bluuebunny/crossref_metadata_2025 huggingface dataset:
Lipoxygenase inChlorella pyrenoidosa
Authors: Zimmerman D. C. , Vick B. A.
Published: November 2006

The 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

Liver 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

The 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

Rats 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

A 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

The 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

1‐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

Techniques 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

An 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

Bis‐(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

Lipid 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

The 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

n‐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

The 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

The 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

Our 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

Male 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

A 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

Choline 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.
Lipids of cultured hepatoma cells: VII. Structural analyses of glycerolipids in minimal deviation hepatoma 7288C
Authors: Wiegand Rex D. , Wood Randall
Published: November 2006

Phosphatidylcholine, phosphatidylethanolamine, and triglycerides were isolated from minimal deviation hepatoma 7288C cells cultured as monolayers to confluency in roller flasks containing Swim's 77 medium supplemented with 5% fetal calf serum, plus 20%, 10%, or 5% bovine serum. Fatty acid distribution at each position of glycerol was determined for the 3 glycerolipid classes, and carbon number distributions of triglycerides and diglycerides derived from phosphatidylcholine and phosphatidylethanolamine were quantitated by high temperature gas liquid chromatography. Fatty acid composition was only marginally affected by the level of bovine serum in the culture medium. Percentage composition of fatty acids esterified at each position of the 3 glycerolipids was different, indicating a nonrandom distribution of acyl groups in triglycerides and the 2 diacyl phosphatides. The carbon number distribution of diglycerides derived from phosphatidylcholine and phosphatidylethanolamine was different, and neither carbon number distribution agreed with the calculated 1‐random, 2‐random diacyl distribution, thus indicating pairing of certain acids in the diglycerides derived from these phospholipid classes. The determined triglyceride carbon number distributions did not show complete agreement with those calculated, assuming a 1‐random, 2‐random, 3‐random type of fatty acyl distribution, suggesting preferential pairing of some acids in this lipid class. The 1‐, 2‐diglycerides derived from phosphatidylcholine, phosphatidylethanolamine, and triglycerides differed, indicating either selectivity in utilization of diglyceride species in biosynthesis of these glycerolipids, or modification of glycerolipids after their initial synthesis.
KCN Inhibition of lipoxygenase in purple, green, and white eggplants
Authors: Flick George J. , Angelo Allen J. St. , Ory Robert L.
Published: November 2006

Lipoxygenase activity in three cultivars (purple, green, and white) of eggplant,Solanum melongena, were compared. Activity was greatest in the purple and lowest in the white variety. In contrast to reports that NaCN did not inhibit eggplant lipoxygenase, in these studies cyanide completely inhibited the enzyme in all three varieties.
Stimulatory effect of glucose upon triglyceride synthesis from acetate, decanoate, and palmitate by mammary gland slices from lactating mice
Authors: Rao G. Ananda , Abraham S.
Published: November 2006

Slices prepared from the mammary glands of lactating mice incorporate only small amounts of (1‐14C) acetate, (1‐14C) decanoate, or (1‐14C) palmitate into lipids. However, when glucose is added to the incubation medium, fatty acid incorporation is stimulated—13‐fold from acetate, 17‐fold from decanoate, and 2‐fold from palmitate. Over 90% of the14C activity in the lipid fraction is in triglycerides. Analysis of fatty acids in the triglycerides showed that almost all of the decanoate and the palmitate were incorporated as intact molecules, while acetate yielded acids of varying chain lengths. The glucose stimulation of triglyceride synthesis is not solely due to its effect upon chain elongation but also could involve glyceride‐glycerol availability, as well as other unknown factors. However, from measurements of the amounts of glycerol 3‐phosphate in the tissue incubated in the presence of palmitate, it would appear that glyceride‐glycerol availability is not rate limiting in triglyceride synthesis.
Cis‐5‐polyenoic acids inLarix leptolepis seed oil
Authors: Plattner R. D. , Spencer G. F. , Kleiman R.
Published: November 2006

cis‐5,cis‐9‐Octadecadienoic acid (2.7%) andcis‐5,cis‐9,cis‐12‐octadecatrienoic acid (24.9%) are present in the seed oil ofLarix leptolepis. The double bond positions were identified by ozonolysis and by gas chromatography‐mass spectrometry of methoxy derivatives. Small quantities of branched chain acids of various chain lengths were indicated by gas chromatography. The presence of C17 and C19 branched methyl esters was confirmed by gas chromatography‐mass spectrometry.
The incorporation of orally fed radioactive γ‐linolenic acid and linoleic acid into the liver and brain lipids of suckling rats
Authors: Hassam A. G. , Sinclair A. J. , Cramwford M. A.
Published: November 2006

