bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fatty acid positional distribution in egg yolk triglycerides from various avain species
Authors: Couch J. R. , Saloma A. E. 
Published: November 2006

AbstractThe fatty acid composition and distribution in egg yolk triglycerides and phosphatides from the turkey, duck, prairie chicken, bobwhite quail, Japanese quail, and inbred‐hybrid and midget mutant hens were determined after all species had been fed diets of similar fat and fatty acid content for 90 days. Total volk lipids were composed of ca. two‐thirds neutral lipids and one‐third polar lipids. The predominant fatty acids were palmitic and stearic. There were statistically significant differences in the my ristic, palmitic, palmitoleic, linoleic, and linolenic acids in the yolk triglycerides and in the proportion of 16∶1, 18∶0, 18∶2, arachidonic, docosanoic, docosahexaenoic, and tetracosanoic acids in the phosphatides among the various species. Linoleic acid predominantly was linked at the 2‐position in the yolk triglycerides followed by the 20∶4 acid. The 18∶1 acid also was found preferentially at the 2‐position. There was a low level of 18∶2 in the yolk triglycerides and phosphatides from the duck and an especially high level of 20∶4 acid in the phosphatides. The triglycerides in the species studied have essentially the same distribution of fatty acids in the 2‐position. In all the species, the affinity for the fatty acids at the 2‐position is in the following order: 18∶2=20∶4>18∶1 =18∶3>18∶0=16∶1>14∶0>16∶0 Differences observed among the various genera did not appear to follow taxonomic boundaries. The duck has an efficient system for converting 18∶2 into 20∶4 by elongation and desaturation. The prairie chicken apparently has a high requirement for 18∶2 but an inadequate system for its conversion into 20∶4.
Regulatory function of mitochondria in lipogenesis
Authors: Harris Robert A. , Leland Michael C. , Mahoney Joan Munroe , Mapes James P. 
Published: November 2006

AbstractA cell‐free system, consisting of particle‐free rat liver cytoplasm plus purified mitochondria, was used to study the synthesis of fatty acid from14C‐U‐alanine. Incorporation of label into lipid was dependent upon the presence of both cytoplasm and mitochondria. However, the metabolic state of the animal, prior to sacrifice, determined the capacity of various mitochondrial preparations to reconstitute the system. Mitochondria prepared from the livers of starved, fat‐fed, or alloxan‐diabetic rats failed to support fatty acid synthesis to the same extent as mitochondria prepared from control animals. Likewise, less14CO2 was produced in the system reconstituted with liver mitochondria prepared from starved rats. Possible mechanisms are discussed.
Stimulation of ion transport by phosphoglycerides
Authors: Harris Robert A. , Farmer Barbara 
Published: November 2006

AbstractPhosphoglyceride extracts of beef heart mitochondria stimulated the transport of cations and “permeable” anions across a membrane barrier of chloroform in a U‐tube. Neutral lipids fractionated from total lipid extracts of heart mitochondria were essentially void of transport activity. Remarkable differences were noted between the capacity of the various phospholipids to support transport of ions in the U‐tube system.
Metabolism of 1,2‐(1‐14C) dipalmitoyl phosphatidylcholine in the developing brain
Authors: Dhopeshwarkar G. A. , Subramanian Carole , Mead James F. 
Published: November 2006

AbstractThirteen‐day‐old rats were divided into two groups; one group received 1,2‐(1‐14C) dipalmitoyl phosphatidylcholine and the other 1‐14C palmitic acid in the form of an intraperitoneal injection. One half of the total number of rats in each group was sacrificed 24 hr after injection, and the other half was allowed to survive for 17 days after the injection. Radioactivity incorporated into brain and liver total lipids and into individiual polar lipid components of the brain was determined at both intervals. Phosphatidylcholine was isolated and partially deacylated with phospholipase A2 fromCrotalus Admanteus venom. The ratio of radioactivity FA 2/FA 1 (fatty acid attached to 2 and 1 carbon of the glycerol moiety) 24 hr after the injection was 8.3, when the tracer was radioactive phosphatidylcholine, compared to only 0.7 when radioactive palmitate was injected. From this different labeling ratio and different pattern of labeling the polar lipid components, it was concluded that the radioactive phosphatidylcholine was not deacylated completely before being taken up directly into the brain. Possibilities are discussed to show that the observed radioactive ratio could result from direct uptake of intact phosphatidylcholine, with little or no restriction from the blood brain barrier system, followed by partial degradation by phospholipase A1 in the brain itself.
Fatty acid concentrations in synchronous cultures ofChlorella pyrenoidosa, grown in the presence and absence of glucose
Authors: Reitz Ronald C. , Hamilton James G. , Cole Francis E. 
Published: November 2006

