bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of dietary fat on the lipogenic activity and fatty acid composition of rat white adipose tissue
Authors: Nelson Gary J. , Kelley Darshan S. , Schmidt Perla C. , Serrato Claire M. 
Published: November 2006

AbstractThe in vivo fatty acid synthesis rate, selected enzyme activities and fatty acid composition of rat white adipose tissue from animals fed semisynthetic diets of differing fat type and content were studied. All animals were starved for 48 hr and then refed a fat‐free (FF) diet for 48 hr. They were then divided into three groups. One group was continued on the FF diet for 48 hr. Another group was fed a diet containing 44% of calories from corn oil (CO). The final group was fed a diet containing 44% of calories from completely hydrogenated soybean oil (HSO). The animals on the FF diet had a marked increase in adipose tissue fatty acid synthesis during the 96‐hr feeding peroid (as measured by3H incorporation into adipose fatty acids). Addition of either CO or HSO to the diets did not significantly inhibit fatty acid synthesis in dorsal or epididymal adipose tissue. The activities of the enzymes' fatty acid synthetase, ATP‐citrate lyase and glucose‐6‐phosphate dehydrogenase increased on the FF diet and generally were not inhibited significantly by the addition of either fat to the diets. Linoleic acid was the major polyunsaturated fatty acid (ca. 22%) in adipose tissue. Monounsaturated fatty acids (palmitoleic, oleic,cis‐vaccenic) made up ca 38% of the total adipose fatty acids, while saturated fatty acids accounted for about 32% (myristic, palmitic and stearic). White adipose tissue in mature male rats was a major depot for n−3 fatty acids. There were differences in the fatty acid composition of epididymal and dorsal adipose tissue, particularly in their content of long chain, polyunsaturated fatty acids with epididymal tissue containing more of these compounds than dorsal fat. The fatty acid composition of the white adipose tissue did not change significantly during fasting or 96 hr of refeeding the FF diets. The addition of HSO to the diet for 48 hr had little influence on the adipose tissue fatty acid composition, but the addition of CO to the diet caused a 7% increase in the dorsal adipose tissue linoleate content (as percentage of total dorsal adipose tissue fatty acids) within 48 hr compared to animals fed the stock diet and those starved for 48 hr. The fatty acid synthesis data indicated that adipose tissue in the rat can continue to be a source of de novo fatty acid synthesis in animals consuming high‐fat diets.
Hepatic Δ9 and Δ6 desaturase activities during the recovery period following carbon tetrachloride poisoningdesaturase activities during the recovery period following carbon tetrachloride poisoning
Authors: Carreau Jean‐Paul , Frommel Dominique , Nguyen Thi Thé , Mazliak Paul 
Published: November 2006

AbstractThe liver microsomal Δ9 and Δ6 desaturase activities have been studied in rats with carbon tetrachloride‐induced hepatitis. Immediately after poisoning, significant decreases were observed for both types of desaturase activity. However, recovery kinetics were slower for the Δ6 desaturase than for the Δ9 desaturase. The activities of NADH‐ferricyanide and NADH‐cytochrome C reductases, proteins involved in the electron transfers associated with microsomal desaturation, were also measured. There was a fall in both activities after poisoning, but this decrease was less than that of the desaturase activities.
Analysis of autoxidized fats by gas chromatography‐mass spectrometry: VI. Methyl 9,15‐ and 12,15‐octadecadienoate
Authors: Frankel E. N. , Dufek E. J. , Neff W. E. 
Published: November 2006

AbstractThe gas chromatography‐mass spectrometry (GC‐MS) method developed in preceding papers was extended to the structural analysis of autoxidation products of methylcis‐9,cis‐15‐octadecadienoate and of an 87% concentrate ofcis‐12,cis‐15‐octadecadienoate. Eight isomeric hydroxydienes with one allylic and one isolated double bond were identified from oxidized 9,15‐diene and 2 conjugated hydroxydienes from oxidized 12,15‐diene, after reduction of the hydroperoxides. The proportions of 16‐(15%) and 17‐hydroperoxides (22%) from 9,15‐diene were significantly higher than that of the other isomers (8–12% each: 8‐, 9‐, 10‐, 11‐, 14‐ and 15‐OOH). Similarly, the amount of 16‐hydroperoxide from 12,15‐diene was larger (42%) than the 12‐hydroperoxide (31%). Substantial amounts of dihydroxy esters with one OH substituent on carbons‐8,‐9,‐10 or‐11 and the other OH on carbons‐14,‐16 or‐17, were identified after hydrogenation in highly oxidized 9,15‐diene. The implications of these hydroperoxide analyses are discussed in relationship to the precursors of flavor deterioration of oils and partially hydrogenated oils containing an ω‐3 double bond.
Preparation of radiolabeled tetracosa mono‐ and dienoic acid methyl esters from rat erythrocyte lipids by thin layer chromatography
Authors: Rao G. Ananda , Kilpatrick Robert L. , Goheen Steven C. , Larkin Edward C. 
Published: November 2006

