bluuebunny/crossref_metadata_2025 huggingface dataset:
Fatty acid composition of fats of differing melting points extracted from ram subcutaneous tissue
Authors: Johnson Cecil B. , Purchas Roger W. , Birch E. John
Published: November 2006

The observation that the subcutaneous fat of pasture‐fed Southdown rams consists of two distinct regions is reported. Fatty acid composition of fat from the outer and inner regions of subcutaneous tissue taken from the rib region of eight Southdown rams fed pasture were determined. Relative to the harder inner regions (mean melting point 43.1°C), the softer outer regions (mean melting point 31.8°C) were shown to contain more 9∶0‐, 15∶0‐, 17∶0‐, 17∶1‐, 18∶1‐cis and total 18∶1 fatty acids; less 14∶0‐, 16∶0‐, 18∶0‐ and 18∶1‐trans fatty acids; and a greater variety and a greater concentration of branched‐chain components. Proportions of medium chain‐length fatty acids other than 9∶0, did not differ between the layers.

The fatty acid contents of serial samples taken at 1‐mm intervals through these tissues were determined. Changes in concentrations of components among samples were gradual through the tissues. There was no clear connective tissue sheet, as has been reported for pigs. The inner region of the tissues contains apparently nonrandom fluctuating changes in fatty acid composition.
Effect of various steroids on the biosynthesis of arachidonic acid in isolated hepatocytes and HTC cells
Authors: Marra Carlos A. , de Alaniz María J. T. , Brenner Rodoifo R.
Published: November 2006

The effect of various steroids on the incorporation and desaturation of eicosa‐8,11,14‐trienoic acid in normal hepatocytes and HTC cells was investigated. After 3 hr incubation with 11‐deoxycorticosterone, both kinds of cells showed an increase in the incorporation of eicosatrienoic acid. In contrast, progesterone, cortexolone, 17‐β‐estradiol, testosterone, estriol, aldosterone, corticosterone, dexamethasone, dehydroepiandrosterone, 11‐β‐hydroxyandrosterone, 11‐ketoaetiocholanolone, epiaetiocholanolone and 5‐β‐pregnane‐3α,20α‐diol, provoked no significant changes in the uptake of the exogenous acid. Of all the steroids tested, only 11‐dexycorticosterone, dexamethasone and 17‐β‐estradiol evoked a significant inhibition on the arachidonate biosynthesis in both kinds of cells. Testosterone, estriol, aldosterone and corticosterone provoked a significant inhibition of Δ5‐desaturase in HTC cells. In dexamethasone, this effect was dose‐dependent (0 to 10−4 M). Simultaneous incubation with 17‐β‐ estradiol or 11‐deoxycorticosterone with dexamethasone led to an extent of inhibition on arachidonate biosynthesis that did not surpass the effect of each drug. Pretreatment of isolated hepatocytes with the antiglucocorticoid, cortexolone, prevented the dexamethasone‐induced inhibition of arachidonate biosynthesis. Normal rat liver microsomes preincubated in vitro with dexamethasone, 11‐deoxycorticosterone, 17‐β‐estradiol, corticosterone or estriol (10−6 or 10−4 M concentration), showed no significant changes in the Δ5‐desaturase activity. The results obtained suggest that the effect of the steroids on arachidonic acid biosynthesis in normal hepatocytes and HTC cells requires receptor occupancy and probably is mediated through a common biochemical mechanism.
A diet containing n−3 and n−6 fatty acids favorably alters the renal phospholipids, eicosanoid synthesis and plasma lipids in nephrotic rats
Authors: Barcelli U. O. , Beach D. C. , Thompson B. , Weiss M. , Pollak V. E.
Published: November 2006

The nephrotic syndrome was induced in rats by intravenous adriamycin (3 mg/kg). The rats were then divided into four groups which, for six weeks, were pair‐fed diets containing beef tallow (BT), fish oil (FO), a source of n−3 fatty acids, evening primrose oil (EPO), a source of n−6 fatty acids, or a combination of evening primrose oil and fish oil, 75∶25 (EPO:FO). The fat content of the diets was 15%. Significant incorporation of the fatty acids into kidney phospholipids was demonstrated. Diets containing FO, EPO and EPO:FO lowered plasma triglycerides and total cholesterol levels as compared with diets containing BT. Only EPO:FO raised high density lipoprotein (HDL) cholesterol levels, as compared with BT. The combination EPO:FO prevented the tenfold suppression of aortic 6‐keto‐PGF1α caused by FO. These changes in plasma lipids and eicosanoid production are potentially antiatherogenic and may prevent glomerular sclerosis. The combination of EPO and FO, containing n−6 and n−3 fatty acids may offer advantages over either family of fatty acids in this model of nephrotic syndrome.
The composition of red cell membrane phospholipids in Canadian Inuit consuming a diet high in marine mammals
Authors: Innis Sheila M. , Kuhnlein Harriet V. , Kinloch David
Published: November 2006

A study of the fatty acid composition of red cell phosphatidylcholine and phosphatidylethanolamine and serum cholesterol was undertaken in 185 Canadian Inuit (age 2 months‐82 years). Samples from 24 Canadian men and women (21–50 years) living in Vancouver were also analyzed as a reference for the Inuit in this age range. Dietary survey of the Inuit community (325 Inuit) demonstrated a diet based on traditional foods in which the principal source of n−3 fatty acid was marine mammal flesh (mean intake: 164 g/person/day) rather than fish (mean intake: 13 g/person/day). Compared to the Vancouver samples, the Inuit phosphatidylethanolamine had higher 20∶5n−3 and 22∶6n−3 and lower 20∶4n−6, but similar 18∶2n−6 levels. The level of 20∶5n−3 was higher and 20∶4n−6 was lower in the Inuit than in the Vancouver red cell phosphatidylcholine. Despite these differences in percentage content of C20 and C22 n−6 and n−3 fatty acids, the mean chain length and unsaturation index of the Inuit and Vancouver red cell phosphatidylcholine and phosphatidylethanolamine were very similar. Serum cholesterol concentration showed no sex difference within the Inuit, and no difference from Vancouver men and women of similar age. The analyses suggest that the fatty acid composition of the Inuit red cell phospholipids are primarily a reflection of their diet‐fat composition.
Formation of fluorescent substances from degradation products of methyl linoleate hydroperoxides with amino compound
Authors: Iio Toshihiro , Yoden Kazuaki
Published: November 2006

