may be related to a decrease in the polyunsaturated fatty acid (PUFA) content of the diet as the rat begins to consume laboratory chow instead of mother's milk. The 900×g supernatant fraction of rat lung parenchymal cell homogenates is capable of incorporating linoleate, linolenate, and arachidonate into both triacylglycerols and phospholipids. Lung tissue from rats less than 20 days old incorporates these PUFA into phospholipids at a greater rate than lung, tissue from adult rats. The incorporation of these PUFA into phospholipids in neonatal lung tissue occured at a greater rate than their incorporation into triacylglycerols. In contrast, lung tissue from adult rats incorporated PUFA into triacylglycerols at a greater rate than into phospholipids. These data show that PUFA, known to be elevated in neonatal rat lungs, are used primarily for phospholipid biosynthesis in neonatal lung tissue whereas in adult lung tissue they are preferentially esterified to glycerol.
Fatty acid composition of polar lipids in goats' milk
Authors: Cerbulis J. , Parks O. W. , Farrell H. M.
Published: November 2006

Silicic acid column chromatography was used to separate the polar lipids of goats' milk into glycolipid, phosphatidylethanolamine, phosphatidylserine plus phosphatidylinositol, phosphatidylcholine, and sphingomyelin fractions. Each fraction was purified by column chromatography and its fatty acid profile determined by gas liquid chromatography and mass spectrometry. The glycerophospholipids each contained 18∶1 as the predominant fatty acid (∼45%). The sphingolipids contained a high percentage of long‐chain saturated fatty acids (C22 to C24>45%); the glycolipid fraction also contained ca. 2% 2‐hydroxy fatty acids. The data represent a comprehensive cross‐sectional study of the major polar lipids found in goats' milks.
Chemical lonization mass spectrometry of wax esters
Authors: Plattner R. D. , Spencer G. F.
Published: November 2006

Chemical ionization (CI) mass spectra of long‐chain saturated, monenoic and dienoic wax ester analogues, using isobutane and methane as reagent gases, are reported and compared. Because less fragmentation occurs, CI spectra are simpler than the electron impact spectra. The quasi molecular ion (M+1) is the base peak in the spectra. Saturated, monenoic and dienoic wax ester mixtures have been analyzed by this technique.
Complexities in lipid quantitation using thin layer chromatography for separation and flame lonization for detection
Authors: Crane R. Thomas , Goheen Steven C. , Larkin Edward C. , Rao G. Ananda
Published: November 2006

The use of thin layer chromatography (TLC) for separation (using silica gel coated quartz rods) and subsequent flame ionization for detection (FID) was examined to determine whether this method could be used for the quantitation of lipids. However, response factors (RF) for various lipids were different and depended upon several variables including the amount of material analyzed. For example, RF were 3‐fold greater when 10 μg of tripalmitin was analyzed as compared to 1 μg of the same material. The amount of lipid detected by FID was also dependent upon the rate at which it passed through the flame. During analysis of methylpentadecanoate, detector response increased with scan speed, while at all speeds it was completely removed from the rod. On the other hand, depending upon the amount of cholesterol or phospholipid analyzed, the response either increased, remained unchanged or decreased with scan speed. During a fast scan, detector response was reduced because some material remained on the rod. Thus, the detector response is influenced by sample volatility. In conclusion, there appears to be a complex relationship between detector response and the amount of heat available per microgram of sample. Since we could not find a direct correlation between detector response and sample quantity, it would be difficult to use TLC‐FID as a tool for quantitating the components of a lipid mixture.
Electron spin resonance spectra of the chromanoxyl radicals derived from tocopherols (vitamin E) and their related compounds
Authors: Matsuo Mitsuyoshi , Matsumoto Shigenobu
Published: November 2006

The well resolved electron spin resonance (ESR) of the tocopheroxyl and chromanoxyl radicals derived from α‐, β‐, γ‐ and δ‐tocopherols (vitamin E), 5,7‐dimethyltocol, tocol and their model compounds in degassed toluene by treatment with 2,2‐diphenyl‐1‐picrylhydrazyl were recorded. Their hyperfine coupling constants were determined and assigned using spectrum simulation. Their g‐factors were also measured. On the basis of these parameters, the α‐tocopheroxyl radical is similar to the 2,2,5,7,8‐pentamethylchroman‐6‐oxyl, 5,7‐dimethyltocoxyl and 2,2,5,7‐tetramethylchroman‐6‐oxyl radicals. This suggests that the presence of methyl groups at C‐5 and C‐7 in tocopherols and chroman‐6‐ols is of great importance to their antioxidant action. The ESR parameters obtained here are very useful for the identification and quantification of a variety of tocopheroxyl radicals.
Analysis of conjugated bile acids by high performance liquid chromatography and mass spectrometry
Authors: Mingrone G. , Greco A. V. , Boniforti L. , Passi S.
Published: November 2006

