bluuebunny/crossref_metadata_2025 huggingface dataset:
Gas liquid radiochromatography of intact natural triglycerides
Authors: Breckenridge W. C. , Kuksis A.
Published: November 2006

Gas liquid radiochromatography was successfully applied to the simultaneous analysis of mass and radioactivity of intact standard and natural triglycerides labeled with14C in their fatty acid or glycerol moieties. Quantitative measurements of mass and radioactivity were made with a gas chromatograph equipped with dual glass columns, stream splitters, combustion train, and a proportional gas counter. Under optimum conditions, as little as 500 cpm/peak of tristearin could be detected with a relative error of 10%. At higher counting rates the error was less than 5% and the achieved resolution of radioactivity was only slightly inferior to that of the mass. The counting efficiency of the system was better than 90%. The study showed that the detected radioactivity was proportional to the mass and not the moles of the labeled triglyceride measured in the hydrogen flame ionization detector. Practical application of the system is limited by the need for samples of relatively high specific activity (500–1000 dpm/50 μg/peak).
Activation of long chain fatty acids by subcellular fractions of rat liver: II. Effect of ethylenic bond position on acyl‐CoA formation oftrans‐octadecenoates
Authors: Lippel Kenneth , Gunstone F. D. , Barve J. A.
Published: November 2006

The rates of acyl‐CoA biosynthesis of thetrans Δ4 to Δ15 octadecenoates have been studied using rat liver microsomes and mitochondria as the enzyme(s) source. Acyl‐CoA formation was lowest when the Δ9 isomer was the substrate and increased as the double bond was moved to either end of the fatty acid chain. Maximal activation was observed when the Δ6 and Δ14trans‐octadecenoates were substrates. All‐trans retinoate caused differential inhibition in the activation rates of the varioustrans‐octadecenoate isomers. In contrast, the activation profile relative to double bond position was not altered by changing the incubation temperature, pH, or buffer or by adding fatty acid free albumin to the incubation medium or by aging the enzyme. These results do not support the suggestion that more than one enzyme activates the varioustrans‐octadecenoate positional isomers. Triton X‐100 differentially activated acyl‐CoA biosynthesis of the various isomers resulting in a uniform rate of activation. Release of the isomers from the detergent micelle is suggested to be rate‐limiting under these conditions.
Enhancement of liver microsomal acyl CoA‐lysophospholipid acyltransferase activity in pyridoxine‐deficient rats
Authors: Zehaluk C. M. , Walker B. L.
Published: November 2006

In rats deficient in pyridoxine and essential fatty acids, liver phospholipids contained less arachidonic acid and more oleic and eicosatrienoic acids than those from animals only deficient in essential fatty acids. This pattern persisted after the animals were supplemented with linoleate for 6 days. Liver oleyl and arachidonyl CoA‐lysophospholipid acyltransferase activities were significantly higher in pyridoxine‐deficient animals. Supplementation with linoleate for 6 days resulted in a marked increase in arachidonyl CoA‐acyltransferase activity in pyridoxine‐deficient rats but a relatively small increase in the supplemented animals. Differences in fatty acid composition between pyridoxine‐deficient and supplemented rats can not be ascribed to lower liver transacylase activity in the deficient animals.
Effects of ethanol on membrane lipids III. Quantitative changes in lipid and fatty acid composition of nonpolar and polar lipids of mouse total liver, mitochondria and microsomes following ethanol feeding
Authors: Miceli Joseph N. , Ferrell William J.
Published: November 2006

The effects of ethanol on the total, nonpolar, and polar lipids of whole liver, mitochondria, and microsomes have been evaluated. Differences in the fatty acid composition of various lipid subclasses have been compared in control and ethanol treated mice. On the whole polyunsaturated fatty acids, especially arachidonic (20∶4) and docosahexaenoic (22∶6), were found to decrease. The significance of an enzymatic mechanism vs. a peroxidative mechanism to explain the results is discussed. Decreases also were observed in the ratios of arachidonate/linoleate following ethanol feeding. These changes are thought to be associated with decreases in the activity of the chain elongation‐desaturation system.
Biosynthesis of phospholipids in subcellular particles from cultured cells of human tissue
Authors: Tsao Shuang‐Shine , Cornatzer W. E.
Published: November 2006

A time study of the incorporation of32Pi into the phospholipids of HeLa, KB, human heart, and liver tissue‐culture cell lines has been carried out. The incorporation of32Pi at various time‐intervals into the phospholipids of nuclei, mitochondria, and microsomes of HeLa and KB cells was investigated. The labeling of the isotope into the phospholipids was divided into three groups.