The degradation products formed from methyl linoleate hydroperoxides by reaction with heme were fractionated by Sephadex LH‐20 column chromatography and by reverse‐phase high performance liquid chromatography, and the ability of each compound to form fluorescent substances through reaction with amino compound was compared. Maximum formation of fluorescent substances was obtained from monomeric degradation products with amino compound, but low molecular weight aldehydes such as hexanal, 2‐hexenal and 2,4‐decadienal, formed only a small amount of fluorescent substances. However, the major monomeric degradation products described previously, the hydroxy‐, keto‐ and epoxy‐derivatives, do not significantly contribute to the formation of fluorescent substances through reaction with amino compound. It was suggested that formation of fluorescent substances from lipid peroxides with amino compound may originate from a precursor present in monomeric degradation products formed from hydroperoxide of methyl linoleate during lipid peroxidation, and that low molecular weight aliphatic aldehydes are not involved in fluorescent substance formation. Moreover, the majority of TBA‐reactive substances in secondary oxidation products prepared from autoxidized methyl linoleate are also unrelated to the formation of fluorescent substances through reaction with amino compound.
Predicting coordinated lipid biosynthesis: Application to the surfactant‐accommodated epidermis
Authors: Ando Howard Y. , Gazdick Gary G. G. , Sugita Edwin T. , Schnaare Roger L.
Published: November 2006

Factorialized correlation analysis is proposed as a method for predicting the coordination of multiple enzyme pathways. The approach can be used potentially to find new relationships and to predict relationships that have been established in other tissues. However, careful tracer studies are needed to verify the cause‐and‐effect relationships between precursor and products. In this study, guinea pigs that were chronically treated with an anionic, a nonionic and a cationic surfactant passed through an irritation stage to a clinical state that appeared normal. The method was used to examine binary coordination of lipid biosynthesis in the epidermis by using a factorialized table of regression coefficients. Coordinated lipid relationships that have been reported in other tissues were predicted between sphingomyelin and cholesterol, as well as between phosphatidylcholine, phosphatidylserine and phosphatidylethanolamine. A new inverse relationship was found between triglycerides and both sphingomyelin and cholesterol, using this method. These data are discussed with respect to a membrane fluidization model for the accommodated state.
Quantification of oxysterols in dutch foods: Egg products and mixed diets
Authors: van de Bovenkamp Peter , Kosmeijer‐Schuil Truus G. , Katan Martijn B.
Published: November 2006

A sensitive and specific method is described for quantifying various cholesterol oxidation products in foodstuffs, including 7β‐hydroxycholesterol, cholesterol‐α‐epoxide, cholestane‐triol, 7‐ketocholesterol and 25‐hydroxycholesterol. A chloroform‐methanol extract of the food was fractionated over two successive silica columns. Two fractions containing different classes of oxysterols were then analyzed as trimethylsilyl derivatives by capillary gas liquid chromatography, using on‐column injection and a temperature gradient from 70 to 200°C. The detection limit was about 0.5 μg/g dry weight for egg yolk powder. Fresh egg yolk contained only 1.2 μg/g of total oxides per g dry weight, showing that artifactual oxidation during the procedure was minimal. Recovery of 5 pure oxysterols added to egg yolk at levels of 6.5 and 10 μg/g was between 93 and 102%. In commercial egg yolk and whole egg powder stored for one year, total amounts of oxysterols ranging from 21 to 137 μg/g dry weight were found. In duplicates of mixed Dutch diets, total amounts ranged from 3.6 to 6.2 μg/g dry weight. Duplicates containing mostly fried and baked foods did not have higher levels than duplicates in which foods had been prepared by boiling or left raw. We conclude that a normal mixed diet provides only minor amounts of cholesterol oxidation products.
Characterization of 12‐methyl‐cis‐4‐tetradecenoic acid fromCorynebacterium sepedonicum
Authors: Henningson Paul J. , Vick Brady A. , Bugbee William M. , Gudmestad Neil C.
Published: November 2006

A previously uncharacterized fatty acid found inCorynebacterium sepedonicum was analyzed by gas chromatography‐mass spectrometry and infrared spectrometry and determined to be 12‐methyl‐cis‐4‐tetradecenoic acid. This fatty acid represents nearly 6% of the total fatty acids ofC. sepedonicum, but it is present at significantly lower levels in otherCorynebacterium species. Therefore, 12‐methyl‐cis‐4‐tetradecenoic acid provides a useful marker in distinguishingC. sepedonicum from other microorganisms.
Esterification of 8,11,14‐eicosatrienoate and arachidonate into alkylacyl‐ and diacylglycerophosphocholine by vascular endothelial cells
Authors: Rosenthal Miriam D. , Brown Morris E. , Jones Janet E.
Published: November 2006

