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PubMed2005

Plasma coagulation factor VII activity and its correlates in healthy men.

OBJECTIVE: The aim of this study was to investigate the plasma coagulation factor VII activity and its correlates in healthy Australian men. DESIGN: Cross-sectional study. SETTING: Free living subjects. SUBJECTS: A total of 139 healthy Australian males aged 20-55 y with widely varying intakes of individual fatty acids. OUTCOME MEASURES: The concentration of phospholipid fatty acids and the parameters of biochemistry were analysed by standard methods. Citrated plasma factor VII activity was measured by using the ACL 200 system with commercially available kits. RESULTS: In the stepwise multiple regression, controlled for age, body mass index and dietary groups, the two most important variables of factor VII activity were selected in the forward entry model with R (2) = 0.474 and P < 0.0001 from 19 independent variables, which were significantly correlated with plasma factor VII activity in age-adjusted bivariate analysis where significance was considered at P < 0.01. Plasma factor VII activity was strongly negatively correlated with prothrombin time (PT) (Std. Coeff. -0.550), and significantly positively correlated with plasma phospholipid (PL) stearic acid (Std. Coeff. 0.285). CONCLUSIONS: Increased factor VII activity was associated with shortening of PT. All types of fatty-acid concentrations of PLs were significantly positively correlated with factor VII activity; however, stearic acid was more potent than other fatty acids in healthy Australian men. SPONSORSHIP: Meat Research Corporation of Australia.

Adult↗
PubMed1994

Quenching of merocyanine 540 triplet state by nitroxyl radicals in liposomal systems: a laser flash photolysis study.

Laser flash photolysis experiments were undertaken to investigate the interaction between stearic acid nitroxide spin probes and photoexcited merocyanine 540 (MC540) in dimyristoyl-L-alpha-phosphatidylcholine liposomes (membrane model). The measurements of the paramagnetic signal decay kinetics of four different spin-labelled stearic acids (n-DSA) show that the direct interaction between the dye and the probe is affected by the position of the nitroxyl group along the carbon chain. Laser flash photolysis results reveal a significant decrease in the MC540 triplet lifetime in the presence of n-DSA, the effect depending on the depth at which the nitroxyl moiety is localized in the bilayer. Previous results on the rate of disappearance of the electron spin resonance (ESR) nitroxide signal on continuous photolysis of the same systems do not show the same dependence on the localization of the nitroxyl moiety in the liposome. Although the MC540 triplet state seems to be implicated in the reaction process, the results suggest that ESR and laser flash experiments demonstrate two different kinds of mechanism.

Dimyristoylphosphatidylcholine↗
PubMed1985

Reduction in the stearic to oleic acid ratio in leukaemic cells--a possible chemical marker of malignancy.

Total lipid extracts of peripheral blood cells from patients with chronic leukaemias were analysed for relative values of saturation of the eighteen carbon chain length fatty acids (C 18 FA). The results are expressed as saturation index (C 18 S:C 18 U) of the saturated C 18 FA (stearic acid) over the unsaturated C 18 FA (oleic, linoleic and linolenic acids). The saturation indices of the white blood cells (WBC) and the red blood cells (RBC) in specimens from 14 patients with chronic granulocytic leukaemia (CGL) and 17 patients with chronic lymphocytic leukaemias (CLL) were significantly and consistently lower than control specimens. It is proposed that the relative increase in the unsaturated oleic acid could prove to be a chemical marker of malignancy reflecting a deficient cellular control of the process of stearic acid desaturation. The theoretical implications of the implied increase in membrane fluidity for the cells are discussed.

Chromatography, Gas↗
PubMedDate not supplied

Dietary lipid and intestinal brush border membrane phospholipid fatty acid composition and glucose transport of channel catfish.

