bluuebunny/crossref_metadata_2025 huggingface dataset:
Calibration of the Iatroscan‐Chromarod system for marine lipid class analyses
Authors: Parrish C. C. , Ackman R. G.
Published: November 2006

A two‐step development procedure with partial scanning after the first development resolves seawater lipids into seven classes. The low concentration in seawater of some of these classes necessitates calibration close to the detection limit of the flame ionization detector (FID). From 0.2 to 5.0 μg the FID response usually is curvilinear, necessitating multilevel calibration. Interrod precision was poor for most of this range, and this prompted an investigation of factors affecting FID responses.

Peak areas were found to depend on the distribution of lipid material on the Chromarod. Also investigated were the effects of temperature, humidity, acid cleaning and double developments. All of these factors had some effect of Rf values, on absolute FID responses and on reproducibility, but they were not the major cause of variability in the Iatroscan‐Chromarod system. Similarly, double developments improve peak shape and response, but results in only a small increase in precision for some compounds. The differences among the FID responses obtained from 10 rods within a set imply that the normalization of FID responses to that of an internal standard, or the use of intrarod rather than interrod data, should result in an increase in reproducibility. Neither of these approaches was found to improve the precision for all lipid classes. An understanding of both interrod and intrarod variability, and the use of calibration curves, is essential for accurate determination of the lipid classes of 1 liter of seawater.
Quantitative class separation of coal liquids using thin‐layer chromatography with flame lonization detection
Authors: Selucky M. L.
Published: November 2006

The paper illustrates the use of TLC/FID for the separation of heavy distillates and is a summary of work done by our group over the last few years and published in detail elsewhere. For those who are unfamiliar with fossil fuel analysis, the basic terms and methods are explained with emphasis on the merits and disadvantages of TLC/FID as compared to column and solubility separations. Also, problems with the determination of concentration/response dependence and with absolute detector calibration are outlined.
Uptake and interconversion of cholesterol and cholesteryl esters byPhytophthora cactorum
Authors: Elliott C. G. , Knights B. A.
Published: November 2006

When cholesterol, cholesteryl palmitate and cholesteryl acetate were added individually to sterol‐free cultures ofPhytophthora cactorum, the free sterol was at first taken up more rapidly. By 24 hr, the uptake of esters and free sterol was similar. The 2 esters apparently are taken up by different mechanisms, since much acetate was found in extracts of the mycelium at early harvests, but very little palmitate. In cultures supplemented with a mixture of cholesterol and cholesteryl palmitate, the palmitate‐derived cholesterol was preferentially incorporated into the free sterol fraction of mycelial extracts. Cholesteryl palmitate and acetate were both hydrolyzed, and free cholesterol esterified by filtrates of cultures grown on sterol‐free medium. Reverse‐phase chromatography on hydroxyalkoxy‐propyl‐Sephadex resolved the sterol esters of mycelial extracts into 3 zones, the most polar comprising mainly the linolenate ester, the next linoleate, and the least polar mainly oleate. Linoleate was predominant among the first sterol esters synthesized by the mycelium whether the supplement was free sterol, palmitate or acetate. Later, oleate became predominant.
Competitive deposition oftrans‐12‐ andcis‐9‐octadecenoates into egg yolk lipids
Authors: Lanser A. C. , Emken E. A.
Published: November 2006

The deposition oftrans‐12‐octadecenoate‐12(13)‐3H (12t‐18∶1‐3H) was compared tocis‐9‐octadecenoate‐10‐14C (9c‐18∶1‐14C) in the major egg yolk neutral lipids and phospholipids.trans‐12‐Octadecenoate was preferentially incorporated into cholesteryl esters (CE), phosphatidylcholines (PC), and phosphatidylethanolamines (PE) but was discriminated against in triglycerides (TG). Isotopic ratios indicate that 5.9 and 5.6 times more 12t‐18∶1‐3H than 9c‐18∶1‐14C was esterified at the 1‐acyl position of PE and PC, respectively. The combined 1‐ and 3‐acyl positions of TG and the 2‐acyl position of TG, PE and PC were each preferentially esterified with 9c‐18∶1‐14C.
Lipids of dermatophytes
Authors: Khuller G. K. , Chopra A. , Bansal V. S. , Masih R.
Published: November 2006

This investigation deals with phosphatides and fatty acid content ofEpidermophyton floccosum, Microsporum cookie andTrichophyton mentagrophytes during different phases of growth. Total phosphatide content of these dermatophytes decreased with age, which was reflected in constituent major phosphatides. The zwitterionic and anionic phospholipids tended to maintain a constant ratio. Short chain fatty acids increased significantly with age inE. floccosum whereas these fatty acids represented a minor fraction of the total fatty acids inM. cookie andT. mentagrophytes. The ratio of saturated to unsaturated fatty acids increased 4‐fold during growth inE. floccosum, whereas this increase was marginal inM. cookie. This ratio decreased inT. mentagrophytes.
Thromboxane B2 biosynthesis and phospholipids hydrolysis in platelets from hypercholesterolemic rabbits
Authors: Kawaguchi H. , Ishibashi T. , Imai Y.
Published: November 2006

Thromboxane B2 biosynthesis from arachidonic acid was increased in platelets from hypercholesterolemic rabbits. The enzymic activity of phospholipase A2 which releases arachidonic acid, the precursor for the biosynthesis of thromboxane B2, showed hardly any change in hypercholesterolemic platelets. Phospholipase C and diglyceride lipase activities also were not changed in platelets from hypercholesterolemic rabbits. Furthermore, phospholipid concentration in platelets were not increased in this state. Thus, we conclude that the supply of precursor for thromboxane B2 biosynthesis was not increased in platelets from hypercholesterolemic rabbits as compared to controls. These results suggest that the enzyme activity of thromboxane B2 biosynthesis may be enhanced in platelets from hypercholesterolemic rabbits.
The prevention of alcoholic fatty liver using dietary supplements: Dihydroxyacetone, pyruvate and riboflavin compared to arachidonic acid in pair‐fed rats
Authors: Goheen S. C. , Pearson E. E. , Larkin E. C. , Rao G. A.
Published: November 2006

