bluuebunny/crossref_metadata_2025_split huggingface dataset:
Incorporation of radioactive polyunsaturated fatty acids into liver and brain of developing rat
Authors: Sinclair A. J. 
Published: November 2006

AbstractThe incorporation of radioactivity from orally administered linoleic acid‐1‐14C, linolenic acid‐1‐14C, arachidonic acid‐3Hg, and docosahexaenoic acid‐14C into the liver and brain lipids of suckling rats was studied. In both tissues, 22 hr after dosing, 2 distinct levels of incorporation were observed: a low uptake (from 18∶2‐1‐14C and 18∶3‐1‐14C) and a high uptake (from 20∶4‐3H8 and 22∶6‐14C). In adult rats, the incorporation of radioactivity into brain lipids from 18∶2‐1‐14C and 20∶4‐3H was considerably lower than the incorporation into the brains of the young rats. In the livers of the suckling rats, the activity from the 18 carbon acids was associated mostly with the triglyceride fraction, whereas the activity from the 20∶4‐3H8 and 22∶6‐14C was concentrated in the phospholipid fraction. In the brain lipids, the activity from the different fatty acids was associated predominantly with the phospholipids. In the liver and brain phospholipid fatty acids, some of the activity in the 18∶2‐1‐14C and 18∶3‐1‐14C experiments was associated with 20 and 22 carbon polyunsaturated fatty acids; however, radioactivity from orally administered 20∶4‐3H8 and 22∶6‐14C was incorporated intact into the tissue phospholipid to a much greater extent compared with the incorporation of radioactivity into 20∶4 and 22∶6 in the experiments where 18∶2‐1‐14C and 18∶3‐1‐14C, respectively, were administered. Possible reasons for these differences are discussed. Rat milk contains a wide spectrum of polyunsaturated fatty acids, including linoleate, linolenate, arachidonate, and docosahexaenoate. During the suckling period in the rat, there is a rapid deposition of 20∶4 and 22∶6 in the brain. The results of the present experiments suggested that dietary 20∶4 and 22∶6 were important sources of brain 20∶4 and 22∶6 in the developing rat.
Evidence for distinct precursor pools for biliary cholesterol and primary bile acids in cebus and cynomolgus monkeys
Authors: Stephan Zouhair F. , Hayes K. C. 
Published: November 2006

AbstractThe abnormal metabolism and distribution of plasma lipoproteins have been associated with atherosclerosis and gallstones. To better understand the process of cholesterol excretion, a study was designed to determine whether the contribution of lipoprotein free14C‐cholesterol (as LDL or HDL) to biliary cholesterol or primary bile acids differs in two species of nonhuman primates, cebus and cynomolgus monkeys, having opposite plasma LDL/HDL ratios. Since amino acid conjugation might influence bile acid synthesis or secretion, the taurine and glycine conjugates of newly synthesized primary bile acids, cholic acid (CA) and chenodeoxycholic acid (CDCA), were measured in the species capable of conjugating with taurine or glycine (cynomolgus). After total bile acid pool washout, monkeys were infused with human LDL or HDL labeled with free14C‐cholesterol, and the specific activities (SA) of biliary cholesterol and primary bile acid conjugates were determined. In both species, regardless of the lipoprotein infused, the SA of biliary cholesterol and CA were greater than those for total bile acids and CDCA, respectively. In cynomolgus, the SA of glycine conjugates was higher for CA than CDCA, while the SA of taurine conjugates was greater for CDCA than CA. Under these conditions, (i) infused lipoprotein free cholesterol (as either LDL or HDL) contributed more to biliary cholesterol than to bile acids and more to CA than to CDCA; (ii) glycine conjugated preferentially with CA rather than CDCA, while taurine was the preferred conjugate for CDCA. Further, whereas the two primary bile acids had similar rates of synthesis and turnover in cynomolgus, basal bile acid synthesis was much greater in cebus and the CDCA turnover appeared disproportionately large.
Fatty acid composition of phospholipids and neutral lipids during embryonic and early larval development in Atlantic herring (Clupea harengus, L.)
Authors: Tocher D. R. , Fraser A. J. , Sargent J. R. , Gamble J. C. 
Published: November 2006

