bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extremely decreased release of prostaglandin E2‐like activity from chopped lung of ethyl linolenate‐supplemented rats
Authors: Hansen Harald S. , Fjalland Bjarne , Jensen Benny 
Published: December 2006

AbstractThree groups of weanling male rats were reared on a fat‐free diet for 13 weeks. One group received only the fat‐free diet (FF rats), the other 2 groups received the fat‐free diet and a daily supplement of 2 energy% ethyl linoleate ([n−6] rats), or 2 energy% ethyl linolenate ([n−3] rats). The chopped lung preparation was used to illustrate an in vitro prostaglandin formation. PGE2‐like activity was quantified on rat stomach strip. The release of PGE2‐like activity expressed as ng PGE2‐equivalent per g lung tissue (mean±SD) was 23±7, <6, and 65±20 for the FF rats, the (n−3) rats, and the (n−6) rats, respectively. PGE2 quantification by radioimmunoassay of the chopped lung effluent collected after passing over the rat stomach strip revealed the same release pattern as the bioassay. Fractionation of chopped lung effluent on HPLC with radioimmunoassay detection indicated that the lung tissue from (n−3) rats released very little PGE3, if any, in spite of a 20∶5(n−3)/20∶4(n−6) ratio of 5.2 in the lipids of the lung. It is suggested that the pool of arachidonic acid for prostaglandin production in vitro is different from the one which functions in vivo, and that these pools are differently affected by dietary EFA.
The binding of micellar lipids to chitosan
Authors: Nauss J. L. , Thompson J. L. , Nagyvary J. 
Published: December 2006

AbstractThe lipid binding capacity of chitosan (partially deacetylated chitin) was determinined with respect to micellar solutions of bile salts, dodecyl sulfate, natural ox bile and an artificial mixed microemulsion. The stoichiometry was determined following the separation of the solid phase by filtration or centrifugation. The major variables in the extent of binding were the pH and ionic strength, suggesting that the interactions are mainly of ionic nature. It is noteworthy that under optimal conditions chitosan could bind, i.e., coprecipitate, with 4–5 times of its weight with all the lipid aggregates tested. These results have a bearing on the nutritional and pharmacological applications of chitosan. The analyses of the components from the precipitates with microemulsion and ox bile show a significant selectivily of binding caused by hydrophobic interactions.
Phospholipid synthesizing enzymes of dermatophytes: II. Characterization of choline kinase
Authors: Kasinathan C. , Govindarajan U. , Chopra A. , Khuller G. K. 
Published: December 2006

AbstractCholine kinase was located in the cytosolic fractions of the filamentous, pathogenic fungi,Microsporum gypseum andEpidermophyton floccosum. A broad pH optima (6.0–9.0) was observed for theM. gypseum enzyme, but theE. floccosum enzyme was active at pH 8.4 as well as 10.5, the activity being higher at pH 8.4. Enzyme from both dermatophytes had Km value of 3.3×10−4 M for choline; however, for ATP, it was 6.6×10−4 M and 12.6×10−4 M forM gypseum andE. floccosum, respectively. Choline kinase of both dermatophytes showed SH‐group requirement. TheM. gypseum choline kinase was inhibited to a greater extent by Mn2+, Ca2+ and Ba2+ than was theE. floccosum enzyme. In comparison to other nucleotides, ATP was the most effective phosphate donor for phosphorylating choline in both dermatophytes. Higher concentrations of ATP inhibited the enzyme inM. gypseum as well asE. floccosum. Phosphorylcholine inhibited the choline kinase activity from both fungi, whereas phosphoethanolamine and glycerol 3‐phosphate were stimulatory.
Sterols of the spongeTethya amamensis: Occurrence of (24E)‐24‐ethylidenecholesta‐5,7‐dienol, (24E)‐24‐propylidenecholesta‐5,7‐dienol, and (24Z)‐24‐propylidenecholesta‐5,7‐dienol
Authors: Teshima Shin‐Ichi , Kanazawa Akio , Yamada Ichimaro , Tanaka Yoshito 
Published: December 2006