The incorporation of radioactivity from orally administered γ‐linolenic acid‐1‐14C and linoleic acid‐3H into the liver, plasma, and brain lipids of suckling rats was studied. Significantly more radioactivity from the former compound was incorporated into the liver and brain lipids 22 hr after dosing. The distribution of the radioactivity in the fatty acids of the liver and brain lipids was different for each isotope. Most of the3H was still associated with linoleic acid, whereas most of the14C was in the 20∶3 and 20∶4ω6 fractions. These results suggest that the desaturation of linoleic to γ‐linolenic acid in vivo is a rate‐limiting step in the conversion of linoleic to arachidonic acid.
Inhibition of diplopterol synthesis inTetrahymena pyriformis by a hypocholesteremic compound
Authors: Babiak Z. , Carlisle T. L. , Holmlund C. E.
Published: November 2006

The hypocholesteremic compound, 3β‐(β‐dimethylaminoethoxy)‐androst‐5‐en‐17‐one was earlier shown to inhibit the synthesis of tetrahymanol and two unidentified lipids. It now has been demonstrated that one of the unidentified compounds is diplopterol.
Identification and quantitation of cholanoic acids in hepatic and extra‐hepatic tissues of rat
Authors: Oh Suk Yon , Dupont Jacqueline
Published: November 2006

Tissues of rats were examined for the presence of cholanoic acids. Quantitation of extraction, deconjugation, and isolation were verified by use of radioactive standards. Identification was made by thin layer and gas liquid chromatographic comparison to standards and mass spectrometry. All tissues examined were found to contain several conjugated cholanoic acids. Liver contained primarily cholic acid and peripheral tissues primarily dihydroxy compounds, mainly hyodeoxycholic acid.
Mass spectrometric determination of positions of double bonds in polyunsaturated fatty acid pyrrolidides
Authors: Andersson Bengt Å. , Christie William W. , Holman Ralph T.
Published: November 2006

Low resolution mass spectra of pyrrolidides of isomeric octadecadienoic acids and other polyunsaturated straight chain fatty acids are presented and discussed. The spectra of the pyrrolidides contain mainly ions from the polar part of the molecule and give spectra that are specific for each isomer. The interpretation follows, in most cases, the rule developed for monounsaturated fatty acid pyrrolidides.
Effect of inhibitors and phenobarbital pretreatment upon hepatic lipid peroxidation during protein and riboflavin dietary stress in male rats
Authors: Patel J. M. , Galdhar N. R. , Javalgekar S. Y. , Pawar S. S.
Published: November 2006

Male young albino rats divided into three groups were maintained on the following diets. The normal group was maintained on 13% casein, 45% corn starch, 31% sucrose, 6% salt mixture, 4% peanut oil, and 1% vitamin mixture. The low protein group animals recieved only 5% casein, and the riboflavin‐deficient group was fed normal diet, except that the riboflavin was absent from the vitamin mixture and ordinary casein was replaced by 13% vitamin‐free casein. The effects of various inhibitors upon triphosphopyridine nucleotide, reduced form‐linked lipid peroxide formation by the supernatant fraction of liver at 9000 × g from rats fed a normal diet, a low protein diet, or a riboflavin‐deficient diet for 2,4, and 7 weeks were investigated. A significant decrease in triphosphoryridine nucleotide, reduced form‐linked and ascorbate‐induced lipid peroxidation was noticed in rats fed on low protein and riboflavin‐deficient diet. Glutathione inhibited the triphosphopyridine nucleotide, reduced form‐linked lipid peroxidation in rats from all three groups. However, the observed response was variable due to the nature of the diet. The magnitude of inhibition was greater in low protein‐fed animals than in animals from the riboflavin‐deficient and control groups. Cytochrome C inhibited peroxide formation, but the inhibition was greater in rats from the low protein and riboflavin‐deficient groups than in animals from the normal group. Tocopherol exhibited the antioxidant property in all three groups of rats. Deoxycholate inhibited lipid peroxide formation in all the three groups.
Fatty acid synthetase of bovine mammary: Properties and products
Authors: Kinsella J. E. , Bruns D. , Infante J. P.
Published: November 2006