Agonist‐stimulated phospholipases release arachidonate, but not 8,11,14‐eicosatrienoate, from human endothelial cells. One source of the arachidonic acid is deacylation of 1‐alkyl‐2‐arachidonoyl‐glycerophosphocholine, with subsequent conversion of some of the resultant lysophospholipid to platelet‐activating factor. This study has compared the distribution of incorporated 8,11,14‐[14C]‐eicosatrienoate in alkylacyl‐GPC and diacyl‐GPC with that of [14C]arachidonate synthesized endogenously by desaturation of the 8,11,14‐[14C]eicosatrienoate. Cells were incubated for 24 or 48 hr with 8,11,14‐[14C]eicosatrienoate, and the resultant mixture of14C‐fatty acids in the cellular lipids was characterized by gas chromatography. The choline phospholipids were then separated, hydrolyzed with phospholipase C and derivatized to diradylbenzoates. Gas chromatographic analysis indicated extensive incorporation of [14C]eicosatrienoate, as well as [14C]arachidonate, into alkylacyl‐GPC. Although the ratio of esterified [14C]arachidonate to [14C]eicosatrienoate was greater in alkylacyl‐GPC than in diacyl‐GPC, the enrichment with [14C]arachidonate was far less than the ratio of arachidonate/eicosatrienoate released from these cells. These results thus support the hypothesis that the acyl specificity of polyunsaturated fatty acid release is provided by the agonist‐stimulated phospholipase A2 rather than the composition of the alkylacyl‐GPC.
Comparison of fatty acid and triacylglycerol metabolism of macrophages and smooth muscle cells
Authors: Bergstraesser Lynn M. , Bates Sandra R.
Published: November 2006

The response of macrophages and smooth muscle cells to culture in free fatty acid has been compared. Because oleate and linoleate promoted triacylglycerol enrichment of smooth muscle cells, whereas palmitate had little effect, oleate was used for these studies. The kinetics of the accumulation of triacylglycerol produced by oleate was comparable between smooth muscle cells and macrophages. When grown in increasing concentrations of oleic acid at various fatty acid to albumin molar ratios, the extent of triacylglycerol accumulation in both cell types was dependent on the concentration of oleate, the concentration of albumin, and the oleate to albumin molar ratio. However, macrophages contained 2.6‐fold more triacylglycerol than smooth muscle cells in the presence of oleate at 0.36 mM or greater and at levels of albumin higher than 0.15 mM. The cellular triacylglycerol content of macrophages was linearly related to the oleate to albumin molar ratio at both a constant albumin concentration and a constant oleate concentration, whereas the accumulation of triacylglycerol in smooth muscle cells showed a curvilinear relationship. When cells were preloaded with triacylglycerols, smooth muscle cells showed a greater loss of lipid when exposed to albumin than macrophages did. Over a two‐hr time period, macrophages incorporated twice as much labeled fatty acid as smooth muscle cells. Thus, while smooth muscle cells and macrophages showed similar responses to exogenous fatty acid and albumin, there were also significant quantitative distinctions.
Influence of dietary soybean and egg lecithins on lipid responses in cholesterol‐fed guinea pigs
Authors: O'Brien Barbara C. , Corrigan Sheila M.
Published: November 2006

The comparative influence on plasma and tissue lipids of dietary soybean and egg lecithins, which have contrasting fatty acid compositions, was studied in the hypercholesterolemic guine apig. The polyunsaturated to saturated fatty acid (P/S) ratios of the soybean and egg lecithins were 3.4 and 0.38, respectively. Hypercholesterolemia was induced by feeding guinea pigs a purified diet that contained 15% lard enriched with 0.5% cholesterol. Subsequently, guinea pigs were fed for six wk the same diet supplemented with either soybean or egg lecithin as 7.5% of the diet. A control group continued to be fed the lecithin‐free diet. Parameters measured included body weight and relative liver weight; in plasma, total cholesterol, high density lipoprotein cholesterol (HDLC), phospholipid, and nonesterified cholesterol; in liver, total fat, cholesterol, and the specific activity of the catabolic enzyme cholesterol 7α‐hydroxylase; (EC 1.14.13.17); and in the aorta, cholesterol. Among the most noteworthy observations were the 49% decrease in total plasma cholesterol of the soybean lecithin group without decreasing HDLC and the 177% increase in HDLC of the egg lecithin group without a significant increase in total cholesterol compared with those values in the control group. These data suggest that dietary lecithin is particularly effective in increasing the HDLC/total cholesterol ratio in plasma. However, the absolute concentrations of those plasma lipids seem to depend upon the fatty acid composition of the lecithin.
Malondialdehyde‐containing proteins and their relationship to vitamin E
Authors: Manwaring John D. , Csallany A. Saari
Published: November 2006

A high molecular weight (Sephadex G‐15 void volume), water‐soluble, fluorescent material that was found to increase significantly in the mouse liver in response to vitamin E deficiency was separated into six proteins by high performance liquid chromatography (HPLC) using a TSK G2000 SW column. One of these proteins increased significantly in concentration due to vitamin E deficiency and had a molecular weight of 20,000 daltons. This protein was found to contain malondialdehyde, an end product of lipid peroxidation, attached to it presumably in a Schiff‐base type structure with amino groups. This appears to be the first report in the literature of direct evidence that malondialdehyde is attached to protein in vivo.
Effects of dietary corn oil and salmon oil on lipids and prostaglandin E2 in rat gastric mucosa
Authors: Grataroli Renée , Léonardi Jeannie , Charbonnier Monique , Lafont Raymond , Lafont Huguette , Nalbone Gilles
Published: November 2006

Three groups of male rats were fed either a corn oilenriched diet (17%, w/w), a salmon oil‐enriched diet (12.5%) supplemented with corn oil (4.5%) or a low‐fat diet (4.4%) for eight wk to investigate the possible relationships between dietary fatty acids and lipid composition, and prostaglandin E2 level and phospholipase A2 activity in the rat gastric mucosa.

High‐fat diets induced no important variation in total protein, phospholipid and cholesterol contents of gastric mucosa.

Compared with a low‐fat diet, corn oil produced a higher n−6/n−3 ratio in mucosal lipids, whereas this ratio was markedly lowered by a fish oil diet.

In comparison with the low‐fat diet, the production of prostaglandin E2(PGE2) in gastric mucosa of rats fed salmon oil was significantly, decreased by a factor of 2.8. In the corn oil group, PGE2 production tended to decrease, but not significantly.