Because of the known advantages of coupling high performance liquid chromatography with mass spectrometry (HPLC‐MS) in biological fluids, studies on the reversed‐phase HPLC‐MS system for direct analysis of conjugated bile acids in human bile samples are described. Ten samples of gallbladder bile of apparently healthy subjects were examined. The amounts of each tauro‐ and glycoconjugated bile acid as trifluoracetate were determined by mass fragmentography. Quantitation of at least 1 ng of each bile acid was possible.
Alteration in membrane permeability by diacylglycerol and phosphatidylcholine containing arachidonic acid
Authors: Yorio Thomas , Torres Susana , Tarapoom Nimnan
Published: November 2006

The phospholipid metabolites, stearoylarachidonylglycerol and diarachidonylglycerol, stimulate transepithelial sodium transport in frog skin epithelium. The increase in Na transport is due to an increase in the unidirectional influx of sodium, is amiloride sensitive and is prevented with pretreatment with indomethacin, mefanamic acid and phospholipase inhibitor, mepacrine. The data suggest a possible role of phospholipid metabolism and prostaglandin biosynthesis in the regulation of transepithelial ion transport.
Sterol composition of two freshwater molluscs of genusDiplodom
Authors: Pollero Ricardo J. , Gros Eduardo G. , Brenner Rodolfo R.
Published: November 2006

The sterol composition of two taxonomically related freshwater species,Diplodom patagonicus andDiplodom variabilis, respectively, from Lake Nahuel Huapi and the Río de la Plata river were studied by gas liquid chromatography and mass spectrometry. Cholesterol was the main sterol in both species and it was followed by 24‐methylcholesta‐5, 22‐dien‐3β‐ol, 24‐methylcholest‐5‐en‐3β‐ol, 24‐ethylcholesta‐5,22‐dien‐3β‐ol and 24‐ethylcholest‐5‐en‐3β‐ol. The river species collected within the proximity of marine influence showed less cholesterol and more 24‐methylcholesta‐5,22‐dienol, 24‐methylcholest‐5‐enol and 24‐ethylcholesta‐5,22‐dienol than the lake species.
Lipid composition and prostaglandin synthesis in mouse lung microsomes: Alterations following the ingestion of menhaden oil
Authors: Lokesh B. R. , Kinsella J. E.
Published: November 2006

Three groups of male mice were fed a normal diet or a semisynthetic diet containing either 10% hydrogenated coconut oil (CO group) or 10% menhaden oil (MO group) for two wk. The synthetic diet altered the fatty acid composition of lung microsomal lipids. Mice ingesting menhaden oil contained greater amounts of eicosapentaenoic acid (20∶5 n−3), docosapentaenoic acid (22∶5 n−3) and docosahexaenoic acids (22∶6 n−3) and decreased amounts of n−6 fatty acids such as arachidonic and adrenic. Synthesis of prostaglandin E2 and prostaglandin F2α from exogenous arachidonic acid was significantly depressed in n−3 fatty acid‐enriched lung microsomes. These studies indicated that dietary fish oil not only alters the fatty acid composition of lung microsomes but also lowers the capacity of lungs to synthesize prostaglandins from arachidonic acid.
Fluorescent pigments by covalent binding of lipid peroxidation by‐products to protein and amino acids
Authors: Fukuzawa Kenji , Kishikawa Katsuya , Tokumura Akira , Tsukatani Hiroaki , Shibuya Masayuki
Published: November 2006

