bluuebunny/crossref_metadata_2025 huggingface dataset:
The influence of vitamin E and selenium on lipid peroxidation and aldehyde dehydrogenase activity in rat liver and tissue
Authors: Lee Hye‐Sung , Csallany A. Saari
Published: November 2006

Malondialdehyde (MDA) production and cytosolic aldehyde dehydrogenase (ALDH) response were examined in rat liver tissues after feeding different levels of dietary vitamin E and/or selenium and polyunsaturated fat for 12–38 wk. MDA production was significantly increased by vitamin E deficiency or by high levels of polyunsaturated fat intake, but not by selenium deficiency. The activity of cytosolic ALDH increased upon increased production of MDA after 12–16 wk of feeding the lipid peroxidation‐inducing diets. However, ALDH activity was suppressed after 38 wk of feeding the vitamin E‐deficient diet. The results indicate that the hepatic cytosolic ALDH may be involved in the metabolism of MDA during a relatively short‐term increase inin vivo lipid peroxidation, but that ALDH activity becomes suppressed after more severein vivo lipid peroxidation has been produced. Hepatic and plasma α‐tocopherol levels and lipid peroxidation products were measured for the various dietary groups.
Meningioma phospholipid profiles measured by31P nuclear magnetic resonance spectroscopy
Authors: Seijo Luis , Merchant Thomas E. , van der Ven Leo T. M. , Minsky Bruce D. , Glonek Thomas
Published: November 2006

Fourteen cases of intracranial meningioma were characterized after chloroform/methanol extraction by31P nuclear magnetic resonance (NMR) spectroscopy at 202.4 MHz. Each phospholipid class detected in the extracts was identified and quantitated in terms of its molar percentage relative to the total phospholipids measured. The following phospholipids were assayed by31P NMR: phosphatidylglycerol, phosphatidic acid, diphosphatidylglycerol, ethanolamine plasmalogen, phosphatidylethanolamine (PE), lysophosphatidylinositol, phosphatidylserine, sphingomyelin, lysophosphatidylcholine (LPC), phosphatidylinositol (PI), sphingosylphosphorylcholine and phosphatidylcholine. In addition, two unidentified phospholipids were detected with resonances at 0.13 and −0.78 ppm, respectively. Three distinct types of spectra were obtained on the extracts and grouped accordingly for comparison purposes. Type 1 tumors showed unusual31P NMR profiles with low levels of PE and PI and elevated levels of LPC; type 2 tumors were characterized by low levels of the ethanolamine phospholipids and near equivalent levels of PI and LPC. The spectra of type 1 and type 2 tumors were characteristic of degenerative cells that lacked membrane permeability associated with loss of ethanolamine plasmalogen in the presence of significant phospholipid turnover. Meningiomas belonging to the third spectral type showed characteristics similar to those of normal tissues with normal levels of PE and ethanolamine plasmalogen, as well as very low levels of LPC relative to PI. Type 3 tumors lacked the characteristic signs of degeneration noted in type 1 and type 2 tumors. The data corroborate and augmentin vivo spectroscopic findings reported earlier and demonstrate the value of31P NMR spectroscopic phospholipid analysis on lipid extracts for the characterization of meningiomas.
The hypercholesterolemic effect of dietary coconut fatversus corn oil in hypo‐ or hyperresponsive rabbits is not exerted through influencing cholesterol absorption
Authors: Meijer G. W. , Lemmens A. G. , Versluis A. , Van Zutphen L. F. M. , Beynen A. C.
Published: November 2006

In two inbred strains of rabbits with high or low response of plasma cholesterol to dietary saturatedversus polyunsaturated fatty acids, the efficiency of intestinal cholesterol absorption was measured. The feeding of a cholesterol‐free purified diet containing saturated fatty acids in the form of coconut fat, when compared with a diet containing corn oil as polyunsaturated fatty acids, did not influence the efficiency of cholesterol absorption in the two rabbit strains. Irrespective of the dietary fat source, the hyperresponsive rabbits absorbed cholesterol more efficiently. It is concluded that the hypercholesterolemic effect of dietary coconut fatversus corn oil is not exerted by influencing cholesterol absorption.
Thermotropic phase properties of the hydroxyceramide/cholesterol system
Authors: Wiedmann Timothy S. , Salmon Amir
Published: November 2006

The interaction of cholesterol with ceramides containing α‐hydroxy fatty acyl chains (hydroxyceramides) has been studies as a foundation for characterizing the lipid bilayers of thestratum corneum. A relatively large quantity of cerebrosides was obtained from bovine brain and converted to ceramides through removal of the carbohydrate side chain. The ceramides were separated based on the absence or presence of hydroxy fatty acyl chains. The lyophilized hydroxyceramides showed a broad melting region at 92°C. Hydroxyceramides dispersed in water produced a relatively narrow, thermotropic transition at 75°C. The effect of cholesterol on this thermotropic phase transition of hydroxyceramides was determined by differential scanning calorimetry. With respect to the main transition, cholesterol caused a broadening of the phase transition at relatively low levels as well as a decrease in the peak transition temperature. The presence of cholesterol at levels in excess of 7 wt% gave rise to an additional low‐temperature transition at 55°C. Upon immediate rescanning, this transition was exothermic, but with increasing incubation time the area under the excess heat capacity curve as a function of temperature became smaller. After two days or more, the transition observed was endothermic. At cholesterol levels between 40 and 50 wt%, multiple peaks were observed. From comparisons with related systems, the cooperative thermal transitions of hydroxyceramides with cholesterol are suggested to result from changes in hydrogen bonding or be due to phase separation. The composition of isolated brain ceramides is being compared with that reported for thestratum corneum.
Lymphatic absorption of structured glycerolipids containing medium‐chain fatty acids and linoleic acid, and their effect on cholesterol absorption in rats
Authors: Ikeda Ikuo , Tomari Yoshiaki , Sugano Michihiro , Watanabe Soichiro , Nagata Junichi
Published: November 2006