The first had two components: phosphatidyl inositol and polyglycerol phosphatides, which showed the greatest incorporation of the isotope as demonstrated in the specific activity values and the percentage of total radioactivity after 15 to 30 minutes of incubation. A second group was composed of the major phospholipids of all tissue‐culture cell lines studied, phosphatidyl choline, and phosphatidyl ethanolamine. At first, there was a delayed labeling of these phospholipids; however, after one hour of incubation, a rapid increase was shown in the incorporation of32Pi. A third group of lipids containing sphingomyelin and phosphatidyl serine demonstrated low specific activity values.

The phospholipids of the subcellular fractions, nuclei, mitochondria, and microsomes, had a high degree of incorporation of the isotope into the individual phospholipids and probably represented an active process in the membranes of these cellular units or a renewal of the biological membrane structures.
I. Synthesis ofsn‐glycerol‐cyclic‐phosphodiester isomers
Authors: Buchnea Dmytro
Published: November 2006

A procudure for the synthesis of stereochemically puresn‐glycerol‐cyclic‐phosphodiesters has been developed. The process involves the following sequence of reactions: benzyl‐sn‐glycerol→benzyl‐sn‐glycerol‐cyclic(phenyl)‐phosphodiester→sn‐glycerol‐cyclic‐phosphodiester. The following isomers have been synthesized:sn‐glycerol‐2,3‐1,2‐, 1,3‐cyclic‐phosphodiesters and the racemic mixturer. The 2,3‐ and 1,2‐cyclic‐phosphodiesters of glycerol are optically active antipodes. They are five‐membered ring asymmetrical compounds, with specific rotations of −1.6°±0.1° and +1.6°±0.1°, respectively. These two enantiomers and their racemate are thick liquids and are unstable; therefore they were converted into Ba(glycerol‐cyclic‐phosphodiester)2 salts, which can be better stored. The six‐membered ringsn‐glycerol‐1,3‐cyclic‐phosphodiester is a crystalline, stable compound. The physical and chemical properties of these cyclic‐phosphodiesters of glycerol are described and their chemical analyses are reported.
Studies in vitro of lipogenesis in rat testicular tissue
Authors: Whorton A. R. , Coniglio J. G.
Published: November 2006

Testicular tissue was shown to contain the full complement of enzymes required for de novo synthesis of fatty acids. The enzymes capable of snythesizing palmitic acid from citrate, acetate, or acetyl CoA were found to be present in the soluble (cytoplasmic) fraction. These included fatty acid synthetase, acetyl CoA carboxylase, citrate‐cleavage enzyme, malic enzyme, glucose‐6‐phosphate dehydrogenase, and 6‐phosphogluconate dehydrogenase. Optimal conditions for assaying activities of fatty acid synthetase and acetyl CoA carboxylase in the soluble fraction from rat testes were established, and the activities of these two enzymes were determined to be 0.54±0.1 and 0.030±0.002 (nmoles of substrate incorporated into fatty acid per min per mg of soluble fraction protein), respectively. The activities of citrate‐cleavage enzyme, malic enzyme, and the glucose‐6‐phosphate dehydrogenase/6‐phosphogluconate dehydrogenase pair were also measured. The activities were 6.0±0.7, 34.9±4.2, and 29.9±9.3 nmoles/min/mg, respectively.
Intestinal lipid absorption: Evidence for an intrinsic defect of chylomicron secretion by normal rat distal intestine
Authors: Sabesin S. M. , Holt P. R. , Clark S. B.
Published: November 2006

Intracellular triglyceride accumulation and delayed chylomicron secretion were demonstrated in distal but not in proximal rat intestine following prolonged steady state fat absorption. After 1 and 4 hr of intraduodenal triolein infusion, the mucosal triglyceride content in distal intestinal segments was greatly increased compared with proximal segments. Electron microscopy at each time interval disclosed greater quantities of lipid droplets within the distal cells and these were much larger than the intracellular droplets in the proximal cells, some attaining an enormous size (9000 mμ). When proximal and distal cells were compared at intervals after cessation of a 4 hr triolein infusion, the differences in intracellular lipid accumulation were also evident because, even after 6 hr the distal cells were still filled with large droplets, whereas the proximal cells were almost devoid of fat. These results indicate a basic cellular difference between proximal and distal intestine in the processing of fat and, in contrast to current concepts, suggest that defective chylomicron secretion is not necessarily associated with limited B‐apoprotein availability.
Elongation and desaturation of dietary fatty acids in turbotScophthalmus maximus L., and rainbow trout,Salmo gairdnerii rich
Authors: Owen J. M. , Adron J. W. , Middleton C. , Cowey C. B.
Published: November 2006

