bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of silica gel‐sintered plate to thin layer lipid chromatographic analysis
Authors: Itoh T. , Tanaka M. , Kaneko H. 
Published: November 2006

AbstractThe merits and disadvantages of using the silica gel‐sintered plate for lipid chromatographic analysis were investigated in detail. The commercially available sintered plate could be used repeatedly, employing the reconditioning procedure which involved chromic‐sulfuric acid treatment and subsequent activation. The reconditioned sintered plate has now been used successfully 20 times, for lipid analysis without any deterioration of the excellent resolution power for complex lipid mixtures for all the solvent systems. Since the sintered plate is sturdy, the chromatogplate could be immersed directly in the liquid reaction mixture, so that spots on the chromatogram could be seen and impregnated plates prepared simply. The sintered plate was found to be much more economical than the silica gel‐coated plate.
Lipoxygenase inChlorella pyrenoidosa
Authors: Zimmerman D. C. , Vick B. A. 
Published: November 2006

AbstractThe presence of lipoxygenase enzyme is observed when cells ofChlorella pyrenoidosa are homogenized under anaerobic conditions. This is the first report of this enzyme in a lower form of plant life. The major product ofChlorella lipoxygenase with linoleic acid as substrate is 13‐hydroperoxyoctadecadienoic acid.
Studies on liver phosphatidyl cholines: II. Effect of sex, age and species differences on phosphatidyl cholines from liver mitochondria and microsomes
Authors: Miller James E. , Cornatzer W. E. 
Published: November 2006

AbstractLiver mitochondrial and microsomal phosphatidyl cholines differing in the degree of unsaturation of their fatty acids have been separated into four fractions by silver ion silica gel TLC. The levels of the four phosphatidyl choline fractions were determined for male and female rats and mice, fetal and young rabbits, and female hamsters and guinea pigs. The sum of phosphatidyl choline fractions 1, 2, and 3 of mitochondria and microsomes was greater in the female rat than in the male rat with the difference being a reflection of a higher level of fraction 3 which contains arachidonic acid. The female rat has greater concentration of phosphatidyl choline fractions 1 and 3 of mitochondria. Similar results were seen in mouse liver microsomes but not in mitochondria. The levels of the individual four fractions varied from species to species. No change occurred in the levels of the phosphatidyl choline fractions of fetal (−9 and −3 days) rabbits, but an increase was seen in the level of fraction 4 between day 3 and day 35 in both the mitochondria and microsomal fractions of liver. The concentration of mitochondrial and microsomal protein, total phospholipid and total lecithin phosphorus were determined in rat, mouse, hamster and guinea pig. The total phospholipid phosphorus/protein (μg/mg) of microsomes was greater in all species than that observed in mitochondria. Liver microsomes contain 45–50% of total phospholipid phosphorus as lecithin whereas mitochondria contains 32–37%. The fatty acid patterns of mitochondria and microsomal phosphatidyl cholines were determined and the ratio of palmitate to stearate was greater than two for mice and hamsters and approximately 0.5 for rat and guinea pigs.
Boron trifluoride as catalyst to prepare methyl esters from oils containing unusual acyl groups
Authors: Kleiman R. , Spencer G. F. , Earle F. R. 
Published: November 2006

AbstractThe procedure of Metcalfe et al. (3) for the preparation of fatty acid methyl esters, using boron trifluoride as catalyst, is shown to be suitable for use with oils containing fatty acids of unusual structures, such as conjugated unsaturation, hydroxyl or epoxy groups, and cyclopropenes in addition to oils with only the common acids. In some cases, boron trifluoride was less destructive to unusual groups than conventional mineral acid catalysts; in others, derivatives were formed that were suitable for quantitation in subsequent gas chromatographic analysis.
Probable sources of plasma cholesterol during phosphatide induced hypercholesterolemia
Authors: Byers Sanford O. , Friedman Meyer 
Published: November 2006