The effects of various structured triglycerides containing medium‐chain (caprylic or capric acids) and long‐chain (linoleic acid) fatty acids on fatty acid and cholesterol absorption were studied in lymph‐cannulated rats. A considerable portion of capric and caprylic acid was absorbed through the lymph duct, although to a lesser extent than was linoleic acid. Capric and linoleic acid located at the 2‐position of 2‐decanoyl‐1,3‐dilinoleoyl‐glycerol (18∶2/10∶0/18∶2) and 2‐linoleoyl‐1,3‐didecanoyl‐glycerol (10∶0/18∶2/10∶0), respectively, tended to be absorbed more efficiently than those located at the 1‐ and 3‐position or those from tricaprin (10∶0/10∶0/10∶0) or trilinolein (18∶2/18∶2/18∶2). A similar trend was observed when the medium‐chain fatty acid was caprylic acid instead of capric acid. Caprylic acid absorption from 2‐octanoyl‐1,3‐dilinoleoylglycerol (18∶2/8∶0/18∶2) was significantly greater (p<0.05) than from 2‐linoleoyl‐1,3‐dioctanoyl‐glycerol (8∶0/18∶2/8∶0) or tricaprylin (8∶0/8∶0/8∶0). Preferential absorption of caprylic and linoleic acid was not observed when the 1 to 2 and the 2 to 1 mixtures of 8∶0/8∶0/8∶0 and 18∶2/18∶2/18∶2, respectively, were administered. The structured lipids did not affect the lymphatic absorption of cholesterol. The results suggest that structured triglycerides composed of medium‐chain fatty acids and linoleic acid may be more useful for the treatment of lipid malabsorption than are mixtures of medium‐chain triglyceride (MCT) and long‐chain triglycride (LCT).
Oxysterol incorporation into rat aorta resulting in elastin compositional changes
Authors: Blankenship J. W. , Van Gent C. M. , Sandberg L. B. , Roos P. J. , Scharffenberg J. A.
Published: November 2006

The incorporation of dietary cholestan‐3β, 5α, 6β‐triol (triol) into rat thoracic aortic tissue and changes in amino acid composition of the elastin were investigated to identify the cytotoxic properties of the triol. Weanling male Sprague‐Dawley rats were fed the following diets for three months: (i) normal chow, (ii) normal chow with 1% (w/w) cholesterol added, or (iii) normal chow with 0.9% (w/w) cholesterol and 0.1% (w/w) triol added. Triol levels in the blood and in the thoracic aortic tissue were measured. Compositional changes of elastin were also determined. After three months on the triol‐containing diet, triol was found in the thoracic aorta but was not detected in the blood. Amino acid analyses of the aortic tissue elastin revealed that the proline levels in the triol‐fed animals were significantly greater than in the other two diet groups, while the elastin levels of leucine, aspartate, arginine, and phenylalanine decreased significantly. The mechanism for these observed changes induced by triol may reflect alternate splicing of elastin messenger ribonucleic acid (mRNA) resulting in structural changes in the elastin molecule. Dietary triol does contribute to tissue triol content and is associated with aortic elastin compositional changes. How these changes may contribute to the development of cardiovascular disease is not known.
Effect of n−3 fatty acids on the key enzymes involved in cholesterol and triglyceride turnover in rat liver
Authors: Al‐Shurbaji Ayman , Larsson‐Backström Carin , Berglund Lars , Eggertsen Gösta , Bjökhem Ingemar
Published: November 2006

The effect of long‐chain n−3 fatty acids on hepatic key enzymes of cholesterol metabolism and triglyceride biosynthesis was investigated in two rat models. In the first model, rats were intravenously infused for two weeks with a fat emulsion containing 20% of triglycerides in which either n−6 or n−3 fatty acids predominated. The treatment with n−3 fatty acids led to a reduction primarily of serum cholesterol (45%), but also of serum triglycerides (18%). HMG‐CoA reductase activity and cholesterol 7α‐hydroxylase activity were reduced by 45% and 36%, respectively. There were no significant effects on diacylglycerol acyltransferase (DGAT) or phosphatidate phosphohydrolase (PAP) activities. In the second model, rats were fed a diet enriched with sucrose, coconut oil and either sunflower oil (n−6 fatty acids) or fish oil (long‐chain n−3 fatty acid ethyl esters). The treatment with n−3 fatty acids decreased serum triglycerides (41%) and, to a lesser extent, serum cholesterol (17%). Neither glycerol 3‐phosphate acyltransferase (GPAT) or DGAT were affected by n−3 fatty acids. In contrast, PAP activity was reduced by 26%. HMG‐CoA reductase was not significantly affected, whereas cholesterol 7α‐hydroxylase activity was reduced by 36%. The results indicate that part of the TG‐lowering effect of long‐chain n−3 fatty acids may be mediated by inhibition of the soluble phosphatidate phosphohydrolase. The effect on serum cholesterol may be partly due to inhibition of HMG‐CoA reductase.
Hypolipidemic activity of 3‐ and 4‐phenyl‐piperidine‐2,6‐diones and selected N‐substituted derivatives
Authors: Murthy Akula R. K. , Maguire James H. , Alphin Robert S. , Day Patricia A. , Hall Iris H.
Published: November 2006