Fatty acid synthetase purified (20 times) from lactating bovine mammary tissue had an approximate mot wt of 485,000. The enzyme had a high content of acidic and hydrophobic amino acid residues; 62±4 sulhydryl groups and one 4′ phosphopantetheine residue/mole of enzyme. The enzyme was relatively stable when stored (3 mg/ml) in potassium phosphate buffer (250 mM), containing dithiothreitol (5 mM) at −5 C or at −30C or as a lyophilized powder at −30 C. Preincubation at 37 C in presence of dithioltreitol (5 mM) was necessary for obtaining maximum activity at the optimum pH of 6.8. Maximum specific activity of the isolated enzyme was 55 nmoles acetyl‐coenzyme A min−1mg−1 incorporated A min−1mg−1 incorporated into fatty acids. Butyryl‐coenzyme A or acetyl‐coenzyme A (30μM), malonyl‐coenzyme A (65 μM), and nicotinamide adenine dinucleotide phosphate, reduced form (300 μM) were required for optimum fatty acid synthesis. Malonyl‐coenzyme A decarboxylase activity (5 nmoles min−1mg−1) associated with the enzyme permitted fatty acid synthesis in the presence of nicotinamide adenine dinucleotide phosphate, reduced form and malonyl‐coenzyme A. The enzyme utilized acetyl‐coenzyme A, butyryl‐coenzyme A, and hexanoyl‐coenzyme A as primers, with butyryl‐coenzyme A giving the maximum rate of fatty acid synthesis. Apparent Km values of 22,6.7, 3, 22, and 20 μM were obtained for malonyl‐coenzyme A, acetyl‐coenzyme A, butyryl‐coenzyme A, hexanoyl‐coenzyme A, and nicotinamide adenine dinucleotide phosphate, reduced form, The fatty acid synthetase was inhibited by N‐ethylmaleimide, iodoacetamide, and progressively inhibited by increasing concentrations of long chain acyl‐coenzyme A, i.e. palmityl‐coenzyme A and myristyl‐coenzyme A. This inhibition was relieved by bovine serum albumin or β‐lactoglobulin (3 mg/ml). Palmitic acid was the major product of bovine mammary fatty acid synthetase. However, small amounts of fatty acids, 4∶0–14∶0 inclusive, also were synthesized. The pattern of fatty acids was altered by varying malonyl‐coenzyme A to acetyl‐coenzyme A ratios and by increasing the enzyme levels in the assays. At high concentrations of enzyme (0.5 mg/ml), greater amounts of short and medium chain fatty acids were generated.
Electron spin resonance study of serum lipoproteins of salmon (Oncorhynchus kisutch): Structural alterations produced in high density lipoproteins by mercury and cadmium
Authors: Reichert William L. , Malins Donald C.
Published: November 2006

High denisty lipoproteins from the serum of salmon (Oncorhynchus kisutch), containing a maleimide spin label (4‐male‐imido‐2,2,6,6‐tetramethylpiperidinooxyl), were exposed to HgCl2, CdCl2, and CH3HgCl under physiological conditions. Electron spin resonance spectrometry revealed that HgCl2 and CdCl2 produce significant alterations at sites representing weakly and strongly immobilized label. The observed changes appear to be taking place primarily in the surface architecture. No alterations were found in the normal spectra of high density lipoproteins exposed to CH3HgCl under similar conditions. Each metal species binds strongly with the apo‐high density lipoproteins; however, marked differences exist in the effects produced upon high density lipoprotein structure by the inorganic ions and CH3HgCl.
Increase of gangliosides in atherosclerotic human aortas
Authors: Breckenridge W. C. , Halloran J. L. , Kovacs K. , Silver M. D.
Published: November 2006