AbstractTotal cellular fatty acids, of a high‐temperature strain ofChlorella pyrenoidosa, were measured during a synchronous growth cycle in continuous light in the presence and absence of glucose.The fatty acid composition, consisting of saturated monoenoic, dienoic, and trienoic C16 and C18 fatty acids, remained essentially the same whether or not the cells were grown on glucose.Nearly all of the fatty acids increased irregularly in concentration during the growth cycle, showing a periodism during the prenuclear and cell‐division stages of growth. Cultures exposed to glucose showed a more pronounced drop in the concentration of most of the fatty acids during both stages.None of the fatty acid concentrations, some of which have been implicated in the Hill reaction of a number of photosynthetic organisms, reflected the periodism in photosynthetic activity which was previously observed during the synchronous growth cycle of this organism.The changes in fatty acid concentration are discussed with relation to concurrent metabolic and cytological changes during cell maturation in this organism.
Digestion of butyrate glycerides by pancreatic lipase
Authors: Sampugna J. , Quinn J. G. , Pitas R. E. , Carpenter D. L. , Jensen R. G. 
Published: November 2006

AbstractThe racemic triglycerides, glyceryl‐1‐palmitate‐2,3‐dibutyrate (PBB), glyceryl‐1‐butyrate‐2,3‐dipalmitate (PPB), glyceryl‐2‐butyrate‐1,3‐dipalmitate (PBP), and the diglyceride, racemic glyceryl‐1‐palmitate‐3‐butyrate (P‐B) were synthesized and digested with pancreatic lipase. Each triglyceride was mixed with equimolar amounts of triolein (OOO) prior to incubation.The following order of digestion rates was observed: PBB>PPB>PBP>P‐B. There was no evidence for short‐chain fatty acid specificity; however the triglycerides containing butyric acid were hydrolyzed more rapidly than OOO. Based upon the fatty acid composition of partial glycerides, digestion of butyrate glycerides was not a simple phenomenon. For example, in the digestion of PBB, butyric acid accumulated faster than palmitic acid in the diglycerides, and monobutyrin was found to accumulate when the diglyceride, P‐B, was digested. As evidenced by the fatty acid composition of the monoglycerides, positional specificity of pancreatic lipase was always maintained.
Human placental lipid metabolism. III. Synthesis and hydrolysis of phospholipids
Authors: Robertson Alex , Sprecher Howard 
Published: November 2006

AbstractBoth diacyl GPC (glycerylphosphorylcholine) and diacyl GPE (glycerylphosphorylethanolamine) are synthesized in human placental tissue from their respective monoacyl precursors. The origin of the monacyl phosphatides is apparently not the result of placental phosphatide acyl‐hydrolase activity. The most likely source is maternal serum. The declining level of 1‐acyl GPC in maternal serum is not attributable to lysophosphatide acylhydrolase activity and is probably explained by placental utilization for the synthesis of diacyl GPC.
Inhibition by cyclopropene fatty acids of the desaturation of stearic acid in hen liver
Authors: Allen E. , Johnson A. R. , Fogerty A. C. , Pearson Judith A. , Shenstone F. S. 
Published: November 2006

AbstractThe mechanism of the hardening of body fats of animals by dietary lipids which contain cyclopropene fatty acids has been studied. Dietary methyl sterculate increased the stearic acid content of egg yolk lipid and decreased the activity of the stearic acid desaturase system of hen liver. The cyclopropene fatty acids were specific inhibitors of the stearic acid desaturase system of hen livers since other fatty acids, including two possible metabolites of sterculic acid, failed to inhibit the system at equivalent concentrations. Sterculic acid was a more effective inhibitor of the system than malvalic acid. Kinetic studies have shown that the inhibition is irreversible. Apparent kinetic constants were determined for the system.The results support the hypotheses that cyclopropene fatty acids inactivate an essential component of the desaturase system, probably by combination with‐SH groups, and that this inhibition causes many of the effects of dietary cyclopropene fatty acids, including permeability disorders of eggs.
Plasma lipid and glucose levels in the adrenalectomized rat following triglyceride ingestion
Authors: Lenz Paul H. , Fleischman Alan I. , Hayton Thomas 
Published: November 2006