The fluorescent products formed on reaction of 12‐oxo‐cis‐9‐octadecenoic acid (12‐keto‐oleic acid) with about 20 different amino acids, polylysine and bovine serum albumin (BSA) were studied. Besides glycine, only the basic amino acids histidine, lysine and arginine gave products with strong fluorescence. N‐Acetylation of amino acids greatly reduced the fluorescence of their reaction products. The formation of fluorescent products was inhibited strongly by SH‐amino acids such as N‐acetyl‐cysteine and glutathione. Polyacrylamide gel electrophoresis showed that BSA treated with 12‐keto‐oleic acid was more acidic than untreated or ricinoleic acid‐treated BSA, indicating that basic amino acid residues in BSA were modified by reaction with the keto fatty acid. None of the structural analogs of 12‐keto‐oleic acid tested–12‐oxo‐trans‐10‐octadecenoic acid, 12‐oxo‐octadecanoic acid, 12‐hydroxy‐cis‐9‐octadecenoic acid (ricinoleic acid),cis‐9‐octadecenoic acid (oleic acid) and linoleic acid—reacted with glycine to give a fluorescent product. The fluorescent products formed on reaction of 12‐keto‐oleic acid methyl ester with benzyl amine and glycine methyl ester were shown to be 8‐(N‐substituted‐4,5‐dihydro‐4‐oxo‐5‐hexyl‐5‐hydroxy‐2‐pyrrolyl) octanoic acid methyl esters. The fluorescence properties of these compounds were attributed to the chromophobic system NC=CC=O which contains 6π electrons. This investigation contributes to insight of the mechanism of formation of fluorescent pigments, probably by a similar reaction of other compounds of the β,γ‐unsaturated carbonyl type.
Evidence for diplasmalogen as the major component of rabbit sperm phosphatidylethanolamine
Authors: Touchstone Joseph C. , Alvarez Juan G. , Levin Sidney S. , Storey Bayard T.
Published: November 2006

The question of whether diplasmalogens [1,2‐di(O‐1′‐alkenyl) phosphatidyl derivatives] make up part of the plasmalogen component of cell phospholipids was examined using rabbit epididymal spermatozoa. These cells are readily obtained as a highly homogeneous suspension and long have been known to have high plasmalogen content. Phospholipids were determined by thin layer chromatography (TLC) with CuSO4 staining. Plasmalogens were determined by hydrolysis of the phospholipids with TCA/HCl, followed by TLC and CuSO4 staining. Ethanolamine derivatives were determined by ninhydrin. The phosphatidylethanolamine (PE) content of these cells was 29±2 μg/108 cells, 90% of which was assayed as diplasmalogen and 10% as diacyl PE. No monoplasmalogen could be detected. The presence of diplasmalogen as the major component of PE was given further support from infrared and proton nuclear magnetic resonance (1H‐NMR) spectroscopy, which showed the presence of O‐1′‐alkenyl substituents but near absence of O‐acyl substituents. The phosphatidylcholine (PC) content of the cells was 104±5 μ/108 cells, of which 50% was monoplasmalogen with the 1′‐alkenyl group on the 2 position of the glycerol moiety. No diplasmalogen was found in PC. The other phospholipids in rabbit sperm were phosphatidylglycerol (PG), cardiolipin (CL), sphingomyelin (SP) and lysophosphatidylcholine (LPC). Phosphatidylserine (PS) and phosphatidylinositol (PI) were present at the limits of detectability of the TLC method. None of these phospholipids contained plasmalogen. The PE component of rabbit sperm phospholipids appears to differ from that of the other cells in having the previously unreported diplasmalogen as its major constituent.
Purification of the human anionic polypeptide fraction of the apo‐bile lipoprotein complex by zonal ultracentrifugation
Authors: Martigne M. , Domingo N. , Lafont H. , Nalbone G. , Hauton J. C.
Published: November 2006

The two main proteic constituents of the human Apo‐bile lipoprotein complex (BLC), i.e., the anionic polypeptide fraction (APF) and the IgA fragments, were separated by preparative zonal ultracentrifugation using a sucrose gradient containing 1.5 mM glycodesoxycholate. The purification of the APF was verified by sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis and immunology, and its amino acid composition then was determined. This procedure was used to obtain a polyclonal antiserum directed solely against the APF.
Effect of very long chain fatty acids on peroxisomal β‐oxidation in primary rat hepatocyte cultures
Authors: Christiansen Erling N. , Gray Tim J. B. , Lake Brian G.
Published: November 2006