Male Sprague‐Dawley rats were fed for 30 days a high‐fat liquid ethanol diet with dihydroxyacetone, pyruvate and riboflavin added as supplements (AMA‐). Plasma triglyceride (TG) levels were 6‐fold greater in these rats than in those fed and alcohol with without the supplements (AA‐). The liver TG content in rats fed the AMA‐diet was similar to that of rats fed a control diet (CA‐) in which alcohol was replaced with isocaloric amounts of dextrose. Livers of rats fed the AA‐ diet had 3 times more TG than controls. Alcohol ingestion also enhanced the hepatic content of cholesteryl esters (CE) and phospholipids (PL). These lipids were reduced to levels found in livers of rats fed the control diet (CA‐) when dihydroxyacetone, pyruvate and riboflavin were included in the alcohol diet. The fatty acid compositions of TG, CE and PL from livers of rats fed the AMA‐diet were similar to those of corresponding lipids from rats fed the control diet (CA‐) but differed from compositions when fed the alcohol diet (AA‐). Regardless of the diet fed, TG had the same fatty acid composition in plasma and liver. The same was true of PL fatty acid composition. However, the fatty acid composition of CE differed between liver and plasma. The major fatty acid in liver CE was 18∶1 whereas in plasma it was arachidonic acid (20∶4). Reduced fatty liver was observed in an earlier study when rats were fed ad libitum an ethanol diet containing 20∶4. In the present study, we pair‐fed the same diet and fatty liver was not reduced. Dihydroxyacetone, pyruvate and riboflavin did not prevent alcohol‐induced fatty liver when 20∶4 was included in the AMA‐diet. Our results confirm that dietary dihydroxyacetone, pyruvate and riboflavin prevent alcohol‐induced fatty liver, and show that this effect may result from increased mobilization of fat from liver.
The role of lipid peroxidation during chronic and acute exposure to ethanol as determined by pentane expiration in the rat
Authors: Litov R. E. , Gee D. L. , Downey J. E. , Tappel A. L.
Published: November 2006

Weanling rats were fed one of 3 diets containing 0, 11 or 200 international units (IU) dl‐α‐tocopherol acetate/kg diet for 4 weeks. Following this period, the drinking water was replaced with an 18% solution of ethanol (v/v). An isocaloric D‐glucose solution was substituted for the drinking water of a control group of rats fed the vitamin‐E‐deficient diet for 4 weeks. The 4 treatment groups were maintained on the diet and drinking regimen for 20 weeks. Basal levels of expired pentane were determined at weeks 0, 1, 3, 5, 7 and 9. Chronic ethanol consumption did not influence basal pentane production during the 9‐week treatment. Basal levels of expired pentane were affected by dietary vitamin E. Rats supplemented with vitamin E had basal pentane levels less than one‐half of the level of rats fed a vitamin‐E‐deficient diet (p<0.001). After 14 weeks of treatment, the 2 groups of rats fed a vitamin‐E‐deficient diet were administered p.o. an acute dose of 6 g of ethanol/kg body wt. Pentane expired above basal levels during the following 4‐hr period correlated with the amount of hepatic triglycerides determined at the conclusion of the experiment. The etiology of ethanol toxicity is a complex and multifactorial system made up to many biological variables that influence lipid peroxidation. The appropriate choices of experimental designs and methods are important in examining the role of lipid peroxidation.
Purification of phospholipids by preparative high pressure liquid chromatography
Authors: Geurts van Kessel W. S. M. , Tieman M. , Demel R. A.
Published: November 2006

A method is described for the purification of a number of phospholipids by preparative high performance liquid chromatography (HPLC). Purification of digalactosyl‐diglyceride from spinach and egg phosphatidylcholine, 1,2‐dioleoyl‐sn‐glycero‐3‐phosphocholine and 1,2‐dioleoyl‐sn‐glycero‐3‐phosphoethanolamine from its reaction mixture have been resolved. The lipid separation is performed on a polygosil column and the individual compounds are monitored directly by refractive index detection. Chloroform/methanol mixtures are used as eluent systems, providing a wide polarity range to separate the classes of lipids. The developed equipment can be used for columns between 10 and 50 cm long and 4 and 50 mm inner diameter. The flow rate could be varied between 1 and 100 ml/min and applied pressures between 10 and 450 bars.
Studies on biochemical effects of nitrogen dioxide: I. Lipid peroxidation as measured by ethane exhalation of rats exposed to nitrogen dioxide
Authors: Sagai M. , Ichinose T. , Oda H. , Kubota K.
Published: November 2006

This research was in order to follow the periodic fluctuation of lipid peroxidation by a new method in rats exposed to nitrogen dioxide. Wistar male rats were examined for lipid peroxidation as demonstrated by ethane exhalation. In rats continuously exposed to 10 ppm nitrogen dioxide for 2 weeks, the amount of ethane exhaled fluctuated in a complex manner during the exposure. Ethane exhalation decreased slightly after the first day of exposure and then increased rapidly. The maximal values were observed after the fourth day of exposure and then decreased gradually to the initial level. Furthermore, the activity of glutathione peroxidase in lungs of rats exposed to 10 ppm nitrogen dioxide varied symmetrically against the change of ethane formation. Similar changes in ethane exhalation were observed in rats exposed to the lower levels of nitrogen dioxide (0.4, 1.2 and 4.0 ppm) for 4 months. Compared to 10 ppm nitrogen dioxide exposure for 14 days, the characteristics in rats exposed to the low levels (0.4–4.0 ppm) of nitrogen dioxide were: the decline of ethane formation, the delay in alterations, and the tendency toward gradual increased during the longer period exposure.
Identification of acidic steroids in feces of monkeys fed β‐sitosterol
Authors: Kritchevsky D. , Davidson L. M. , Mosbach E. H. , Cohen B. I.
Published: November 2006

