bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on the in vivo metabolism of retinoic acid in the rat
Authors: Geison R. L. , Johnson B. C. 
Published: November 2006

AbstractA time study of the metabolism of 6,7‐14C‐retinoic acid after intraperitoneal injection of physiological levels (17 μg, 0.39 μc) into vitamin A deficient rats, which had been repleted with retinoic acid for two weeks up to two days before injection, resulted in a rapid metabolism to more polar compounds in the small intestine and its contents and a slower metabolism to primarily different materials in the liver and kidney. The major route of metabolism resulted in the urinary excretion of 60% of the injected dose in 24 to 27 hr. Urinary metabolites of 15‐14C‐retinoic acid were eluted from silicic acid at a similar concentration of solvents as the ring labeled metabolites although only 32% of the injected dose was recovered in 24 hr. Compounds chromatographically similar to the urinary metabolites were observed at various times in the liver, kidney and small intestine plus contents in addition to retinoic acid and other metabolites. The relative amounts of the metabolites in the different tissues studied varied as a function of the tissue and the time of analysis after injection. Most of the radioactivity from all tissues was extractable into methanol. A liver subcellular distribution of the radioactivity derived from the intraperitoneal injection of 650 μg of 6,7‐14C‐retinoic acid (25.9 μc) after 3 hr indicated a minimal level of association of radioactivity (150–250 dpm/mg protein) with all fractions and a greater association of radioactivity with the lysosomal‐microsomal fraction (300–350 dpm/mg protein) and the 60–100% ammonium sulfate precipitable (750–800 dpm/mg protein) and 100% ammonium sulfate soluble fractions (422 dpm/mg protein) of the soluble supernatant.
Correlation between post‐heparin lipase and phospholipase activities in human plasma
Authors: Vogel William C. , Bierman Edwin L. 
Published: November 2006

AbstractThe hypothesis that a single lipolytic enzyme in post‐heparin plasma effects the hydrolysis of both triglyceride and phospholipid was tested. After intravenous heparin, activity in plasma with the two substrate classes appeared and disappeared in parallel. The activities were not separable by the fractionation methods of zone electrophoresis, gel filtration, anion‐exchange, ultracentrifugation, or by combinations of these techniques. The degree of purification of the two activities with the use ofn‐butanol was similar. Lipolytic activity appeared to be associated with a large high density molecular aggregate. However, the concept of a single post‐heparin enzyme does not explain all the observations since the ratio of activity with triglyceride substrate to activity with phospholipid substrate decreased markedly in some subjects after increased amounts of intravenous heparin.
Specificity of flaxseed lipoxidase
Authors: Zimmerman D. C. , Vick B. A. 
Published: November 2006

AbstractMass spectrometric data indicate that products of linoleate oxidation by flaxseed lipoxidase consist of 80% 13‐hydroperoxyoctadecadienoate and 20% 9‐hydroperoxyoctadecodienoate; the products of linolenate oxidation by flaxseed lipoxidase consist of 88% 13‐hydroperoxyoctadecatrienoate and 12% 9‐hydroperoxyoctadecatrienoate. Flaxseed lipoxidase possesses a high degree of specificity for attachment of oxygen to linoleic and linolenic acid molecules.
Composition of the surface lipids of pea leaves (Pisum sativum)
Authors: Kolattukudy P. E. 
Published: November 2006

AbstractSurface lipid of pea leaves (Pisum sativum var. Frosty) was analyzed with column, thin layer and gas liquid chromatography in conjunction with mass spectrometry and infrared spectroscopy. It contained 42%n‐hentriacontane and 7.3%n‐hentriacontan‐16‐ol. About 5% was wax esters, C40–C50 consisting of primarily C26 and C28 alcohols and C16–C22 acids. Almost 5% was aldehydes, mainly C26 and C28. Primary alcohols, chiefly C26 and C28, made up 20% of the surface lipid.
Incorporation of 1,2‐14C‐ethanolamine into subfractions of rat liver phosphatidylethanolamines and phosphatidylcholines
Authors: Tinoco J. , Sheehan G. , Hopkins S. , Lyman R. L. 
Published: November 2006

