bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of the structure of lecithins
Authors: Blank M. L. , Nutter L. J. , Privett O. S. 
Published: November 2006

AbstractA method is described for the determination of the classes of lecithins in terms of unsaturated and saturated fatty acids based on a total fatty acid composition, the composition of the fatty acids in the β‐position, and the amount of disaturated class determined via mercuric acetate adduct formation. The accuracy of the method was determined on lecithins of known composition and the method was applied to lecithins isolated from milk serum and egg lipids, safflower and soybean oils.
Uptake of blood triglyceride by various tissues
Authors: Scow Robert O. , Hamosh Margit , Blanchette‐Mackie E. Joan , Evans Anthony J. 
Published: November 2006

AbstractTriglycerides are transported in the blood in chylomicrons and very low density lipoproteins. Electron microscopic studies indicate that these particles, which range in diameter from 0.03–0.6 μ, cannot cross the capillary endothelium in most tissues. There is now considerable evidence that the triglycerides are hydrolyzed to free fatty acids (FFA) during uptake and that this process is catalyzed by lipoprotein lipase. The enzyme is found in nearly all tissues that utilize circulating triglyceride, and the level of activity, in individual tissues, varies with nutritional and physiological states that affect triglyceride uptake, such as fasting, diabetes and pregnancy. Studies in perfused adipose tissue with doubly labeled chylomicrons showed that hydrolysis occurs outside of the blood stream. Two‐thirds of the fatty acids are incorporated into tissue triglyceride and the rest are release as FFA, with glycerol, to the blood. Infusion of heparin causes immediate release of lipoprotein lipase activity to the blood and decreases the amount of chylomicron‐triglyceride hydrolyzed by the tissue. Electron microscopic cytochemical studies showed that hydrolysis of blood glycerides by lipoprotein lipase in adipose tissue occurs within the capillary endothelial cells and in the subendothelial space near the pericytes, but not in the capillary lumen or near the fat cells. The results indicate that the fatty acids of chylomicrons cross the capillary endothelium as glycerides and FFA, within a membrane‐bounded system, and cross the extravascular space to the fat cells as FFA.
Surface tension studies of phosphatidyl glycerol isolated from the lungs of Beagle dogs
Authors: Henderson Rogene F. , Pfleger Raymond C. 
Published: November 2006

AbstractPhosphatidyl glycerol, isolated from Beagle dog pulmonary surfactant, was found to have surface tension properties similar to phosphatidyl choline (isolated from the same source and chemically synthesized). The results show that another phospholipid in addition to dipalmitoyl‐glyceryl‐phosphoryl‐choline contributes to the characteristic surface tension behavior of pulmonary surfactant.
Composition and concentration of lipoproteins in the serum of normal rats and rats deficient in essential fatty acids
Authors: de Pury G. G. , Collins F. D. 
Published: November 2006

AbstractA comparison is made of the concentration and chemical composition of serum lipoproteins of normal rats and rats deficient in essential fatty acids. The concentration of very low density lipoproteins (VLDL) and of low density lipoproteins (LDL) in serum of deficient rats is about half that found in normal rats, but the concentration of high density lipoproteins (HDL) is higher than normal and they contain an increased amount of cholesterol esters. The proportion of cholesterol that is esterified is much greater than normal in the serum of deficient rats. The deficiency of essential fatty acids also appears to result in compensating changes occurring in the composition of serum lipoproteins. In both VLDL and LDL of deficient rats the proportion of protein is raised and that of phospholipid lowered compared to normal, while the proportions of trigly ceride and cholesterol esters are unchanged.
The hypolipidemic effect of calcium‐containing compounds and vitamin D2 in the rat
Authors: Fleischman Alan I. , Bierenbaum Marvin L. , Lenz Paul H. 
Published: November 2006