AbstractThe spongeTethya amamensis, collected from Kagoshima Bay, Japan, contained at least 24 sterols, including Δ5‐sterols (82.2% of total sterols) and Δ5, 7‐sterols (17.8%). The predominant sterols were cholesterol (29.0%), cholesta‐5,22‐dienol (13.8%), 24‐methylcholesta‐5,22‐dienol (10.9%), 24‐methylenecholesterol (8.3%), 24‐methylcholesta‐5,7,22‐trienol (6.8%), 24‐ethylcholest‐5‐enol (6.1%), and isofucosterol *4.1%). Combined gas liquid chromatography‐mass spectrometry suggested the presence of 3 uncommon sterols, (24E)‐24‐ethylidenecholesta‐5,7‐dienol, (24E)‐24‐propylidenecholesta‐5,7‐dienol, and (24Z)‐24‐propylidenecholesta‐5,7‐dienol as minor components. The sterols ofT. amamensis also contained small amounts of 24‐norcholesta‐5,7,22‐trienol and (24Z)‐24‐ethylidenecholesta‐5,7‐dienol.
Initiation of lipid peroxidation by a peroxidase/hydrogen peroxide/halide system
Authors: Kanner Joseph , Kinsella John E. 
Published: December 2006

AbstractA lactoperoxidase/H2O2/halide system caused the initiation of linoleate peroxidation as indicated by diene conjugation. Coupled lipid peroxidation was accelerated by iodide, chloride and bromide ions at pH 4.0 and 6.2. No peroxidation occurred in the presence of H2O2 or lactoperoxidase alone. The rate of linoleate peroxidation by lactoperoxidase in the presence of chloride depended on the concentration of H2O2. Linoleate peroxidation by the enzymatic system was inhibited by high concentration of H2O2 by methionine, tryptophan and BHT. Oxygen was absorbed during peroxidation and the major products were the 13‐hydroperoxides. The mechanisms of the initiation of lipid peroxidation by a peroxidase/H2O2/halide system are discussed.
Effect of the plasticizer di(2‐ethylhexyl) adipate (dioctyladipate, DOA) on lipid metabolism in the rat: I. Inhibition of cholesterolgenesis and modification of phospholipid synthesis
Authors: Bell Frank P. 
Published: December 2006

AbstractDOA (di[2‐ethylhexyl] adipate, dioctyladipate), a plasticizer used in the manufacture of polyvinylchloride plastic products, has been considered as a suitable substitute for di(2‐ethylhexyl)phthalate (DEHP) in some applications. In the present studies, hepatic lipid metabolism was examined in liver mince preparations from rats fed 0.5% or 1.0% DOA in the diet for 2 weeks. By studying patterns of lipid synthesis from [14C] acetate, [14C] oleate, [14C] mevalonate, and [14C] octanoate, it was concluded that DOA feeding inhibits hepatic cholesterolgenesis and alters the pattern of phospholipids synthesized by the liver. DOA also exerted a cholesterol‐lowering effect at the 1% level but did not affect plasma triglyceride levels. The results suggest that the biological effects of DOA in the rat are similar to those produced by DEHP.
Absorption and metabolic fate of dietary3H‐squalene in the rat
Authors: Tilvis Reijo S. , Miettinen Tatu A. 
Published: December 2006

AbstractThe absorption and metabolic fate of dietary squalene were investigated on the rat by administering a single oral dose of3H‐squalene and14C‐cholesterol. Experiments on rats with cannulated thoracic duct revealed that3H‐squalene was, like14C‐cholesterol, absorbed through the lymphatic vessels and that ca. 20% of absorbed3H‐squalene was cyclized to sterols during the transit through the intestinal wall. Feces contained3H‐sterols, indicating that newly synthesized mucosal sterols had been secreted into the gut lumen. In intact animals,3H‐squalene appeared in the circulation more rapidly than14C‐cholesterol and did not persist to any significant extent in the squalene‐rich adipose and muscle tissues. The increase in dietary squalene load (8–48 mg) decreased the absorption percentage of3H‐squalene (45–26%) but did not affect the absorption of14C‐cholesterol (47%). Determination of fecal steroids revealed that during the first days absorbed3H‐squalene was eliminated to a significantly higher extent than14C‐cholesterol as fecal bile acids (34% vs 11%). The experiments indicate that the rat intestine has a marked capacity for absorbing dietary squalene and that the absorbed squalene is preferentially converted to bile acids in the liver.
Modulation of platelet thromboxane and malonaldehyde by dietary vitamin E and linoleate
Authors: Hamelin Suzanne S. ‐J. , Chan Alvin C. 
Published: December 2006