AbstractRats in isotopic steady state with respect to 4‐14C‐cholesterol were infused intravenously with massive amounts of lecithin and also injected once with Na acetate3H. During the following 8 hr their plasma gained an average of 11.3 mg of cholesterol; the specific activity of14C‐cholesterol fell in plasma while total14C‐cholesterol and3H activity doubled as compared to controls. The specific activity of14C‐cholesterol diminished in livers of rats receiving lecithin but not in controls. Specific activity of either isotope in cholesterol of intestine, lungs, muscle, skin and brains was the same in control and experimental groups. Total activity of14C and3H fell in cholesterol of liver. The results show that plasma accumulation of cholesterol during lecithin infusion derives from both cholesterol pre‐existing prior to infusion and from that newly synthesized after the start of infusion and that about one third of this cholesterol of mixed origin is supplied from the liver. The authors speculatively suggest skin as a likely source for most of the remainder, with a small additional contribution from brain.
Enterohepatic circulation of cholic acid and cholesterol metabolism in the rat
Authors: Peric‐Golia Ludvik 
Published: November 2006

AbstractA role for cholic acid in the regulation of body cholesterol levels is emphasized by the following experiment and findings. Fifteen rats with biliary and duodenal fistulae were divided into three groups. 4‐14C‐cholesterol was admistered intravenously to all animals on day 1. Two groups received a duodenal infusion of either sodium taurocholate or of cholesterol at the same time and thereafter daily. Bile samples were collected daily for 15 consecutive days. Cholic, chenode‐oxycholic acid and cholesterol were the major labeled compounds in the bile. Labeled cholic acid disappeared from the bile of control animals after day 8 while it persisted in the group receiving unlabeled cholic acid up to day 15. The decrease of specific radioactivity of labeled biliary cholic acid in the rats receiving unlabeled cholesterol corresponded to that of control animals. A significant increase in the concentration of cholesterol was found in the plasma of animals receiving cholic acid and in the liver of those receiving unlabeled cholesterol.
Comparative effect of a protein diet on the desaturation, elongation and simultaneous desaturation and elongation of linoleic acid
Authors: De Gómez Dumm I. N. T. , Peluffo R. O. , Brenner R. R. 
Published: November 2006

AbstractThe effect of a protein diet on the biosynthesis of polyunsaturated fatty acids of the linoleic acid family was studied by incubation of rat liver microsomes with labeled linoleic acid. The incubation was performed in desaturating, elongating and desaturating‐elongating conditions. In desaturating conditions, linoleic acid was converted to γ‐linolenic acid, whereas in elongating conditions it was converted to 20∶2, 22∶2 and 24∶2. In desaturating‐elongating conditions, labeling was found in γ 18∶3, 20∶2, 20∶3, 20∶4 and 22∶2. A protein diet increased the oxidative desaturation of linoleic acid to γ‐linolenic and arachidonic acid biosynthesis, whereas the elongating reaction was not enhanced in the experimental conditions tested. It is suggested that the main controllable step in the linoleic acid family is the oxidative desaturation of linoleic acid to γ‐linolenic acid.
Lysolecithin acyltransferase in hamster intestinal mucosa
Authors: Mansbach Charles M. 
Published: November 2006

Abstract1‐Acyl‐lysolecithin acyltransferase has been demonstrated in the microsomal fraction of hamster intestinal mucosa. The characteristics of the enzyme, with respect to substrate concentration, time of incubation and protein concentration, were studied. Ca++ was found to severely inhibit enzymatic activity. More modest inhibitors were found to be Mg++ and F−; EDTA and albumin had no effect. Enzyme activity was reduced when palmityl CoA was substituted for oleoyl CoA as substrate. The specific activity of intestinal microsomes was modestly greater than liver microsomes.
Analysis of prostaglandins in rat vesicular glands
Authors: Tan W. C. , Privett O. S. 
Published: November 2006

AbstractTechniques are described whereby problems in the analysis of endogenous prostaglandins in rat vesicular glands are obviated by the use of powdered glands prepared by grinding the tissues in the frozen state. Freshly excised glands were cut into small pieces, frozen on dry ice and then pulverized to a fine powder. These powders were used as such or extracted with acetone. In the latter technique, the endogenous prostaglandins were quantitatively extracted into acetone, and most of the biological activity for prostaglandin synthesis was retained in the residual cake. Application of the techniques showed that the E2form was the major prostaglandin of the E series in rat vesicular glands.
Presence oftrans‐6‐Hexadecenoic acid in the White JellyfishAurelia auritaLamarck and in a Caribbean gorgonian
Authors: Hooper S. N. , Ackman R. G. 
Published: November 2006