AbstractTwo per cent dietary calcium carbonate alone (Group 1), in combination with vitamin D2 (Group 2) or oyster shell calcium with vitamin D2 (Group 3), was added to an atherogenic diet containing 20% fat and 2% cholesterol and fed to adult male Holtzman strain rats to evaluate the hypolipidemic effects of these supplements. A control group received the same diet, but the calcium was replaced by sand. After 21 days the serum cholesterol concentrations were lower by 35, 27 and 22%, respectively, in experimental groups 1, 2 and 3, compared to the controls. Serum triglyceride concentrations were lower by 10% in experimental groups 1, 2 and 3, compared to the controls. Serum triglyceride concentrations were lower by 10% in groups 1 and 2, and 17% in group 3. Concomitant with these decreases in serum lipids, there were increases in fecal 3‐β‐hydroxy‐5‐ene sterol, total glyceride and free fatty acid excretion. Serum calcium was elevated in the rats fed diets containing calcium when compared with the controls, whereas serum magnesium was depressed in thesy animals. Less calcium was excreted in the feces of rats fed calcium carbonate in combination with vitamin D than in those fed calcium carbonate. The results indicate a possible means of simultaneously treating both calcium deficiency and hyperlipidemia with a single agent.
Eicosenoic and docosenoic acid incorporation in serum lipoproteins in rats fed rapeseed oil
Authors: Szlam F. , Sgoutas D. S. 
Published: November 2006

AbstractRats were fed rapeseed oil rich in eicosenoic (20∶1) and docosenoic (22∶1) acids for 7 days, and the fatty acid composition of the lipid classes of serum and serum lipoproteins was determined. Concentrations of 20∶1 and 22∶1 acids in the lipid classes were variable, especially among lipoproteins, and were a direct function of the alimentary state of the animal. The results suggest differences in the incorporation of the above acids among the major lipoprotein types and various lipid classes within a given lipoprotein type. The quick partial disappearance of very low density lipoproteins (VLDL) and of low density lipoproteins (LDL) containing 20∶1 and 22∶1 acids upon starvation and the preferential incorporation of these acids in the triacylglycerols of high density lipoproteins (HDL) are discussed.
Effect of extended hypocholesterolemic drug treatment on peripheral and central nervous system sterol content of the rat
Authors: Ramsey Robert B. 
Published: November 2006

AbstractExtended treatment of developing or adult rats with a variety of hypocholesterolemic drugs has shown that both the central nervous system (CNS) and peripheral nervous system (PNS) sterol content could be affected in both age groups by this type of treatment. Treatment of developing animals was begun at 5 days of age and continued for 45 days. Adult rats, 300 g at onset, were treated for 35 days. The influence of these drugs on PNS sterol composition has not been previously examined. Diazacholesterol administration caused an accumulation of desmosterol in the CNS and 7‐dehydrodesmosterol and desmosterol in the PNS. Zuclomiphene induced a build‐up of desmosterol in either tissue. Both of these drugs had a more pronounced effect on developing CNS and PNS than on adult CNS and PNS. Addition of AY‐9944 or Triparanol to the zuclomiphene treatment of the developing animals reduced desmosterol accumulation but brought about a build‐up of 7‐dehydrocholesterol and 7‐dehydrodesmosterol.
Plasma cholesterol levels in suckling and weaned kittens, puppies, and guinea pigs
Authors: Hamilton R. M. G. , Carroll K. K. 
Published: November 2006

AbstractPlasma cholesterol levels in kittens and puppies were low at birth, rose during the suckling period, and then decreased at about the time of weaning. The increase during the suckling period was much greater in puppies than in kittens. No significant differences in plasma cholesterol levels were observed in puppies fed two different types of diet, horse meat or dog chow, after weaning. Guinea pigs had lower plasma cholesterols than either kittens or puppies. The level was highest on the first day after birth, decreased during the next 3 wk, and then remained fairly constant after the animals were weaned.
Origin of fatty acids of cholesteryl ester accumulated by Fu5AH cells in culture
Authors: Rosen Joel M. , Rothblat George H. 
Published: November 2006

AbstractThe Fu5AH rat hepatoma cell line accumulates cholesteryl ester (CE) upon incubation in medium supplemented with hyperlipemic serum or hyperlipemic serum lipoproteins. This cell line was used to investigate the origin of the fatty acids esterified to cholesterol in intracellular accumulations of CE. The intracellular CE‐fatty acid distribution was found to be markedly different from that of the lipoprotein which stimulated the accumulation. Free fatty acids added to the culture medium were found esterified to cholesterol in the cells, demonstrating that cellular esterification contributes to the accumulation of CE. Using a subline of Fu5AH cells containing radioactively labeled intracellular fatty acids, it was found that about one‐third of the fatty acid moiety of CE accumulated by the cells during a 24 hr incubation with hyperlipemic serum was derived from endogenous fatty acids. The drug chloroquine was found to inhibit cellular cholesterol esterification, so that only 4% of CE‐fatty acids were derived from endogenous fatty acids. Evidence is presented suggesting a major role for cellular esterification in CE accumulation by Fu5AH cells.
Leucine and isoleucine as in vitro precursors for lipid synthesis by rat aorta
Authors: Stillway Lewis W. , Weigand Dorothy A. , Riefler John F. , Buse Maria G. 
Published: November 2006