Previous studies have demonstrated that certain high fat diets can induce peroxisomal fatty acid β‐oxidation in rodent liver and that this may be due to their content oftrans 22∶1 fatty acids. In this study we have examined the effects ofcis andtrans 22∶1 fatty acids (erucic and brassidic) and oleic acid (18∶1) on palmitoyl‐CoA oxidation, carnitine acetyltransferase and carnitine palmitoyltransferase activities in primary rat hepatocyte cultures. Brassidic and erucic acid and, to a lesser extent, oleic acid were cytotoxic to rat hepatocytes. However, at a concentration of 0.1 mM, brassidic acid produced small increases in palmitoyl‐CoA oxidation and carnitine acetyltransferase activities in hepatocytes cultured 70 hr. Treatment of cells with 0.1 and 0.3 mM of either erucic or oleic acid had no effect on any of the enzymes measured.
Effect of dietary cholesterol protected against ruminal hydrogenation on the plasma cholesterol and liver of sheep
Authors: Ashes J. R. , Cook L. J. , Sidhu G. S.
Published: November 2006

Dietary supplements containing cholesterol or sunflower oil were prepared to protect them against degradation in the rumen. On feeding daily supplements containing 1–2 g protected cholesterol and/or 100g protected sunflower oil to sheep, along with a basal ration of crushed oat grain and lucerne chaff, a rise in the plasma cholesterol was observed when compared with control animals. Livers from sheep fed protected cholesterol were enlarged, friable and cirrhotic in appearance and contained large deposits of esterified and free cholesterol, while livers from animals fed protected sunflower oil alone contained much less cholesterol. Octadecenoates constituted the major fatty acids in cholesterol esters, which, in animals fed protected sunflower oil, were mainly polyunsaturated. The factors involved in the deposition of liver lipid at very low dietary cholesterol concentrations (0.11–22%) in sheep compared with monogastric animals are discussed.
Influence of acute injection of chloroquine on the biliary secretion of lipids and lysosomal enzyme on rats
Authors: Lafont H. , Chanussot F. , Dupuy C. , Lechene P. , Lairon D. , Charbonnier‐Augeire M. , Chabert C. , Portugal H. , Pauli A. M. , Hauton J. C.
Published: November 2006

Phospholipids and cholesterol combine with a protein fraction (IgA and an acid polypeptide) in bile to form the bile lipoprotein complex.

We wished to determine whether lysosomes participated only in IgA secretion or if their secretory role also involved the lipid components of the bile complex. This aspect was studied with a single acute injection of chloroquine, a lysosomotropic drug. The results show that a nonnegligible quantity of IgA travels through the lysosomes. In addition, phospholipid and cholesterol levels undergo a significant (P<0.05) decrease 1 hr after injection before increasing to normal levels. In contrast to the total inhibition of protein secretion (β‐glucuronidase, acid phosphatase), a transitory decrease of the secretion of bile lipids takes place that suggest secretory mechanisms involving organelles other than lysosomes.
The composition of cardiac phospholipids in rats fed different lipid supplements
Authors: Charnock J. S. , Abeywardena M. Y. , McMurchie E. J. , Russell G. R.
Published: November 2006

Changes in dietary lipid intake are known to alter the fatty acid composition of cardiac muscle of various animals. Because changes in cardiac muscle membrane structure and function may be involved in the pathogenesis of arrythmia and ischemia, we have examined the effects of dietary lipid supplements on the phospholipid distribution and fatty acid composition of rat atria and ventricle following 20 weeks feeding of diets supplemented with either 12% sunflower‐seed oil or sheep fat.

Neither lipid supplement produced significant changes in the proportions of cholesterol, total phospholipids or phosphatidylcholine, phosphatidylethanolamine or diphosphatidylglycerol,—the phospholipid classes that together account for more than 90% of the total phospholipids of rat cardiac muscle. Significant changes were found in the profiles of the unsaturated fatty acids of all 3 phospholipid components of both atria and ventricle. Although similar, the changes between these tissues were not identical. However, in general, feeding a linoleic acid‐rich sunflower seed oil supplement resulted in an increase in the ω‐6 family of fatty acids, whereas feeding the relatively linoleic acid‐poor sheep fat supplement decreased the level of ω‐6 fatty acids but increased the levels of the ω‐3 family, resulting in major shifts in the proportions of these families of acids. In particular, the ratio of arachidonic acid: docosahexaenoic acid (20∶4, ω‐6/22∶6, ω‐3), which is higher in all phospholipids of atria than ventricle, is increased by feeding linoleic acid, primarily by increasing the level of arachidonic acid in the muscle membranes. As dosahexaenoic acid does not occur in the diet, the increase in this acid which occurs after feeding animal fat, presumably arises from increased conversion of the small amounts of linolenic acid in all diets when the amount of linoleic acid present is reduced.
Lipid composition and protoplast‐forming capicity ofStreptomyces antibioticus
Authors: Zuñeda M. C. , Guillenea J. J. , Dominguez J. B. , Prado A. , Goñi F. M.
Published: November 2006