AbstractAdrenalectomy did not significantly alter plasma cholesterol, triglycerides and phospholipids in fasted naturally hypertriglyceridemic rats. Oral administration of cottonseed oil resulted in elevations in plasma cholesterol and phospholipids within 2 hr. Adrenalectomy negated these elevations. Triglycerides rose to an equal extent in both groups at the same time. A secondary rise in plasma glucose was noted at about 7 hr in the control rats; this rise was also negated by adrenalectomy.
Formation of diglycerides of long turnover time from labeled acetate and glucose in rat tissues
Authors: Herodek Sándor 
Published: November 2006

AbstractRat adipose tissue pieces were incubated with acetate‐2‐14C and glucose‐14C(U), respectively, and liver slices with acetate‐2‐14C. The labeled tissues were then reincubated in inactive medium, and the changes of radioactivity in the different lipid classes were determined. In all three experiments a significant amount of radioactivity was incorporated in the diglycerides. During 1 hr of reincubation in inactive medium the radioactivity of diglycerides decreased from 35 to 26% of the total lipid activity in the adipose tissue labeled with acetate. In the adipose tissue labeled with glucose radioactivity fell from 25 to 19%. In liver slices 11% of the labeled acetate was incorporated in the diglycerides, and during the 2 hr of reincubation this value fell to its half. The radioactivity of the uniformly labeled glucose was distributed equally in the fatty acids and the glycerol. The distribution of radioactive glycerol between diglycerides and triglycerides was similar to that of the labeled fatty acids. Triglyceride synthesis seems to always be accompanied by the formation of diglycerides with a lastint turnover time.
Dietary lipid, fatty acid synthesis and cholesterol metabolism in aging rats
Authors: Dupont Jacqueline , Mathias Melvin M. , Cabacungan Nenita B. 
Published: November 2006

AbstractMale and female rats were fed diets containing 2% of calories as corn oil or that plus 40% of calories as beef tallow or corn oil. After 3, 6, 12 and 18 months groups were given 4‐14C‐cholesterol ip, and feces were collected for 9 days. Just prior to necropsy3H‐acetate was administered ip. Samples of serum, liver, heart and carcass were obtained for analysis. Concentrations of fatty acids and cholesterol, synthesis of those and recovery of ring‐labeled steroid are reported. Mortality from acute respiratory disease was very high in male rats fed beef tallow or low fat diets and very low in those fed the corn oil diet. In females, only beef tallow diet resulted in a high mortality rate, and this was lower and at a later age than in males. The most notable effects of age were in relation to fatty acid synthesis and presence of14C‐acidic steroid in the carcass. In 3‐month‐old rats both fats depressed fatty acid synthesis in comparison to the low fat diet. At later ages beef fat ceased to depress fatty acid synthesis in both sexes. Corn oil continued to depress fatty acid synthesis up to 12 months in males and 18 months in females. The presence of14C‐acidic steroid in carcass was substantial in 6‐month‐old rats and constituted ca. 40% of recovered14C in 18‐month‐old rats. The possibility that the increase in acetate incorporation into fatty acids with age in fat feeding is related to chain elongation rather than de novo synthesis is discussed. Both the presence and amount of acidic steroid in the carcass are notable and may be of importance in constructing models of cholesterol turnover.
Health physics practices in laboratories using3H‐ and14C‐labeled tracers
Authors: Berger J. D. , Cloutier R. J. 
Published: November 2006

AbstractTritium and14C are often considered relatively safe radionuclides to handle because their permissible body‐burdens are orders of magnitude greater than those for most radionuclides. This is reflected in the U.S. Atomic Energy Commission regulations that do not require a license for the use of amounts up to 1000 μCi of3H and 100 μCi of14C. Although many tracer studies are performed with much smaller quantities, poor control of even these small amounts can result in contamination, causing an internal radiation hazard or the loss of valuable experimental data. This paper discusses the methods of handling radioactive materials that minimize the risks of contamination, and it emphasizes the needs for proper storage, secondary containers, monitoring air and surfaces, and analysis of bioassay samples for measuring body burdens. The user's responsibilities for licensing, waste disposal and transportation are also included. The authors' experience at a laboratory handling both tracer and curie amounts of14C and3H required for labeling and synthesizing compounds and methods of accident prevention and decontamination are described.
Acyl migration solid phase isomerization of 1,2‐diglycerides to 1,3‐isomers
Authors: De Groot W. Th. M. 
Published: November 2006