Preparations of human thoracic aortas containing intima and media were obtained post‐mortem, and gangliosides were isolated by standard techniques. The quantity of ganglioside sialic acid, as assayed by gas liquid chromatography, was lowest in normal aortas (33±9 nmoles N‐acetyl neuraminic acid/g wet tissue) and progressively increased in aortas containing predominantly fatty streaks (54±1 nmoles N‐acetyl neuraminic acid/g wet tissue), raised yellow plaques (88±23 nmoles N‐acetyl neuraminic acid/g wet tissue), and ulcerated lesions (270±44 nmoles N‐acetyl neuraminic acid/h wet tissues). Both thin layer chromatography of the gangliosides and gas liquid chromatography of the constituent sugars demonstrated the presence of a ganglioside with properties similar to a monosialyl lactosyl ceramide (GM3) as the major ganglioside. A ganglioside with similar chemical characteristics was isolated from plasma and low density lipoproteins.
X‐ray diffraction study of some normal alkyl esters of long‐chain acids
Authors: Lutz D. A. , Eddy C. R. , Hunter J. J.
Published: November 2006

X‐ray powder diffraction data are reported for 15 normal long‐chain esters. The compounds represent all combinations of acid and alcohol where the acid portion is n‐tetradecanoic, n‐hexadecanoic, or n‐octadecanoic acid, and the alcohol portion is n‐tetradecanol, n‐pentadecanol, n‐hexadecanol, n‐heptadecanol, or n‐octadecanol. The individual compounds can be identified and distinguished by the diffraction data. Several of the esters have long spacings that are a linear function of the number of carbon atoms in the molecule and are consistent with a similar function for ethyl esters of long‐chain acids. The remainder of the compounds crystallize in other polymorphic forms and therefore do not follow this function.
Quantitative and qualitative lipid correlation in experimental endogenous hyperlipemia
Authors: Butkus Antanas , Berretoni J. N.
Published: November 2006

The reversible endogenous hyperlipemia in dogs, elicited by the detergent Triton which was given intravenously, was used to study the interrelations of serum lipids. In the cholesterol ester fraction an increase occurs in both monounsaturated and in saturated fatty acids, excepting myristic; while a decrease occurs in polyunsaturated fatty acids. The fatty acids of cholesterol esters of normal dogs contain 22% oleic acid, and only 24% when serum lipids are increased to almost double their normal value (TC=400–500 mg/100 ml). However there is a critical level above which a rapid rise in oleic acid occurs and, in severe hyperlipemia (TC=1500 ±430 mg/100 ml), this acid constitutes almost half of the esterified fatty acid component.

Since there is no evidence that Triton directly regulates fatty acid synthesis, the lipid fraction‐fatty acid interrelationship may be secondary to lipid mobilization from endogenous sources. This concept is supported by the fact that the increased serum fatty acids are only those which can be synthesized by animals. It is suggested, on the basis of a marked increased of endogenously produced fatty acids, that, at critical lipid levels, shortage of polyunsaturated fatty acids from exogenous sources occurs. This might be of sufficient degree to accelerate fatty acid synthesis to meet the need for fatty acids for energy requirements. There may also be need of fatty acid for esterification of chiefly the accumulated free cholesterol split from lipoprotein by Triton.

Triton‐induced changes in cholesterol ester fatty acids result in patterns which closely resemble those in the adipose tissue of dog and man and in the serum of human endogenous hyperlipemia.
Eicosenoic acid and other fatty acids ofSapindaceae seed oils
Authors: Hopkins C. Y. , Swingle R.
Published: November 2006

The seed oils of 11 species ofSapindaceae were examined, and their fatty acid composition was determined.cis‐11‐Eicosenoic acid was identified as the major fatty acid ofKoelreuteria paniculata. It was present in nine of the 11 species in amounts from 8–60% of the total fatty acids and is evidently a common component of oils of this plant family. Arachidic acid was present in amounts up to 11%. Only three of the oils had acids of chain length greater than C‐20. Seed oils of certain species ofKoelreuteria andCardiospermum are good potential sources of 11‐eicosenoic acid.
Fatty acid alterations during migration and early sea water growth of chum salmon (Oncorhynchus keta)
Authors: Saddler J. B. , Koski K. V. , Cardwell R. D.
Published: November 2006