In comparison with the low‐fat diet, both specific and total gastric mucosal phospholipase A2 activities were increased (+18 and 23%, respectively) in the salmon oil group; they were unchanged in the corn oil group.

It is suggested that the decrease of gastric PGE2 in rats fed fish oil is not provoked by a decrease in phospholipase A2 activity but may be the result of the substitution of arachidonic acid by n−3 PUFA or activation of PGE2 catabolism.
Perfluorodecanoic acid and lipid metabolism in the rat
Authors: Van Rafelghem Marc J. , Vanden Heuvel John P. , Menahan Lawrence A. , Peterson Richard E.
Published: November 2006

Alterations in lipid metabolism were axamined in adult male Sprague‐Dawley rats seven days after a single intraperitoneal injection of perfluorodecanoic acid (PFDA; 20, 40 or 80 mg/kg). Because PFDA treatment caused a dose‐related reduction in feed intake, the response of vehicle‐treated rats pair‐fed to those receiving PFDA was monitored to distinguish direct effects of the perfluorinated fatty acid from those secondary to hypophagia. Carcass content of lipid phosphorus and free cholesterol decreased in dose‐dependent fashion in both PFDA‐treated and pair‐fed rats. Carcass triacylglycerols diminished in a similar manner, yet PFDA‐treated rats at each dose had a higher concentration of neutral acylglycerols than their vehicle‐treated, pair‐fed counterparts. In vehicle‐treated, pair‐fed rats at the 80 mg/kg dose level, lipid phosphorus and free cholesterol as a proportion of carcass fat increased, whereas the share of the triacyl‐glycerols declined. Because of the higher concentration of triacylglycerols in the carcass of rats treated with 80 mg/kg PFDA, enrichment of lipid phosphorus and free cholesterol in carcass fat was less than in their pair‐fed partners. The amount of lipid phosphorus and free cholesterol per hepatocyte was similar in both PFDA‐treated rats and their pair‐fed partners. Liver triacyl‐glycerols were markedly increased in PFDA‐treated rats. A similar but less extensive augmentary effect of PFDA on hepatic esterified cholesterol was found. Concentration of triacylglycerols in plasma was not elevated in PFDA‐treated rats, in spite of hepatic accumulation of esterified compounds. Also, the plasma level of free fatty acids and 3‐hydroxybutyrate was similar in all treatment groups, including those receiving PFDA. Thus, the administration of PFDA appears to divert fatty acids from oxidation toward esterification in the liver.
The phospholipid fatty acids of the marine spongeXestospongia muta
Authors: Carballeira Néstor M. , Maldonado Lilliam
Published: November 2006

The rare phospholipid fatty acids 3,7,11‐trimethyldodecanoic (1), 5,9‐hexadecadienoic (2) and 12‐methyl‐hexadecanoic (3) were identified in the marine spongeXestospongia muta. Branched fatty acids inX. muta accounted for 35% of the total fatty acid mixture. It was observed that the occurrence of the 5,9‐hexadecadienoic acid (2) coincides with the complete absence of the very long chain fatty acid 5,9‐hexacosadienoic. The acid 5,9,19‐octacosatrienoic seems to be found in mostXestospongia species.
The composition of furan fatty acids in the crayfish
Authors: Ishii Kazuo , Okajima Haruo , Koyamatsu Tsuyoshi , Okada Youji , Watanabe Hiroshi
Published: November 2006

Capillary gas chromatography‐mass spectrometry (GC‐MS) analysis of the sterol ester fatty acid methyl esters of the crayfish hepatopancreas revealed the presence of at least 30 kinds of unusual furan fatty acids (F acids), which accounted for 28.49% of the total sterol ester fatty acids. On the other hand, only small amounts were found in triacylglycerols (0.5%) and phospholipids (0.7%). Among the F acids, 17 acids were the hitherto unknown ones, the major component being 12,15‐epoxy‐13,14‐dimethyleicosa‐12,14‐dienoic acid (F6) (41.83% of the total F acids). These novel acids possessed chain lengths of C12 to C22, with the largest concentration at C20 (45.38%), C18 (41.97%) and C16 (10.35%). Odd‐numbered F acids also were found, though in a very small amount (0.4%). In the living things other than the crayfish, the longest chain F acid (C24) was detected in the sterol ester of the carp hepatopancreas. The bullfrog, an amphibian, and the turtle, a reptilian, were found to have F acids as well in their livers.

Olefinic furan fatty acids, which were detected by GC‐MS, were found to have resulted during the analytical process from cyclodehydration of the diketo‐ene formed by autoxidation of the F acids.
Trans fatty acids. 2. Fatty acid composition of the brain and other organs in the mature female pig
Authors: Pettersen Jan , Opstvedt Johannes
Published: November 2006

Female pigs were fed from three wk of age and up to two years a diet containing partially hydrogenated fish oil (PHFO, 28%trans monoenoic fatty acids), partially hydrogenated soybean oils (PHSBO, 36%trans fatty acids) or lard. No consistent differences were found between PHFO and PHSBO with regard to incorporation oftrans fatty acids in organ lipids, buttrans incorporations were highly organ‐specific. Notrans fatty acids were detected in brain phosphatidylethanolamine (PE). The incorporation of monoenoictrans isomers, as a percentage of totalcis + trans, in other organs was highest in subcutaneous adipose tissue and liver mitochondria PE, followed by blood lipids with the lowest level in heart PE. The percentage oftrans isomers compared with that of dietary lipids was consistently lower for 20∶1, compared with 18∶1 in organs from PHFO‐fed pigs. The only effect of dietarytrans fatty acids on the fatty acid pattern of brain PE was an increased level of 22∶5n−6. Heart PE and total serum lipids of pigs fed the hydrogenated fats contained higher levels of 18∶2n−6, and these lipids of the PHFO‐fed group also contained slightly elevated amounts of 20∶3n−6, 18∶3n−3 and 20∶5n−3. Liver mitochondria PE of the PHFO group also contained higher levels of 20∶3n−6 and 22∶5n−6. Dietarytrans fatty acids caused a consistent decrease of saturated fatty acids compensated by increased levels of monoenes. Thus, it may be concluded that dietary long‐chaintrans fatty acids in PHFO behaved similarly metabolically to 18∶1‐trans in PHSBO in pigs, without noticeable influence on brain PE composition and with moderate to slight effects on the fatty acid profile of the other organs.
Distal small bowel resection does not modify the intestinal 3‐hydroxy‐3‐methylglutaryl CoA reductase activity
Authors: Molina M. T. , Vazquez C. M.
Published: November 2006