AbstractThromboxane (TXB2) and malonaldehyde (MDA) production by thrombin‐stimulated washed platelet were evaluated in rats fed 6 combinations of dietary vitamin E (0, 100, 1000 ppm) and linoleate (6.5 and 17.0 en%) for 23 weeks. The molar ratio of MDA:TXB2 was consistently near 3 in all groups studied. In animals receiving the lower linoleate diets, TXB2 and MDA synthesis were inversely related to the dietary vitamin E concentrations and the levels of MDA and TXB2 were positively correlated (r=0.99) with decreasing vitamin E in the diet. High dietary linoleate (17.0 en%), independent of vitamin E status, reduces TXB2 and MDA synthesis. The importance of dietary antioxidant on platelet prostanoid synthesis is discussed.
Temperature effects on in vitro lipid accumulation in asexual embryos ofTheobroma cacao L.
Authors: Wright Daniel C. , Janick Jules , Hasegawa Paul M. 
Published: December 2006

AbstractAsexual embryos of cacao were grown for 40–50 days in a modified Murashige and Skoog liquid medium with sucrose concentration increased stepwise from 3 to 27% at temperatures of 10, 17, 20, 23, 26, 29, 32 or 35 C. Temperature influenced overall embryo growth as well as lipid accumulation and composition. Maximum growth occurred at 29 C, whereas maximum lipid and fatty acid accumulation occurred at 26 C. The proportion of individual fatty acids as total fatty acids accumulated per asexual embryo was constant at each temperature but varied with temperature from 10 to 35 C. The fatty acid composition of asexual embryos grown at 26 C was the most similar to that of cocoa butter, the lipid from mature zygotic embryos produced in vivo.
Elevated levels of arachidonic acid in fish from northern Australian coastal waters
Authors: Sinclair Andrew J. , O'Dea Kerin , Naughton Joan M. 
Published: December 2006

AbstractThe fatty acid composition of 10 species of fish caught off the northwest coast of Australia (latitude 17°S) was examined. All species contained high levels of ω6 fatty acids (9.6–23.1% of total fatty acids) with arachidonic acid being the major ω6 fatty acid (5.9–14.8% of fatty acids). Docosatetraenoic and docosapentaenoic acids of the ω6 series accounted for 3–8% of the total fatty acids. The ratio of ω6 to ω3 fatty acids in these fish varied from 0.38 to 0.93, compared with an average ratio of 0.16 for fish from the northern hemisphere (latitude >30°N). The present data and figures from the literature indicate that the marine food chain in the southern hemisphere contains significant quantities of ω6 fatty acids.
A simple synthesis of 5,8,11‐eicosatrienoic acid
Authors: Parish Harlie A. , Gilliom Richard D. , Purcell William P. 
Published: December 2006

AbstractA straighforward synthesis of Z,Z,Z‐5,8,11‐eicosatrienoic acid is described that gives a pure product without chromatography. The C20‐polyacetylenic acid is purified by recrystallization and then reduced by a Lindlar catalyst in an aprotic solvent with a trace quantity of quinoline.
Hydroxylation of secondary bile acids in the perfused prairie dog liver
Authors: Cohen Bertram I. , Singhal Anil K. , Mongelli Joseph , Rothschild Marcus A. , McSherry Charles K. , Mosbach Erwin H. 
Published: December 2006

AbstractTaurolithocholic acid and deoxycholic acid were perfused into isolated prairie dog livers. Taurolithocholic acid was 7α‐hydroxylated to form taurochenodeoxycholic acid, whereas deoxycholic acid was conjugated and 7α‐hydroxylated to form taurocholic acid. The low concentrations of secondary bile acids observed in prairie dog bile are due, at least in part, to active bile acid 7α‐hydroxylase(s) in the liver of these animals.
Tissue culture of cocoa bean (Theobroma cacao L.): Incorporation of fatty acids into lipids of cultured cells
Authors: Tsai C. H. , Kinsella J. E. 
Published: December 2006