AbstractThe in vitro conversion of14C‐labeled leucine, isoleucine, and pyruvate to specific lipids was compared in rat aorta, diaphragm, and fat pad. Total lipid specific radioactivity from all precursors was greatest in aorta. The ratio of label incorporated into polar lipids vs. neutral lipids by aorta was generally several‐fold that incorporated by muscle and fat pad. The labeling of sterols in the aorta from14C‐leucine and pyruvate was equivalent. It is concluded that leucine may be a substantial precursor to polar lipids and to sterols in rat aorta.
Gas chromatographic separation of triglycerides based on their degree of unsaturation
Authors: Takagi Toru , Itabashi Yutaka 
Published: November 2006

AbstractGas liquid chromatographic separation of long chain triglycerides based on their degree of unsaturation has been carried out on a polar siloxane, SILAR 10C. The equivalent chain lengths of triglycerides with 36–54 acyl carbons and 0–9 double bonds are presented. The resolution of triglycerides of coconut oil by combining argentation thin layer chromatography and gas chromatography on SILAR 10C is described.
Positional isomers of unsaturated fatty acids in rat liver lipids
Authors: Schmitz Brigitte , Murawski Uwe , Pflüger Manfred , Egge Heinz 
Published: November 2006

AbstractThe fatty acids of liver lipids from rats raised on a fat free diet from the 30th to the 90th day after birth were analyzed with special regard to the detection of positional isomers of mono‐, di‐, tri‐, and tetraenoic fatty acids. The methyl esters obtained after transesterification of total lipids were separated by argentation chromatography into five fractions: I saturated, II monoenoic, III dienoic, IV dienoic nonmethylene interrupted, V triand tetraenoic fatty acid esters. After hydroxylation of the double bonds with osmium tetroxide, the analysis of the poly‐O‐trimethylsilyl derivatives by gas liquid chromatography on S.C.O.T. columns combined with mass spectrometry revealed the presence of 19 monoenoic, 15 dienoic, and 9 trienoic as well as 3 tetraenoic fatty acid isomers including the normally occurring representatives of the (n−3), (n−6), (n−7), and (n−9) fatty acid families. The majority of the identified isomers can be coordinated to one of these families like 7–16∶1; 11–20∶1; 6,9–18∶2; 8,11–20∶2; 5,11–20∶2; 5,8,11–20∶3; 7,10,13–22∶3 to the (n−9) family, 11–18∶1; 13–20∶1; 5,11–18∶2; 7,13–20∶2; 6,11–18∶2; 6,9–16∶2; 8, 11–18∶2; 10,13–20∶2; 5,8,11–18∶3; 7,10,13–20∶3; 4,7,10,13–20∶4 to the (n−7) family and 11,14–20∶2; 5,11,14–20∶3; 6,9,12–18∶3; 8,11,14–20∶3; 5,8,11,14–20∶4; 7,10,13,16–22∶4 to the (n−6) family. All these naturally occuring isomers can be placed into a network of desaturation and chain elongation steps which allows certain conclusions about the substrate specificity of the Δ6‐, Δ5‐and Δ4‐desaturase systems. The great number of isomers found in the (n−7) family indicates that the members of this family are actively metabolized in partial essential fatty acid deficiency.
Comparative intestinal and colonic absorption of [4‐14C] cholesterol in the rat
Authors: Roy T. , Treadwell C. R. , Vahouny G. V. 
Published: November 2006

Abstract[4‐14C] Cholesterol was administered as an aqueous emulsion with triolein and dry non‐fat milk either directly into the upper duodenum or into the ileocaecal junction of lymph duct cannulated rats. Lymph flow rates were similar in the two groups of animals. Whereas ca. 53% of the administered tracer dose of cholesterol was absorbed when introduced into the upper small intestine, only 0.06% appeared in lymph when administered into the caecum. Furthermore, less than 0.01% of the administered isotope was detected in urine and blood. The data demonstrate that the large intestine does not contribute significantly to the absorption of exogenous cholesterol in the rat.
Neutral lipids from the temporal gland of the African elephant,Loxodonta africana
Authors: Cmelik S. H. W. , Ley H. 
Published: November 2006