Vervet monkeys were fed a suspension of β‐sitosterol in corn oil Acidic steroids, were separated from a 4‐day pool of feces and subjected, after fraction, to gas liquid chromatography and mass spectrometry. Evidence for the presence of derivatives of 27‐carboxysitosterol, 27‐carboxysitostanol and 7‐hydroxy, 27‐carboxysitostanol is adduced.
Arachidonic acid: Occurrence in the reproductive tract of the male house cricket (Acheta domesticus) and field cricket (Gryllus spp.)
Authors: Worthington R. E. , Brady U. E. , Thean J. E. , Wilson D. M.
Published: November 2006

Reproductive tissues from male house and field crickets were investigated for the presence of arachidonic acid. Arachidonic acid was identified by retention behavior on 3 gas liquid chromatographic column systems—SE‐30, OV 225, and Silar 10C—and by gas liquid/positive ion chemical ionization mass spectrometry. Arachidonic acid constituted 0.3 and 1.2% of total fatty acids in the house and field cricket, respectively. Freeze‐dried male reproductive tissues from house and field cricket contained ca. 0.02 and 0.16% arachidonic acid and 8.2 and 8.6% total fatty acids. Other fatty acids found in reproductive tracts of both species of crickets were 16∶0, 18∶0, 18∶1, 18∶2, 20∶0, 20∶1 and 20∶3.
Antioxidants in neoplastic cells: IV. Evidence that the phenolic antioxidant A274 is 9‐(4‐hydroxyphenyl)xanthene, an artifact in tissue culture media
Authors: Arneson R. M. , Hinds J. L. , Wander J. D.
Published: November 2006

An extensively conjugated phenol (A274), recently shown to be present as a common trace constituent in randomly selected batches of commercial tissue culture media, was diazomethylated; the monomethyl derivative so prepared was shown to exhibit gas chromatographic and mass spectrometric properties identical to those observed for synthetically prepared 9‐(4‐methoxyphenyl)xanthene, but different from those of several isomeric compounds. The structure 9‐(4‐hydroxyphenyl)xanthene is thus proposed for A274.
Long chain polyenoic acid levels in viably sorted, highly enriched mouse testis cells
Authors: Grogan W. McLean , Farnham William F. , Szopiak Bernice A.
Published: November 2006

Twenty‐and 22‐carbon fatty acids of the linoleic (n‐6) and linolenic (n‐3) acid families were measured in murine spermatogonia and preleptotene spermatocytes (early), pachytene primary spermatocytes (10) round spermatids (RS), condensing spermatids (CS) and Leydig cells enriched by staput velocity sedimentation at 1 G, followed by viable microflow sorting on the basis of light scatter and DNA content. 22: 5(n‐6) increased progressively from 2 to 20% of total fatty acid in the progression of germinal cell differentiation, early »10»RS»CS, but decreased in mature sperm. The precursor 20:4(n‐6) showed a roughly reciprocal relationship. 22:6(n‐3) showed no significant correlation with cell type. 22:5(n‐6) was found highest in triglycerides of later differentiation stages whereas 20:4(n‐6) and 22:6(n‐3) were found primarily in phospholipid in all cell fractions.
Incorporation of [1‐14C] acetate into fatty acids of the crustaceansDaphnia magna andCyclops strenus in relation to temperature
Authors: Farkas T. , Kariko K. , Csengeri I.
Published: November 2006

Daphnia magna andCyclops strenus were maintained in aquaria containing sodium [1‐14C] acetate and the effect of temperature on labeling of their lipids was investigated. Incorporation of radioactivity in total lipids was slowed by a factor of 4 in cold‐exposed (5C) specimens compared to those incubated at 25 C. There was no significant difference in the distribution of label in the lipid classes of animals incubated at the two extreme temperatures. Decrease of the temperature from 25 to 5 C brought about a considerable reduction in the formation of palmitic and stearic acids and an increase in labeling of monounsaturated (18∶1) fatty acids inD. magna. Docosapolyenoic acids were absent from lipids of this crustacean.C. strenus directed a higher proportion of radioactivity into both oleic and docosahexaenoic acids upon cold exposure. In response to decrease of the temperature,D. magna formed a less unsaturated fatty acid population, as judged from dpm ratios of total saturated to total unsaturated fatty acids, thanC. strenus. Inability to form and accumulate docosapolyenoic fatty acids byD. magna might be related to their poor survival at reduced temperatures.
Application of methoxy‐bromomercuri‐adduct fractionation to the analysis of fatty acids of partially hydrogenated marine oils
Authors: Sebedio J‐L. , Ackman R. G.
Published: November 2006

The fatty acids of a refined and of a partially hydrogenated menhaden oil, iodine value (IV) 84.5, were separated into different classes (e.g., monoene, diene, including pentaene and hexaene) by thin layer chromatography (TLC) of their methoxy‐bromomercuri‐adducts (MBM). In the solvent system hexane: dioxane, the separation of fatty acids occurred according to the degree of unsaturation. No influence was exerted by either the geometry or the position of the ethylenic bonds. The effect of the various chain lengths (C14−C22) was to broaden the bands, but no overlap occurred among the chain lengths. A wide range of C20 unsaturated fatty acids were prepared by the hydrazine reduction of 20∶5‐Δ5,8,11,14,17. These were separated into groups as MBM adducts and identified by comparison of their experimental and calculated equivalent chain lengths (ECL) in gas liquid chromatography (GLC) on SILAR‐5CP and SILAR‐7CP columns. This confirmed that GLC did not totally separate all groups of isomers of different degrees of unsaturation. The quantitative analysis of both refined and partially hydrogenated (IV‐84.5) menhaden oils by GLC was effected by the recovery of the fatty acid methyl esters from the MBM adduct TLC bands with the addition of methyl heptadecanoate (17∶0) as an internal standard, followed by analysis of the different fractions on open‐tubular columns coated with SILAR‐5CP. For methylene‐ and nonmethylene‐interrupted unsaturated acids, 100% recovery from the MBM adducts was achieved, but in the case of the conjugated dienes the maximal recovery was 70%.
The OV 275‐packed stainless steel column intrans‐fatty acid research: A note of caution
Authors: Walker Brian L.
Published: November 2006