AbstractIn mixtures of 1,2‐ and 1,3‐diglycerides stored some degrees below their melting points, a rather rapid isomerization of almost all the 1,2‐ diglycerides to the 1,3‐isomers occurred. This solid‐phase isomerization leads to a substantial increase in the yield of saturated and unsaturated mono‐ and mixed‐acid 1,3‐diglycerides.
The triglyceride composition of 17 seed fats rich in octanoic, decanoic, or lauric acid
Authors: Litchfield Carter , Miller Earline , Harlow R. D. , Reiser Raymond 
Published: November 2006

AbstractSeed fats of eight species ofLauraceae (laurel family), six species ofCuphea (Lythraceae family), and three species ofUlmaceae (elm family) were extracted, and the triglycerides were isolated by preparative thin‐layer chromatography. GLC of the triglycerides on a silicone column resolved 10 to 18 peaks with a 22 to 58 carbon number range for each fat. These carbon number distributions yielded considerable information about triglyceride compositions of the fats.The most interesting finding was withLaurus nobilis seed fat, which contained 58.4% lauric acid and 29.2–29.8% trilaurin. A maximum of 19.9% trilaurin would be predicted by a 1, 2, 3‐random, a 1, 3‐random‐2‐random, or a 1‐random‐2‐random‐3‐random distribution of the lauric acid3. This indicates a specificity for the biosynthesis of a simple triglyceride byLaurus nobilis seed enzymes.Cuphea lanceolata seed fat also contained more simple triglyceride (tridecanoin) than would be predicted by the fatty acid distribution theories.
Decomposition of unsaturated fatty acid hydroperoxides by hemoglobin: Structures of major products of 13L‐hydroperoxy‐9,11‐octadecadienoic acid
Authors: Hamberg Mats 
Published: November 2006

Abstract13L‐Hydroperoxy‐9,11‐octadecadienoic acid was decomposed rapidly in the presence of hemoglobin. The product consisted of five major compounds, i.e. 13‐keto‐9,11‐octadecadienoic acid, 13L‐hydroxy‐9,11‐octadecadienoic acid,erythro‐11‐hydroxy‐12,13‐epoxy‐9‐octadecenoic acid,threo‐11‐hydroxy‐12,13‐epoxy‐9‐octadecenoic acid, and 9DL‐hydroxy‐12,13‐epoxy‐10‐octadecenoic acid.
Identification of β‐sitosterol, campesterol, and stigmasterol in human serum
Authors: Govind Rao M. K. , Perkins E. G. , Connor William E. , Bhattacharyya Ashim K. 
Published: November 2006

AbstractThe presence of 3 plant sterols, β‐sitosterol, campesterol, and stigmasterol, has been demonstrated in the serum from 2 patients with β‐sitosterolemia and xanthomatosis.
Phospholipase C catalyzed formation of sphingomyelin‐14C from lecithin and N‐(14C)‐oleoyl‐sphingosine
Authors: Kanfer Julian N. , Spievlogel Christine H. 
Published: November 2006

AbstractCommercial preparations ofClostridium perfringens were incubated with phosphatidyl choline and N‐1‐(14C) oleoylsphingosine. A radioactive product was formed which cochromatogramed with sphingomyelin standard in three different solvent systems. Several other phospholipases and phosphatases were unable to catalyze this reaction. Neither choline, phosphoryl choline, cytidine diphosphate choline nor p‐nitrophenyl phosphoryl choline were active donors. Sphingomyelin was only slightly active as a phosphoryl choline donor.
Biosynthesis and structure of glycosyl diglycerides, steryl glucosides, and acylated steryl glucosides
Authors: Elbein A. D. , Forsee W. T. , Schultz John C. , Laine Roger A. 
Published: November 2006