AbstractThe fatty acid compositions of total polar and total neutral lipids of Atlantic herring eggs and larvae were determined immediately before fertilization, after fertilization and at various times during subsequent embryonic and early larval development. Within 3 hr after fertilization the percentage of total PUFA in neutral lipid decreased from 33% to 20%, with a reciprocal increase in monoenes. Thereafter the percentage of PUFA in the neutral lipids increased progressively, attaining the original level in ripe eggs by the time of yolk sac absorption. During the larval stages the percentage of PUFA continued to increase in the neutral lipid, reaching almost 44% of the total by day 32 after fertilization, although it was reduced to 32% by day 36. The percentage of monoenes in the neutral lipid displayed a progressive decrease during the whole period of development from 3 hr after fertilization. Throughout all the developmental periods the fatty acid composition of total polar lipids remained essentially constant. The polar lipids of the yolk sac displayed virtually the same fatty acid composition as the larval bodies, but the neutral lipids of the yolk sac were low in PUFA compared to the larval bodies. The results are discussed with reference to changes in lipid class composition during development. The conservation of high levels of PUFA in lipids during embryogenesis and early larval development reflects the importance of these fatty acids during development.
Lipid class composition during embryonic and early larval development in Atlantic herring (Clupea harengus, L.)
Authors: Tocher D. R. , Fraser A. J. , Sargent J. R. , Gamble J. C. 
Published: November 2006

AbstractThe lipid class compositions of Atlantic herring eggs and larvae were determined immediately before fertilization, after fertilization and at various times during subsequent embryonic and early larval development. Total lipid constituted 15% of the dry wt of ripe eggs, 70% of the total lipid being polar lipid with phosphatidylcholine (PC) accounting for almost 90% of the polar lipid. In general, the total lipid content decreased gradually during embryogenesis and in particular during larval development. Within 3 hr after fertilization the relative percentage of neutral lipid decreased slightly. This was followed by a general decrease in polar lipid which, by the stage of yolk sac absorption, was reduced to 52% of the total lipid. The decreased percentage of polar lipid was due entirely to a decrease in PC, which was reduced to 66% of the polar lipids at the stage of yolk sac absorption. The accompanying increase in the percentage of neutral lipids was mainly due to increased percentages of triacylglycerols (TAG) up to yolk sac absorption and cholesterol esters in the larval stages. During the first 4 days after hatching, phospholipids and to a lesser extent cholesterol were preferentially depleted in the yolk sacs, which also had higher levels of free fatty acids. The results are discussed in relation to possible roles of different lipids during embryonic and early larval development.
Lipid analyses of isolated surface membranes ofLeishmania Donovani promastigotes
Authors: Wassef Momtaz K. , Fioretti Thomas B. , Dwyer Dennis M. 
Published: November 2006

AbstractConstituent lipids of surface membranes (SM) isolated fromLeishmania donovani promastigotes were analyzed and compared with those obtained from whole cells and an isolated kinetoplast‐mitochondrion fraction (KM). On a dry weight basis, the total extractable lipids constituted ≈47%, 12% and 24% of the SM, cells and KM, respectively. The total lipids of SM, cells and KM all were composed of ≈70% phospholipids (PL), 20–25% neutral lipids and 5–10% glycolipids. Sterols and diglycerides composed 60% and 30%, respectively, of the various neutral lipid fractions. Several mannose‐ and galactose‐containing glycolipids were fractionated but not identified. The glycolipid fractions from cells and SM had demonstrable antigenic activities with rabbit anti‐SM sera. Striking quantitative differences were apparent between the PL profiles of the 3 cellular components examined. The PL of SM, whole cells and KM, respectively, were composed of: 15%, 51% and 24% phosphatidylcholine; 37%, 13% and 11% phosphatidylethanolamine (PE); 18%, 10% and 14% phosphatidylinositol; 10%, 1% and 4% phosphatidylserine and traces of cardiolipin, phosphatidylglycerol and phosphatidic acid. An unknown PL containing sphingosine, choline and vicinal hydroxyl groups but no free amino moieties made up ≈19% of the PL of SM and whole cells, but it constituted ≈27% of the PL of KM. The PL side chain constituents of whole cells and SM were composed mainly of longchain fatty acids (C18–20). Further, over 50% of the PE of SM was in the alkyl and alK‐1‐enyl ether forms. These SM properties might contribute to the organism's resistance to digestion in the hydrolytic environs of both its insect vector and mammalian hosts.
Decrease in alkaline triglyceride lipase in primary cultured hepatocytes from mice with sarcoma 180
Authors: Masuno Hiroshi , Okuda Hiromichi 
Published: November 2006