The activity of 3‐hydroxy‐3‐methylglutaryl coenzyme‐A reductase (HMG‐CoA red.) has been evaluated in rat jejunal, caecal and colonic mucosa adapting to 50% or 75% distal small bowel resection (SBR). Six wk after surgery, the total activity and the activity state (active form) of the enzyme were determined. The results show that HMG‐CoA red. activity was stimulated per organ but not per unit mass in the mucosa adapting to SBR. As a side result, we noted regional differences in the active/total reductase ratio (RA/RT) for HMG‐CoA red. that was lower in small intestine compared with that of the large intestine.
Effect of dietary menhaden oil and vitamin E onin vivo lipid peroxidation induced by iron
Authors: Hu Miao‐Lin , Frankel Edwin N. , Tappel Al L.
Published: November 2006

Weanling rats were fed diets containing 10% menhaden oil (MO) or 10% corn oil‐lard (1∶1, COL) with low (≤5 IU/kg) or supplementary (35 IU/kg) vitamin E for six weeks. The rats were killed 30 min after injection with 24 mg iron/kg as ferrous chloride because thiobarbituric acid‐reactive substances (TBARS) in liver homogenates were highest at 30 min after injection of iron into rats fed a standard diet. Tissue homogenates were used either without incubation (zero‐time) or after incubation at 37°C for 1 hr. In addition to TBARS and conjugated dienes, headspace hexanal and total volatiles (TOV) determined by capillary gas chromatography were useful indices of lipid peroxidation since they were decreased by vitamin E supplementation and were increased with increasing iron dose. Regardless of the dietary lipid used, vitamin E supplementation decreased headspace hexanal, TOV, TBARS and conjugated dienes in both zero‐time and incubated homogenates of liver and kidney. Dietary MO increased TBARS in both zero‐time and incubated homogenates of tissue from rats injected with iron. In contrast, dietary MO decreased hexanal and TOV in incubated tissue homogenates. The study demonstrated the usefulness and limitations of using hexanal and TOV as indices of lipid peroxidation.
Biokinetics of dietaryRRR‐α‐tocopherol in the male guinea pig at three dietary levels of vitamin C and two levels of vitamin E. Evidence that vitamin C does not “spare” vitamin Ein vivo
Authors: Burton G. W. , Wronska U. , Stone L. , Foster D. O. , Ingold K. U.
Published: November 2006

The net rates of uptake of “new” and loss of “old”2R,4′ R,8′ R‐α‐tocopherol (RRR‐α‐TOH, which is natural vitamin E) have been measured in the blood and in nine tissues of male guinea pigs over an eight week period by feeding diets containing deuterium‐labelled α‐tocopheryl acetate (d6‐RRR‐α‐TOAc). There was an initial two week “lead‐in” period during which 24 animals [the “high” vitamin E (HE) group] received diets containing 36 mg of unlabelled (d0)RRR‐α‐TOAc and 250 mg of ascorbic acid per kg diet, while another 24 animals [the “low” vitamin E (LE) group] received diets containing 5 mgd0‐RRR‐α‐TOAc and 250 mg ascorbic acid per kg diet. The HE group was then tivided into three equal subgroups, which were fed diets containing 36 mgd6‐RRR‐α‐TOAc and 5000 mg [the “high” vitamin C (HEHC) subgroup], 250 mg [the “normal” vitamin C (HENC) subgroup] and 50 mg [the “low” vitamin C (HELC) subgroup] ascorbic acid per kg diet. One animal from each group was sacrificed each week and the blood and tissues were analyzed ford0‐ andd6‐RRR‐α‐TOH by gas chromatography‐mass spectrometry. The LE group was similarly divided into three equal subgroups with animals receiving diets containing 5 mgd6‐RRR‐α‐TOAc and 5,000 mg (LEHC), 250 mg (LENC) and 50 mg (LELC) ascorbic acid per kg diet with a similar protocol being followed for sacrifice and analyses. In the HE group the totald0‐+d6‐)RRR‐α‐TOH concentrations in blood and tissues remained essentially constant over the eight week experiment, whereas in the LE group the totalRRR‐α‐TOH concentrations declined noticeably (except in the brain, an organ with a particularly slow turnover of vitamin E). There were no significant differences in the concentrations of “old”d0‐RRR‐α‐TOH nor in the concentrations of “new”d6‐RRR‐α‐TOH found in any tissue at a particular time between the HEHC, HENC and HELC subgroups, nor between the LEHC, LENC and LELC subgroups. We conclude that the long‐postulated “spring” action of vitamin C on vitamin E, which is well documentedin vitro, is of negligible importancein vivo in guinea pigs that are not oxidatively stressed in comparison with the normal metabolic processes which consume vitamin E (e.g., by oxidizing it irreversibly) or elminate it from the body. This is true both for guinea pigs with an adequate, well‐maintained vitamin E status and for guinea pigs which are receiving insufficient vitamin E to maintain their body stores.