AbstractSuspension cell cultures of cocoa bean rapidly incorporated palmitic, stearic, oleic and linoleic acids into cellular lipids. Thus, 75 and 20% of [1‐14C] palmitic acid was incorporated into polar lipids and triglycerides, respectively, after 48 hr. When [1‐14C] oleic and [1‐14C] linoleic acid were added separately, polar lipids consistently contained most of the radioactive fatty acids. Ca. 60% of the stearic acid accumulated as unesterified fatty acid in the cells. Palmitic and stearic acid were not desaturated, but oleic acid and linoleic acid were further desaturated. The kinetics of conversion of oleic acid and linoleic acid suggested a sequential desaturation pathway of 18∶1→18∶2→18∶3 in cocoa bean cell suspensions.
Identification of 27‐nor‐(24R)‐24‐methylcholesta‐5,22‐dien‐3β‐ol and brassicasterol as the major sterols of the marine dinoflagellateGymnodinium simplex
Authors: Goad L. John , Withers Nancy 
Published: December 2006

AbstractThe major 4α‐monomethyl sterol of the dinoflagellateGymnodinium simplex was identified as (24S)‐4α,24‐ dimethylcholestan‐3β‐ol. The major 4‐demethyl sterols were characterized as (24R)‐24‐methylcholesta‐5,22‐dien‐3β‐ol (brassicasterol) and 27‐nor‐(24R)‐24‐methylcholesta‐5,22‐dien‐3β‐ol. The latter sterol has the opposite configuration at C‐24 to that assigned to occelasterol, which has the same basic structure and has previously been reported as a constituent of the sterols of a marine worm. 24‐Nor‐cholesta‐5,22‐dien‐3β‐ol was also identified along with several other trace sterols. The co‐occurrence of 27‐nor‐(24R)‐cholesta‐5,22‐dien‐3β‐ol together with 24‐nor‐cholesta‐5,22‐dien‐3β‐ol and brassicasterol provides new evidence for the biosynthetic origins of the two former nor‐sterols. It is suggested that they may be produced de novo by a route involving nor‐isoprenoid pyrophosphates and nor‐squalene as intermediates, rather than as bacterial degradation products of brassicasterol (or related sterols) as previously suggested in the literature.
Effect of inhibitors on ω‐and (ω‐1)‐hydroxylation of lauric acid by frog liver microsomes
Authors: Miura Yoshiro 
Published: December 2006

AbstractTo investigate the involvement of different cytochrome P‐450 monooxygenases in fatty acid hydroxylation in frog liver microsomes, the effect of various inhibitors of cytochrome P‐450 monooxygenases on the ω‐ and (ω‐1)‐hydroxylation of laurate was examined. The ω/ω‐1‐hydroxylation ratios were changed significantly by various levels of carbon monooxide (CO) inhibition; the formation of ω‐hydroxylaurate was more sharply inhibited by various levels of CO than was the formation of (ω‐1)‐hydroxylaurate. On the contrary, metyrapone inhibited only the formation of (ω‐1)‐hydroxylaurate and stimulated the formation of ω‐hydroxylaurate. 7,8‐Benzoflavone as well as CO was more inhibitory to the ω‐hydroxylation of laurate. At low concentrations of KCN (0.2 and 0.1 mM), the (ω‐1)‐hydroxylase activity was stimulated, but both the ω‐ and (ω‐1)‐hydroxylase activities were inhibited at the higher concentrations (5–10 mM). The effect of drugs and hydroxylaurate isomers on the ω‐ and (ω‐1)‐hydroxylation was also examined. Aminopyrine showed a stimulative effect on ω‐hydroxylase activity and no effect on the (ω‐1)‐hydroxylase activity, whilep‐nitroanisole inhibited the (ω‐1)‐hydroxylase activity and showed almost no effect on the ω‐hydroxylase activity. 12‐Hydroxylaurate inhibited both the ω‐ and (ω‐1)‐hydroxylase activities, but the ω‐hydroxylase activity was inhibited to a much greater extent. 11‐Hydroxylaurate had no effect on either hydroxylation. These findings strongly support the hypothesis that different cytochrome P‐450 species are involved in the hepatic microsomal hydroxylation of laurate at ω‐ and (ω‐1)‐positions in the frog.
Source of lung surfactant phospholipids: Comparison of palmitate and acetate as precursors
Authors: Sato Tadahiro , Akino Toyoaki 
Published: December 2006