Three‐ and 4‐phenyl‐piperidine‐2,6‐dione derivatives were investigated for hypolipidemic activity at 20 mg/kg/day intraperitoneally in rodents. The 3‐phenyl compound afforded the best activity and effectiveness in both normal and hyperlipidemia‐induced mice. The agent lowered lipids by blocking the de novo hepatic synthesis of cholesterol and triglycerides, specifically at the sites of ATP‐dependent citrate lyase, acetyl CoA synthetase,sn‐glycerol‐3‐phosphate acyl transferase and phosphatidylate phosphohydrolase. The agent caused a more rapid clearance of cholesterol by the fecal route. Cholesterol levels of the chylomicrons, very low density lipoprotein and low density lipoprotein (LDL) were reduced, whereas high density lipoprotein cholesterol was significantly elevated after drug administration. Triglyceride content was lowered in the chylomicron and LDL fractions. These modulations of lipid content of serum lipoproteins by the drug suggest a favorable situation for treatment of hyperlipidemic states.
Regulation of liver cell ganglioside composition by extracellular fluid viscosity
Authors: Yedgar Saul , Reisfeld‐Granot Nutrit , Sela Ben‐Ami
Published: November 2006

The viscosity of plasma and extracellular fluid has been shown to be a regulator of lipoprotein production both in cultured hepatocytes and in vivo. The possibility that this extracellular effect on cell function involves modulation of cell surface membrane components was examined. In the present work, we studied the effect of medium viscosity on liver cell gangliosides known to be involved in various membrane functions and to be located predominantly at the cell surface membrane. Cultivation of isolated hepatocytes as primary cultures markedly reduced the ganglioside content, but this reduction process was attenuated by increasing the viscosity of the culture medium. Elevation of extracellular fluid viscosity inhibited the degradation of the cell gangliosides and secretion of lysosomal enzymes involved in ganglioside degradation. The cellular activity of these enzymes as well as the activity of enzymes involved in ganglioside synthesis, CMP‐NANA:GM1 sialyltransferase, CMP‐NANAP:GM3 sialyltransferase and UDP‐galactose:GD2 galactosyltransferase, were not affected bymodulation of the extracellular medium viscosity. It is proposed that the modulation of cell ganglioside content by extracellular fluid viscosity is due to an effect on enzymes involved in ganglioside catabolism.
New intermediates in the conversion of stigmasterol to cholestanol in the Mexican bean beetle
Authors: Svoboda James A. , Cohen Charles F. , Lusby William R. , Thompson Malcolm J.
Published: November 2006

Three intermediates involved in the conversion of stigmasterol to cholestanol in the Mexican bean beetle,Epilachna varivestis, were isolated and identified from an insect for the first time. The three new insect sterols, 22‐stigmastenol, 22,24‐cholestadienol and 24‐cholestenol, were shown to be metabolites of [3H]stigmasterol and accumulated in insect tissues when larvae were fed lima bean leaves coated with azasteroid inhibitors. The side chain metabolism of the ubiquitous phytosterol stigmasterol in the Mexican bean beetle is similar to that in other species that produce cholesterol from C28 and C29 phytosterols; however, the Mexican bean beetle initially reduces the Δ5‐bond and produces mainly cholestanol and lesser amounts of lathosterol as dealkylation products.
New synthesis ofcis‐3,cis‐5‐ andtrans‐3,cis‐5‐tetradecadienoic acids, pheromone constituents ofattagenus elongatulus andA. megatoma
Authors: DeJarlais W. J. , Emken E. A.
Published: November 2006

A new method for the synthesis ofcis‐3,cis‐5‐ andtrans‐3,cis‐5‐tetradecadienoic acids, pheromone constituents of the dermestid beetlesAttagenus elongatulus andA. megatoma, was developed. The syntheses are based upon the formation oftrans‐2‐tetradecen‐5‐ynoic acid by reaction of 4‐bromo‐2‐butenoic acid with 1‐decynylmagnesium bromide. The enynoic acid undergoes alkali‐induced isomerization to yield a mixture of acids from whichcis‐3‐ andtrans‐3‐tetradecen‐5‐ynoic acids were separated in 31% and 34% yields, respectively. Methyltrans‐2‐tetradecen‐5‐ynoate was similarly prepared and isomerized to furnish methylcis‐3‐tetradecen‐5‐ynoate in 8% yield. Reduction of the tetradecenynoic acids with dicyclohexylborane gavecis‐3,cis‐5‐andtrans‐3,cis‐5‐tetradecadienoic acids in 4% and 39% yields, respectively. A better yield (49%) in the reduction ofcis‐3‐tetradecen‐5‐ynoic acid tocis‐3,cis‐5‐tetradecadienoic acid was obtained by hydrogenation over Lindlar's catalyst. Similarly, reduction of methylcis‐3‐tetradecen‐5‐ynoate with disiamylborane gave 22% methylcis‐3,cis‐5‐tetradecadienoate.
Fatty acid distribution in the phospholipids ofFrancisella tularensis
Authors: Anderson Robert , Rashid Bhatti A.
Published: November 2006

Francisella tularensis, LVS (live vaccine strain) grown in a chemically defined medium was found to have a lipid content of 21% by dry weight. The two major phospholipids were identified as phosphatidylethanolamine (PE; 76%) and phosphatidylglycerol (PG; 24%) by thin layer chromatographic analysis, staining characteristics and quantitative chemical analyses of fatty acid, phosphate and glycerol constituents. PE contained a high proportion of 24∶0 fatty acid, with lesser amounts of 24∶1, 22∶0 and 10∶0. The major fatty acids of PG were 18∶1 and 22∶0. Hydroxy fatty acids, which are prominent components ofF. tularensis, were conspicuously lacking in these phospholipids; it is therefore concluded that hydroxy fatty acids are constituents of other structures of the organism.
Rice bran oil and hypocholesterolemia in rats
Authors: Sharma R. D. , Rukmini C.
Published: November 2006