Turbot and rainbow trout, which had previously received diets free of fat, were fed [1‐14C] fatty acids. The distribution of radioactivity in the tissue fatty acids was examined 6 days later. In rainbow trout fed [1‐14C] 18∶3ω3, 70% of the radioactivity was present in 22∶6ω3 fatty acid. In contrast, turbot fed [1‐14C] 18∶1ω9, 18∶2ω6, or 18∶3ω3 converted only small amounts of labeled fatty acids (3–15%) into fatty acids of longer chain length. The major product of the limited modification found in turbot was the dietary acid elongated by 2 carbon atoms.
Hepatic lipid metabolism in experimental diabetes: III. Synthesis and utilization of triglycerides
Authors: Van Harken Donald R. , Brown Thomas O. , Heimberg Murray
Published: November 2006

Livers removed from normal rats, from alloxan diabetic rats maintained on insulin for two weeks (ADI+), and from insulin‐treated diabetic rats from which insulin had been withdrawn two days before use (AD) were perfused in vitro with 120 mg (468 μmoles) palmitic acid‐1‐C14. Under these conditions, output of TG (triglyceride) was depressed in livers from ADI+ rats and was negligible with livers from AD animals. The total incorporation of C14 into perfusate TG paralleled the chemical measurments of TG output. The concentration of hepatic TG increased during perfusion of livers from normal or ADI+ rats but decreased during perfusion of livers from AD animals.

A load of 120 mg of palmitic acid/3 hr was inadequate to maintain net accumulation of TG in livers from AD rats; furthermore it is implicit in this observation that the total load of NEFA (nonesterified fatty acid) perfusing livers from AD rats must be increased considerably to obtain a fatty liver. The total incorporation of C14 into hepatic TG and the specific activity of hepatic TG were depressed during perfusion of livers from AD rats. The production of ketone bodies by livers from AD animals was about five times the normal rates; the output of ketone bodies did not differ from results of other experiments (1) in which the load of palmitic acid added to the medium was varied from 0–80 mg. These observations were discussed with reference to mechanisms for ketogenesis and fatty liver in alloxan diabetes.
Biosynthesis of polyunsaturated fatty acids in the developing brain: I. Metabolic transformations of intracranially administered 1‐14C linolenic acid
Authors: Dhopeshwarkar Govind A. , Subramanian Carole
Published: November 2006

Thirteen‐day old rats were given intracranial injections of 1‐14C linolenic acid (allcis 9,12,15 octa decatrienoic acid) and were sacrificed after 8 hr. Analysis of brain fatty acids showed that 16∶0, 18∶0, 18∶1, 18∶3, 20∶3, 20∶4, 20∶5, 22∶5, and 22∶6 were labeled. The total fatty acid methyl esters were separated into classes according to degree of unsaturation on a AgNO3∶SiO2 impregnated plate. The bands were scraped off and the eluted fatty acids were first analyzed by radiogas liquid chromatography and then subjected to reductive ozonolysis to determine double bond position. The saturated acids, 16∶0, and 18∶0, as well as the mono‐unsaturated 18∶1, must have been formed from radioactive acetate produced by β oxidation of the injected linolenate. Among the polyunsaturated fatty acids, the triene fraction was characterized and identified as 18∶3 ε3 (Δ9,12,15), the starting material, and 20∶3 ω3 (Δ11,14,17); the tetraene fraction was identified as 20∶4 ω3 (Δ8,11,14,17); the pentaene fraction was identified as 20∶5 ω3 (Δ5,8,11,14,17) and 22∶5 ω3 (Δ7,10,13,16,19); and, finally, the hexaene fraction was shown to be 22∶6 ω3 (Δ4,7,10,13,16,19). The biosynthesis of these ω3 family fatty acids in the brain in situ is discussed.
Structure of bovine milk fat triglycerides: II. Long chain lengths
Authors: Breckenridge W. C. , Kuksis A.
Published: November 2006