AbstractThe phospholipids and the fatty acid compositions of major phospholipids in rat lung parenchyma, microsomes, lamellar bodies and alveolar wash were quantified. Adult rats were injected simultaneously with [3H] palmitate and [14C] acetate into the femoral vein. The appearance of labeled phosphatidylcholine (PC), disaturated phosphatidylcholine (DSPC) and phosphatidylglycerol (PG) in each lung fraction was measured during short periods of time (5 min to 2 hr) after isotope administration. Relatively more PC, DSPC and PG labeled with acetate radioactivity in lung microsomes entered lamellar body and alveolar wash fractions than those labeled with palmitate radioactivity. However, there was no difference between palmitate and acetate labeled phospholipids in the transport from microsomes to lamellar bodies by phospholipid exchange proteins. On the other hand, prior injection of colchicine resulted in decrease in the transport of PC from microsomes to alveolar space to a relatively greater extent in the acetate radioactivity than in the palmitate radioactivity.
Stimulation of hepatic squalene and triglyceride synthesis by dimethylsulfoxide, in vitro
Authors: Bell Frank P. , Hubert Edna V. 
Published: December 2006

AbstractThe incorporation of [14C] mevalonate and [14C] acetate into squalene by rat liver slices was increased over 7‐fold by the presence of 5% dimethylsulfoxide (DMSO) in the incubation medium. The stimulation of squalene synthesis was dose‐related over the concentration range of 1–5% DMSO and did not affect the incorporation of [14C] mevalonate, into the C27‐sterol fraction (cholesterol) but did increase (about 50%) incorporation into C30‐sterol (lanosterol) at a level, of 5% DMSO. The stimulation of squalene synthesis was observed under both anaerobic (N2 atmosphere) and aerobic (ambient air or 95% O2/5% CO2) conditions and may represent a direct effect of DMSO on squalene synthetase. At a level of 5%, DMSO also stimulated 7‐fold the incorporation of [14C] acetate into triglycerides by liver slices; this occurred without changes in incorporation into the phospholipid or free fatty acid fractions. The disproportionate increase in lipid labeling from [14C] acetate suggests that the effects of DMSO are not simply a matter of increasing [14C] acetate entry into the tissue.
Effects of cereals and culture filtrate ofTrichoderma viride on lipid metabolism of swine
Authors: Qureshi Asaf A. , Burger Warren C. , Elson Charles E. , Benevenga Norlin J. 
Published: December 2006

AbstractSwine were fed corn‐or barley‐based diets with, or without, culture filtrate (CF) ofTrichoderma viride for 21 days. Weight gains were nonsignificantly but slightly increased by CF. The activities of β‐hydroxy‐β‐methylglutaryl coenzyme A (HMG‐CoA) reductase, cholesterol 7α‐hydroxylase, acetyl‐CoA carboxylase (ACX), fatty acid synthetase (FAS) and other lipogenic enzymes in several tissues were determined. Significant decreases in the activities of HMG‐CoA reductase and cholesterol 7α‐hydroxylase in all tissues of swine fed the CF‐diets were observed. The major site for the regulation of cholesterol biosynthesis was adipose tissue followed by the intestine, liver, lung and muscle in order of activity The concentrations of cholesterol in serum and muscle were decreased 27% and 23%, respectively, by CF. ACX and FAS activities increased ca. 2‐fold when CF was fed with either of the cereal‐based diets. The major sites for fatty acid synthesis was the adipose tissue and, to a lesser extent, the liver. Very low rates of synthesis were detected in intestine, lung and muscle. Similar distributions of activities were found for related lipogenic enzymes.
Lipid profiles of taste and non‐taste epithelial tissues from steer tongues
Authors: Rabinowitz Joseph L. , Brand Joseph G. , Bayley Douglas L. 
Published: December 2006