Gas chromatographic analysis of fatty acid methyl esters in a 6.1 m stainless steel column packed with 15% OV 275 and operated at 220 C resulted in poor recovery of polyunsaturated esters relative to their saturated or monoenoic counterparts. Relative responses of the esters declined with increasing unsaturation, were concentration‐dependent at low concentrations and changed as the column aged. Decomposition of polyunsaturated compounds in the hot stainless steel column appeared to be the major reason for their poor recovery and renders this particular column of doubtful value in analysis of complex ester mixtures.
On the mechanisms of fatty acid transformations in membranes
Authors: Gan‐Elepano Minerva , Aeberhard Ernesto , Mead James F.
Published: November 2006

Concentrations of albumin in excess of 1% in the incubation mixture inhibited the elongation of added fatty acids and their incorporation into microsomal lipids whereas these reactions were not inhibited with endogenous microsomal membrane fatty acids. The results of these and other studies support the idea that such reactions of membrane lipid fatty acids with membrane‐bound enzymes normally occur entirely within the membrane without release of free fatty acids to equilibrate with the fatty acid pool during the process.
Endogenous lipolytic activities during autolysis of highly enriched hepatic lysosomes
Authors: Beckman Jeffrey K. , Owens Kenneth , Weglicki William B.
Published: November 2006

Highly enriched (50‐ to 70‐fold) fractions of “native” lysosomes were isolated using continuous flow electrophoresis from livers of rats which had not been pretreated with Triton WR‐1339. Incubation of lysosomes for 30 min at pH 5.0 in the presence of 5 mM EDTA resulted in a dramatic loss in the content of fatty acids bound to triacylglycerols (137 down to 10 μmol/mg protein) and to phospholipids and an elevation in the level of unesterified fatty acid. Phosphatidylcholine, phosphatidylethanolamine and sphingomyelin concentrations decreased whereas those of lysophosphatidylethanolamine (0.8 up to 8.5% of total lipid‐P) and lysophosphatidylcholine (1.9 up to 16.7%) rose in a manner parallel to their respective, fully acylated lipids. Other phospholipids, including phosphatidylinositol, did not change in concentration during incubation. These results indicate that lysosomal phospholipase A, sphingomyelin and triacylglycerol lipase are activated by incubation at acid pH, enabling them to hydrolyze endogenous lysosomal lipids. However, lysosomal phosphatidylinositol‐directed phospholipase C is apparently unable to interact with phosphatidylinositol of the lysosomal membrane.
Identification and quantification of prostaglandin E3 in renal medullary tissue of three strains of rats fed fish oil
Authors: Ferretti Aldo , Schoene Norberta W. , Flanagan Vincent P.
Published: November 2006

Three strains of rats were fed a fish oil diet to verify their ability to incorporate and convert dietary eicosapentaenoic acid (20∶5ω3) into trienoic prostaglandins. Our results show that such conversion indeed occurs in kidney medullae homogenates. Specifically, the presence of prostaglandin E3 (PGE3) was established by gas chromatographic‐mass spectrometric (GC‐MS) analysis. That compound was conclusively identified by comparison of fragment ions and their relative intensities with those obtained from authentic PGE3. Further evidence was provided by studying the recovery of exogenously added PGE3. The crude ethyl acetate extracts of the medullary homogenates were methylated and cleaned up by liquid‐gel chromatography with Lipidex‐5000 prior to conversion to PGB3 for GC‐MS analysis. The PGE3 was quantified by selected ion monitoring (SIM) with [3,3,4,4‐2H4PGE2 as internal standard. The levels of PGE3 were similar, about 3 ng/mg of wet tissue, in the 3 strains of rats. Identical in vivo conversion of the 20∶5ω3 fatty acid to PGE3 could not be positively established by analysis of pooled urine specimens.
Biosynthesis of (Z,Z)‐6,9‐heptacosadiene in the American cockroach
Authors: Dwyer Lawrence A. , de Renobales Mertxe , Blomquist Gary J.
Published: November 2006

The biosynthesis of (Z,Z)‐6,9‐heptacosadiene, the major cuticular hydrocarbon component of the American cockroach, was examined by radiotracer and13C‐nuclear magnetic resonance (NMR) techniques. Sodium [1‐14C] acetate was incorporated about equally into the saturated and diunsaturated hydrocarbons, whereas [1‐14C] linoleate preferentially labeled the C27 alkadiene and [9,10‐3H] oleate labeled the C27 alkadiene almost exclusively.13C‐NMR demonstrated that [2‐13C] acetate labeled carbons 25 and 27 but not carbon 3 of the C27 alkadiene. In addition, ozonolysis of the diene labeled from [1‐14C] acetate followed by radio‐gas liquid chromatography showed that carbons 1–6 were not labeled, whereas the fragment containing carbons 10–27 was labeled. The data presented in this paper indicate that linoleate from the diet or synthesized de novo is elongated by the addition of acetate units and is then decarboxylated.
Absence of cholesterogenesis regulation in the liver and prostate of the BIO 87.20 hamster
Authors: Schaffner Carl P. , Brill David R. , Singhal Anil K. , Bonner Daniel P. , Goldstein Neil I. , Wang Geng M.
Published: November 2006