Rats fed rice bran oil at 10% level for a period of eight weeks showed significantly lower levels of total cholesterol, low density lipoprotein and very low density lipoprotein cholesterol, both on cholesterol‐containing and cholesterol‐free diets. High density lipoprotein cholesterol was increased but triglyceride showed a decrease that was not statistically significant. Liver cholesterol and liver triglycerides were also reduced. Fecal excretion of neutral sterols and bile acids was increased after ingestion of rice bran oil.
Selective use of palmitic acid over stearic acid for synthesis of phosphatidylcholine and phosphatidylglycerol in lung
Authors: Tsao Francis H. C.
Published: November 2006

The incorporation of [3H]palmitic acid and [14C]stearic acid into phospholipids in rabbit lung tissue was studied. Under equal molar concentrations of palmitate and stearate, palmitate was incorporated to the 1‐ and 2‐positions of phosphatidylcholine (PC) and phosphatidylglycerol (PG) 2–3 times more than stearate. By contrast, palmitate was 30% less than stearate in phosphatidylethanolamine, phosphatidylinositol and phosphatidylserine. These results suggest that preferential utilization of palmitate over stearate, rather than substrate availability, determines the high content of palmitoyl at the 1‐ and 2‐positions of PC and PG in lung.
Plasma and lipoprotein fatty acid composition in glycogen storage disease type I
Authors: Levy Emile , Letarte Jacques , Lepage Guy , Thibault Louise , Roy Claude C.
Published: November 2006

Nocturnal intragastric feeding has been shown to be an effective means to improve clinical and biochemical features in glycogen storage disease type I (GSD‐I). In this study, we investigated the fatty acid patterns in a whole plasma and in circulating lipoproteins in patients on this therapy. The results demonstrated massive concentration of total fatty acids coupled with higher levels of triglycerides, free cholesterol, cholesterol ester and phospholipids. This hyperlipidemia involved all fatty acids without distinction of carbon or bond numbers. However, the increase was more pronounced for saturated than polyunsaturated fatty acids, as was demonstrated by the ratios of both oleic acid to linoleic acid (1.91±0.40 vs 0.80±0.09 in controls) and of ω3+ω6 to ω9 fatty acid families (0.92±0.11 vs 1.66±0.08 in controls). The fatty acid patterns in very low (VLDL), low (LDL) and high (HDL) density lipoprotein showed substantial differences in composition, reflecting an association between an abnormal lipoprotein pattern and essential fatty acid deficiency. Furthermore, GSD‐I patients exhibited a significant increase in VLDL (17±2 vs 47±7 mg/dl) and LDL cholesterol (124±7 vs 206±24 mg/dl), coupled with a decrease in HDL cholesterol (49±4 vs 28±3 mg/dl). These data documenting high LDL cholesterol and low HDL cholesterol associated with an increased concentration and proportion of saturated fatty acids suggest that GSD‐I patients on nocturnal intragastric feeding are at high risk for atherosclerosis and its complications.
Electron microscopic cytochemistry of cyclopropenoids in cottonseed (Gossypium hirsutum L.) tissues
Authors: Yatsu Ly , Kircher H. W.
Published: November 2006

An electron microscopic cytochemical procedure for locating cyclopropenoids (CYP) in oilseeds is proposed. The procedure is based on the fact that metallic silver is produced when AgNO3 reacts with CYP. Since so many other compounds react with AgNO3, we treated specimens that do and not contain CYP with AgNO3 and looked for electron‐dense stains that were unique to CYP(+) seeds. Virtually everything in all seed specimens, regardless of the presence or absence of CYP, was stained. However, cottonseeds contained two additional staining constituents not found in controls: (i) certain large, intracellular droplets, and (ii) the cuticles, both occurring exclusively in the axial organs. Extraction of the speciments with ether abolished the stainability of the droplets but did not affect cuticles. Arguments for the validity of the test are presented.
Loss of NADPH during assays of HMG‐CoA reductase: Implications and approaches to minimize errors
Authors: Ness Gene C. , Pendleton Laura C. , Pendleton A. Stacia
Published: November 2006

In assays of 3‐hydroxy‐3‐methylglutary coenzyme A (HMG‐CoA) reductase activity, preincubation of isolated washed microsomes with NADPH led to a time‐ and protein concentration‐dependent, loss of enzyme activity. This occurred despite the presence of an NADPH regenerating system. Addition of fresh NADP, glucose 6‐phosphate and glucose 6‐phosphate dehydrogenase restored activity. Of the individual components, only NADP was effective. Errors due to loss of NADPH are most pronounced in assays using high microsomal protein, low NADPH levels and preincubation with NADPH and when glutathione rather than dithiothreitol is present. To minimize the effects of NADPH depletion, it is recommended that (i) NADP and NADPH not be present during the preincubation period; (ii) incubation periods be relatively short; (iii) microsomal protein concentrations be less than 1 mg; and (iv) NADPH concentrations be 1 to 2 mM.
Analysis of lipids containing hydroxy fatty acids
Authors: Ahmad Fasih , Maier René , Mukherjee Kumar D. , Mangold Helmut K.
Published: November 2006

Lipids containing hydroxy fatty acids or hydroxyacyl moieties are acetylated with [1‐14C]acetic anhydride or [3H]acetic anhydride, and the content of hydroxy fatty acids or hydroxyacyl moieties is estimated from the specific radioactivity of the acetylated products with respect to that of radioactive standards, such as radioacetylated ricinoleic acid or triricinoleoylglycerol. Mixtures of triacylglycerols containing one, two and three hydroxyl groups per molecule are derivatized in a similar manner, and the resulting acetates are fractionated by thin layer chromatography according to the number of acetate groups per molecule. The relative proportion of each type of triacylglycerols in the mixture is estimated from the distribution of radioactivity in the various fractions. Applications of these techniques are demonstrated by the analysis of several seed lipids.
Medium chain triglycerides and structured lipids
Authors: Babayan Vigen K.
Published: November 2006

Lipids are an essential component of our body composition and necessary in our daily food intake. Conventional fats and oils are composed of glycerides of long chain fatty acids and are designated as long chain triglycerides (LCT). Body fat as well as the fats and oils in our daily intake fall into this category. In enteral and parenteral hyperalimentation, we can identify such LCT fats and oils. Soy, corn, safflower and sunflowerseed oils are typical of the LCT oils.