The lipid and fatty acid composition of a strain ofStreptomyces antibioticus has been studied as a function of culture age and glycine concentration in the growth medium. Under all conditions, the main polar lipids were phosphatidylethanolamine, cardiolipin and phosphomannoinositides in order of decreasing abundance; no ornithinolipids were detected. Acylglucoses and menaquinones were found among the nonpolar lipids. The main fatty acids present were anteiso 15∶0 and anteiso 17∶0. The lipid composition of the cells varied with the age of the culture, but no uniform pattern of variation was found in the cultures grown on different amounts of glycine. Among the cells harvested at the end of the exponential phase of growth, those grown on 2% glycine give the highest yield of protoplast formation. These cells were found to contain low amounts of nonpolar lipids and of phosphatidylethanolamine, and high proportions of anteiso fatty acids. We propose that the membrane bilayer of these cells, because of its peculiar lipid composition, is particularly stable and fluid. As a consequence, the yield and stability of derived protoplasts should be increased.
Steroids from aquatic organisms: V. Main sterols of the fresh water snail,Biomphalaria tenagophila
Authors: Seldes Alicia M. , Gros Eduardo G.
Published: November 2006

The free sterols of the snail,Biomphalaria tenagophila, were isolated and characterized by means of gas chromatography and gas chromatography‐mass spectrometry techniques. The mixture contains the common steroids found in freshwater molluscs, principally cholesterol. The presence of cholesta‐5,7‐dien‐3β‐ol is without precedent in freshwater organisms. The occurrence of 7‐oxo‐cholesterol in freshwater snails, but not bivalves, from the same freshwater source, would indicate a difference in the physiology of such snails and bivalves.
Brown adipose tissue triacylglycerol fatty acids of obese and lean mice: In situ and in transplants
Authors: Roberts Jennifer L. , Ashwell Margaret , Enser Michael
Published: November 2006

The triacylglcyerols of white adipose tissue (WAT) from animals with high rates of lipogenesis, such as obese hyperglycemic mice or hypothalamically lesioned rats, contain high proportions of palmitoleic acid (16∶1) and low proportions of linoleic acid (18∶2). These differences appear to result from dilution of dietary 18∶2 by synthesized fatty acids, particularly 16∶1. To test this we have investigated the triacylglycerol fatty acid composition of brown and white adipose tissue of lean and obese mice, as brown adipose tissue (BAT) has a higher lipogenic rate than WAT and lipogenesis is faster in obese than in lean mice. Between three and eight weeks of age the proportions of fatty acids in the tissues changed, with a marked fall in milk‐derived lauric and myristic acids. From 8 to 16 weeks they were more stable and the proportions of 16∶1 and 18∶2 in the different tissues were as expected, with the highest and lowest proportions, respectively, in BAT from obese mice. When BAT from obese mice was transplanted under the kidney capsule of lean mice, or vice versa, for one month, the fatty acid composition of the grafts changed toward that of the host BAT. The proportions of 18∶2 and, to a lesser extent, 16∶1 were slightly higher in the grafts than in the hosts but since this also occurred in lean‐to‐lean and obese‐to‐obese grafts it was probably a transplantation artifact. Overall, the results confirm than the physiological environment, rather than the source of the adipose tissue, is the major determinant of its fatty acid composition.
Desaturation and chain elongation of essential fatty acids in isolated liver cells from rat and rainbow trout
Authors: Hagve Tor‐Arne , Christophersen Bjørn O. , Dannevig Birgit H.
Published: November 2006