AbstractA particulate enzyme fraction fromMycobacterium smegmatis catalyzed the transfer of14C‐glucose from UDP‐14C‐glucose into neutral glycolipids. The two major radioactive components were purified by column chromatography on 0‐diethylamino ethyl cellulose (acetate) and thin layer chromatography on silica gel in several solvents. The first product yielded a water‐soluble component upon saponification, which had a hexoseglycerol ratio of 1∶1 with all of the hexose being identified as glucose. The second product yielded a water‐soluble component upon saponification which contained hexose and glycerol in a 2∶1 ratio and, in addition to glucose, contained lesser amounts of mannose and galactose. Palmitate and oleate were the predominant fatty acids and were present in equimolar amounts. The products thus have been identified as monoglycosyldiglyceride and diglycosyldiglyceride. The diglycosyldiglyceride could also be labeled with14C‐galactose when UDP‐14C‐galactose served as the donor, but the monoglycosyldiglyceride was only slightly labeled with14C‐galactose. Membrane fractions from mung bean seedlings catalyzed the transfer of14C‐glucose from UDP‐14C‐glucose into a neutral glycolipid which has been purified by thin layer chromatography and analyzed by combined gas liquid chromatographymass spectrometry. It was determined to be a steryl glucoside with the two major sterol components being β‐sitosterol and stigmasterol linked to β‐D‐glucose. Particulate fractions from developing cotton fibers also catalyzed the formation of steryl glucosides and, in addition, they catalyzed the esterification of steryl glucosides at the 6 position of glucose with fatty acids (primarily palmitate and oleate) from an endogenous acyl donor. Both the glucosyl transferase and the acyltransferase have been solubilized with Triton X‐100 and partially purified by chromatography on Sephadex G‐200. The acyltransferase activity was reconstituted by the addition of the steryl glucoside and a phospholipid acyl donor.
Oxidative desaturation of α‐linolenic, linoleic, and stearic acids by human liver microsomes
Authors: De Gómez Dumm Irma N. T. , Brenner Rodolfo R. 
Published: November 2006

AbstractThe desaturation of stearic, linoleic, and α‐linolenic acids by human liver microsomes were studied. The microsomes were isolated from liver biopsies obtained during operations. It was shown that human liver microsomes are able to desaturate 1‐14C‐α‐linolenic acid to octadeca‐6,9,12,15‐tetraenoic acid; 1‐14C‐linoleic acid to γ‐linolenic acid; and 1‐14C‐stearic acid to oleic acid in the same system described in the rat. However, the desaturation activity obtained was low compared to other mammals. This effect was attributed to fasting, premedication, or the anaesthesia.
Effect of acute dietary alteration upon intestinal lipid synthesis
Authors: Mansbach Charles M. 
Published: November 2006

AbstractThe specific activities of three enzymes engaged in complex lipid synthesis, diglyceride acyltransferase, cholinephosphotransferase, and lysolecithin acyltransferase were studied in intestinal mucosa of hamsters fed either saline, hydrolyzed casein, or corn oil for 9 1/2 hr. In the most proximal intestine, saline feeding was associated with a reduced specific activity in villous tips with all three enzymes studied when compared with the two caloric supplemented groups. In the most distal intestine, oil feeding increased the activity of lysolecithin acyltransferase and choline phosphotransferase twofold as compared to casein fed hamsters; diglyceride acyltransferase was increased one‐ and one‐half‐fold. The response of lysolecithin acyltransferase and diglyceride acyltransferase to fat feeding was incomplete when compared to hamsters fed a fat supplemented diet for 7 days, suggesting that their pattern of response to dietary substrate was similar to the disaccharidases. By contrast, the response of cholinephosphotransferase to fat feeding was complete at 24 hr, suggesting that it responds in a manner similar to the glycolytic enzymes.
Purification and properties of aortic cholesteryl ester hydrolase
Authors: Kothari Himinshu V. , Kritchevsky David 
Published: November 2006

AbstractThe enzyme(s) present in acetonedried powder of rat and rabbit aortas, which catalyzes the synthesis and hydrolysis of cholesteryl ester, was purified partially by acid precipitation, acetone fractionation, 0‐(diethylaminoethyl) cellulose chromatography, and Sephadex G‐100 filtration. The synthetic activity was purified by 120‐fold (rat) and 140‐fold (rabbit). Purification of hydrolytic activity was 90‐fold (rat) and 103‐fold (rabbit). Cholesteryl ester hydrolase activity was separated from nonspecific, esterase by column chromatography. Both synthetic and the hydrolytic activities are apprently the functions of one enzyme. The mol wt of the enzyme was estimated to be 140,000 dalton as determined by Sephadex G‐200 gel filtration. The extracts of the acetone‐dired powders of aortas of both species contained an inhibitor of synthetic activity. The inhibitor was nondialyzable and was precipitated at pH 5.7 Both activities were found to be fairly nonspecific with regard to sterol and fatty acids. With oleic acid, the relative rates of sterol ester synthesis were: cholesterol, 100; cholestanol, 94; desmosterol, 35; corprostanol, 24; ergosterol, 20; and β‐sitosterol, 19. Epicholesterol was not esterified. Oleic acid was most active in cholesteryl ester synthesis, the relative rates being: oleic>linoleic>arachidonic>palmitic>stearic>butyric. The rate of hydrolysis was maximum with cholesteryl linoleate followed by oleate, linolenate, palmitate, stearate and laurate in decreasing order.