In the search for alternative noncarbohydrate fuels, medium chain triglycerides (MCT) are unique and have established themselves in the areas of malabsorption syndrome cases and infant care and as a high energy, rapidly available fuel. Structure lipids with a MCT backbone and linoleic acid built into the triglyceride molecule have been developed to optimize the triglyceride structure that is best for patients, particularly the critically ill. Structured lipids with built‐in essential fatty acid components or other polyunsaturated fatty acids promise greater flexibility in patient care and nitrogen support.
Medium chain triglycerides and structured lipids as unique nonglucose energy sources in hyperalimentation
Authors: Mascioli Edward A. , Bistrian Bruce R. , Babayan Vigen K. , Blackburn George L.
Published: November 2006

This brief review will discuss recent work concerning new intravenous lipid emulsions for future use in clinical patients. Intravenous lipid emulsions currently available in the United States are derived from soybean or safflower oils and serve as sources of nonglucose, nitrogen‐sparing calories and the essential fatty acid linoleic acid. Because of concerns that much of the infused long chain triglyceride is not oxidized readily and that there may be some immune system impairment, newer emulsions utilizing medium chain triglycerides have been developed.
Absorption of safflower oil and structured lipid preparations in patients with cystic fibrosis
Authors: Van Hubbard S. , McKenna Mary C.
Published: November 2006

Patients with cystic fibrosis (CF) and pancreatic insufficiency usually have decreased linoleic and increased oleic, palmitoleic and eicosatrienoic (20∶3ω9) acids compared to normal values of blood and tissue lipids. These changes are consistent with early essential fatty acid deficiency and are observed despite the regular use of exogenous pancreatic enzyme supplementation. As part of a study to determine the relative role of malabsorption as the etiology for the altered fatty acid status, the change in total plasma fatty acids and in area percent of plasma linoleic acid was determined in CF patients and control subjects following the ingestion of various lipid supplements, including two safflower oil preparations and two structured lipid preparations. Fasting subjects consumed 33 g of lipid in a milkshake containing 15 g of protein and 45 g of carbohydrate. Plasma samples obtained 0, 2, 4, 6 and 8 hr after the meal showed that the CF patients absorbed all preparations when administered with their regular dose of pancreatic enzyme supplement. Comparison of the patterns of increase for total plasma fatty acids and area percent of plasma linoleic acid following the administration of the different lipid supplements in CF patients and control subjects suggests that(a) malabsorption alone is not the cause of the abnormal fatty acid composition in the lipids of CF patients and that increased caloric intake along with consumption of adequate amounts of linoleic acid should improve the linoleic acid status of CF patients; (b) there may be selectively increased metabolism of certain fatty acids from the ingested lipids in the relatively malnourished CF patient compared to control subjects; and (c) conditions favoring the persistence of nonpancreatic lipases seem also to favor absorption and utilization of the structured lipid preparation containing medium chain length fatty acids and linoleic acid in CF patients compared to control subjects.
Medium chain triglyceride in early life: Effects on growth of adipose tissue
Authors: Hashim Sami A. , Tantibhedyangkul Phienvit
Published: November 2006

Effects of feeding early in life a diet high in either long chain (LCT) or medium chain triglyceride (MCT) were studied on the development of adipose tissue in post‐weanling rats. The diets were similar in calorie distribution and identical in nutrients except for type of fat. The caloric distribution of the two diets by percent was LCT (corn oil)/protein/carbohydrate, 70/18/12 and MCT/corn oil/protein/carbohydrate, 66/4/18/12. Male littermates with less than 5% weight difference were pair‐fed the two diets randomly at age 18–20 days. One‐fourth of the rats were killed at 10, 16, 22 and 28 weeks of age and analyzed for adipose depots and adipose tissue cellularity. Results showed that the LCT‐fed rats were significantly heavier, with larger epididymal, retroperitoneal, omental and subcutaneous fat pads than the respective pair‐fed MCT rats. Also, LCT‐fed rats had larger size and number of adipocytes than MCT‐fed littermates. It is concluded that the type of fat in the diet, namely LCT or MCT, when fed early in life can influence the development of adipose tissue. MCT appears less lipogenic than LCT. The mechanism for the diminished adiposity of MCT‐fed rats is related to extensive oxidation of MCT and its enhancement of thermogenesis leading to lessened energy efficiency.
The effect of medium and long chain triglyceride on human adipose tissue metabolism
Authors: Katz David P. , Knittle Jerome L.
Published: November 2006