The biokinetics of vitamin E uptake and loss in the HE guinea pigs are compared with analogous data for rats reported previously (Lipids 22, 163–172, 1987). For most guinea pig tissues the uptake of vitamin E under “steadystate” conditions was faster than for the comparable rat tissues. However, the brain was an exception with the turnover of vitamin E occurring at only one‐third of the rate for the rat.
Chain elongation of polyunsaturated fatty acids by vascular endothelial cells: Studies with arachidonate analogues
Authors: Garcia Martha C. , Sprecher Howard , Rosenthal Miriam D.
Published: November 2006

This study has utilized radiolabeled analogues of arachidonic acid to study the substrate specificity of elongation of long‐chain polyunsaturated fatty acids. Human umbilical vein endothelial cells were incubated for 2–72 hr in medium supplemented with 0.9–2.6 μM [14C]fatty acid, and cellular glycerolipids were analyzed by gas‐liquid chromatography with radioactivity detection. Elongation of naturally occurring C20 polyunsaturated fatty acids occurred with eicosapentaenoate (20∶5(n−3))>Mead acid (20∶3(n−9))>arachidonate (20∶4(n−6)). Chain length markedly influenced the extent of elongation of 5,8,11,14‐tetraenoates (18∶4>19∶4>20∶4>21∶4); effects of initial double bond position were also observed (6,9,12,15–20∶4>4,7,10,13–20∶4. Neither 5,8,14‐ nor 5,11,14–20∶3 was elongated to the extent of 5,8,11–20∶3. Differences between polyunsaturated fatty acids were observed both in the initial rates and in the maximal percentages of elongation, suggesting that the content of cellular C20 and C22 fatty acids may represent a balance between chain elongation and retroconversion.

Umbilical vein endothelial cells do not exhibit significant desaturation of either 22∶4(n−6) or 22∶5(n−3). By contrast, incubation with 5,8,11,14‐[14C]18∶4(n−4) resulted in formation of both [14C]20∶5(n−4) and [14C]22∶5(n−4). The respective time courses for the appearances of [14C]22∶5(n−4) and [14C]20∶5(n−5) suggests Δ6 desaturation of [14C]22∶4(n−4) rather than Δ4 desaturation of [14C]20∶4(n−4).
Cholesteryl ester analogs inhibit cholesteryl ester but not triglyceride transfer catalyzed by the plasma cholesteryl ester‐triglyceride transfer protein
Authors: Busch Steven J. , Harmony Judith A. K.
Published: November 2006

A lipid transfer protein complex (LTC), purified from human plasma by immunoaffinity chromatography, catalyzed the interlipoprotein transfer of cholesteryl esters (CE) and triglycerides (TG). The CE transfer activity of LTC was governed by the strucutre of the CE. Incubation of LTC with long chain CE both activated and stabilized LTC. Short chain CE also enhanced the CE and TG transfer activity of LTC during the initial time of incubation. However, LTC's incubation with short chain CE induced a subsequent and time‐dependent loss of CE transfer activity without concomitant loss of TG transfer activity. The data indicate that the CE and TG transfer activity of LTC can be reglated independently.
Measurement of malondialdehyde by high performance liquid chromatography with fluorescence detection
Authors: Tatum Vickie L. , Changchit Charus , Chow Ching K.
Published: November 2006

A method has been developed to measure malondial‐dehyde (MDA) in biological systems. MDA was reacted with 2‐thiobarbituric acid (TBA) in the presence of butylated hydroxytoluene (BHT) to minimize formation of artifacts. Initial separation of the TBA‐MDA adduct was accomplished by isobutanol extraction. Further elimination and separation of interfering substances was achieved by high performance liquid chromatography. The mobile phase consisted of a 1∶1 (v/v) mixture of methanol and water with 0.05% (w/v) tetrabutyl ammonium dihydrogen phosphate added as an ion pairing reagent. At a flow rate of 1 ml/min, the TBA‐MDA adduct was eluted from a 15‐cm, c‐18, reversed phase column in approximately 4.9 min. The TBA‐MDA adduct was quantitated with a fluorescence detector set at 515 nm excitation and 550 nm emission. Using this method, picomole quantities of MDA can be easily detected in plasma and liver samples.
Sterol composition of the phytolaccaceae and closely related families
Authors: Xu Shihua , Patterson Glenn W.
Published: November 2006

Total sterols were analyzed from 28 species of Phytolaccaceae and from 29 species of closely related families—Basellaceae, Portulaccaceae, Molluginaceae, and Stegnospermataceae. Eighteen of twenty‐eight species of Phytolaccaceae contained dominant Δ7‐sterols while six species had dominant Δ5‐sterols. Three species had dominant Δ0‐sterols. Sterol composition strongly reflected taxonomic position. Nineteen of twenty‐nine species from Basellaceae, Portulaccaceae, Molluginaceae, and Stegnospermataceae contained dominant Δ7‐sterols while ten species contained dominant Δ5‐sterols. Until recently Δ7‐sterols were considered rare in higher plants. It appears that a large number of species in the order Caryophyllales contain primarily Δ7‐sterols.
Metabolism of peripheral nerve monogalactosylceramides
Authors: Yao Jeffrey K.
Published: November 2006

The metabolism of hydroxy galactocerebrosides (GalCe‐OH) and nonhydroxy galactocerebrosides (GalCe) was investigated during the nerve development, degeneration and regeneration by endoneurial injection of [14C]acetate and byin vitro incubation of rat sciatic endoneurium with [14C]acetate, [3H]galactose or [3H]glucose. After endoneurial microinjection, [14C]acetate was found to be incorporated first into GalCe‐OH and later, and to a much lesser degree, into GalCe. The ratio of14C‐labeled GalCe‐OH to GalCe decreased with time and remained fairly constant after 4 hr. On the other hand,in vitro incorporation of [14C]acetate resulted in higher14C‐labeling in GalCe and monogalactosyl diacylglycerol (MGDG) and lower14C‐labeling in GalCe‐OH, diminishing with incubation time. After 24 hr, only GalCe and MGDG were labeled. When [3H]galactose or [3H]glucose, instead of [14C]acetate, were used as precursorin vitro, a similar preference for labeling of GalCe‐OH was demonstrated in regenerating nerve. These data suggest that hydroxy fatty acids and hydroxy ceramides are the preferred substrates in peripheral nervous system for the sphingosine acyltransferase and the UDP‐galactose:ceramide galactosyltransferase reactions, respectively. The α‐hydroxylation system did not appear to be fully functional underin vitro conditions. The biosynthesis of GalCe‐OH was greatly enhanced during nerve fiber regeneration and decreased rapidly with increasing age. This suggests that a close interrelation exists between α‐hydroxylation and peripheral nerve myelination.
Effect of aging and dietary restriction on bile acid metabolism in rats
Authors: Ferland G. , Tuchweber B. , Perea A. , Yousef I. M.
Published: November 2006