AbstractAn unusual fatty acid,trans‐6‐hexadecenoic, previously found in the lipids of marine turtles, the ocean sunfish and a sea anemone, is also present in the lipids of the white jellyfish and in a common Caribbean sublittoral gorgonian.
Bis‐(monoacylglyceryl)‐phosphate of rat and human liver: Fatty acid composition and NMR spectroscopy
Authors: Wherrett J. R. , Huterer S. 
Published: November 2006

AbstractBis‐(monoacylglyceryl)‐phosphate was isolated from liver lysosomes that had been prepared from rats pretreated with Triton WR‐1339. Analysis of the fatty acids in this lipid by gas chromatography and mass spectrometry revealed that they were composed of 69% docosahexenoic acid. NMR spectroscopy of bis‐(monoacylglyceryl)‐phosphate isolated from liver of a patient who had a lipid storage disease revealed that the peak corresponding to the chemical shift of protons of esterified secondary carbons of glycerol was absent. This suggests that fatty acids are esterified to the primary position of both glycerols.
The lipids of the aging human brain
Authors: Fillerup Dorothy L. , Mead James F. 
Published: November 2006

AbstractLipid compositions of the brains of human beings of different ages from 26 to 80 years have been determined by a combination of chromatographic techniques. No significant differences in composition were found among any of the adult agegroups, and it thus appears that the decline in brain weight and function with age is not associated with loss of any particular type of lipid.
The biosynthesis of cyclopropane and cyclopropene fatty acids in plant tissues
Authors: Johnson A. R. , Pearson Judith A. , Shenstone F. S. , Fogerty A. C. , Giovanelli J. 
Published: November 2006

AbstractThe biosynthesis of cyclopropane and cyclopropene fatty acids was investigated in seeds of several species of the order Malvales, including species with a high content of sterculic acid, a high content of malvalic acid, and a low content of these cyclopropene fatty acids. The fatty acid composition of the lipids in young and developing seeds is compared with particular attention to variations in cyclopropane and cyclopropene fatty acid contents.Incubation studies employing several14C compounds indicate that the methyl group of methionine is the most likely precursor of the ring‐methylene carbon. A pathway for the synthesis of the cyclopropane and cyclopropene fatty acids is postulated. The origin of malvalic acid is also considered.
Nature of alkanes in beef heart lipids
Authors: Bandurski Eric L. , Nagy Bartholomew 
Published: November 2006

Abstractn‐Alkanes have been found to be the major saturated hydrocarbon components in the fatty tissues on beef heart. These alkanes consist of a homologous series C14–C35, with the C29 and C31 n‐alkanes being most abundant. C16, C19, and C20 isoprenoid alkanes also were identified. A C17 isoprenoid alkane tentatively was identified. The fatty tissues on beef heart contained 32 μg/g saturated hydrocarbons. The distribution pattern of these saturated hydrocarbons is in marked contrast to the alkane distribution in beef liver where branched and cyclic alkanes are predominant. The enrichment and the similarity of the n‐alkane distribution in the fatty tissues on heart and in pasture plants may have implications for the physiological aspects of hydrocarbons in the diet.
Studies of lipid class and fatty acid profiles of rat mammary tumors induced by 7,12‐dimethylbenz(a) anthracene
Authors: Tan W. C. , Chapman C. , Takatori T. , Privett O. S. 
Published: November 2006

AbstractThe lipid class and fatty acid composition profiles of mammary glands of female rats fed a nutritionally adequate diet are compared to those of tumors induced in the mammary glands by intravenous injection of dimethylbenz(a)anthracene of animals fed the same diet. Ca. 95% of the lipids of the mammary glands of the control group of animals consisted of triglycerides; glycolipids and phospholipids were present in only minor amounts. In contrast, the lipids of the mammary tumors contained much lower amounts of neutral lipids and higher concentrations of phospholipids. The glycolipid fraction was a minor component of both tissues but differed greatly in composition. The composition of the phospholipid and neutral lipid fractions, particularly the latter, of the mammary tumors also differed from that of the mammary glands of the control animals. The neutral lipids of the tumor tissues contained elevated levels of free fatty acids and cholesterol and much lower concentrations of triglyceride compared to the mammary gland lipids. Differences also were observed in the fatty acid composition of tumor and mammary gland lipid. The greatest differences occurred in the concentrations of polyunsaturated fatty acids which were generally much higher in the tumor lipids.
Sterol metabolism: XXXIII. On derivation of cholesterol 7‐alkoxyl ethers
Authors: Kulig Martin J. , Teng Jon I. , Smith Leland L. 
Published: November 2006