AbstractLipids from inactive and active temporal glands of the African elephant,Loxodonta africana, were isolated and fractionated. The inactive gland had a much higher total lipid content per gram of fresh tissue than the active gland. Lipids from the inactive gland consisted predominantly of neutral lipids while the active gland contained large quantities of phospholipids. Neutral lipids from the active gland contained much more hydrocarbons, cholesterol, and alkoxy glycerides than neutral lipids from an inactive gland. The alkoxy glyceride fraction did not contain any alkenyl glycerides. The hydrocarbons consisted of a mixture containing predominantly straight chain even numbered saturated and unsaturated hydrocarbons from C18–C30. Fatty acids from various fractions were investigated by gas liquid chromatography. Those from the active gland were characterized by a higher percentage of unsaturated acids. The change, from inactive to the active state involves mainly a reduction in palmitic and an increase in oleic acid content.
Epoxides as products of lipid autoxidation in rat lungs
Authors: Sevanian Alex , Mead James F. , Stein Robert A. 
Published: November 2006

AbstractThe nature and content of lipid epoxides in rat lung were examined in air‐breathing control rats and those exposed to nitrogen dioxide. Exposure to 6.5 ppm NO2 for 24 hr resulted in significantly greater epoxide content in a number of lipid classes. It is proposed that lipid autoxidation in lung tissues may contribute to the levels of epoxide‐containing lipids. Furthermore, the processes involved in epoxide formation may be predicted from autoxidation studies utilizing a system of unsaturated fatty acid monolayers on silica gel which serves as a model for biomembranes. The findings indicate that exposure to oxidizing gases can lead to an accumulation of lipid epoxides in both lung parenchymal tissue and on the alveolar surface.
The incorporation of orally administered radiolabeled dihomo γ‐linolenic acid (20∶3ω6) into rat tissue lipids and its conversion to arachidonic acid
Authors: Hassam A. G. , Crawford M. A. 
Published: November 2006

AbstractRadioactivity from orally administered radiolabeled dihomo‐γ‐linolenic acid (20∶3ω6) was recovered from the liver, plasma and brain lipid fractions. After administration the fatty acid was metabolized to arachidonic acid, the 22 carbon chain length fatty acid, and was also β‐oxidized. However, 22 hr after administration of [1‐14C]20∶3 between one‐third and one‐half of the recovered radioactivity was still associated with dihomo‐γ‐linolenic acid in the liver and plasma lipid fractions. Orally administered dihomo‐γ‐linolenic acid is incorporated into lipid fractions and is, therefore, available in the metabolic pool for PGE1 synthesis.
Effect of feeding protected cholesterol on ruminant milk fat secretion
Authors: Gulati S. K. , Cook L. J. , Ashes J. R. , Scott T. W. 
Published: November 2006

AbstractFeeding 1–2 g/day of cholesterol protected against ruminal hydrogenation caused a 20–30% drop in the secretion of milk fat by goats and cows. The effect was observed with goats fed conventional rations or with goats and cows fed rations supplemented with protected lipids, but was not observed with cows fed conventional rations, or when unprotected cholesterol and protected β‐sitosterol was fed to these animals. The results suggest that this depression in milk fat is due to a decreased uptake of plasma triacylglycerol fatty acids by the mammary gland, induced by dietary cholesterol.
Fatty acid composition of unfertilized and fertilized eggs of the sea urchin,Arbacia punctulata
Authors: Meizman M. S. , Mastroianni A. , Strauss J. F. 
Published: November 2006

AbstractFatty acid compositions of polar lipids and triacylglycerols isolated from eggs of the sea urchin,Arbacia punctulata, were examined before and 15 min after insemination. The main fatty acids present in polar lipids and triacylglycerols were palmitate, palmitoleate, eicosaenoate, arachidonate and eicosapentaenoate, while palmitate and palmitoleate predominated in triacylglycerols. There were no significant changes in weight percentrage of individual fatty acids of either polar lipids or triglycerides of eggs after insemination.
Reaction between peroxidized phospholipid and protein: II. Molecular weight and phosphorus content of albumin after reaction with peroxidized cardiolipin
Authors: Nielsen Henning 
Published: November 2006