Studies have been performed to assess the effects, in vivo and in vitro, of lipid emulsions on human adipose tissue prostaglandin production. Subcutaneous adipose tissue obtained either during elective surgery or by needle aspiration was studied in tissue culture or by using a perifusion apparatus. Physical mixtures of emulsions of long chain triglyceride (LCT) and/or medium chain triglyceride (MCT) were added to the tissue culture medium so that the final concentration was 400 mg/dl. After a 3‐day incubation period the tissue was harvested, placed in buffer and used to determine in vitro production of prostaglandin E2, prostacyclin I2(measured as its stable end product 6‐keto PGF1α) and thromboxane A2(measured as TXB2) by radioimmunoassay. The results demonstrated that samples incubated in 100% MCT had the most significant increase in prostaglandin production, while those incubated in 100% LCT had the most significant decrease in activity of the three prostaglandins assayed. The addition of LCT to MCT caused a stepwise decrease in adipose tissue prostaglandin production. The data suggest a pharmacological rather than a physiological effect of lipid emulsions containing MCT and/or LCT on adipose tissue prostaglandin production. In vivo effects of a 20% safflower oil emulsion, containing high levels of the essential fatty acid linoleate, were assessed in five pediatric patients. Adipose tissue was obtained before and after two and four weeks of treatment. Fatty acid profiles and prostaglandin production were determined. The results demonstrated that intravenous fat infusion increased the concentrations of linoleic and arachidonic acids found in adipose tissue within a short interval. The effect of intravenous fat infusion on human adipose tissue prostaglandin production was less predictable and may have been a function of the patients' disease and subsequent clinical course. These findings suggest that lipid emulsions should not be viewed solely as a source of intravenous energy, because they may have the potential to elicit changes in prostaglandin production as demonstrated by a human adipose tissue model.
Role of brown adipose tissue in thermogenesis induced by overfeeding a diet containing medium chain triglyceride
Authors: Baba Nahla , Bracco E. Filippo , Hashim Sami A.
Published: November 2006

The role of brown adipose tissue in the mechanism of medium chain triglyceride (MCT)‐induced thermogenesis was investigated. Under anesthesia, the interscapular brown adipose tissue (IBAT) was excised in male Sprague‐Dawley rats, and the animals were fitted with gastrostomy tubes. After a 10‐day recovery period, the animals were divided into two groups: one group received a diet containing MCT as 50% of calories, and the other group received an isocaloric diet containing long chain triglyceride (LCT). The diets were fed for 6 wk at a level of calorie intake that was 150% of the ad libitum intake of a parallel control group. During the last week of the study, resting and norepinephrine (NE)‐stimulated O2 consumption and CO2 production were measured in a Noyons diaferometer. At the end of 6 wk, the animals were weighed and killed. The individual fat pads were dissected and weighed, and an aliquot of the right retroperitoneal fat pad was used to measure adipocyte size and number. The results showed that body weight and adipocyte size (but not adipocyte number) were significantly smaller in the MCT‐fed compared to the LCT‐fed animals. Resting as well as maximal NE‐stimulated oxygen consumption values were significantly higher in the MCT‐fed than the LCT‐fed rats. It is concluded that the enhanced thermogenesis induced by MCT persists despite the absence of IBAT and that the phenomenon is likely related to more extensive oxidation of MCT‐in contrast to LCT‐derived fatty acids, thus leading to increased oxygen consumption, enhanced dissipation of energy as heat and diminished efficiency of weight gain and deposition of body fat.
Effects of triton WR 1339 and orotic acid on lipid metabolism in rats
Authors: Takeuchi Nozomu , Murase Mitsuharu , Nomura Yasuharu , Takase Haruto , Uchida Kiyohisa
Published: November 2006

In order to investigate the effect of hepatic cholesterol flux on biliary bile acids, Triton WR 1339 and orotic acid were administered to rats, and the biliary cholesterol, phospholipids and bile acids were analyzed together with serum lipoproteins and hepatic lipids. Triton, which raised serum very low density lipoprotein and lipid levels and decreased serum high density lipoprotein liver lipid levels, increase the biliary cholic acid group/chenodeoxycholic acid group ratio (CA/CDCA) in the bile without affecting the total amount of bile acids and the other biliary lipids. Orotic acid, which decreased serum lipid and lipoprotein concentrations and increased liver lipid levels, increased the biliary excretion of cholesterol and phospholipids, but produced no significant change in the total amount of bile acids and in the CA/CDCA ratio in bile.
Formation of diacyl and alkylacyl glycerophosphocholine in rabbit alveolar macrophages
Authors: Sugiura Takayuki , Sekiguchi Nobuyuki , Nakagawa Yasuhito , Waku Keizo
Published: November 2006

The incorporation of various labeled precursors into alkenylacyl, alkylacyl and diacyl phospholipids in rabbit alveolar macrophages was studied. The incorporation rates of the individual precursors were shown to be quite different among the three subclasses of phospholipids. [3H] Glycerol, [14C]16∶0, [14C]18∶1, [14C]18∶2 and [32P]‐orthophosphate were preferentially incorporated into choline glycerophospholipids (CGP), especially into diacyl glycerophosphocholine (GPC), indicating that the de novo synthesis of diacyl GPC is extremely high. Considerable portions of the radioactiveties of [14C]16∶0, [14C]18∶1, [14C]18∶2 and [32P] orthophosphate were also found in alkylacyl GPC, the incorporation being higher than or comparable to that in the case of diacyl glycerophosphoethanolamine (GPE). We then examined the activities of cholinephosphotransferase and ethanolaminephosphotransferase, and found that the activity of cholinephosphotransferase was remarkably high in macrophage microsomes compared with that in microsomes from several other tissues. This suggests that diradylglycerols were preferentially utilized by cholinephosphotransferase, which is consistent with the results obtained for intact cells. We confirmed that a considerably higher amount of diacyl GPC as well as alkylacyl GPC was formed through this enzyme reaction with macrophage microsomes than with brain microsomes. The high formation of alkylacyl GPC could be responsible, at least in part, for the accumulation of this unique ether phospholipid, a stored precursor form of plateletactivating factor in macrophages.
Effects of parenteral nutrition with high doses of linoleate on the developing human liver and brain
Authors: Martinez Manuela , Ballabriga Angel
Published: November 2006