AbstractPrimary cultured hepatocytes from normal mice and mice with Sarcoma 180 were characterized. The viability of freshly isolated heptocytes from both sources was over 90% and the cells had a relatively stable population of DNA for a minimum of three days. After incubation with (3H)leucine, the syntheses and secretions of (3H)labeled trichloracetic acid‐insoluble materials by hepatocytes from both normal and tumor‐bearing mice increased similarly. However, the alkaline triglyceride lipase activity of a homogenate of freshly isolated hepatocytes from tumor‐bearing mice was one‐third that of cells from normal mice. the activity of hepatocytes from tumor‐bearing mice inceeased less during culture than did the activity of cells isolated from normal mice.
Polyphosphoinositides and the shape of mammalian erythrocytes
Authors: Quist Eugene , Powell Patricia 
Published: November 2006

AbstractThe relationship between polyphosphoinositide and phosphatidic acid (PA) metabolism and Mg‐ATP dependent shape and viscosity changes in erythrocyte ghosts from four mammalian species was examined. Ghosts prepared from rabbit, dog, human and guinea pig erythrocytes were transformed from echinocytes to discocytes within 15 min in the presence of 1 mM Mg‐ATP at 25 C. In all species these Mg‐ATP shape transformations were associated with a 30–45% decrease in the specific viscosity of the ghost suspensions. Mg‐ATP induced a second transformation of discocytic ghosts to cup shape forms without a further decrease in viscosity. A considerable species variation in the rates of Mg‐ATP dependent viscosity and shape changes and incorporation of32P into phosphatidylinositol‐4′ phosphate (PIP), phosphatidylinositol‐4′5′bisphosphate (PIP2) and especially PA form MG‐[γ32P]‐ATP in ghosts was found. However, the rates of Mg‐ATP dependent synthesis of PIP and PIP2 and shape and viscosity changes in each species were of the same magnitude. Ca2+ or neomycin strongly inhibited PIP labeling and Mg‐ATP shape and viscosity changes in ghosts of the different species. Ca2+ or neomycin usually increased or had little effect on32P incorporation into PA and PIP2. The possibility that Mg‐ATP‐induced changes in erythrocyte membrane shape and deformability are dependent on increases in membrane PIP and PIP2 is discussed.
Chromogenic determination of lipid hydroperoxides by sesamol dimer
Authors: Kikugawa Kiyomi , Nakahara Takami , Taniguchi Yasumichi , Tanaka Masami 
Published: November 2006

AbstractA specific chromogenic assay for lipid hydroperoxides was established. The principle of the assay was based on the reaction of sesamol dimer and lipid hydroperoxides in the presence of hemoglobin (methemoglobin, oxyhemoglobin or carbonmonoxyhemoglobin) which produced violet‐colored quinone or semiquinone dimer (IḬ) having an absorption maximum at 550 nm (SD method). By this method, 0.1 μmol methyl linoleate hydroperoxide could be determined with higher sensitivity than the conventional peroxide value (POV) method. This method requires 0.2–5 mg of the sample for determination of lipid hydroperoxides. The extent of oxidation of oleic acid, linoleic acid, methyl oleate, methyl linoleate, soybean oil, sesame oil, hog fat, beef fat, chicken fat and the fat‐fraction of processed foods could be determined, although the sensitivity varied with the samples and with the degree of autoxidation.
Intestinal cholesterol uptake: Comparison between mixed micelles containing lecithin or lysolecithin
Authors: Reynier M. O. , Lafont H. , Crotte C. , Sauve P. , Gerolami A. 
Published: November 2006

AbstractThe aim of our study was to define the mechanism by which cholesterol uptake is inhibited by lecithin but not by lysolecithin. The work compared the cholesterol uptake by everted rat jejunal sacs from bile salt‐lecithin‐cholesterol or bile salt‐lysolecithin‐cholesterol micelles. The micellar size and the cholesterol saturation were measured.The size or molecular weight increases when the lecithin concentration rises, and the cholesterol uptake decreases and leads to zero when the micelles contain more than 30% lecithin. The size of bile salt‐lysolecithin‐cholesterol micelles is smaller than that of lecithin micelles in comparable molar ratios. Consistent with this result is the fact that, for a given phospholipid concentration, cholesterol uptake is greater in the presence of lysolecithin than in the presence of lecithin. The diffusion rate of the micelles through the unstirred water, layer decreases when micellar size increases. However, the comparison of uptakes from lecithin or lysolecithin micelles similar in size and in cholesterol saturation showed that the cholesterol uptake is still lower for lecithin micelles. This shows that with larger micelles some factor other than micellar size and cholesterol content of the micelles is important. We observe that lysolecithin absorption is 15‐fold greater, than lecithin absorption. We suggest that lysolecithin absorption results in a rapid supersaturation with cholesterol leading to cholesterol absorption.
The effect of penicillin on fatty acid synthesis and excretion inStreptococcus mutans BHT
Authors: Brissette Janice L. , Pieringer Ronald A. 
Published: November 2006