AbstractThe facile acid‐catalyzed conversion of cholest‐5‐ene‐3β,7α‐diol (but not of cholest‐5‐ene‐3β, 7β‐diol) in methanol or ethanol solution to the corresponding 7α‐methyl or 7α‐ethyl ethers and epimerization of the 7α‐alkyl ethers to the corresponding 7β‐alkyl ethers were established. The epimeric cholest‐5‐ene‐3β, 7‐diols, their 7‐methyl ethers, and their 7‐ethyl ethers are readily interconverted in acidified solvents, the quasiequatorial 7β‐epimer predominating in each case. Both 7α‐ and 7β‐alkyl ethers may be encountered as artifacts in analyses of sterol mixtures from mammalian tissues.
Tumor extracellular triglycerides in mice during growth of ehrlich ascites carcinoma
Authors: Kannan R. , Baker N. 
Published: November 2006

AbstractOur earlier work with Swiss‐Webster mice has shown that most of the lipid in Ehrlich ascites tumor extracellular fluid is in the form of free fatty acids. This finding is in direct contradiction to earlier and subsequent reports from another laboratory that has found free fatty acids to be a very minor component and triglycerides to be the major lipid of Ehrlich ascites tumor extracellular fluid. In light of these contradictory reports, we have carried out a study patterned after that of other workers, but using our Swiss‐Webster mice. As predicted from our earlier study, we have found very little triglyceride in Ehrlich ascites tumor extracellular fluid. Although we could demonstrate a significant, transient hypertriglyceridemia during tumor growth, maximum plasma triglyceride concentrations were an order of magnitude lower than those reported by other workers. In addition, and again in contrast to other reports, we found that plasma triglyceride and tumor extracellular fluid triglyceride levels in tumorous mice fell significantly with fasting. Thus, interesting differences in triglyceride metabolism between mouse and/or tumor strains seem to exist. Our present findings suggest, but do not prove, that triglycerides in the tumor extracellular fluid probably are not a major source of the rapidly turning over, tumor extracellular fluid free fatty acid in our mice.
Effects of dietary triglyceride on the properties and lipid composition of plasma lipoproteins: Acute experiments in rats fed safflower oil
Authors: Dunn G. Dewey , Wilcox Henry G. , Heimberg Murray 
Published: November 2006

AbstractMale rats were administered 1.5 ml safflower oil by gastric intubation 0, 4, and 8 hr after a 16 hr fast. Plasma, liver, and adipose tissue were collected 16 hr after the last fatty meal. Rats fasted for 16 hr served as controls. Following fat feeding, the fatty acid composition of the very low density lipoprotein, triglyceride, and hepatic triglyceride were similar, as were the percentages of 18∶2 in the very low density lipoprotein and hepatic cholesteryl esters. The phospholipids of liver and plasma lipoproteins were similar in the control groups, except that more 16∶0 was present in the plasma lipoproteins. After fat feeding, the plasma lipoprotein phospholipids were enriched with 18∶2 more than were the hepatic phospholipids. Furthermore, the percentage of 18∶2 in phospholipid was much less than in triglyceride or cholesteryl esters. Clearly, esterified lipids of liver and plasma lipoproteins (very low density lipoprotein, low density lipoprotein and high density lipoprotein), and to a lesser extent, adipose tissue, were enriched with 18∶2 derived from dietary triglyceride fatty acid even 16 hr after the terminal meal. A major proportion of the very low density lipoprotein isolated by ultracentrifugation in zonal rotors from plasma of fat fed animals had a faster rate‐zonal mobility than did the very low density lipoprotein isolated from plasma of control animals. The very low density lipoprotein isolated from plasma of fat fed rats contained fewer moles of phospholipids, cholesterol, and cholesteryl esters, relative to triglyceride than did the very low density lipoprotein from plasma of animals not receiving safflower oil. The molar ratio triglyceride:phospholipid:cholesterol:cholesterol esters in the very low density lipoprotein was 100∶42.0∶22.1∶44.5 in the control group and 100∶35.4∶17.8∶19.5 in the fat fed animals. It is postulated that an important biochemical mechanism by which dietary triglyceride fatty acids consumed by the animal over a long period of time alter plasma concentrations of triglyceride, phospholipids, and cholesterol esters is the directive influence of plasma free fatty acid, derived from dietary triglyceride, on the secretion of very low density lipoprotein lipids by the liver.
Synthesis of cholesterol esters in the plasma and liver of sheep
Authors: Noble R. C. , Crouchman M. L. , Moore J. H. 
Published: November 2006