AbstractThe incorporation of 1,2‐14C‐ethanolamine into the liver phosphatidylethanolamines (PE) and phosphatidylcholines (PC) in female rats was studied. These phosphatides were fractionated according to their degrees of unsaturation and the specific activities of monoenoic, dienoic, tetraenoic and hexaenoic fractions were measured at intervals of 1, 20, 60 and 300 min after injection of the labeled precursor. Hexaenoic and dienoic PE incorporated and lost the label rapidly. Although the labeled precursor was incorporated into tetraene PE at a similar rate, this fraction attained a relatively low specific activity that remained essentially constant between 10 and 300 min after injection of the label. Hexaenoic PC had the highest specific activity among the PC fractions at all time periods. Estimations of the rate of loss of radioactivity in the hexaenoic PE fraction and its appearance in hexaenoic PC indicate that the docosahexaenoic acid is conserved, possibly by being reincorporated into PE after becoming a part of the hexaenoic PC species. The high rate of turnover of the hexaenoic PE also suggests that this fraction might have some special role in endogenous choline synthesis.
Analyses of fatty acids from Newfoundland copepods and sea water with remarks on the occurrence of arachidic acid
Authors: Ackman R. G. , Hooper S. N. 
Published: November 2006

AbstractComparisons of the total fatty acids from some North Atlantic (Newfoundland) spring copepods (mostlyTemora longicornis) and from associated sea water have been made. The animal fatty acids were similar in composition to published data for other copepods and this suggests a basic differentiation among planktonic crustacea by which species and genus fatty acid compositions may be compared. The fatty acids recovered from sea water unexpectedly showed a high proportion (∼9%) of arachidic acid, which is normally a very minor component in marine lipids of either plant or animal origin. The evidence bearing on widespread occurrence of this acid in sea water and sediments is reviewed.
Fatty acid biosynthesis and incorporation into lipid classes in seeds and seed tissues of flax
Authors: Dybing C. Dean , Craig B. M. 
Published: November 2006

AbstractFatty acid metabolism in developing flaxseeds was studied by incubating whole seeds or isolated seed tissues in buffered solutions of 1‐14C‐acetate, 2‐14C‐malonate and14CO2. Lipid classes were separated by thin layer chromatography, and fatty acid labeling in phospholipids, diglycerides and triglycerides was determined by combined thin layer and gas liquid chromatographic techniques. Incorporation of14C from acetate into embryo lipids was very rapid with phospholipids and 1,2‐diglycerides becoming highly labeled in treatment times as short as 5 min. Triglycerides were labeled more slowly. Phospholipid radioactivity was largely associated with the phosphatidyl choline fraction. Oleic acid had the highest specific activity of all major fatty acids in short treatment periods. This was followed in decreasing order of activity by palmitic, linoleic, stearic and linolenic acids. As the treatment period was lengthened to 90 min or longer, linoleic and linolenic activities were markedly increased. Use of malonate or CO2 rather than acetate as the substrate increased the labeling of the saturated acids. Incorporation of14C from acetate into lipids of endosperm tissues and whole flax seeds was slower than incorporation into embryo lipids. Stearate had the highest specific activity of the fatty acids in endosperm and whole seeds.
Glyceride studies: Part IX: Intraglyceride distribution of vernolic acid and of five conjugated octadecatrienoic acids in seed glycerides
Authors: Conacher H. B. S. , Gunstone F. D. , Hornby G. M. , Padley F. B. 
Published: November 2006

AbstractVernolic (epoxyoleic) acid, present in six seed oils over the range 19–72%, appears to be preferentially attached to the secondary glycerol hydroxyl group. The distribution of five isomeric conjugated octadecatrienoic acids (8, 10, 12 and 9, 11, 13) in 18 seed oils has been examined by lipase‐catalyzed deacylation. The results are not entirely consistent and more species must be examined before a rational distribution pattern becomes apparent.
The effect of peroxidized arachidonic acid upon human platelet aggregation
Authors: Mickel Hubert S. , Horbar Jeffrey 
Published: November 2006

AbstractHuman platelet aggregation was studied in vitro following exposure to free arachidonic acid and peroxidized arachidonic acid. A slow aggregation response was caused by free arachidonic acid, whereas a rapid, marked response resulted from exposure to peroxidized free arachidonic acid. Aggregation resulting from peroxidized arachidonic acid was not counteracted by adenosine nor by prostaglandin E1, both in high concentrations. Peroxide‐induced platelet aggregation required the presence of added calcium ions in vitro. The aggregation resulting from exposure to peroxidized arachidonic acid was abolished by prior treatment of the lipid peroxide with tocopherol and butylated hydroxy toluenne.
Inhibition of phospholipase C by isosteric phosphinic acid analogues of lecithin
Authors: Rosenthal Arthur F. , Chodsky Sergei V. 
Published: November 2006