Although the influences of dietary carbohydrate and protein on intestinal brush border membrane functions are well known, the responses to different dietary lipids are less clear, particularly for ectotherms. Therefore, we examined intestinal brush border membrane phospholipid fatty acid composition and rates of glucose transport of catfish fed two diets with different fatty acid profiles. Intestinal brush border membranes of fish fed a diet containing stearic acid had higher concentrations of monoenes, dienes, and trienes but were lower in polyenes and had a lower unsaturation index than those of fish fed a diet with menhaden oil. Rates of glucose transport at low, mid, and high temperatures were higher for intact tissues and vesicles prepared from the brush border membrane of fish fed the stearic acid diet. Our findings indicate that dietary lipids influence intestinal brush border membrane fatty acid composition and the relationship between temperature and rates of glucose transport. However, we can not exclude the possibility that dietary lipids can induce changes in transporter site densities and/or the physical characteristics of membrane microdomains in which the transporters might reside.

Animals↗
PubMed1983

Differential effect of cholesterol on two types of 5-hydroxytryptamine binding sites.

The specific binding of [3H]5-hydroxytryptamine ([3H]5-HT, [3H]serotonin) to rat cerebral cortex is increased approximately 1.5 to 2.0 fold by cholesterol hydrogen succinate (CHS) and is solubilized into the supernatant fraction by 12 mM CHS. [3H]5-HT binding sites can be constituted by incubating the supernatant fraction obtained from CHS-treated cerebral cortex with cerebellum in which no significant [3H]5-HT binding is detectable. The constituted [3H]5-HT binding could be displaced by unlabeled 5-HT, d-lysergic acid diethylamide (d-LSD) and spiperone as could the binding to cortex membranes. Unlabeled 5-HT, d-LSD and spiperone each inhibited specific [3H]5-HT binding to constituted binding sites by 50% at about 1 X 10(-9) M. Specific [3H]spiperone binding was not detectable in the constituted membranes. Stearic acid which is reported to have similar effects on membrane fluidity as cholesterol also increased specific [3H]5-HT binding in cortical membranes. Stearic acid does not affect specific [3H]spiperone binding. These results suggest that [3H]5-HT and [3H]spiperone binding sites are affected differently by membrane fluidity.

Animals↗
PubMed1994

Nutritional evaluation of spent grains from sorghum malts and maize grit.

Potential use of the high protein by-product of beer production from 77% sorghum malt and 23% maize grit was investigated. Red sorghum spent grains (RSSG) and white sorghum spent grains (WSSG) contained 23.4 and 19.3% crude protein (CP), 54 and 43% dietary fiber (NDF), 1.44 and 0.78% ash, 4.5 and 3.2% hexane extract and tannin content of 7.5 and 1.0 mg/g catechin equivalent respectively. Magnesium was the most abundant mineral in both RSSG and WSSG--185 and 140 mg/kg, respectively. Calcium, zinc, iron and copper were generally low. Both samples contained cadmium 1.12 (WSSG), 1.19 (RSSG) and lead at 1.38 mg/kg. Lysine was the limiting amino acid (chemical score 0.55) in both samples. Other essential amino acids were adequate or surplus. Stearic acid was the predominant fatty acid with varying levels of lauric, myristic, palmitic, and oleic acids in both samples. Feed intake and weight gain were highest in rats fed 26.3% WSSG (contributing 50% of the diet protein) but protein efficiency ratio (PER) and net protein retention (NPR) were highest in diets where spent grains contributed just 25% of the diet protein. True digestibility of diets decreased as dietary fiber content increased such that animals on diets containing 100% spent grain protein (above 20% NDF) lost weight.

Amino Acids↗
PubMedDate not supplied

Kinetics of human spermatozoa long-chain fatty acid: CoASH ligase.

The kinetics of long-chain saturated fatty acid activation were studied in the supernatant obtained from Triton-treated human spermatozoa. Sperm long-chain fatty acid: CoASH ligase (AMP) (E.C. 6.2.1.3) was able to activate myristic, palmitic, and stearic acids, but was incapable of utilizing lauric, arachidic, and behenic acids. Peak activity was obtained with palmitic acid. Although the Kms for each fatty acid were similar (4.3 to 5.0 microM), the Vmax was several-fold higher for palmitate. In contrast, ligase from liver homogenates assayed under identical conditions activated lauric through stearic acids, with maximal rates being noted with myristic acid. When compared with nongerminal tissues, sperm ligase appears unique because of its narrower acyl substrate specificity.

Adenosine Triphosphate↗
PubMed1985

Modulation of phospholipid metabolism in murine keratinocytes by tumor promoter, 12-O-tetradecanoylphorbol-13-acetate.