AbstractAn easy method of obtaining pure fatty acid methyl esters (FAME) of tetracosa mono‐ and dienoic acids (24∶1, 24∶2) using thin layer chromatography (TLC) is described. The total lipids isolated from rat erythrocytes were treated with methanolic‐NaOH. Sphingomyelin was unaffected by this treatment and was separated from FAME of glycerolipids and cholesterol by TLC. FAME of sphingomyelin were then prepared by acid methanolysis. These esters migrated into 2 distinct bands on TLC. The slow moving band contained FAME of 16∶0, 16∶1, 18∶0, 18∶1, 19∶0 and 20∶0 whereas the fast moving band contained FAME of 22∶0, 23∶0, 24∶0, 24∶1 and 24∶2. After AgNO3‐TLC, the FAME of the fast moving band separated into 3 species; esters of saturated acids, 24∶1 and 24∶2, respectively. With erythrocyte lipids of rats fed a fat‐free diet and injected with14C‐18∶1, this method yielded14C‐24∶1. From rats injected with14C‐18∶2 and maintained on a corn oil diet,14C‐24∶2 was obtained.
The Δ5 and Δ6 desaturation of fatty acids of varying chain length by rat liver: A preliminary report
Authors: Pollard Michael R. , Gunstone Frank D. , Morris Lindsay J. , James Anthony T. 
Published: November 2006

AbstractThe Δ6 desaturase of rat liver can accommodate substrates with a wide range of chain lengths. Δ9‐cis,12‐cis‐Dienoic acids of chain lengths 14–22 carbon atoms were all desaturated at the Δ6 position by microsomal preparations from rat liver. By contrast, the Δ5 desaturase appeared much more chain‐length sensitive. The percentage Δ5 desaturation of a series of Δ8‐cis‐ and Δ9‐trans‐monoenoic acids increased with increasing chain length (from C16 to C20).
Techniques for the isolation and identification of steroids in insects and algae
Authors: Thompson Malcolm J. , Patterson Glen W. , Dutky Samson R. , Svoboda James A. , Kaplanis John N. 
Published: November 2006

AbstractAnalytical techniques, methods and instrumentation employed for the extraction, isolation separation, purification and identification of steroids from algae and insects are presented. The techniques include adsorption and argentation column chromatography and counter‐current distribution for separating the individual steroids, and thin layer chromatography and gas liquid chromatography for monitoring the purification process. Double bond, steric and alkyl substituent separation factors and relative retention times are reported for a large number of sterols on 4 different column systems. Their use permits the tentative structural assignment of sterols. Ultraviolet, infrared, nuclear magnetic resonance (NMR) and mass spectral analyses are discussed in light of their significance in the isolation and identification of steroids from insects and algae. Numerous examples are presented, including the use of 220 MHz NMR spectrometry, which permits the differentiation and characterization of C‐24 epimetric sterols and allows for a semiquantitative estimate of the 24α‐ and 24β‐epimers present in a mixture.
Identification of sterols and bile acids by computerized gas chromatography‐mass spectrometry
Authors: Elliott William H. 
Published: November 2006

AbstractIn mass spectrometry, sterols and bile acids form fragment ions characteristic of certain steroid structures. After separation of derivatized sterols or bile acids by the gas chromatograph and fragmentation in the mass spectrometer, data collected by the computer can be collated to provide a reconstructed gas chromatogram and a series of fragment ion current chromatograms in which the relative abundances of characteristic fragment ions are plotted vs time or scan number. Intensities of these fragment ions will be greatest and hence coincide with peak elution of unidentified sterols or bile acids. The use of known amounts of labeled appropriate sterols or bile acids permits quantitation of the identified sterol or bile acid.
Determination of molecular formula and stereoconfiguration of unique steroids by X‐ray diffraction analysis
Authors: Karle Jerome 
Published: November 2006