Normal, adult golden Syrian hamsters and the inbred stain BIO 87.20 Syrian hamsters were maintained on either control, cholesterol, candicidin or clofibrate diets for time periods of up to 4 months. The ventral prostate gland in both species was found to synthesize cholesterol at a greater rate than the liver. Also, our results show that, while hepatic cholesterol synthesis in the normal Syrian hamster is under feedback control with dietary cholesterol, hepatic cholesterol synthesis in the BIO 87.20 hamster, and prostatic cholesterol synthesis in either species, is under no such control. This apparent regulatory defect in the BIO 87.20 hamster, which results in a dramatic accumulation of cholesterol in the liver and serum, renders this animal a potentially valuable in vivo model for the study of cholesterol‐related disorders.
Production of prostaglandins in homogenates of kidney medullae and cortices of spontaneously hypertensive rats fed menhaden oil
Authors: Schoene N. W. , Ferretti A. , Fiore D.
Published: November 2006

Menhaden oil (MO), whose polyunsaturated fatty acids consist mainly of (n−3) fatty acids, was fed to spontaneously hypertensive rats to determine the effect of (n−3) fatty acid on the in vitro production of prostaglandins produced from arachidonic acid (20∶4[n−6]). Capacity to form PGE2 and PGF2α was impaired in homogenates of kidney medullae and cortices from rats fed the MO diet compared to rats fed the control diet. The lower amounts of diene prostaglandins produced corresponded to the decrease in the amount of 20∶4 (n−6) in the tissue. Possibly changes produced in tissue lipids by dietary fatty acids affect prostaglandin production by reducing the availability of substrate in tissue lipids.
Positional specificity oftrans fatty acids in fetal lecithin
Authors: Moore Carolyn E. , Dhopeshwarkar Govind A.
Published: November 2006

Differences in the positional incorporation of 9‐trans[1‐14C] octadecenoic (elaidic) and 9‐trans,12‐trans[1‐14C] octadecadienoic (linoelaidic) acids in fetal lecithin of rats were demonstrated. On the 20th day of gestation, a14C‐labeled albumin complex of elaidic or linoelaidic acid was injected into the jugular vein of pregnant rats. For comparative purposes, 9‐cis[1‐14C] octadecenoic (oleic) or 9‐cis,12‐cis[1‐14C] octadecadienoic (linoleic acid) was injected into the maternal circulation of rats. Animals were killed 6 hr later. Distribution of label in total lipids and phospholipids (PL) of fetal tissue was measured by TLC. Irrespective of the label, the highest percentage of total radioactivity was associated with PL‐59 to 67%. Within PL, the major portion of radioactivity was found in choline phosphoglycerides (CPG)‐53 to 67%, and in ethanolamine phosphoglycerides (EPG)‐18 to 33%. While linoelaidic acid was predominantly esterified in the 2‐position of CPG, elaidic acid was nearly equally distributed between positions 1 and 2 of lecithin. Distribution of radioactivity within fatty acid methyl esters (FAME) of CPG measured by radio‐GLC suggested that oleic and possibly linoleic acids may be converted to nervonic and arachidonic acid, respectively, in the rat by the 20th day of gestation. Following injection of elaidate, radioactivity of FAME was distributed between palmitate and elaidic acid indicating that rat fetal tissue may metabolize elaidic acid via β‐oxidation. In contrast, following injection of linoelaidate, radioactivity of FAME was primarily associated withtt‐18∶2, suggesting little biotransformation to other fatty acids by fetal tissues.
Hyperlipidemia in rats fed retinoic acid
Authors: Gerber Leonard E. , Erdman John W.
Published: November 2006

This report describes a series of experiments that attempt to characterize the lipidemia accompanying retinoic acid administration. After feeding young adult male Sprague‐Dawley rats, 1.2 Retinol Equivalents (R.E.) retinyl acetate plus supplemental retinoic acid (100 μg/g dry diet) for three days and fasting for 6–8 hr, triglyceride, cholesterol, and phospholipid content of various serum lipoprotein fractions were determined. When compared to unsupplemented controls, both the serum very low density lipoprotein (VLDL) and the high density lipoprotein (HDL) fractions of the retinoic acid‐fed rats were found to harbor an elevated triglyceride content. While VLDL cholesterol and phospholipid content were also elevated, total serum cholesterol and phospholipids were not statistically altered. The detergent Triton WR‐1339 was used to depress serum triglyceride clearance in order to assess the effects of retinoic acid feeding on serum triglyceride levels. Triglyceride accumulation started earlier after Triton treatment and was greater when rats were fed 100 μg/g retinoic acid for three days prior to testing. Red and white gastrocnemius muscle, cardiac ventricular muscle, and perirenal adipose tissue were removed from rats following retinoic acid feeding. Analysis of these tissues for lipoprotein lipase (EC 3.1.1.3) activity showed a decrease in adipose tissue, a large depression in both areas of gastrocnemius muscle and no change in cardiac muscle as a result of retinoic acid feeding.
Myelin subfractions isolated from mouse brain: Analysis of the lipid composition at three developmental stages
Authors: Rhein Linda D. , Sampugna Joseph
Published: November 2006

Lipids were examined in whole myelin and 8 myelin subfractions isolated from mouse brain at 18–24, 44–48 and 80–90 days of age. Relative to protein, total lipid was lowest in whole myelin isolated from the oldest animals as well as from subfractions isolated at greater sucrose densities, thus partially accounting for the observed myelin subfraction distribution pattern which shifted during development from an average peak density banding between 0.55 and 0.65 M sucrose to one banding between 0.60 and 0.70 M sucrose. Whole myelin and each myelin subfraction isolated at one age contained nearly the same ratio of sterol and phospholipid to galactolipid; these ratios decreased uniformly during development suggesting enrichment with galactolipid in all myelin subfractions. Sulfatide, as percentage of total galactolipid, was relatively constant during development and appeared to be slightly enriched in the denser myelin subfractions. The findings suggest that regardless of the origin(s) of the subfractions, an age‐related mechanism exists in the central nervous system which modifies myelin lipid composition relatively uniformly.
Acylglycerol structure of genetic varieties of peanut oils of varying atherogenic potential
Authors: Manganaro F. , Myher J. J. , Kuksis A. , Kritchevsky D.
Published: November 2006