The possibility that phospholipid deacylation may be a critical event in the 12-O-tetradecanoylphorbol-13-acetate (TPA)-associated effects on mouse skin prompted us to examine in vitro the effects of TPA on arachidonic acid metabolism in neonatal mouse keratinocytes. Three-day old neonatal keratinocytes were prelabeled with [14C]arachidonic acid ([14C]AA) and [14C] stearic acid ([14C]ST) and used to characterize the lipases that were activated when these cells were treated with TPA in culture. Data from these studies demonstrate that phosphatidylcholine (PC) and phosphatidylinositol (PI) are the major phospholipids that undergo early hydrolysis to release arachidonic acid when challenged by TPA. Of particular interest was the novel observation of the hydrolysis of 14C-labeled PI in these keratinocytes, the accumulation of [14C]1,2-diacylglyceride and the lack of the [14C]diacylglyceride phosphorylation to form [14C]phosphatidic acid. This lack of [14C] phosphatidic accumulation implied that although TPA enhanced the hydrolysis of [14C]PI resulting in increased [14C]diacylglyceride it did not enhance the resynthesis of the [14C]PI via the phosphorylation of the [14C]diacylglyceride. Therefore, TPA probably is not involved in the turnover of PI in these cells but is involved in the activation of PC hydrolyzing phospholipase A2 and PI hydrolyzing phospholipase C in these keratinocytes releasing arachidonic acid which then undergoes oxygenation reactions to provide biologically active eicosanoids.

Animals↗
PubMed1979

Amniotic fluid palmitic acid/stearic acid ratios. Lecithin/sphingomyelin ratios and palmitic acid concentrations in the assessment of fetal lung maturity in diabetic pregnancies.

The lecithin/sphingomyelin (L/S) ratio, palmitic acid concentration and palmitic to stearic acid (P/S) ratio were estimated on samples of amniotic fluid obtained from 66 patients with diabetes. These were compared with similar estimates on amniotic fluid obtained from 127 non-diabetic patients. At 35 to 40 weeks, significant differences were observed between the L/S ratio and palmitic acid concentration in diabetics and non-diabetics, whereas the P/S ratio was similar in the two groups. The amniotic fluid L/S ratio, palmitic acid concentration, and P/S ratio were estimated on amniotic fluid obtained from 20 diabetic patients within 48 hours of induction, and the clinical outcome of the newborn infant was used to assess the predictive value of the three parameters. In 19 out of 20 diabetics the P/S ratio correctly predicted fetal lung maturity, whereas the palmitic acid concentration was correct in 12 patients and the L/S ratio in only 10 patients.

Amniotic Fluid↗
PubMed1990

Erythrocyte stearic to oleic acid ratio in prostatic carcinoma.

The red cell membrane stearic acid to oleic acid ratio was analysed in 34 men with histologically proven carcinoma of the prostate and distant metastases. This ratio was expressed as the saturation index (SI). A mean SI of 0.97 was found in control patients without evidence of any malignancy whereas all patients with advanced prostatic cancer showed a reduced stearic to oleic acid ratio (mean SI 0.466). Untreated patients had a significantly lower SI (mean 0.36) than those who had responded to hormonal therapy (mean 0.547; P less than 0.0001). A drop in SI correlated well with more advanced disease as judged by radiological findings and serum PSA. It is suggested that red cell membrane SI correlates well with radiological and biochemical markers of advanced prostatic carcinoma and may be used as a marker to assess progress and response to treatment.

Biomarkers, Tumor↗
PubMed2003

Triacylglycerol and phospholipid fatty acids of the silverleaf whitefly: composition and biosynthesis.