AbstractFour synthetic diether phosphinate analogues of lecithin were studied for inhibitory activity againstClostridium perfringens phospholipase C. An order of inhibitory effectiveness of phosphonate and phosphinate was, thereby, developed. The inhibitions seem relatively independent of specific structural features; this is discussed with emphasis on physical effects which complicate the inhibition kinetics.
Oral contraceptive‐α‐tocopherol interrelationships
Authors: Aftergood L. , Alfin‐Slater R. B. 
Published: November 2006

AbstractAfter observing that some of the side effects of the administration of oral contraceptive drugs to rats resemble those resulting from vitamin E deficiency, a possibility of an increased requirement for vitamin E during oral contraceptive therapy was considered. Female rats were kept on the following diets all of which contained 15% stripped corn oil: (A) basal (no tocopherol), (B) basal + α‐tocopherol to provide 1 mg/rat/day, (C) basal+butylated hydroxytoluene, and (D) basal with the α‐tocopherol given only during drug administration. At 13 weeks of age, Enovid E was administered orally at a level corresponding to 0.002 mg mestranol and 0.05 mg norethynodrel/day for either 4 or 28 days, at which time the rats were sacrificed. In addition to previously shown changes, lowering of plasma tocopherol levels was observed in rats receiving the drug. On the other hand, the effects of an oral contraceptive were not as drastic in vitamin E deficient rats. Possible implications of these findings are discussed.
Effects of ethanol upon lipid metabolism
Authors: Lieber Charles S. 
Published: November 2006

AbstractEthanol abuse produces fatty liver which cannot be prevented by supplementation in protein, minerals, vitamins, and choline. In rats, protein and choline deficiencies potentiate the effect, whereas replacement of dietary fat by medium chain triglycerides or carbohydrates decreases the capacity of ethanol to produce steatosis. Administration of a single dose of ethanol to rats represents a stressful condition associated with moderate hepatic accumulation of fatty acids derived from adipose tissue. By contrast, chronic ethanol administration produces more pronounced steatosis with a predominance of endogenously synthesized and, when available, dietary fatty acids. These accumulate because of decreased fat oxidation. Ethanol also stimulates hepatic lipogenesis. These various effects can be explained by the increase in the hepatic nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide ratio secondary to the oxidation of ethanol via the alcohol dehydrogenase pathway. In addition there are more lasting changes in intermediary metabolism, such as increased hepatic ketogenesis which could be linked to the persistent alteration in mitochondrial function and structure found after chronic ethanol ingestion. The ultrastructural changes also are characterized by proliferation of the hepatic smooth endoplasmic reticulum. The latter was documented by subfraction. This led to the description of a new pathway for ethanol metabolism, the microsomal ethanol oxidizing system, which doubles in activity after ethanol feeding. The existence of the microsomal ethanol oxidizing system may contribute to our understanding of increased cholesterol and lipoprotein synthesis. Other effects upon lipid metabolism include decreases in free fatty acids and glycerol concentrations and free fatty acid turnover which result from inhibition of peripheral fat mobilization by acetate, a metabolite of ethanol.
Effects of anabolic and progestational agents upon triglycerides and triglyceride kinetics in normals and hyperlipemic patients
Authors: Fallat Ronald , Glueck Charles J. 
Published: November 2006

AbstractProgestational and anabolic‐androgenic compounds may have extensive effects upon plasma triglycerides, triglyceride clearing enzymes, and upon mechanisms of triglyceride clearing from the plasma. This article centers upon recent advances in the understanding of the mode of action of these compounds, both in normals and in patients with hypertriglyceridemia.
Effect of (−)‐hydroxycitrate upon the accumulation of lipid in the rat: II. Appetite
Authors: Sullivan Ann C. , Triscari Joseph , Hamilton James G. , Miller O. Neal 
Published: November 2006