AbstractSome hypotheses on taste reception have implicated lipids of taste cells as major receptor constitutents. This study reports detailed lipid profiles of the taste bud‐containing epidermis from circumvallate papillae and fungiform papillae as well as profiles from two non‐taste bud tissues: circumvallate papillae dermis and epidermis from the lateral posterior of the tongue. Differences in levels of triglycerides and phosphatidylcholines were observed but these were not directly related to the presence of taste buds. At this level of analysis, it is evident that there are no unusual distributions of phospholipid classes in the taste bud epidermis when compared with the non‐taste bud lingual epidermis.
Partial purification and characterization of a Ca2+‐stimulated lipoxygenase from soybean seeds
Authors: Dreesen Thomas D. , Dickens Martha , Koch Robert B. 
Published: December 2006

AbstractA highly purified Ca2+‐stimulated lipoxygenase was isolated from the Hill variety of soybean seeds. Separation of Ca2+‐stimulated lipoxygenase from lipoxygenase active in the absence of Ca2+ (lipoxygenase‐1) was readily obtained using a DEAE‐cellulose column. Sample size applied to the ion exchange column was found to be critical. Both enzymes were bound to the column, although some highly active Ca2+‐stimulated lipoxygenase eluted with buffer in the presence of bound lipoxygenase‐1. Ca2+‐stimulated lipoxygenase bound to DAAE‐cellulose required the use of a NaCl gradient for elution. Ca2+‐stimulated lipoxygenase showed an apparent isoelectric point at pH 5.90 and optimum activity at pH 7.5 and at 1.1 mM calcium. Lipoxygenase‐1 was inhibited over 95% in the presence of 60 μM methyl mercuric chloride, while Ca2+‐stimulated lipoxygenase showed a maximum of only 20% inhibition under the same conditions.
Temperature sensitivity of cholesteryl ester hydrolases in the rat testis
Authors: Durham Lucian A. , Grogan W. McLean 
Published: December 2006

AbstractCholesteryl ester hydrolase (CEH) (EC 3.1.1.13) activity was assayed in the 104,000×g supernatant (S104) of rat and mouse testes and livers at various temperatures between 27 C and 44 C. The CEH activity in the testis dropped from 44 pmol [4‐14C] cholesteryl oleate hydrolyzed/hr/mg protein to 14 pmol hydrolyzed/hr/mg protein (a 68% decrease) between testicular and abdominal temperatures (32 C and 37 C, respectively) in the rat. This decrease in activity is essentially a reversible phenomenon. CEH from the testis S104 was stabilized in 10 mM EDTA and was purified by HPLC size exclusion. These steps did not alter the temperature effect previously noted. The temperature effect on the testicular CEH was demonstrated in vivo by assaying the enzyme following unilateral cryptorchidism. The HPLC purification yielded 3 peaks of CEH activity from the testicular S104. The 28,000 MW peak was found to be temperature insensitive while the 70,000 and 420,000 MW peaks were temperature labile. The liver CEH of both species remained relatively constant over the range 32—37 C. CEH is a potential regulator of both steroidogenesis and membrane composition in the testis and its temperature lability may suggest a unique regulatory mechanism responsible for impaired spermatogenesis seen with elevated testicular temperatures.
Distribution of methylene and nonmethylene‐interrupted dienoic fatty acids in polar lipids and triacylglycerols of selected tissues of the hardshell clam (Mercenaria mercenaria)
Authors: Klingensmith J. Scott 
Published: December 2006

AbstractFatty acid profiles of polar lipids and triacylglycerols were determined for 6 tissues of the hardshell clam (Mercenaria mercenaria), namely, mantle, gill, mouth, foot, digestive tract/gonadal tissue and adductor muscle. The largest concentrations of nonmethylene‐interrupted dienoic (NMID) fatty acids were found in the gill, mantle, and foot. Structural analyses were undertaken to determine the double bond configurations of the various NMID isomers. The major 22C NMID species were Δ7,13‐ and Δ7,15‐docosadienoic acid. The major 20C NMID species were Δ7,11‐ and Δ7,13‐eicosadienoic acid and Δ5,11‐eicosadienoic acid.