AbstractPeroxidized cardiolipin (diphosphatidylglycerol) reacts covalently with albumin. Incubation of albumin with increasing amounts of peroxidized cardiolipin produces a gradual increase in molecular size. Incubation with a small amount of peroxidized cardiolipin (molar ratio of cardiolipin/albumin 21) produces a mixture of complexes that differs considerably with respect to the number of cardiolipin molecules bound per molecule of albumin. With larger amounts of peroxidized cardiolipin (molar ratios of cardiolipin/albumin 54 and 114), the complexes formed seem to be of a more uniform type since the numbers of cardiolipin molecules bound per molecule of albumin are similar. No polymerization occurs for reactions in which up to at least 15 moles of cardiolipin have become bound per mole of albumin, and 20–25 moles may be bound with only very little polymerization. Only when the ratio of peroxidized cardiolipin to albumin was increased to a high value of 314 did polymerization occur. The present findings show that extensive covalent binding of peroxidized cardiolipin to albumin can occur without intermolecular crosslinking of the protein.
Serum α‐lipoprotein responses to variations in dietary cholesterol, protein and carbohydrate in different non‐human primate species
Authors: Srinivasan Sathanur R. , Radhakrishnamurthy Bhandaru , Dalferes Edward R. , Berenson Gerald S. 
Published: November 2006

AbstractSerum α‐lipoprotein responses to variations in dietary cholesterol, protein, and carbohydrate were studied in different nonhuman primate species. Chimpanzee, rhesus, green, patas, squirrel and spider monkeys all showed significant interspecies differences in serum total cholesterol responses to 1.84 mg/kcal exogenous cholesterol. Dietary cholesterol significantly increased the α‐lipoprotein cholesterol in all species except rhesus and chimpanzee. Among these species, there was no relationship between the basal serum lipoprotein profile and subsequent lipoprotein responses to dietary cholesterol. Although the level of dietary protein at 6%, 12%, and 37% of calories had no appreciable main effect on serum total cholesterol in spider monkeys, very low protein diet (6% of calories) produced a significant elevation in α‐lipoprotein cholesterol. Serum α‐lipoprotein responses to exogenous cholesterol (1.84 mg/kcal) was highest for the very low protein diet and lowest for low protein diet (12% of calories). Diets with high sucrose (76.5% of calories) and low saturated fat (12.5% of calories) containing no added cholesterol were tested in squirrel and spider monkeys and produced a consistent serum total cholesterol response; the α‐lipoprotein response was significantly higher in squirrel monkeys than in spider monkeys. The above findings have implications in experimentally induced and comparative atherogenesis.
Separation of conjugated bile acids by reverse phase thin layer chromatography
Authors: Touchstone J. C. , Levitt R. E. , Levin S. S. , Soloway R. D. 
Published: November 2006

AbstractSeven conjugated bile acids were separated by 1‐dimensional reverse phase thin layer chromatography using ethanol/0.3 M calcium chloride/dimethylsulfoxide (25∶25∶2) as mobile phase.
Activation of sterol ester hydrolase of bovine corpus luteum by N6,O2′‐dibutyryl cyclic adenosine 3′∶5′‐phosphate
Authors: Bisgaier Charles L. , Treadwell C. R. , Vahouny V. 
Published: November 2006

AbstractThe direct activation of sterol ester hydrolase (E.C. 3.1.1.13) in homogenates of bovine corpus luteum by N6O2′·dibutyryl cyclic adenosine 3′∶5′‐phosphate, (dibutyryl cAMP), adenosine triphosphate (ATP), and Mg2+ has been demonstrated. Variability in the extent of activation by the additions was minimized by homogenization of the tissue in 5 mM Mg2+. Baseline sterol ester hydrolase activity was primarily associated with the 105,000 × g soluble fraction, and significant activation of the enzyme preparation preincubated with dibutyryl cAMP, ATP and Mg2+ occurred within the first 15 min, prior to addition of substrate. A requirement for protein kinase in the system was demonstrated by blocking the cofactor‐dependent enzyme activation with commercial protein kinase inhibitor.