Isolated hepatocytes from rainbow trout and rat were incubated with14C‐labeled linoleic acid, linolenic acid, dihomogammalinolenic acid or eicosapentaenoic acid. The most striking difference in the desaturase activity was the lower level of Δ5 desaturase in trout than in rat. No Δ4 desaturation of 22∶4(n−6) to 22∶5(n−6) was observed in either of the two species, while the conversion of 22∶5(n−3) to 22∶6(n−3) was significant in both groups and highest in rainbow trout. The chain‐elongating activity was remarkably similar in the two species, except for the “dead‐end” elongation which was distinctly more important in fish.
Properties of diacylglycerol kinase purified from bovine brain
Authors: Lin C‐H. , Bishop H. , Strickland K. P.
Published: November 2006

A nearly homogeneous but somewhat unstable diacylglycerol kinase (ca. MW 72,000 daltons) was purified from bovine brain by modification of the procedure of Kanoh et al. (Kanoh, H., Kondoh, H., and Ono, T. [1983]J. Biol. Chem. 258, 1767–1774). The purification consisted of four steps (brain cytosol isolation and successive chromatography on DEAE‐cellulose, Sephadex G‐25 for desalting and ATP‐agarose) carried out in buffers stabilized with EDTA, ATP and dithiothreitol (DTT). Specific activities, determined within 4 hr of purification, ranged from 908–1857 nmol ATP incorporated/min/mg protein, with the variation reflecting the instability. Optimal activities required deoxycholate (0.1%), one of the phosphoglycerides [phosphatidylcholine (PC), phosphatidylethanolamine (PE) or phosphatidylserine (PS)] (0.025–0.25 mM), ATP (5 mM, apparent Km=0.57 mM), 1,2‐dioleoyl‐rac‐glycerol (5 mM, apparent Km=1 mM) and Mg2+ (10 mM, apparent Km=2.2 mM). Phosphatidylinositol (PI) was slightly less effective than PC, PE or PS and noninhibitory in combination with PC, PE or PS. Relative to PC phosphatidic acid (PA) (52%), sphingomyelin (48%), lyso‐PC (1.5%) and lyso‐PI (28.6%) were less effective activators. The sulfhydryl reagents,p‐chloromercuribenzoic acid (PCMB) (1.0 mM),N‐ethylmaleimide (NEM) (1.0 and 2.0 mM) and 5,5′‐dithiobis‐(2‐nitrobenzoic acid) (DTNB) (1.0 mM), showed strong inhibition of activity which was prevented by 0.5 mM DTT. In contrast to other reports, this purified enzyme showed no monoacylglycerol kinase activity. Comparison of diacylglycerols of varying fatty acid composition indicated that the enzyme showed a preference for substrates with at least one unsaturated fatty acid, particularly in the 2‐position. With saturated fatty acids the order of preference was C10 and C12>C14>C16>C18. Such a pattern indicates that the enzyme shows little selectivity that favors the generation of particular molecular species of PA.
Dexamethasone blocks arachidonate biosynthesis in isolated hepatocytes and cultured hepatoma cells
Authors: Marra Carlos A. , de Alaniz Maria J. T. , Brenner Rodolfo R.
Published: November 2006

The effect of dexamethasone on the incorporation and conversion of [1‐14C]eicosa‐8,11,14‐trienoic acid to arachidonic acid in isolated hepatocytes and in hepatoma tissue culture (HTC) cells was studied. In both kinds of cells, no changes in the exogenous acid incorporation were found when the hormone was added to the incubation media at 0.1 or 0.2 mM concentration, while the biosynthesis of arachidonic acid was significantly depressed. The effect on the biosynthesis was faster in isolated normal liver cells (60 min) than in tumoral cells (120 min) and reached an inhibition of ca. 50% after 3 hr of treatment. The addition of cycloheximide (10−6 M) also caused a marked decrease in the biosynthesis of this polyun‐saturated fatty acid, but when dexamethasone was added to the media simultaneously with cycloheximide, a synergistic action was not observed. The results obtained show that protein synthesis would be involved in the modulation of the biosynthesis of arachidonic acid by glucocorticoids. The changes in the Δ5 desaturation of labeled 20∶3ω6 to arachidonic acid correlated with changes in the fatty acid composition in isolated cells.
Effects of pre‐ and postweaning undernutrition on polyphosphoinositide pools in rat kidney
Authors: Ananth Uma S. , Ramakrishnan C. V. , Hauser George
Published: November 2006