The long chain triglycerides of bovine milk fat were isolated by thin layer chromatography, and their chemical structure determined by combined thin layer and gas liquid chromatography, and a stereospecific analysis of a molecular distillate of butteroil of comparable composition. The milk fat fraction (39% of total) contained C8–C20 fatty acids which were distributed among the glycerides of 40–56 acyl carbon atoms in a manner not unlike that found for the same acids in the short chain triglycerides. Although individual triglycerides were not identified, the specific distribution of the fatty acids could best be accounted for by assuming a common pool of long chain 1,2‐diglyceride precursors from which the bulk of both short and long chain triglycerides are synthesized by a stereospecific introduction of C4–C18 fatty acids in position 3 of sn‐glycerol. This hypothesis is compatible with the results of stereospecific analyses of the short and long chain fractions and of the total butteroil. It is supported by the nonrandom distributions demonstrated for the molecular weights of the milk fat triglycerides of different degrees of saturation.
Lung lamellar bodies lack certain key enzymes of phospholipid metabolism
Authors: Garcia Agustina , Sener Stephen F. , Mavis Richard D.
Published: November 2006

Palmitoyl CoA‐glycerol‐3‐phosphate acyltransferase, phosphatidate phosphohydrolase, and phospholipase A were assayed in subcellular fractions of rat lung, including lamellar bodies, the putative site of storage and secretion of lung surfactant. The specific activity of each of these enzymes in lamellar bodies was relatively low and could be entirely accounted for by a small contamination of the lamellar bodies fraction by microsomes, as quantitated by the presence of the microsomal marker reduced triphosphopyridine nucleotide cytochromec reductase. These data indicate that lamellar bodies are not the site of synthesis of the lipid component of pulmonary surfactant by pathways involving these enzymes.
Novel interference in thiobarbituric acid assay for lipid peroxidation
Authors: Baumgartner W. A. , Baker N. , Hill V. A. , Wright E. T.
Published: November 2006

The thiobarbituric acid test for lipid peroxidation, when applied to a mixture of acetaldehyde and sucrose, produces a 532 nm aborbing chromogen which is indistinguishable from that formed by malonaldehyde and thiobarbituric acid. Unless special procedures are adopted to correct for this effect, the combined action of acetaldehyde and sucrose interferes seriously with the assay of lipid peroxidation reactions, notably those implicated in alcohol‐induced liver injuries. However, this unusual thiobarbituric acid effect also can be used as a sensitive method for the detection of acetaldehyde.
Cardiac fatty acids in rats fed marine oils
Authors: Teige B. , Beare‐Rogers J. L.
Published: November 2006

Cardiac fatty acids were studied in young rats fed marine oils for 1 week. When the diet contained 0, 0.5, 1, 2, 4, 8 or 16% by weight of partially hydrogenated oil from Norwegian capelin, the concentration of fatty acids in the cardiac tissue was elevated only at the highest level. The amount of the lipid and the content of docosenoic acid in the heart were less than those observed with 15% partially hydrogenated oil from Canadian herring. Nonhydrogenated Peruvian anchovy oil lacking docosenoic acid produced no change in the amount of fat deposited. The extent of fatty acid accumulation in the heart was related to the dietary C22 acids.
Distribution of cholesteryl esters and other lipid in subcellular fractions of the adrenal gland of the pig
Authors: Cmelik S. H. W. , Ley H.
Published: November 2006

Total lipids from whole pig adrenal glands as well as from their mitochondria, microsomes, liposomes, and cell sap were extracted and fractionated first into neutral lipids and phospholipids. The highest percentage of neutral lipids was found in the cell sap, and the lowest in the microsomal fraction. Neutral lipids were subfractionated into cholesteryl esters, free cholesterol, triglycerides, and free fatty acids. Cholesteryl esters were distributed throughout the liposomes. Free fatty acids represented a substantial part of cell sap lipids, but were present also in the mitochondria, microsomes, and liposomes. Fatty acids of all fractions were analyzed by gas liquid chromatography. Free fatty acids and cholesteryl ester fatty acids from all cellular fractions were similar in composition and were characterized by considerable quantities of linoleic and arachidonic acid. Triglycerides were characterized by an increased percentage of palmitic and a low content of arachidonic acid. Phosphatidyl choline, phosphatidyl ethanolamine, diphosphatidyl glycerol, and sphingomyelin plus phosphatidyl inositol were isolated from the lipids by preparative thin layer chromatography, and their fatty acids analyzed by gas liquid chromatography. Phosphatidyl choline and phosphatidyl ethanolamine from mitochondria, microsomes, and cell sap were very similar in respect of their fatty acid composition. Sphingomyelin plus phosphatidyl inositol was characterized by a high content of C22:2ω6. Diphosphatidyl glycerol was present in mitochondria and in the cell sap.
Rat testicular lipids and dietary isomeric fatty acids in essential fatty acid deficiency
Authors: Jensen Benny
Published: November 2006