The identification and composition of the fatty acids of the major lipid classes (triacylglycerols and phospholipids) within Bemisia argentifolii Bellows and Perring (Homoptera: Aleyrodidae) nymphs were determined. Comparisons were made to fatty acids from the internal lipids of B. argentifolii adults. The fatty acids, as ester derivatives, were analyzed by capillary gas chromatography (CGC) and CGC-mass spectrometry (MS). All lipid classes contained variable distributions of eight fatty acids: the saturated fatty acids, myristic acid (14:0), palmitic acid (16:0), stearic acid (18:0), arachidic acid (20:0); the monounsaturated fatty acids, palmitoleic acid (16:1), oleic acid (18:1); the polyunsaturated fatty acids, linoleic acid (18:2), linolenic acid (18:3). Fourth instar nymphs had 5-10 times the quantities of fatty acids as compared to third instar nymphs and 1-3 times the quantities from adults. The fatty acid quantity differences between fourth and third instar nymphs were related to their size and weight differences. The percentage compositions for fatty acids from each lipid class were the same for the pooled groups of third and fourth instar nymphs. For nymphs and adults, triacylglycerols were the major source of fatty acids, with 18:1 and 16:0 acids as major components and the majority of the polyunsaturated fatty acids, 18:2 and 18:3 were present in the two phospholipid fractions, phosphatidylethanolamine and phosphatidylcholine. Evidence was obtained that whiteflies indeed synthesize linoleic acid and linolenic acid de novo: radiolabel from [2-(14)C] acetate was incorporated into 18:2 and 18:3 fatty acids of B. argentifolii adults and CGC-MS of pyrrolidide derivatives established double bonds in the Delta(9,12) and Delta(9,12,15) positions, respectively.

Animals↗
PubMed1982

The nutritional value of Yeheb-nut (Cordeauxia edulis Hemsl.).

The composition of two varieties of Yeheb seeds (Moqley and Suley) was studied. The Suley variety shows somewhat higher protein and fat contents than the Moqley variety. Yeheb seed protein is rich in the essential amino acids lysine and arginine, but deficient in tryptophan and isoleucine. The component fatty acids of Yeheb seed lipids are: palmitic acid 26-31%, stearic acid 12-12,5%, oleic acid 31-32% and linoleic acid 25-30%. The distribution of the fatty acids in Yeheb seed triglycerides is discussed.

Amino Acids↗
PubMed2005

Role of adiponectin in the protective action of dietary saturated fat against alcoholic fatty liver in mice.

The protective effect of dietary saturated fatty acids against the development of alcoholic liver disease has long been known, but the underlying mechanism is not completely understood. We examined the involvement of the adipocyte hormone adiponectin. Circulating adiponectin levels were significantly elevated by chronic ethanol administration to mice consuming a diet high in saturated fat. The increase in circulating adiponectin was associated with the activation a set of hepatic signaling pathways mediated through AMP-activated protein kinase, PPAR-alpha, and PPAR-gamma coactivator alpha, which in turn led to markedly increased rates of fatty acid oxidation, prevention of hepatic steatosis, and alleviation of liver enzyme changes. Furthermore, treatment of rat 3T3-L1 adipocytes with saturated fatty acids (palmitic or stearic acids) in the presence of ethanol increased secretion of adiponectin and enhanced activity of a mouse adiponectin promoter. In conclusion, the protective action of saturated fat against the development of alcoholic fatty liver in mice is partially mediated through induction of adiponectin. The present findings suggest a novel paradigm for dietary fatty acids in the pathogenesis of alcoholic liver disease and provide a promising therapeutic strategy-nutritional modulation of adiponectin-in treating human alcoholic fatty liver disease.

3-Hydroxybutyric Acid↗
PubMed1996

[Effect of feeding rapeseed oil to dairy cows on the fatty acid composition of butterfat].

Butter is rich in lauric, myristic, and palmitic acids which are assumed to be hypercholesterolemic. The replacement of usual dietary fat by rapeseed oil induces a serum cholesterol decrease. The objective of the study consisted in measuring the influence of feeding different amounts of full-fat rapeseed or oil-rich rapeseed cake to dairy cows to improve the fatty acid composition of milk fat. The results demonstrate a significant increase of iodine number and spreadability of butter. The percentage of lauric+myristic+palmitic acid (LMP) decreased by about 18% of whole fatty acids. Stearic and oleic acid increased significantly but the percentage of trans octadecenoic acid increased too. It can be concluded that the special butter has a nutritionally improved fat characterized by an increase of cholesterol-lowering fatty acids (C18 and C18:1) and a decline of cholesterol-elevating fatty acids (LMP).

Animals↗
PubMed1975

Fatty acid synthesis from 2-14C-acetate in rat testis mitochondrial and cytosol fractions in vitro.