Detailed investigation was made of the triacylglycerol structure of three varieties of peanut oils of varying atherogenic activity. By means of chromatographic and stereospecific analyses, it was shown that all the oils had markedly nonrandom enantiomeric structures with the long chain saturated fatty acids (C20−C24) confined exclusively to thesn‐3‐position, whereas the palmitic and oleic acids were distributed about equally between thesn‐1‐andsn‐3‐positions, with the linoleic acid being found preferentially in thesn‐2‐position. On the basis of detailed studies of the molecular species of the separatesn‐1,2‐,sn‐2,3‐ andsn‐1,3‐diacylglycerol moieties, it was concluded that the fatty acids in the three positions of the glycerol molecule are combined with each other solely on the basis of their relative molar concentrations. As a result, it was possible to calculate the composition of the molecular species of the peanut oil triacylglycerols (including the content of the enantiomers and the reverse isomers) by means of the 1‐random 2‐random 3‐random distribution. In general, the three peanut oils possessed triacylglycerol structures which where closely similar to that derived earlier for a commercial peanut oil of North American origin. Since their oil has exhibited a high degree of atherogenic potential, it was anticipated that the present oils would likewise be atherogenic, which has been confirmed by biological testing. However, there are certain differences in the triacylglycerol structures among these oils, which can be correlated with the variations in their atherogenic activity. The major differences reside in the linoleic/oleic acid ratios in the triacylglycerols, especially in thesn‐2‐position, and in the proportions in which these acids are combined with the long chain fatty acids. On the basis of the characteristic structures identified in the earlier analyzed atherogenic peanut oil, the peanut oil of South American origin would be judged to possess the greatest atherogenic potential and this has been borne out by biological testing.
Microsomal phosphatidylethanolamine methyltransferase: Some physical and kinetic properties
Authors: Hoffman Dennis R. , Cornatzer W. E.
Published: November 2006

Some physical and kinetic properties of the microsomal enzyme(s) that convert phosphatidyl‐ethanolamine to phosphatidylcholine in rat and guinea pig livers have been investigated. The pH optima, of the reactions were 9.8, 9.3 and 9.5 for the first, second and third methylation reactions, respectively. Incomplete heat denaturation of the protein catalyzing the first reaction contrasts with inactivation at 60 C of the enzymes catalyzing the second and third methylations. The maximal velocity of the first reaction of the guinea pig liver enzyme is 48 p mol/min/mg protein, substantially less than exhibited rate‐limiting reaction of the three step methylation sequence in rat liver, 114 pmol/min/mg. The affinity of the microsomal enzyme for S‐adenosylmethionine is greater in rat liver (Km=18.2 μM) than in guinea pig liver (Km=302 μM).
Analysis of the phospholipid of the nuclear envelope and endoplasmic reticulum of liver cells by high pressure liquid chromatography
Authors: James Jacqueline L. , Clawson Gary A. , Chan Christine H. , Smuckler Edward A.
Published: November 2006

A method is described for the separation and analysis of phospholipids from rat‐liver nuclear envelope and endoplasmic reticulum. The procedure employs a liquid environment, to which antioxidants can be added, and results in separation of NL, PE, PI, PS, and PC in 99% purity in 12 min; analytical columns and a radial compression system may be employed. The procedure results in phospholipids with a large proportion of highly unsaturated fatty acids; some differences in fatty acid distributions were found when nuclear envelope phospholipid fractions were compared with the corresponding fractions from endoplasmic reticulum.
Diplocyclos palmatus L.: A new seed source of punicic acid
Authors: Gowrikumar G. , Mani V. V. S. , Rao T. Chandrasekhara , Kaimal T. N. B. , Lakshminarayana G.
Published: November 2006

The seeds ofDiplocyclos palmatus L. (Cucurbitaceae) contained 23% oil and 15% protein. The UV, IR,1H‐NMR and13C‐NMR spectrometry of the oil, and oxidation, reduction and gas liquid chromatography (GLC) of the methyl ester of conjugated fatty acid isolated by preparative thin layer chromatography (TLC) showed the presence of punicic (octadeca‐cis‐9,trans‐11,cis‐13‐trienoic) acid. The fatty acid composition (wt %), as determined by GLC, is: punicic, 38.2; 18∶2, 43.9; 16∶0, 8.1; 18∶0, 4.9 and 18∶1, 4.9.
Phospholpid studies of marine organisms: 2.1 Phospholipids, phospholipid‐bound fatty acids and free sterols of the spongeAplysina fistularis (Pallas) formafulva (Pallas) (=Verongia thiona)2. Isolation and structure elucidation of unprecedented branched fatty acids
Authors: Walkup Robert D. , Jamieson Gene C. , Ratcliff Milton R. , Djerassi Carl
Published: November 2006