AbstractX‐Ray diffraction analyses can determine chemical composition, molecular formula and stereoconfiguration and can provide geometric parameters with uncertainties for bond distances of the order of 0.01 Å and for bond angles of the order of 1°. These analyses are especially useful when the substance analyzed is present only in very small quantities and is of uncertain composition or molecular formula. Only one suitable crystal is required for the analysis to proceed. There are many instances in which such circumstances have prevailed in the diffraction analysis of steroids. Among the examples given here is a new type of natural plant hormone with profound growth‐stimulating capabilities when applied in nanogram quantities per plant. The structure determination of this substance has greatly facilitated attempts to synthesize it and thereby to derive sufficient quantities for widespread testing.
Effect of diet on choline phosphotransferase, phosphatidylethanolamine methyltransferase and phosphatidyldimethylethanolamine methyltransferase in liver microsomes
Authors: Hoffman Dennis R. , Uthus Eric O. , Cornatzer W. E. 
Published: November 2006

AbstractPhosphatidylcholine (PC) biosynthesis has been investigated in female rats fed a liquid amino acid, choline‐methionine‐free diet by assaying in liver microsomes the specific and total activities of choline phosphotransferase, phosphatidyldimethylethanolamine methyltransferase and phosphatidylethanolamine methyltransferase. There was a significant decrease in the specific activity (sp act) of choline phosphotransferase in the liver of rats fed a choline‐methionine‐free diet. The dietary omission of methionine for 2 wk resulted in a significant decrease in the sp act of choline phosphotransferase. The dietary omission of choline, methionine, B12, folic acid and the addition of a methyl group acceptor, guanidoacetic acid, decreased further the sp act of choline phosphotransferase. The phosphatidyl‐ethanolamine methyltransferase sp act increased with the dietary omission of choline and methionine. The dietary omission of choline, methionine, B12, folic acid and the addition of a methyl group acceptor, guanidoacetic acid, resulted in a decrease in the sp act of phosphatidyldimethylethanolamine methyltransferase and an increase in phosphatidylethanolamine methyltransferase. The dietary omission of choline, methionine, B12, folic acid and the addition of a methylation inhibitor, 2‐amino‐2‐methyl‐1‐propanol, did not result in a significant decrease in the sp act of choline phosphotransferase; however, it did significantly decrease the sp act of phosphatidylethanolamine methyltransferase. The addition of dietary methionine with the inhibitor resulted in a significant decrease in the sp act of the choline phosphotransferase and phosphatidylethanolamine methyltransferase when compared to control and/or when compared to deficient with or without inhibitor. The dietary supply of methionine, as a source of choline, did affect the activity of the enzymes that synthesize PC. The ratio of the substrate, S‐adenosylmethionine, and the inhibitory product, S‐adenosylhomocysteine, affected the enzymatic activity of phosphatidylethanolamine methyltransferase. It is suggested that the concentrations of these 2 compounds may be important in regulating the methylation of phosphatidylethanolamine in the liver cell.
Synthesis of α‐hydroxy stearyl coenzyme A
Authors: Chauhan M. S. , Dakshinamurti K. 
Published: November 2006

AbstractSynthesis of α‐hydroxy stearyl CoA from N‐hydroxysuccinimide ester of a α‐hydroxy stearic acid and coenzyme A is reported. The CoA derivative has been isolated, purified and characterized from its spectral data and chemical properties.
Lipofuscin in vitamin E deficiency and the possible role of retinol
Authors: Bieri John G. , Tolliver Teresa J. , Robison W. Gerald , Kuwabara T. 
Published: November 2006

AbstractThis study was designed to determine if the vitamin A status of rats could affect the degree of lipofuscin formation in vitamin E deficient rats, inasmuch as an earlier report proposed a retinoyl complex in human brain lipofuscin pigment. Female rates were depleted of vitamin E from weaning while being maintained on different intakes of vitamin A (0, 0.8 and 8.0 mg/kg diet). The amount of lipofuscin present in the uterus was estimated at intervals between 2 and 8 months by visual observations, by histological fluorescence and by organic solvent extractable fluorescence. There was no difference in pigment deposition by any of the three criteria used, whether the animals were made retinol deficient and maintained on retinoic acid or were fed a low or high intake of retinol. Organic solvent extractable fluorescence was a poor indicator of the degree of pigment deposition in the uterus. It appears unlikely that retinol is a significant component of lipofuscin pigment in this tissue.
The lipid composition of the spleen and intestinal and popliteal lymph nodes in the sheep
Authors: Christie W. W. , Noble R. C. 
Published: November 2006