Weanling rats were fed essential fatty acid‐deficient diets, either completely fat‐free, or with partially hydrogenated fish oil (PHFO, 28 wt %), or with fractions derived from PHFO containing primarily positional isomers oftrans‐eicosenoate (20∶1, 3 wt %) ortrans‐docosenoate (22∶1, 3 wt %). Control animals were fed a peanut oil‐containing diet (28 wt %). After 5 or 15 weeks on the diet, the content of neutral and phosphorus‐containing lipids in the testes was determined. The fatty acid distribution in major lipid classes was analyzed for animals fed the diets for 15 weeks. The testicular stage of maturation or degeneration was assessed by histology. The group fed PHFO exhibited signs of complete testicular degeneration, or lack of maturation, already after 5 weeks, whereas the animals on the diets with the very long chain monoenoic acids suffered severe degenerations only after 15 weeks. In the PHFO‐fed rats, a sharp decline in the concentration of testicular triacylglycerols was observed. In all of the essential fatty acid‐deficient groups, an increase in testicular sphingomyelin was observed. Cholesterol levels were fairly similar among all dietary groups. The total testicular fatty acids of the PHFO‐fed animals contained somewhat more eicosadienoic acid than found in the other groups, and somewhat less (n−9)‐acids. In all EFA‐deficient groups, (n−6)‐acids were lowered, in particular in triacylglycerols and phosphatidyl cholines. The PHFO group did not show a lower (n−6)‐concentration than the other deficient groups, in spite of the more severe symptoms of deficiency. There was no evidence of a major accumulation of long chain isomeric fatty acids in the degenerated testes of the PHFO‐, 20∶1, and 22∶1‐fed groups.
β‐Oxidative cleavage of octanoyl‐and dodecanoyl‐CoA in rat liver cytoplasm
Authors: Kienle M. Galli , Cighetti G. , Santaniello E. , Fiecchi A. , Galli G.
Published: November 2006

[12‐14C] Dodecanoyl‐CoA and [8‐14C] octanoyl‐CoA were tested as substrates for shortening the chain by two carbon atoms using both the 105,000 x g soluble fraction and the sonicated mitochondrial fraction of rat liver homogenate as the enzyme source. Both substrates were metabolized by the cytoplasmic enzymes giving rise to the accumulation of intermediates of the β‐oxidation process without formation of two carbon units from the methyl carbon of the acyl residue. A new method is described which allows quantitative estimation of volatile fatty acids formed by β‐oxidation of dodecanoyl‐ and octanoyl‐Coenzyme A.
Maximum lipid reduction by partial lleal bypass: A test of the lipid‐atherosclerosis hypothesis
Authors: Buchwald Henry , Moore Richard B. , Varco Richard L.
Published: November 2006

Atherosclerosis is the process responsible for our national epidemic of coronary heart disease. A primary and proven atherosclerotic risk factor is the plasma cholesterol concentration. Yet, proof that a reduction in plasma cholesterol level results in reduction in the incidence or severity of atherosclerosis and atherosclerotic cardiovascular disease stil requires conclusive documentation. The controversial methods of operation and inconclusive results of concluded first and second generation trials are reviewed. These data clearly demonstrate that a definitive test of the lipid hypothesis has not been reported. Evidence is presented to show that the partial ileal bypass operation most nearly fulfills the six features of an “ideal” lipid lowering trial modality: maximum effectiveness (∼50% cholesterol reduction); known mechanism of action; no response “escape” or “rebound”; obligatory effect without patient cooperation; minimal side effects; and relative safety. The basic design and protocol of the National Heart and Lung Institute Program on Surgical Control of the Hyperlipidemias, a secondary intervention trial using a combination of diet therapy and partial ileal bypass surgery, are outlined.
Determination of the structure of lecithins
Authors: Blank M. L. , Nutter L. J. , Privett O. S.
Published: November 2006