AbstractTreatment of exponentially growing cultures ofStreptococcus mutans BHT with growth‐inhibitory concentrations (0.2 μg/ml) of benzylpenicillin stimulates the incorporation of [2‐14C] acetate into lipids excreted by the cells by as much as 69‐fold, but does not change the amount of14C incorporated into intracellular lipids. At this concentration of penicillin cellular lysis does not occur. The radioactive label is incorporated exclusively into the fatty acid moieties of the glycerolipids. The increase in the radioactive content of the extracellular lipids reflects an actual net increase in the total fatty acid content as determined by a chemical assay. During a 4‐hr incubation in the presence of penicillin, the extracellular fatty acid ester concentration (per mg cell dry weight) increases 1.5 fold, even though there is no growth or cellular lysis. No change is observed in the intracellular fatty acid ester content.An indication of the relative rate of fatty acid synthesis was most readily obtained by placingS. mutans BHT in a buffer containing14C‐acetate. Under these nongrowing conditions free fatty acids are the only lipids labeled, a factor which simplifies the assay. The addition of glycerol to the buffer causes all of the nonesterified fatty acids to be incorporated into glycerolipid. The cells excrete much of the lipid whether glycerol is present or not. Addition of penicillin to the nongrowth supporting buffer system does not stimulate the incorporation of [14C]‐acetate into fatty acids. However, if cells are exposed to penicillin in a growth‐supporting medium and then are transferred to the nongrowing buffer system containing no penicillin, the previously exposed cells retain the ability to incorporate [14C]‐acetate into fatty acid at a higher rate than untreated cells over a prolonged period of time. The stimulation of [14C]‐acetate into fatty acids in this system parallels but is not dependent on the stimulation by penicillin of the incorporation of [14C]‐glycerol into glycerolipid and lipoteichoic acid synthesis previously demonstrated by our laboratory.
Adipocyte fatty acid mobilization in vivo: Effects of age and anatomical location
Authors: Hartman Arthur D. 
Published: November 2006

AbstractThe objectives of the present study were to determine if adipocyte trigly ceride fatty acid (TGFA) mobilization in vivo varied among the different adipose tissue depots and whether these rates were affected by age. In order to accomplish these objectives, two groups of rats were studied. The first group initially weighed 84±1 and the second group 333±2. Both groups were placed on a semisynthetic diet containing 6% corn oil (w/w) and 14% triundecanoin (w/w) for a period of 4 wk. Triundecanoin contains an 11‐carbon (C‐11) fatty acid (undecanoic acid) that was used to label the adipocyte TGFA. At the end of the 4‐wk feeding period, triundecanoin was removed from the diet and replaced with an equivalent amount of corn oil. At this time and at weekly intervals for the next 4 wk, 5 rats from each age group were killed for the determination of TGFA composition in isolated dipocytes from the epididymal (Epi), perirenal (PR), subcutaneous (SC) and mesenteric (M) adipose tissue depots. When the content of C‐11 was expressed as mole percent of the total fatty acids, mobilization was significantly more rapid from the PR and M depots than in the other two depots in the young rats. In the older rats mobilization was significantly slower in all depots compared to the younger group. The rates of mobilization were not different between the depots in the older animals. Since fat cell size continued to increase throughout the duration of the study, part of the decrease in C‐11 content can be accounted for by dilution by newly acquired TGFA. When data were compared on the basis of the actual pmoles of C‐11 per cell, rates of mobilization were not different between the depots nor was mobilization affected by age. These results emphasize again the impact the manner in which adipocyte metabolic data are expressed has on interpretation(s) when comparing adipocytes of different depots or from rats of different age.
Activities of liver mixed function oxidase system in rats fedtrans fat
Authors: Nishiyama Kikuko , Ide Takashi , Sugano Michihiro 
Published: November 2006