The aim of the present study was to determine whether increased output of phospholipid in bile during aging may be due to alteration of bile acid composition and stimulated hydrophobic bile acid formation. In female Sprague‐Dawley rats we examined the influence of aging and life long dietary restriction (60% of thead libitum intake) on bile flow, total bile acid secretion, bile acid composition and conjugation pattern, as well as phospholipid output. Rats were cannulated at 3.5, 8–12 and 24–27 months of age and bile collected for analysis. With age, there was a significant reduction in bile flow and total bile acid secretion, however, phospholipid output increased. Restriction of dietary intake exerted a beneficial effect on the age‐related decline in bile formation. Studies of bile composition indicated that 12α‐hydroxylated bile acids (cholic acid and deoxycholic acid) secretion decreased in aged rats compared to 3.5‐month‐old rats. This was associated with a corresponding increase in secretion of chenodeoxycholic acid and hyodeoxycholic‐ursodeoxycholic acid. However, the magnitude of the change in secretion of these bile acids could not account for the increased output of phospholipid in bile.
Characterization of acylmono‐, mono‐, di‐, tri‐ and tetraglycosylsterol and saponin in Adzuki bean (Vigna angularis) seeds
Authors: Kojima Michiyuki , Ohnishi Masao , Ito Seisuke , Fujino Yasuhiko
Published: November 2006

Five sterylglycosides (acylmono‐, mono‐, di tri‐ and tetraglycosylsterol) and a saponin were isolated from Adzuki beans and characterized. In the glycosylsterols, the principal component sterols were sitosterol and stigmasterol; the major sugar component was glucose. The glucose units were shown to be linked by β1,6‐bonds. The three oligoglycosylsterols were shown to be gentiobiosylsterol, gentiotriosylsterol and gentiotetraosylsterol; the latter two are novel sterylglycosides. The saponin was identified as glucopyranosyl‐(β1→2)‐glucopyranurosyl‐(β1→3′)‐soyasapogenol B (Azukisaponin I) which had previously been found in Adzuki beans.
Synthesis and characterization of triacylglycerols containing linoleate and linolenate
Authors: Awl R. A. , Frankel E. N. , Weisleder D.
Published: November 2006

Triacylglycerols containing linoleate and linolenate found in vegetable oils were synthesized in gram quantities for oxidation studies. Two acylation methods were examined to convert diacylglycerols or monoacylglycerols to the desired triacylglycerols. Acylations with fatty acid and 1,1′‐dicyclohexylcarbodiimide in the presence of 4‐dimethylaminopyridine were more rapid, gave triacylglycerols of better isomeric purities and generally better overall yields than the acylations with acid chloride in pyridine. The functional and isomeric purity of the synthetic triacylglycerols were investigated by thin‐layer and gas‐liquid chromatography of the methyl esters, by lipase hydrolysis, and by13C NMR. Quantitative13C NMR provided a valuable tool to determine isomeric structures of the unsaturated triacylglycerols and complemented the lipase hydrolysis method. The triacylglycerols purified by dry column chromatography were obtained in the following respective percent yields, functional and isomeric purities: LLLn, 92.1, 99.4, 98.1; LLnLn, 91.7, 99.2, 97.4; LLnL, 84.2, 99.7, 98.9; and LnLLn 77.5, 97.8, 99.0 (where L=linoleoyl and Ln=linolenoyl glycerol residues). These synthetic triacylglycerols are valuable models to elucidate the interrelationship of unsaturated fatty acids on the oxidative stability of polyunraturated vegetable oils.
Effects of dietary fats on fatty acid composition and Δ5 desaturase in normal and diabetic rats
Authors: Dang A. Q. , Kemp K. , Faas F. H. , Carter W. J.
Published: November 2006

We have studied the effect of various diets on the phospholipid fatty acid composition andin vitro Δ5 desaturase activity of hepatic microsomes derived either from the normal or streptozotocin‐induced diabetic rat. The diets studied were the standard rat chow diet and a basal fat‐free diet supplemented either with 20 percent saturated fat, 20 percent unsaturated fat, or 20 percent menhaden oil. Phospholipid fatty acid composition analysis revealed that the normal rat fed the saturated fat or menhaden oil diet had significantly decreased arachidonate levels, consistent with decreased Δ5 desaturase activities and decreased 18∶2n−6 intake. On the contrary, the unsaturated fat diet decreased dihomo‐γ‐linolenate and increased arachidonate levels, without increased Δ5 desaturase activity. Streptozotocininduced diabetes resulted in decreased arachidonate and Δ5 desaturase activity. The unsaturated fat diet fed to the diabetic rat also failed to correct this decreased Δ5 desaturase activity. The unsaturated fatty acids in this diet also displaced a substantial amount of n−3 fatty acids in both normal and diabetic microsomes, due to the competition between these two fatty acid families for incorporation into the membrane phospholipids. Conversely, the menhaden oil diet fed to the normal and diabetic rats displaced n−6 fatty acids, reduced Δ5 desaturase activity, and enhanced 22∶6n−3 incorporation into diabetic microsomes.
Turnover of fatty acyl‐CoA oxidase in the liver of rats fed on a partially hydrogenated marine oil
Authors: Horie Shuchi , Suga Tetsuya
Published: November 2006