The effects of undernutrition on polyphosphoinositide levels in rat kidneys removed and frozen immediately after animal death or 10 min later were determined. Weanling (21‐day‐old) rats of dams fed a 5 or 22% protein diet and litters fed either normal or protein‐deficient diets for an additional six wk were used. Nutritional deprivation lowered phosphatidylinositol‐4‐phosphate (PtdIns4P) preferentially (35–40%) but but preserved phosphatidylinositol‐4,5‐bisphosphate (PtdIns4,5P2) at weaning. This effect was not completely reversed in animals nutritionally rehabilitated after weaning. Postweaning protein deficiency did not reduce the levels of these lipids. Postmortem loss was the same for all five groups, minimal for PtdIns4P and about one‐third for PtdIns4,5P2.
Practical liquid chromatographic separation of the phenols in technical cashew nutshell liquid fromAnacardium occidentale
Authors: Sood Suresh K. , Tyman John H. P. , Durrani Aziz , Johnson Robert A.
Published: November 2006

The practical separation of cardanol from technical cashew nutshell liquid or its distillate has been effected by liquid chromatography on Silica Gel H 60 (TLC type) with solute/absorbent in the range 1∶5–1∶6. Concentrates of the monoene, diene and triene constituents of cardanol have been prepared by argentation liquid chromatography on Silica Gel H 60 with dry incorporation of 15% silver nitrate. The present use of pressurized columns was made prior to the advent of flash chromatography.
Simultaneous analysis of low plasma levels of deuterium‐labeled saturated and unsaturated fatty acids ast‐butyldimethylsilyl esters
Authors: Parsons H. , Emken E. M. , Marai L. , Kuksis A.
Published: November 2006

A sensitive and accurate method for detection and quantitation of deuterated fatty acids in the presence of large amounts of unlabeled fatty acids is described using mass fragmentography in combination with the preparation of tertiarybutyldimethylsilyl esters (t‐BDMS). The method has been applied to determination of deuterated stearic, oleic, elaidic and linoleic acids in human plasma lipoproteins following duodenal perfusion with a micellar mixture of acids. Over a concentration range of 10–1000 ng/ml, the average coefficient of variation for the linoleate was 3% and for the oleate (elaidate) ester was 2%.
The hydrolysis of very low density lipoproteins and chylomicrons of intestinal origin by lipoprotein lipase in ruminants
Authors: Christie William W. , Noble Raymond C. , Clegg Roger A.
Published: November 2006

The hydrolysis by lipoprotein lipase of a very low density lipoprotein/chylomicron fraction, obtained from the intestinal lymph of sheep, has been studied in vitro. Rapid hydrolysis of triacylglycerols, with an accumulation of free fatty acids, was observed. After an initial lag period, phosphatidylcholine also was hydrolyzed. No specificity for particular fatty acids in the triacylglycerols (or phosphatidylcholines) was observed.
A specific detector for nitrogen and halogen compounds in TLC on coated quartz rods
Authors: Patterson P. L.
Published: November 2006

A new detector has been developed for use with the Iatroscan TH‐10 TLC/FID instrument‐a “solid‐phase” chromatographic system (SPC). This new detection system contains a unique stage of detection that is called a flame thermionic ionization detector or FTID. The FTID evolved from a similar device that recently has been used in gas chromatography. The basic concept of an FTID is that organic sample compounds are first decomposed by combustion in an H2‐air flame. The FTID does not sense any of the ionization produced directly in the flame but, instead, re‐ionizes the combustion products by means of a unique thermionic transducer placed in the downstream effluent of the flame. The thermionic transducer ionizes specifically only those combustion products which are acidic or electronegative in chemical activity. In particular, organic samples containing nitrogen (N) or halogen atoms combust to products which are especially well detected with high sensitivity. Hence, the FTID adds to the Iatroscan a state‐of‐the‐art detection stage which produces large signals for nitrogen and halogen compounds and negligible signals for hydrocarbon compounds.
Improved sample application methods for the Iatroscan
Authors: Read H.
Published: November 2006

A new method of sample application has been developed for Chromarods to give improved interrod and interrun repeatability. A rotary method using a small rig has been constructed to hold and rotate the rod as the sample is applied. Improved interrod repeatability of 0.5–0.7% standard deviation compared to 1.3–3.3% standard deviation using the Iatroscan recommended method has been achieved.