AbstractRats were fed diets containing either camellia oil or partially hydrogenated corn oil, as a source ofcis ortrans octadecenoate, respectively, in the presence of adequate linoleic acid. After 35 days of feeding the diets, activities of several hepatic drug metabolizing enzymes as well as the content of hepatic microsomal cytochrome P‐450 were determined. Geometrical difference in the dietary fat did not affect the amount of microsomal protein nor the content of cytochrome P‐450. Also, activities of NADPH cytochrome C reductase, aminopyrine N‐demethylase and biphenyl hydroxylase were approximately the same between two groups of rats. Aniline hydroxylase was slightly elevated in the rats fedtrans fat. It was concluded that the difference in the geometry of dietary fatty acids had little effect in modulating the hepatic mixed function oxidase system.
Lipids and lipid antioxidant systems in developing eggs of salmon (Salmo salar)
Authors: Cowey C. B. , Bell J. G. , Knox D. , Fraser A. , Youngson A. 
Published: November 2006

AbstractLipid class and fatty acid analyses were carried out on developing salmon eggs at four clearly defined pre‐feeding stages, namely, fertilization, eyed egg stage (50 days), hatching (yolk sac fry, 98 days) and swim up fry (138 days).Measurements of components of the system considered to be involved in defense of cells against lipid peroxidation (glutathione peroxidase, EC 1.11.1.9, glutathione S‐transferase, EC 2.5.1.18, reduced glutathione [GSH], α‐tocopherol and ascorbic acid) were made at the same time. Levels of triacylglycerol decreased markedly during development, but there were few changes in fatty acid composition, indicating a non‐selective utilization of fatty acids. Phosphatidylcholine was the dominant polar lipid (>94% by weight) in fertilized eggs. It was used preferentially during development so that in swim up fry the ratio phosphatidylcholine: phosphatidylethanolamine approached that found in fish muscle. Amounts of docosahexaenoic acid and arachidonic acid in polar lipids were significantly greater (p<0.01) in swim up fry than in fertilized eggs.Activities of the two enzymes were very low in the fertilized egg and remained low until hatching, when there was a concerted increase in their activity and in the concentration of GSH. Egg tocopherol concentrations decreased significantly during development, but whole body concentrations in swim up fry were not dissimilar from those in normal juvenile fish. Ascorbic acid, on the other hand, declined to very low levels in swim up fry; the restoration of this vitamin during first feeding seems vital to the well being of the fish.
Characterization of gangliosides of porcine erythrocyte membranes: Occurrence of ganglioside GD3 as major ganglioside
Authors: Suzuki Yasuo , Suzuki Naoto , Michi Hiroyasu , Matsumoto Makoto 
Published: November 2006

AbstractFour major ganglioside species were isolated from porcine erythrocyte membranes by DEAE‐Sephadex and Iatrobeads column chromatography. Treatment of the lipids with graded neuraminidase and β‐galactosidase, gas chromatographic analysis of their carboyhydrates, sphingosine bases and molecular species of sialic acid revealed that the structure of these gangliosides were GM3(NeuAc), GM3(NeuGc), GD3(NeuAc) and GD3(NeuGc), each of which was 16±2 μg, 304±42 μg, 30±3 μg and 240±26 μg, respectively, per gram of the dry erythrocyte stroma. The amount of GM3 and GD3 accounted for more than 95% of total gangliosides of the erythrocytes. Porcine erythrocytes may provide a good source for large scale preparation of ganglioside GD3 which recently was identified as a human melanoma‐associated antigen.
The effect of fatty acid chain length and unsaturation on the chromatographic behavior of triglycerides on latroscan chromarods
Authors: Kramer J. K. G. , Fouchard R. C. , Farnworth E. R. 
Published: November 2006

AbstractThe chromatographic behavior of lipid classes on Chromarods with common developing solvents used for the Iatroscan system was influenced by the esterified fatty acids present in the lipid class. The Rf value of the lipid class increased with increasing chain length and increasing unsaturation of the fatty acids; the increase in Rf value per methylene carbon was about twice that per double bond. The effect was evident in both triglycerides and phosphatidylcholines. This partial separation of molecular species within a lipid class caused widening of the lipid class band on the Chromarods and can result in poorer resolution, particularly in biological samples.
Lipid peroxidation and oxidation of several compounds by H2O2 activated metmyoglobin
Authors: Kanner Joseph , Harel Stella 
Published: November 2006

AbstractActivated metmyoglobin (MetMb) by H2O2 initiates oxidation of microsomal unsaturated fatty acids, β‐carotene and methional but not formate. Lipid peroxidation by activated MetMb was not inhibited by catalase. The activated species which initiaes lipid peroxidation appears to be a porphyrin cation radical, P∸+FeIV=O, and not a hydroxyl radical.