The developmental changes in the fatty acid composition of ethanolamine phosphoglycerides (EPG) and choline phosphoglycerides (CPG) were studied in the liver and brain of 18 newborn infants with gestational ages ranging from 20 to 44 wk. A small group of five newborns receiving total parenteral nutrition (TPN) with high doses of linoleic acid (18∶2ω6) was also studied and compared to controls of the same gestational age to look for effects on the developmental fatty acid patterns of liver and brain EPG and CPG. TPN with Intralipid 20% was given for 4–12 days, the total fat intake being 14.7–90 g (mean ±S.D.=47.1±29.8 g). The main developmental changes in the liver and brain of the control group were an increase in 22∶6ω3 (docosahexaenoic acid) at the end of gestation and a linear decrease in 20∶4ω6 (arachidonic acid) and 18∶1ω9 (oleic acid) in EPG and CPG. A very good correlation in the percent values of these fatty acids in the brain and liver tissues was obtained. Very significant changes in the fatty acid composition of liver EPG and CPG could be found in the infants receiving TPN with Intralipidmainly an increase in 18∶2ω6, a decrease in the linoleate elongation/desaturation to longer members of the series and a decrease in the 22∶6ω3 levels of liver EPG and CPG. In the brain, only an increase in the 18∶2ω6 value of CPG, not accompanied by any increase in the longer ω6 fatty acids, could be detected. Possible adverse effects of high doses of 18∶2ω6 on the tissue levels of long chain polyunsaturated fatty acids (PUFA), especially of 22∶6ω3, are discussed.
Time course of incorporation of 20‐carbon polyunsaturated fatty acids in a human keratinocyte cell line
Authors: Punnonen Kari , Puustinen Taplo , Jansen Christer T.
Published: November 2006

Human keratinocytes (NCTC 2544) in culture were labeled with equal amounts of either14C‐arachidonic acid,14C‐dihomo‐γ‐linolenic acid or14C‐eicosapentaenoic acid. At various time points, the incubations were stopped and the distribution of the14C‐fatty acids was analyzed. All these eicosanoid precursor fatty acids were effectively incorporated into the cellular lipids of the keratinocytes, and the major radiolabeled individual lipid fraction was phosphatidylethanolamine. The distributions of arachidonic acid and dihomo‐γ‐linolenic acid within cellular lipids were rather the same. However, less eicosapentaenoic acid than either arachidonic acid or dihomo‐γ‐linolenic acid was incorporated into the phospholipids and, correspondingly, more eicosapentaenoic acid was incorporated into the nonphosphorus lipids. In the phosphatidylinositol + phosphatidylserine fraction, there was significantly less eicosapentaenoic acid than either arachidonic acid or dihomo‐γ‐linolenic acid. The present study suggests that these eicosanoid precursor fatty acids are effectively incorporated into the human keratinocytes and that the pattern of incorporation and distribution of eicosapentaenoic acid appears to differ slightly from that of either arachidonic acid or dihomo‐γ‐linolenic acid.
The formation of lysophosphatidylinositol phosphate in human platelet microsomes
Authors: Thomas L. M. , Holub B. J.
Published: November 2006

The formation of lysophosphatidylinositol phosphate (lysoPIP) from lysophosphatidylinositol (lysoPI) via kinase activity was studied in microsomal preparations from human platelets. For this purpose, [3H]lysoPI or [3H]phosphatidylinositol ([3H]PI) was prepared and incubated in the presence or absence of ATP, MgCl2 and Triton X‐100, and the appearances of radioactivity in [3H]lysoPIP and [3H]phosphatidylinositol phosphate ([3H]PIP), respectively, were monitored using thin layer chromatography. Both lysoPI and PI phosphorylations were completely dependent upon the presence of ATP and MgCl2 in the incubation medium; Triton X‐100 addition stimulated both reactions, with the stimulation of PI conversion being considerably greater than that for lysoPI conversion. The present results demonstrate that lysoPI can be converted to lysoPIP by phosphorylation in human platelet microsomes. The potential significance of this enzymatic reaction in stimulated cells is discussed in relation to the generation of inositol‐1,4,5‐trisphosphate, an important intracellular second messenger.
Platelet changes after a saturated fat meal and their prevention by dazmegrel, a thromboxane synthetase inhibitor
Authors: Belch J. J. F. , Saniabadi A. R. , McLaughlin K. , Forbes C. D.
Published: November 2006

A saturated fat meal was given to 10 normal males both before and after pretreatment with UK38,485, a thromboxane synthetase inhibitor (Dazmegrel, Pfizer Central Research, Sandwich, Kent, United Kingdom). Following the fat meal at 2 and 4 hr there was laboratory evidence of platelet activation. Dazmegrel lowered baseline platelet activity and lessened platelet activation following the fat meal. This drug should be investigated further as a potential antithrombotic agent.
Biokinetics of and discrimination between dietaryRRR‐ andSRR‐α‐tocopherols in the male rat
Authors: Ingold K. U. , Burton G. W. , Foster D. O. , Hughes L. , Lindsay D. A. , Webb A.
Published: November 2006