AbstractA study was made with sheep on the formation in vitro of long chain fatty acid esters of cholesterol by the lecithin‐cholesterol‐acyltransferase system present in the plasma and the acyl CoA‐cholesterol‐acyltransferase system present in the liver. The rate of cholesterol esterification in the plasma was 0.024 μmoles/ml/hr. The relative pattern of fatty acids esterified during incubation of the plasma remained constant over the 8 hr period of incubation and was similar to the fatty acids in the plasma cholesteryl esters before incubation began and to the fatty acids in the 2‐position of the plasma lecithin. The predominant cholesteryl esters synthesized contained monoenoic and dienoic fatty acids. Unlike the bovine, there was no apparent discrimination in favor of the 18∶2 containing species of plasma lecithin as donors of fatty acids. This difference could be accounted for by the similarity in the 18∶2 content of the phospholipids present in the high density (density >1.062 and < 1.21) and the low density (density > 1.006 and <1.063) lipoprotein fractions of the sheep plasma. The possibility of some discrimination against 20∶4 during cholesterol ester synthesis in the plasma of the sheep cannot be excluded. In the liver, the predominant cholesteryl esters synthesized contained saturated and monoenoic fatty acids; cholesteryl linoleate was synthesized to a very much less extent. There was considerable similarity between the composition of the unesterified fatty acid fraction of the liver before incubation began and the fatty acid composition of the cholesteryl esters synthesized during incubation. Addition of sonicated suspensions of free fatty acids altered markedly the fatty acid pattern of the cholesteryl esters synthesized by the liver slices. From the evidence presented it is concluded that the cholesteryl esters in sheep plasma are syntheized mainly by the plasma lecithin‐cholesterol‐acyltransferase system. The results are discussed in relation to cholesterol esterification systems demonstrated in the plasma and liver of monogastric animals.
Viral stimulation of choline phosphotransferase in spleen microsomes
Authors: Hoffman D. R. , Skurdal D. N. , Cornatzer W. E. 
Published: November 2006

AbstractCholine phosphotransferase and phosphatidyl ethanolamine methyltransferase enzymatic activities (nmoles phosphatidyl choline/min/mg protein) have been determined in spleen microsomes of Rauscher virus infected BALB/c male mice at 5, 10, 14, and 21 days following inoculation of the virus. There is a significant stimulation of the choline phosphotransferase activity in the virus infected spleens with the peak of activity at about 10 days of viral infection. The specific activity of choline phosphotransferase is 10 times that of the phosphatidyl ethanolamine methyltransferase at 10 days of viral infection. There is a 51‐fold increase over controls for the total microsomal choline phosphotransferase at 14 days of viral infection and only an 18‐fold increase over controls for the phosphatidyl ethanolamine methyltransferase activity. There is a significant (P<0.001) increase over controls in the concentration of total phospholipid‐P, phosphatidyl choline‐P, and phosphatidyl choline‐P fractions as separated by argentation chromatography of microsomes from spleens of mice infected with Friend virus or Rauscher virus for 14 days. The choline phosphotransferase and phosphatidyl ethanolamine methyltransferase specific activities in liver microsomes of 14 day Friend and/or Rauscher virus are unaltered during viral infection.