AbstractLipids were isolated from the spleen, intestinal lymph nodes and popliteal lymph nodes, tissues of potential importance in the metabolism of lymph or lymphocytes, of the sheep. The most abundant lipid classes were the triacylglycerols, free cholesterol and phospholipids, especially phosphatidylcholine, phosphatidylethanolamine and sphingomyelin. In each lipid class, the amounts of the essential fatty acids were lower than in the corresponding lipids of lymph or plasma. The triacylglycerols of each tissue resembled those of adipose tissue in structure, rather than those of lymph or plasma. Also, the structures of the phosphatidylcholines were distinctive. The results are discussed in terms of the metabolism of lipids in lymph. It does not appear probable that lymphoid tissue can supply appreciable amounts of lipid to lymph.
Uptake of secondary autoxidation products of linoleic acid by the rat
Authors: Kanazawa Kazuki , Kanazawa Eri , Natake Masato 
Published: November 2006

AbstractIncorporation of secondary autoxidation products (SP) of linoleic acid into the rat body was investigated. Radioactive SP was administered orally to a group of 5 rats, and excretions of radioactive substances in feces, urine and respiration were measured and compared with excretions from rats fed linoleic acid and its hydroperoxides. The SP‐fed group excreted 45% and the other groups about 10% of the administered radioactivity through feces. Urinary excretion accounted for 52% of activity ingested in the SP group and less than 30% in the other groups. The14CO2 produced in each group was about 25% of the ingested activity. Incorporation of the radioactive substances of SP into tissues and organs was measured periodically after administration of a single dose. The radioactive substances accumulated in the liver between 12–24 hr after administration and accounted for 2.6% of the total amount given, the highest level of all tissues and organs. This accumulation led to an elevation of serum transaminase activities, an increase in hepatic lipid peroxide, as determined by thiobarbituric acid test, and a slight hypertrophy of liver (1.5‐fold). Therefore, absorbed SP appeared to contribute to the deleterious condition of the liver.
Red blood cell tocopherol and liver tocopherol in hyperlipemic rats as compared with plasma tocopherol
Authors: Mino Makoto , Kasugai Osamu , Shimizu Tatsuo 
Published: November 2006

AbstractIn rats with hyperlipemia induced by Triton WR‐1339, changes in tocopherol concentrations in plasma and RBC were compared with those in the liver and its subcellular fractions, microsomes and mitochondria.After daily injection with Triton, plssma total lipids at 3 days and 7 days, respectively, showed elevation 6.5 times and 15 times as high as those in the control rats, and triglycerides showed the most predominant elevation.With the hyperlipemia, the concentrations of tocopherol in RBC and the subcellular fractions decreased, as plasma lipids and plasma tocopherol increased, while no change occurred in tocopherol concentrations in liver homogenates. The changes in the ratio of tocopherol to total lipids in plasma coincided with changes in tocopherol concentrations in the RBC and subcellular fractions.
Moderate changes in linoleate intake do not influence the systemic production of E prostaglandins
Authors: Ferretti Aldo , Judd Joseph T. , Marshall Mary W. , Flanagan Vincent P. , Roman John M. , Matusik Edward J. 
Published: November 2006

AbstractA pilot study was undertaken to determine if moderate changes in linoleate (18∶2ω6) intake would modulate the prostaglandin E turnover concurrently with, or independently of, changes in the plasma prostaglandin (PG) precursor levels. Four adult male volunteers in good health were fed two controlled diets containing 35% of energy from fat, with either 10 (diet L) or 30 g (diet H) linoleate/day, 30 to 50 g saturated fatty acids/day, and the balance mainly monounsaturated fatty acids. All four subjects were consuming sufficient amounts of polyunsaturates before the study. Protein (13–14%) and carbohydrate (51–53%) contribution to total caloric intake was kept constant. The menu cycle was 7 days, and all diets were calculated to provide adequate amounts of nutrients known to be required by man when data were available. Plasma fatty acids were determined by gas‐liquid chromatography, and the turnover of E prostaglandins was assessed by measuring the urinary output of the major metabolite of PGE1+PGE2 (PGE‐M). Whereas we found a clear correlation between 18∶2ω6 intake and 18∶2ω6 concentrations in the neutral lipid (P=0.007) and phosphoglyceride (P=0.012) fractions of plasma, arachidonate (20∶4ω6) concentrations in those same plasma fractions did not respond significantly to changes in linoleate intake. Moreover, we could not detect an influence of moderate changes in dietary levels of 18∶2ω6 on the systemic production of PGE as measured by the daily urinary output of PGE‐M.
Diversity of sterol composition in the family chenopodiaceae
Authors: Salt Thomas A. , Adler John H. 
Published: November 2006