The net rates of uptake of the natural (2R,4′R,8′R) diastereoisomer of α‐tocopherol (α‐T) and the biodiscrimination relative to its 2S‐epimer (2S,4′R,8′R) have been measured, in two experiments, for the blood and 21 tissues of male Sprague‐Dawley rats fed over a period of several months diets containing deuterium‐substituted forms of the α‐T acetates. Gas chromatography‐mass spectrometry was used to measure the amount of deuterated tocopherols taken up relative to the amount of nondeuterated tocopherol remaining. The measurements were performed at different times after the rats, placed for one month on a basal diet containing nondeuterated, natural α‐T acetate, were switched to a diet containing the same total quantity of deuterated forms of either natural α‐T acetate or a mixture of the acetates of the 2R‐ and 2S‐epimers (i.e.,ambo‐α‐T acetate). In experiment 1 the source of vitamin E in the replacement diet was trideuterio‐2R,4′R,8′R‐α‐T acetate. The data obtained provide the first direct measure of the rate at which natural vitamin E is replaced and augmented in the tissues of growing animals under normal laboratory dietary conditions. There are dramatic differences in the tissue kinetics; for example, the apparent half‐life of vitamin E, i.e., the time at which the total amount of ingested trideuterio‐α‐T taken up is the same as the amount of nondeuterated α‐T remaining, varies from ca. 1 wk for the lung to ca. 11 wk for the spinal cord. In experiment 2 the vitamin E in the replacement diet was an equimolar mixture of trideuterio‐2S,4′R,8′R‐ and hexadeuterio‐2R,4′R,8′R‐α‐T acetates. The results show that there is a preferential uptake of the natural diastereoisomer of α‐T by all tissues (except the liver during the first month). Examination of fecal material reveals that the biodiscrimination begins in the gut; the incomplete hydrolysis of the acetates shows clearly that this reaction proceeds to a greater extent with the natural diastereoisomer. The greatest discrimination of all the tissues examined was found to occur in the brain. After five months, the level of the deuterated natural diastereoisomer was more than five times that of the deuterated 2S‐epimer. These results have potential implications for human nutrition.
Studies of lipoproteins and fatty acids in maternal and cord blood of two racial groups in Trinidad
Authors: Taylor G. Oladunni , Albers John J. , Warnick G. Russell , Adolphson Janet L. , McFariane H. , Sullivan D. R. , West C. E. , Sri‐Hari V. , Edwards R.
Published: November 2006

The high mortality rate from coronary heart disease (CHD) among Indians compared to Negroes in Trinidad led us to test plasma lipid profiles to see whether dietary or genetic factors might be involved. There were no interracial differences in the composition of plasma cholesterol ester fatty acids of the tested women and neonates. This finding suggests that dietary fat does not account for the interracial difference in CHD, nor does the cause appear to be due to genetic differences in lipid profiles, as there was no significant difference between values for plasma triglycerides, total cholesterol, high density lipoprotein (HDL) cholesterol, apo‐I, apo‐II, apo B or cholesterol ester fatty acids in the cord blood of each racial group.

Blood samples were collected from 69 nonpregnant and 71 postpartum, fasted Negro and Indian women. Also taken were 71 umbilical cord blood samples. The mean triglyceride level was significantly lower in the Negro nonpregnant and postpartum women than in the Indians. HDL cholesterol and apo‐I values were lower in the Indian women. There were no significant differences in the total cholesterol and apo B measurements. The triglyceride values for postpartum women were higher than those of the nonpregnant Negroes and Indians (75% and 47%, respectively), whereas the total cholesterol and HDL cholesterol, apo A‐I and apo A‐II ranged from 9% to 29% higher in the postpartum women. Apo B was about 40% higher postpartum in both ethnic groups.

The high CHD rate of Indians in Trinidad cannot be explained by dietary factors, plasma total cholesterol or fatty acid composition. However, the lower level of HDL cholesterol and plasma A‐I could play a role in the higher CHD rate in Indians.
Analysis of volatile fatty acids in biological specimens by capillary column gas chromatography
Authors: Fleming S. E. , Traitler H. , Koellreuter B.
Published: November 2006

A method was developed to analyze and quantify volatile fatty acids (VFA) such as acetic, propionic, butyric, isobutyric, valeric and isovaleric acids in biological specimens. To obtain good sample transfer into the chromatographic system an organic solvent had to be used together with an aqueous milieu, thus improving wetting properties of the liquid sample plug introduced into the column. Sample preparation was carried out under alkaline conditions in order to exclude or minimize sample losses due to sample transfer during the extraction and work‐up procedure. A cold on‐column injection was applied to avoid irregular discrimination of the various acids due to sample splitting and an automatic injection technique was used to accommodate the large number of samples generated from biological origin. Connection of a pre‐column of wide internal diameter (0.53 mm) to the analytical column (0.32 m) was optimized and adapted to the nature of the injection solvent mixture consisting of acetonitrile, water and hydrochloric acid. To obtain well‐separated and correctly quantifiable gas chromatographic peaks, it was essential to perform the chromatography under acidic aqueous conditions. Standard resolution conditions and response factors were evaluated. The chromatographic results of applying this method to biological specimens from both rats and humans are provided.
The use of iodine staining for the quantitative analysis of lipids separated by thin layer chromatography
Authors: Palumbo Giuseppe , Zullo Fulvio
Published: November 2006

The method described for quantitative estimation of lipids separated on thin layer chromatography plates exploits the observation that most lipids can be stained by iodine vapor and that, in “controlled” conditions, the intensity of this staining is proportional to the actual amount of lipid in the spot. The method consists of i) exposing the developed plate to iodine vapor; ii) spraying it with a suitable solvent to prevent halogen evaporation; iii) collecting the stained lipids by scraping the spots off the plate; and iv) determining by a rate‐sensing method the absorbed iodine. The final determination is performed by measuring spectrophotometrically (at 410 nm) the rate of decolorization of a solution of Ce(IV) by As(III) in strong acidic conditions. The reaction rate, which is positively related to the concentration of iodine, is derived from the slope of the absorbance change plotted vs time.

Providing that standards and samples are stained simultaneously, a quantitative estimation of lipid components of a mixture is possible in a reasonable time with excellent accuracy and reproducibility. In our hands, the method has been successfully applied to several common phospholipids, long chain fatty acids, cholesterol and deoxycholate, and triacylglycerols, in the range of 5–60 μg.