The change in turnover of fatty acyl‐CoA oxidase (FAO), the rate‐limiting enzyme of the peroxisomal β‐oxidation system, was investigated in rats fed a 30% (w/w) partially hydrogenated marine oil (PHMO) diet. The FAO activity increased five‐fold after two weeks of PHMO feeding, and decreased after withdrawal of the diet. Based onin vivo experiments using L‐[4,5‐3H]leucine and an immunoprecipitation technique, the increase in the activity of FAO could be accounted for by a 1.6‐fold higher rate of FAO synthesis and a 3.4‐fold slower rate of FAO degradation as compared to controls. In the same PHMO‐fed rats, the rates of synthesis and degradation of carnitine palmitoyltransferase were 1.8‐fold higher and 2.0‐fold slower, respectively, as compared to controls. The results indicate that the observed increase in the activity of the enzymes of peroxisomal β‐oxidation is mainly due to a reduced rate of FAO degradation in the liver of rats fed the PHMO diet.
Linoleic acid hydroperoxide concentration in relation to mutagenicity of repeatedly used deep‐frying fats
Authors: Hageman G. , Kikken R. , ten Hoor F. , Kleinjans J.
Published: November 2006

A high‐performance liquid chromatography procedure was developed to measure linoleic acid hydroperoxides (LAHPO) in 19 used, deep‐frying fat samples that were screened for mutagenicity. The detection limit of the method was found to be 10 nmol of LAHPO/g of fat. In eight samples, LAHPO were not detected; levels in the other samples ranged from 17 to 267 nmol/g of fat. LAHPO were not detectable in unusued hydrogenated frying fat samples. Concentrations of LAHPO correlated positively with mutagenicity to Salmonella tester strains TA97 and TA100, in presence of S9 mix only; coefficients of correlation were, respectively, r=0.48 (p<0.05) and r=0.24 (n.s.). Without metabolic activation no significant associations were observed. These results suggest that metabolites or secondary autoxidation products of linoleic acid generated in presence of liver S9 mix may contribute to mutagenicity of some of the used deep‐frying fat samples.
Fatty acid synthesis from [2‐14C]acetate in normal and peroxisome‐deficient (Zellweger) fibroblasts
Authors: Poulos A. , Usher S. , Paton B. C.
Published: November 2006

The incorporation of [2‐14C]acetate into the lipids of normal and peroxisome‐deficient (Zellweger's syndrome) skin fibroblasts was examined. Most of the label was incorporated into triacyglycerol fatty acids in normal as well as Zellweger's syndrome cells. Triacylglycerols and cholesteryl esters in Zellweger's syndrome cells contained increased levels of labelled saturated and monounsaturated very long‐chain fatty acids (VLCFA, that is fatty acids with more than 22 carbon atoms), in particular hexacosanoic (26∶0) and hexacosaenoic (26∶1) acids. As traces of labelled VLCFA with up to 32 carbon atoms were detected in triacylglycerols even in control cells it is probable that these fatty acids are formed naturally during the elongation process. Our data suggest that peroxisomes are involved in the chain shortening of the saturated and monounsaturated VLCFA.
Docosahexaenoic acid increases permeability of lipid vesicles and tumor cells
Authors: Stillwell William , Ehringer William , Jenski Laura J.
Published: November 2006

Docosahexaenoic acid (DHA), a long‐chain polyunsaturated ω3 fatty acid, is tested to determine its mode of action as an anti‐cancer agent. We demonstrate that DHA can increase the permeability of phospholipid vesicles, as monitored by vesicle swelling in isomolar erythritol and leakage of sequestered carboxylfluorescein, and T27A tumor cells, as monitored by swelling in isomolar erythritol and release of sequestered51Cr. DHA was incorporated into lipid vesicles as either the free fatty acid or as 1‐stearoyl‐2‐docosahexaenoyl‐sn‐glycero‐3‐phosphocholine. DHA was incorporated into the tumor cells by fusion with vesicles made from the mixed‐chain phosphatidylcholines. DHA is demonstrated here to be much more effective in increasing permeability than is oleic acid, the major unsaturated fatty acid normally found in tumor plasma membranes. It is proposed that incorporation of DHA makes tumor plasma membranes substantially more permeable, which may explain, in part, its anti‐tumor properties.
Reduction of fatty acid hydroperoxides by human parotid saliva
Authors: Terao Junji , Nagao Akihiko , Yuki Hiroko , Itoh Yoshio
Published: November 2006

Arachidonic acid hydroperoxide (15‐hydroperoxyeicosatetraenoic acid; 15‐HPETE) was introduced into human parotid saliva and incubated at 37°C. Straight phase high‐performance liquid chromatography analysis of the reaction mixture showed that 15‐HPETE was detoxified to its reduced form, 15‐hydroxyeicosatetraenoic acid, in the presence of glutathione. Therefore, it is concluded that human parotid saliva possesses fatty acid hydroperoxide‐reducing ability. However, its effectiveness was found to be lower than that of blood plasma.
The identification of the allylic nitrite and nitro derivatives of methyl linoleate and methyl linolenate by negative chemical ionization mass spectroscopy
Authors: Gallon Aris A. , Pryor William A.
Published: November 2006

The autoxidation of polyunsaturated fatty acids is initiated bothin vivo andin vitro by nitrogen dioxide. The mechanism of the initiation process is believed to involve both addition reactions and hydrogen atom abstraction reactions, with hydrogen abstraction predominating at low levels of nitrogen dioxide. Therefore low levels of nitrogen dioxide should react with polyunsaturated fatty acids to give allylic derivatives; in an anaerobic system these derivations should be allylic nitro and nitrite compounds. Using negative methane chemical ionization mass spectrometry and other analytical techniques, we have identified these allylic nitrite and nitro compounds from the reactions of low levels of nitrogen dioxide with methyl linoleate and methyl linolenate in the absence of oxygen.