The free sterols and phospholipids of the demospongeAplysina fistularis were isolated and analyzed. The free sterols consisted mainly of the unusual 26‐methylated sterols aplysterol (53%) and 24(28)‐dehydroaplysterol (7%) together with 7 commonly occurring sterods. The major phospholipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol, phosphatidylethanolamine, phosphatidylserine and diphosphatidylglycerol. The major fatty acyl components of the phospholipids consisted of 85% C14−C20 acids, including the unprecedented 2,6,10‐trimethyl‐5‐tetradecenoic acid and 11‐methyloctadecanoic acid. The remaining 15% were C27−C30 demospongic acids, including 2 novel acids tentatively assigned the structures 5,9,23‐octacosatrienoic acid and 5,9,23‐nonacosatrienoic acid, and 3 novel acids proven to be 5,9,21‐octacosatrienoic acid, Z,Z‐20‐methyl‐5,9‐hexacosadienoic acid and Z,Z‐22‐methyl‐5,9‐octacosadienoic acid. The biosyntheses of the novel demospongic acids are proposed to occur by chain elongation of monoenoic or branched precursors followed by desaturation. The large quantities of typically bacterial phospholipids and fatty acids found implied the presence of bacteria in the sponge, in agreement with microscopic studies. Analysis of the phospholipid‐bound fatty acids in a sponge cell‐enriched fraction indicated that the demospongic acids, including the 2 branched structures, were the major acids of the sponge cells. The presence inA. fistularis of demospongic acids containing membrane disordering groups—methyl branches or double bonds—on the ω7 carbon is proposed to be due to the need by the sponge for membranes possessing fluidity near the middle of the phospholipid bilayer. It is also proposed that the C26 methyl group of aplysterol causes disordering of the phospholipid bilayer in the same region, and thus also evolved in response to this need.
Phospholipid synthesis in human embryo fibroblasts infected with herpes simplex virus type 2
Authors: Daniel Larry W. , Waite Moseley , Kucera Louis S. , King Lynn , Edwards Iris
Published: November 2006

The effect of herpes simplex virus type 2 infection on the synthesis of phospholipids in human embryo fibroblasts was determined at temperatures permissive (35 C) or nonpermissive (42 C) for virus replication. Incorporation of [32P]i was decreased by herpes simplex virus type 2 in fection after 6 hr, which corresponds to the time of initiation of progeny virus production. No differences were observed in the relative incorporation of [32P]i into phospholipid classes. In another series of experiments, cells were labeled with [3H] ethanolamine before infection and with [14C] ethanolamine after infection. The incorporation of [14C] ethanolamine was also decreased after 6 hr of infection. When choline was substituted for ethanolamine, a similar, although less pronounced, decrease in incorporation was seen in infected cells compared to mock‐infected cells. During abortive infection at 42 C, incorporation of [3H] thymidine into cellular DNA was stimulated, but the incorporation of phospholipid precursors was decreased. Total phospholipid composition and phospholipid acyl group composition were not changed appreciably during abortive or productive infection, regardless of whether the cells were labeled before or after infection. In conclusion, these data indicated that, during herpes simplex virus type 2 infection, the incorporation of lipid prescursors into phospholipid was decreased. The stimulation of cellular DNA synthesis previously observed during abortive infection at 42 C was not paralleled by a detectable stimulation of total phospholipid synthesis. Neither productive nor abortive infection resulted in significant phospholipid compositional changes in the host cell; however, both resulted in a marked inhibition of phospholipid synthesis.
Ketone bodies, glucose and glutamine as lipogenic precursors in human diploid fibroblasts
Authors: Reed W. Douglas , Zielke H. Ronald , Baab Peter J. , Ozand Pinar T.
Published: November 2006

Incorporation of [14C] from acetoacetate, D(‐)‐ and L(+)‐3‐hydroxybutyrate, glucose, glutamine, acetate and palmitate in cellular lipids were studied in cultures in human diploid fibroblasts (HDF). The results showed that acetoacetate was 2–10 times more effective as a lipogenic precursor than was either D‐ or L‐3‐hydroxybutyrate. Its extent of incorporation into lipids was 2‐ to 8‐fold more than the other precursors examined under conditions when the overall rates of nonsaponifiable and saponi‐fiable lipogenesis as measured by3H2O incorporation were essentially unchanged. Acetoacetate supported both saponifiable and nonsaponifiable lipid syntheses with half‐saturation values (Km app.) of 185 μM and 30 μM, respectively. Glucose stimulated acetoacetate incorporation into lipids whereas, conversely, acetoacetate inhibited [14C] glucose incorporation into lipids. The presence of low density lipoproteins (LDL) cholesterol (@40 μg cholesterol/mL) inhibited the incorporation of [14C] from acetoacetate 56% into nonsaponifiable lipids; the inhibition was consistently higher (75%) when [14C] glucose or glutamine were the precrusors. The loss of 3‐hydroxy‐3‐methyl‐glutaryl CoA (HMG CoA) reductase activity upon addition of LDL‐cholesterol was greater than the suppression of [14C] incorporation from acetoacetate or glucose into nonsaponifiable lipids. In the presence of glucose, [14C] acetoacetate was incorporated into 3‐βOH sterols (digitonin precipitable). 7.7±1.1 times more effectively than was [14C] glucose. The results suggest that HDF would be a suitable model to investigate the effects of various precrusors of HMG CoA on the rate of cholesterol biosynthesis.
Effect of Ca++ on triphosphoinositide extraction in fusing myoblasts
Authors: Grove Robert I. , Fitzpatrick David , Schimmel Steven D.
Published: November 2006

Ca++‐dependent degradation of triphosphoinositide has been postulated to regulate levels of membrane‐bound Ca++ and to generate a 1,2‐diacylglycerol fusogen in cell fusion. Triphosphoinositide metabolism was therefore studied during Ca++‐induced fusion of cultured chick embryo myoblasts. Using a frequently cited extraction procedure, it was found that apparent Ca++‐dependent triphosphoinositide degradation was actually due to inhibition of extraction. A new procedure using the ion‐pairing reagent tetrabutylammonium sulfate was developed which was unaffected by Ca++ and gave 2‐ to 20‐fold greater extraction of triphosphoinositide than existing procedures. With this procedure, no changes in triphosphoinositide metabolism were found during myoblast fusion.
Different pools of esterified arachidonic acid in rabbit kidney medulla: Relationship to Ca2+‐stimulated prostaglandin biosynthesis
Authors: Erman A. , Azuri R. , Raz A.
Published: November 2006