Lipid and fatty acid characteristics were examined in chum salmon fry (Oncorhynchus keta) in freshwater, at various stages in their early growth in sea water, and 7 days after their artificial introduction from freshwater into sea water. The average lipid content of salmon fry in freshwater decreased from 2.5% in newly emerged fry (30–40 mm fork length) to 1.7% in older fry (40–50 mm). Lipid content did not appear to change during migration, but steadily declined during the first 4–6 weeks of sea water growth to 1.7%. Within 7 days after artificial introduction into sea water, lipid content of the salmon had declined to 1.4%. Extended residence in freshwater, e.g., 2–3 weeks, resulted in a fatty acid pattern more characteristic of freshwater fish, whereas residence in sea water resulted in patterns more characteristic of marine fish. Salmon artificially introduced into sea water incurred substantial diminutions in polyunsaturated fatty acids. This response did not occur in wild fry in the marine environment and may therefore be due to the stresses of capture, handling, anesthesia, partial starvation and confinement to which the artificially reared fish were exposed.
Effects of ethylp‐chlorophenoxyisobutyrate on biliary secretion of bile acids, cholesterol and phosphatidyl choline
Authors: Horning M. G. , Hebert R. M. , Roth R. J. , Davis D. L. , Horning E. C. , Fischer E. P. , Jordan G. L.
Published: November 2006

The effect of chronic administration of ethylp‐chlorophenoxyisobutyrate (CPIB) on the secretion of bile lipids was studied in four dogs with surgically implanted Thomas cannulae for periods of 2–7 months. The concentration of cholesterol, triglycerides andp‐chlorophenoxyisobutyric acid in serum and of bile acids, cholesterol and phospholipids (phosphatidyl cholines) in bile were measured. Chronic administration of CPIB resulted in a marked increase in the concentration of cholesterol, bile acids and phosphatidyl cholines in the bile of all dogs, and a decrease in serum cholesterol and triglyceride concentration in serum in three of the four dogs. Serum concentrations ofp‐chlorophenoxyisobutyric acid were monitored to insure the presence of the drug in the dogs; however, no correlation between serum levels ofp‐chlorophenoxyisobutyric acid and the concentration of biliary lipids was noted. The bile acids andp‐chlorophenoxyisobutyric acid were determined by gas chromatographic procedures and the structures were confirmed by gas chromatography‐mass spectrometry.
Lipid metabolism of brain tissue in culture
Authors: Menkes John H.
Published: November 2006

Tissue explants from frontal lobes of rat brain were used for the study of cerebral fatty acid metabolism. After tissues had been maintained in serum‐supplemented medium, a lipid free medium was substituted and metabolic studies were carried out. Under these conditions explants continued to take up lipid precursors for at least 48 hr. Stearic acid 1‐C14, palmitic acid 1‐C14 and lignoceric acid 1‐C14 were bound to cells as the free fatty acids or incorporafed into neutral lipids (particularly triglycerides), glycolipids and phospholipids. In the galactolipid fraction, cerebrosides were the principal radioactive lipids. Choline phosphoglycerides, ethanolamine phosphoglycerides, inositol phosphoglycerides and serine phosphoglycerides were the principal radioactive phospholipids. Fatty acids were incorporated into cellular lipids either unchanged or after desaturation, chain elongation, or both. In a patient with a demyelinating disease, precursor uptake was reduced and chain elongation and desaturation of the fatty acid was diminished. In a patient with generalized GM2 gangliosidosis, glycolipids other than cerebrosides were labeled to a greater extent than normal. These studies exemplify the usefulness of tissue explants for prolonged metabolic studies in normal and pathological specimens of brain.
Phospholipid metabolism in cells in culture
Authors: Rytter Darrel J. , Cornatzer W. E.
Published: November 2006

The proportions of the different lecithin fractions have been determined in HeLa and KB tissue culture cells and Ehrlich Ascites tumor. 82.8% of the total phosphatidyl choline phosphorus is found in fraction 3 of HeLa cells. The major phosphatidyl cholines found in KB cells and Ehrlich Ascites tumor are in fractions 3 and 4 and representing 66.6% and 88.7% of the total phosphatidyl choline P, respectively. The incorporation of 1,2‐14C‐choline and 1,2‐14C‐ethanolamine into the various phosphatidyl choline fractions has been assayed to determine their biosynthesis in Ehrlich Ascites tumor. The incorporation of 1,2‐14C‐choline into fractions 3 and 4 is 100 times the 1,2‐14C‐ethanolamine. This evidence indicates that the methylation pathway of phosphatidyl choline synthesis is very low in HeLa, KB and Ehrlich Ascites cells.
Cholesteryl ester metabolism in tissue culture cells: II. Source of accumulated esterified cholesterol in Fu5AH rat hepatoma cells
Authors: Rothblat G. H. , Arbogast L. , Kritchevsky D. , Naftulin M.
Published: November 2006