AbstractThe predominant 4‐desmethylsterols from the leaves of 13 species in eight genera of the family Chenopodiaceae are 24α‐ethylsterols. In four species,Chenopodium ambrosioides L.,C. rubrum L.,Salicornia europaea L. andS. bigelovii Torr., the C‐22(23) double bond is introduced into more than 70% of the 24α‐ethylsterols producing spinasterol (24α‐ethylcholesta‐7,22E‐dien‐3β‐ol) in the first two species and mixtures of spinasterol and stigmasterol (24α‐ethylcholesta‐5,22E‐dien‐3β‐ol) in the latter species. The saturated side chain analogues predominate with more than 70% of the 24α‐ethylsterols in eight species.Salsola kali L.,Suaeda linearis (Ell.) Moq.,Kochia scoparia (L.) Roth., andBassia hirsute (L.) Aschers. synthesize sitosterol (24α‐ethylcholest‐5‐en‐3β‐ol), andAtriplex arenaria Nutt.,C. album L.,C. urbicum L. andC. leptophyllum Nutt. possess mixtures of sitosterol and 22‐dihydrospinasterol (24α‐ethylcholest‐7‐en‐3β‐ol). Sitostanol (24α‐ethyl‐5α‐cholestan‐3β‐ol) was isolated fromSuaeda linearis as an 18% component of the total 4‐desmethylsterol and in lesser amounts from four other species. In all species synthesizing 24‐ethyl‐Δ5‐sterols, a 24ξ‐methylcholest‐5‐en‐3β‐ol was also present at 1.0–20% of the total 4‐desmethylsterol. Avenasterol [24‐ethylcholesta‐7,24(28)Z‐dien‐3β‐ol], isofucosterol [24‐ethylcholesta‐5,24(28)Z‐dien‐3β‐ol), cholesterol (cholest‐5‐en‐3β‐ol) and 24ξ‐methyl‐5α‐cholestan‐3β‐ol also were isolated from several species. Species in the family Chenopodiaceae and the type genusChenopodium may be categorized into one of three groups based on sterol biosynthesis: the Δ7‐sterol producers; the Δ5‐sterol producers, and those producing mixtures of both Δ7‐ and Δ5‐sterols in relatively fixed percentage compositions.
Role of prostanoids and lipid peroxides as mediators of the 12‐O‐tetradecanoylphorbol‐13‐acetate effect on cell growth
Authors: Morisaki Nobuhiro , Tomei L. David , Milo George E. , Cornwell David G. 
Published: November 2006

AbstractConfluent cultures of guinea pig smooth muscle cells (SMC) or human fibroblasts (HNF) were treated with 12‐tetradecanoylphorbol‐13‐acetate (TPA). Prostanoid levels were measured by the radioimmunoassay of 6‐keto‐PGF1α and PGE2, and lipid peroxides were measured by the thiobarbituric acid test for malondialdehyde (MDA). Cells were seeded at low densities, and growth was calculated both from the cell count (Coulter Counter) and the colony number (image analysis). When confluent SMC and HNF were incubated in media alone, 6‐keto‐PGF1α levels were a function of the TPA concentration, increasing to a maximum at 10−8 M TPA and then decreasing at higher TPC concentrations. When confluent SMC and HNF were incubated in media containing exogenous arachidonic acid, 6‐keto‐PGF1α levels again increased to a maximum at 10−8M TPA but decreased at higher TPA concentrations only with SMC. The increase in 6‐keto‐PGF1α levels was much greater in HNF (1310%) than SMC (680%). SMC synthesized similar amounts of 6‐keto‐PGF1α and PGE2, and the stimulatory effect of TPA was similar with 6‐keto‐PGF1α and PGE2. Indomethacin (IM) blocked prostanoid synthesis at all TPA concentrations. TPA did not have a significant effect on MDA levels in either cell line. The lipid antioxidants α‐tocopherol and α‐tocopherylquinone blocked lipid peroxidation without affecting the stimulation of prostanoid synthesis with TPA. Cell number decreased to a minimum at 10−8M TPA in both cell lines. The decrease in cell number was much greater in HNF (72%) than SMC (30%). SMC colony number decreased at 10−8 TPA and then increased at 10−6M TPA. IM did not block the TPA effect on cell number in either cell line. The lipid antioxidant butylated hydroxytoluene (BHT) did not block the TPA effect on SMC cell number. The IM and the BHT data show that the TPA effect on cell growth is not mediated by prostanoid or lipid peroxide products of arachidonic acid metabolism. However, the increase in prostanoid synthesis parallels the decrease in cell number, and the effects are maximal at the same TPA concentration. These correlations suggest a common cellular process affecting both prostanoid synthesis and cell growth that is initiated or enhanced by TPA.