We investigated the effect of Ca2+ ions on renal medulla metabolism of endogenous esterified arachidonic acid in contrast to that of radioactive arachidonate incorporated into medullary lipids. Some striking differences between the release of unlabeled prostaglandin E2 and of14C‐labeled prostaglandin E2 and arachidonic acid were seen in incubations in absence or presence of Ca2+ ions. These differences indicated that exogenous [14C] arachidonate incubated with medulla slices is incorporated into both Ca2+‐sensitive and Ca2+‐insensitive lipid pools of esterified arachidonate and furthermore, the Ca2+‐sensitive pool is itself heterogeneous and consists of at least 2 functionally different lipid pools of esterified arachidonate. The first Ca2+‐sensitive pool is characterized by a higher arachidonate turnover rate and incorporates more rapidly added radioactive arachidonate. The acylhydrolase activity which releases arachidonate from this pool is not efficiently coupled to prostaglandin endoperoxide synthase. In contrast, the second Ca2+‐sensitive lipid pool has a slower arachidonate turnover rate and, consequently, a slower incorporation of added14C‐acid. The acylhydrolase activity associated with this pool is more tightly coupled to prostaglandin endoperoxide synthase, so that a higher portion of released arachidonate is converted to prostaglandin E2. Studies on arachidonic acid metabolic transformations using exogenously radioactive free acid added to tissues should therefore be inerpreted with caution because the results obtained may not reflect accurately the metabolic fate of endogenous, lipid‐esterified arachidonate which is released and metabolized under physiological conditions in vivo.
Effects of zinc deficiency and castration on fatty acid composition and desaturation in rats
Authors: Clejan Sanda , Castro‐Magana Mariano , Collipp Platon J. , Jonas Ernesto , Maddaiah Vaddanahally T.
Published: November 2006

The effects of zinc deficiency and testosterone on fatty acid composition of plasma lipids and microsomes of liver, intestine and testes were studied. The activities of fatty acid desaturase (Δ6 and Δ5) in rat liver and testes were also measured. A significant decrease in the level of arachidonic acid was observed in plasma of normal rats fed the zinc‐deficient diet. Castration significantly decreased arachidonic acid but increased 20∶3 fatty acid, which is negligible in normal rats. Testosterone and zinc administration restored arachidonic acid to normal values. Zinc deficiency does not significantly change the fatty acid profile in liver, but castration decreased both arachidonic and 22∶6 fatty acid. Intestinal mucosal microsomes showed that the predominant fatty acid in this tissue, palmitic acid, is independent of zinc status, whereas polyunsaturated fatty acids 18∶2 and 20∶4 were decreased by zinc‐deficient diet or castration. Zinc deficiency sharply decreased 22∶5 fatty acid and to some extent, other polyunsaturated fatty acids in testis microsomes. These changes in fatty acids are in agreement with increased Δ9 desaturation and decreased Δ5 desaturase activity. In testes, both Δ6 and Δ5 desaturase activities are decreased in zinc deficiency. It appears that zinc influences the conversion of linoleic to arachidonic acid, whereas testosterone influences Δ6 desaturase activity. The data suggest that zinc deficiency may be one of the important factors in the causation of polyunsaturated fatty acid deficiency, which in turn, may induce serum hypertriglyceridemia.
Hepatic bile acid elution by albumin and bile acid content in isolated rat hepatocytes
Authors: Hashimoto Shigeru , Uchida Kiyohisa , Hirata Masaharu
Published: November 2006

Bile acid contents were determined for isolated rat hepatocytes. During the course of isolating the hepatocytes, perfusion of rat liver with buffer containing 2% albumin eluted a significant amount of bile acids. The elution was proportional to the volume of the buffer and attributable to albumin in the buffer. The isolated hepatocytes prepared by perfusion with 0.1% albumin buffer, which eluted a negligible amount of bile acids, contained 95±12 μg/108 cells of bile acids. The major bile acids were cholic acid (22%), β‐muricholic acid (34%) and hyodeoxycholic acid (10%). Levels of the other bile acids were less than 3%. Peak 8, unidentified but presumed to be a trihydroxycholanoic acid, accounted for 19%.
Changes of fatty acid composition of phospholipids in liver mitochondria and microsomes of the rat during growth
Authors: Keränen Antti , Kankare Paavo , Hallman Mikko
Published: November 2006

The fatty acid patterns of rat liver mitochondrial and microsomal phospholipids were analyzed from term fetuses, 1 and 4 days old, and adult rats. The main fatty acids of phosphatidylethanolamine and‐choline were stearic and palmitic acids, although the patterns differed slightly. The fatty acid composition of corresponding phospholipids in mitochondria and microsomes was similar. The fatty acid pattern of cardiolipin was dominated by linoleic acid. The most consistent feature of the developmental changes in the fatty acid patterns of all phospholipids studied was a decrease in the relative amount of monounsaturated fatty acids. The percentages of saturated fatty acids in phosphatidyl‐ethanolamine and‐choline increased during neonatal development. It is suggested that the high levels of fetal monounsaturated fatty acids were due to low availability of polyunsaturated fatty acids.
Regional distribution of glycosylceramide‐sulfates in human kidney
Authors: Samuelsson Bo E.
Published: November 2006

Glycosylceramide‐sulfates were prepared separately from human kidney cortex and medulla. Glycosylceramide‐sulfates were characterized with respect to long‐chain bases, fatty acids, carbohydrates and sulfuric ester group position. Monogalactosylceramide I3‐sulfates were 3 times more concentrated in medulla compared to cortex, whereas lactosylceramide II3‐sulfates were 3 times more concentrated in cortex compared to medulla. The results were discussed in relation to the possible role of glycosyl‐ceramide‐sulfates in sodium‐potassium ion transport.