AbstractThese studies were designed to determine the effect of (−)‐hydroxycitrate upon the accumulation of lipid in the rat by examining appetite, wt gain, and total body lipid profiles. The chronic oral administration of a nontoxic dose of (−)‐hydroxycitrate to growing rats for 11–30 days caused a significant reduction in body wt gain, food consumption, and total body lipid. The administration of equimolar amounts of citrate did not alter wt gain, appetite, or body lipid. No increase in liver size or liver lipid content occurred with either treatment. Pair feeding studies demonstrated that the reduction in food intake accounted for the decrease in wt gain and body lipid observed with (−)‐hydroxycitrate treatment.
Acyl‐CoA acyl‐sn glycerol‐3 phosphorylcholine acyl transferase of bovine mammary tissue
Authors: Kinsella J. E. , Infante J. P. 
Published: November 2006

AbstractMicrosomal material from lactating bovine mammary tissue possess very active acyl‐CoA:1‐acyl‐sn‐glycerol‐3‐phosphorylcholine acyl transferase (EC2.3.1.‐1). Oleyl‐CoA was the preferred substrate and rates of 6.3, 6.4, 1.8, 21.0, and 0.1 nmoles acylated/min/mg were obtained for myristyl‐, palmityl‐, stearyl‐, oleyl‐ and linoleyl‐CoA, respectively, when 1‐oleyl‐sn‐glycerol‐3‐phosphorycholine was used compared to 5.2, 4.1, 1.0, 3.5, and 0.2 nmoles/min/mg with 1‐palmityl‐sn‐glycerol‐3‐phosphorylcholine as acyl acceptor. Apparent Km values of 4.5 and 5.2 μM for oleyl‐CoA and 6.5 and 4.6 μM for palmityl‐CoA were obtained with 1‐oleyl‐ and 1‐palmityl‐sn‐glycerol‐3‐phosphorylcholine, respectively. The Km values of 1‐oleyl‐sn‐glycerol‐3‐phosphorylcholine were 20 and 50 μM using oleyl‐CoA and palmityl‐CoA as acyl donors. The possible involvement of this enzyme in membrane dynamics during lipid secretion is discussed.
Total glycerophospholipid fatty acid and phospholipid class composition of nerve ending and related fractions from fetal and adult pig cerebellum and adult pig whole brain cortex
Authors: Geison R. L. , Flangas A. L. , Kornguth S. E. 
Published: November 2006

AbstractMembrane fractions derived from crude mitochondrial fractions of pig cerebellums were separated on a continuous CsCl‐sucrose gradient. Fetal and adult brains were used as starting material. The major differences in total glycerophospholipid fatty acid composition between fetal and adult membranes were an increase with maturation in docosahexaenoic acid and a decrease in palmitic acid which occurred in all membranes, including nerve ending and smooth membrane fractions. Phosphatidylcholine levels decreased, and ethanolamine phosphatide levels increased with maturation in all adult membrane fractions. Phosphatidylserine levels increased primarily in nonmitochondrial fractions in adult tissues. The results indicate that both hydrophobic and hydrophylic characteristics of several membrane fractions, including nerve endings, change with development. The developmental changes in pig cerebellums are similar to those reported for whole brain or brain regions from other species. Mitochondrial enriched fractions derived from adult pig whole brain cortex had significantly reduced palmitate levels and significantly elevated oleate levels compared with nerve ending and smooth membrane fractions.
Behavior of biliary phospholipids in intestinal lumen during fat digestion in rat
Authors: Nalbone G. , Lairon D. , Lafont H. , Domingo N. , Hauton J. , Sarda L. 
Published: November 2006

AbstractThe phospholipids present in the intestinal lumen of rats following ingestion of triglycerides are of biliary origin. They consist of lecithins accompanied by a small proportion of lysolecithins. Their behavior in comparison with the other lipid constituents of the intestinal content was studied by subjecting the latter to gel filtration on an agarose column in the presence of a solution of 6 mM sodium taurocholate in 0.1 M NaCl. Part of the phospholipids is present with the triglycerides and diglycerides in the emulsified phase excluded from the gel where pancreatic lipase and colipase also are found. The remainder is found in optically clear fractions containing fatty acids, monoglycerides, and bile salts. These fractions are eluted at 2.0 column volumes, while mixed fatty acids, monoglycerides, bile salts micelles emerge from the column at 2.4 column volumes in the same chromatographic conditions. This difference in behavior may be explained by the presence of biliary lecithins. This presence could have an important bearing upon the mucosal uptake of the lipolysis products of triglycerides.
Altered stearoyl‐CoA desaturase activities in Morris hepatomas 5123C and 7800
Authors: Raju Pullarkat K. 
Published: November 2006