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The direct activation of sterol ester hydrolase (E.C. 3.1.1.13) in homogenates of bovine corpus luteum by N6O2′·dibutyryl cyclic adenosine 3′∶5′‐phosphate, (dibutyryl cAMP), adenosine triphosphate (ATP), and Mg2+ has been demonstrated. Variability in the extent of activation by the additions was minimized by homogenization of the tissue in 5 mM Mg2+. Baseline sterol ester hydrolase activity was primarily associated with the 105,000 × g soluble fraction, and significant activation of the enzyme preparation preincubated with dibutyryl cAMP, ATP and Mg2+ occurred within the first 15 min, prior to addition of substrate. A requirement for protein kinase in the system was demonstrated by blocking the cofactor‐dependent enzyme activation with commercial protein kinase inhibitor.
Diet‐induced alterations in the discoid shape and phospholipid fatty acid compositions of rat erythrocytes
Authors: Ananda Rao G. , Siler Kathleen , Larkin Edward C.
Published: November 2006

For eight weeks young male rats were fed diets rich in 18∶2 (stock diet, or 10% corn oil, CO) or those devoid of 18∶2 (fat free, FF, or 10% hydrogenated coconut oil, HCNO). The CO and HCNO diets were fed in the absence or presence of eicosa‐5,8,11,14‐tetraynoic acid (TYA). When 18∶2 was excluded, an increase in the level of 16∶1, 18∶1 and 20∶3 and a decrease in 18∶2 was observed in the fatty acids of red cells. On feeding TYA, an increase in 18∶2 and in the case of the HCNO+TYA diet, a decrease of 12∶0 and 14∶0 was also observed. In all cases the levels of 20∶4 in erythrocyte fatty acids were similar. Saturated fatty acids were predominant in phosphatidyl choline (PC), lysophosphatidylcholine, (LPC) and sphingomyelin whereas unsaturated acids were predominant in phosphatidyl ethanolamine (PE), (PS), and phosphatidyl inositol (PI). Acids containing three or more double bonds comprised about 90% of the total acids in PI. In all the phospholipids, the characteristic changes in the composition of fatty acids were observed due to the exclusion of 18∶2 from the diet. However, changes due to the feeding of TYA were found only in PC and LPC. In rats fed the 18∶2‐rich diet, about 60% of the red cells were discocytes. In those fed the 18∶2‐free diet, the level of discocytes decreased to about 23%, and the levels of echinocytes II and III increased. The exclusion of 18∶2 for even a few days decreased the proportion of discocytes. The loss of discoid shape was reversed in a few days by feeding an 18∶2‐rich diet. Fatty acid analysis of erythrocytes of rats of the various dietary manipulations showed that the change in the proportion of discocytes followed the change in the level of 18∶2.
Lactobacillic and methyl‐branched olefinic acids inByrsocarpus coccineus seed oil
Authors: Spencer Gayland F. , Payne‐Wahl Kathleen , Plattner Ronald D. , Kleiman Robert
Published: November 2006

A detailed investigation of the seed oil ofByrsocarpus coccineus Schum. and Thonn. has disclosedcis‐11,12‐methyleneoctadecanoic (lactobacillic) (13%) and two branched octadecenoic acids (0.1%). Other fatty acids in the oil are those normally associated with seed lipids except for an unusually high proportion (12%) ofcis‐11‐octadecenoic acid. Lactobacillic acid has long been known as a constituent of certain bacterial lipids, but this is the first report of its presence in a seed oil. The branched olefinic acids have not heretofore been found to occur in plants.
Fatty acids and sterols ofCronartium fusiforme basidiospores
Authors: Weete J. D. , Kelley W. D.
Published: November 2006

The hydrocarbons, fatty acids, and sterols ofCronartium fusiforme basidiospores were examined by gas chromatography and mass spectrometry. Trace quantities of aliphatic hydrocarbons were detected, but these were probably not fungal products. Principal nonsubstituted fatty acids were palmitic (11.7%), linoleic (17.2%), and linolenic (16.1%) acids; the predominant acid was 9,10‐cis‐epoxyoctadecanoic acid (40.7%). Four sterols were detected, three of which were identified as stigmast‐7‐enol (57.6%), stigmasta‐5,7‐dienol (22.7%), and ergost‐7‐enol (16.0%). The fourth sterol (4%) is a C28 diene. Lipids of the aeciospores and basidiospores ofC. fusiforme are compared.