Previous investigations had demonstrated that Fu5AH rat hepatoma cells accumulated large quantities of esterified cholesterol when grown in hyperlipemic rabbit serum. The present investigation has determined the sources of the cellular esterified cholesterol when the cells were grown in hyperlipemic serum. Cellular esterification of endogenous and exogenous free cholesterol contributed 10% and 30%, respectively. The remaining 60% of the accumulated cellular esterified cholesterol was derived from exogenous (serum) cholesteryl esters. Evidence for the hydrolysis of a portion of the incorporated esterified cholesterol is presented. A stimulation of free cholesterol incorporation and cellular esterification is elicited by hyperlipemic serum and serum lipoproteins when compared to normolipemic serum present at equivalent exogenous cholesterol concentrations. The effect of hyperlipemic serum is reduced by Tween‐80 and Triton WR‐1339. Comparative data on esterified cholesterol accumulation, free cholesterol incorporation, and cellular cholesterol esterification in Fu5‐5 rat hepatoma cells, L‐cells, and rabbit aortic medial cells are presented.
Preparation and purification of lipid hydroperoxides from arachidonic and γ‐linolenic acids
Authors: Funk Max O. , Isaac Ramdas , Porter Ned A.
Published: November 2006

Commercial soybean lipoxygenase may be used under carefully controlled reaction conditions to give high yields of lipid hydroperoxides. Lipid hydroperoxides so derived from γ‐linolenic or arachidonic acid may be purified by high pressure liquid chromatography. Thus, commercial lipoxygenase serves as a viable source for 100 mg quantities of lipid hydroperoxides.
Studies on the 12α and 26‐hydroxylation of bile alcohols by rabbit liver microsomes
Authors: Nicolau Gabriela , Cohen Bertram I. , Salen Gerald , Mosbach Erwin H.
Published: November 2006

12α‐Hydroxylation of two C27‐steroids by rabbit liver microsomes was studied. Optimal assay conditions were determined with 7α‐hydroxy‐4‐cholesten‐3‐one and 5β‐cholestane‐3α,7α‐diol as substrates. The rate of 12α‐hydroxylation of 7α‐hydroxy‐4‐cholesten‐3‐one was found to be greater than that of 5β‐cholestane‐3α,7α‐diol by ca. 60%. Microsomal 26‐hydroxylation of 5β‐cholestane‐3α7α‐diol was also measured, and the ratio of 26‐hydroxylation to 12α‐hydroxylation of 5β‐cholestane‐3α,7α‐diol was found to be ca. 0.4. Rabbit liver 12‐αhydroxylase was more active than that of three other species (man, rat, monkey), explaining in part the predominance of cholic acid in rabbit bile.
Variations in lipid composition and sound velocity in melon from the North Atlantic pilot whale,Globicephala melaena melaena
Authors: Blomberg Jonas , Lindholm Lars‐Erik
Published: November 2006

Nonpolar lipids and sound velocity at different distances from the skin surface within a sample of pilot whale melon were studied. Thin layer chromatography, sensitive radioisotopic methods, and an ultrasonic echo scanner were used. Wax esters had a maximum concentration at 11–12 cm from the skin surface. Non‐ and monoisovalero triglycerides both exhibited a minimum at 8–10 cm, whereas the diisovalero species increased steadily from the skin surface towards the center of the pilot whale head. A minimum of sound velocity, ca. 1340 m/s, was found at 9–11 cm, thus coinciding with a region rich in isovaleric acid esterified in wax and diisovalero triglycerides. These findings are compatible with predictions based on the known correlations between lipid structure and sound velocity. Consequently, additional evidence for refraction of sound in pilot whale melon is presented. This is important in understanding the system of echolocation of toothed whales.