AbstractThe nicotinamide adenine dinucleotide, reduced form, dependent microsomal stearoyl‐CoA desaturase activities were determined in Morris hepatomas 5123C and 7800 and compared with those of the host livers. In hepatoma 5123C, the desaturase activity was ca. one‐third that of the host liver. One week on a fat‐free high‐carbohydrate diet did not alter the desaturase activities of the hepatomas, whereas the host liver desaturase activities increased ca. three times. Fatty acid synthetase activity of the hepatoma 5123C was ca. one‐fourth and that of hepatoma 7800 was ca. the same as that of the host liver, suggesting that the decreased desaturase activity of the hepatoma 5123C is mainly due to the decreased overall lipogenesis.
Search for Barley (Hordeum vulgare L.) with higher lipid content
Authors: Parsons John G. , Price Phil B. 
Published: November 2006

AbstractThe search for a barley with a higher lipid content was concentrated on the USDA Barley World Conllection. Seeds of 14,000 entries were examined visually for an embryo size: total seed size ratio greater than the cultivated barley variety Prilar, and 60 entries were selected. Seeds of the 60 entries were assayed for lipid content by NMR spectroscopy, and the 7 entries with the highest oil content, along with Prilar, were prepared for further analysis. Barley lipids were solvent extracted, classified by silicic acid column chromatography, and separated by thin layer chromatography, and the fatty acid composition was determined by gas liquid chromatography. Total lipid contents of the 8 barleys ranged from 3.4% for Prilar to 4.6% for CI 12116. The seven selections had lipid contents which ranged from 9–35% higher than Prilar. Only slight qualitative differences were noted among the lipid classes of the eight barleys analyzed.
Earthworm lipids: Occurrence of phytanic, pristanic and 4,8,12‐trimethyltridecanoic acids
Authors: Hansen R. P. , Czochanska Zofia 
Published: November 2006

AbstractPhytanic, pristanic, and 4,8,12‐trimethyltridecanoic acids were found to comprise from 2.7% (winter) to 13.3% (spring) of the fatty acids of the neutral lipids of earthworms collected in different seasons from agricultural pasture land. Only small proportions of these isoprenoid acids were present in the phospholipids and glycolipids. It is postulated that these acids originated by microbial action on phytol and were assimilated in the gut of the earthworms from living and dead microorganisms and other fauna in ingested soil.
Tumor lipids: Long chain dienoic acid in sphingomyelin
Authors: Wood Randall 
Published: November 2006

AbstractThe fatty acids derived from sphingomyelin fractions of 10 rat and mouse tumors were examined quantitatively. All tumors, except a nontransplantable fibroadenoma, contained significant levels of a C‐24 dienoic acid which is absent from sphingomyelin of normal tissues or present in only trace amounts. The data suggest an abnormality in the metabolism of sphingolipids of tumor cells.
Studies of unsaponifiables in several vegetable oils
Authors: Gutfinger Tamar , Letan A. 
Published: November 2006

AbstractThe unsaponifiable fractions of soybean, cottonseed, coconut, olive, and avocado oils have been studied in detail. The oils differed in the contents of total unsaponifiables, squalene, tocopherols, and sterols and also in the composition of the tocopherol and sterol fractions. The presence of absence of individual unsaponifiable components may help in establishing the identity of each of the investigated oils and in detecting of admixture by another oil.
Leaf wax ofPortulaca oleracea
Authors: Tulloch A. P. 
Published: November 2006

AbstractWax coating the leaves and stems ofPortulaca oleracea consists of hydrocarbons (21%), esters (53%), acids (2%), alcohols (4%), diol monoesters (2%), and unidentified material (15%). Lesser amounts of esterified and free β‐amyrin and lupeol, stigmast‐4‐en‐3‐one and free diols also are present. The principal component of the hydrocarbons is C33. The C40‐C56 esters are C22‐C28 alcohol esters of C20‐C26 acids; free alcohols are C22‐C30; free acids are C16‐C36; diols of diol monoesters and free diols are C20‐C26.