An in vitro system for acetate incorporation into fatty acids by the mitochondrial and the cytosol fractions of rat testis is described. The rate of incorporation of acetate into fatty acids was twice as fast with the mitochondrial as with the cytosol fraction; both systems were stimulated in the presence of adenosine triphosphate, reduced nicotinamide adenine dinucleotide phosphate, coenzyme A, and MgC1(2). The optimum pH was between 7.0-7.5 for the mitochondrial fraction and between 6.5-8.0 for the cytosol fraction. Radio gas chromatography showed that palmitic acid was the most highly labeled acid, followed by stearic acid, in the mitochondrial fraction in accord with the pathway of de novo fatty acid synthesis. Some of the labeled acetate was also incorporated into the 16:1 and 18:1 fatty acids of this fraction. Distribution of radioactivity among the mitochondrial lipid classes was highest in the phospholipids and monoglycerides, followed by diglycerides and cholesterol; little radioactivity was present in the triglyceride fraction. These observations are in accord with studies of the incorporation of labeled metabolites into testicular lipids following intratesticular injection and indicate the validity of the in vitro system for studies of specific reactions occurring in vivo.

Acetates↗
PubMed1981

Zinc deficiency increases the rate of delta 6 desaturation of linoleic acid in rat mammary tissue.

The effect of zinc deficiency on the delta 6-desaturation of [1-14C]linoleic acid was studied in mammary tissue microsomes from lactating rats. The rats were maintained on zinc-adequate (20 ppm zinc) or zinc-deficient (10 ppm zinc changing to 0.5 ppm zinc during last trimester) diets throughout gestation and for the first 3 days of lactation. Mammary tissue microsomes were incubated with [1-14C]linoleic acid and other samples of mammary tissue, mammary milk and the milk in the stomachs of the pups were analyzed for total fatty acid composition. In mammary microsomes from zinc-deficient rats, delta 6-desaturation of linoleic acid was 3.4 times greater than in microsomes from zinc-adequate rats. This change in metabolism of linoleic acid was reflected by comparable changes in the relative tissue and milk composition of linoleic and arachidonic acids and in the ratios of palmitic to palmitoleic acid, stearic to oleic acid and linoleic and arachidonic acid.

Animals↗
PubMed1986

Effect of nutritional status on the fatty acid composition of rat liver and cultured hepatocytes.

The lipid concentration and fatty acid composition of the whole liver and of cultured hepatocytes isolated from the livers of rats fed ad libitum (fed), fasted for 24 hr (fasted), or fasted for 48 hr and then refed a fat-free, high carbohydrate diet for 48 hr (refed) was studied. Hepatocytes were maintained as monolayer cultures in serum-free, lipid-free media and their fatty acid composition was analyzed at 3, 24, 48, 72 and 96 hr. The livers of fed animals, as well as their hepatocytes, contained less total lipid than those from animals on either of the other dietary regimes. Livers of fasted animals had three times the amount of lipid found in the livers of fed animals, and the livers of refed animals contained five times the amount of lipid as the livers of fed animals (all based on mg lipid/g wet weight of liver). The fatty acid composition of hepatocytes after 3 hr of culturing was very similar to that of fresh liver when compared in each of the dietary regimes. However, while the fatty acid compositions of livers and hepatocytes from fed and fasted animals were similar, the pattern in liver of refed animals was quite distinct from that of the fed animals. In the fed and fasted animals palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1[n-9]), linoleic acid (18:2[n-6]) and arachidonic acid (20:4[n-6]) were the major fatty acids of the liver; in refed animals 16:0, palmitoleic acid (16:1[n-7]), 18:0, 18:1(n-9) and cis-vaccenic acid (the n-7 isomer of oleic acid) were the major fatty acids.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1998

Effect of selenium and vitamin E supplementation on lipid abnormalities in plasma, aorta, and adipose tissue of Zucker rats.

Twenty-nine obese female Zucker rats (fa/fa) were fed with a laboratory chow supplemented or not with a selenium-rich yeast (Selenion), or Selenion + vitamin E, or vitamin E alone. Twelve lean female Zucker rats (Fa/Fa) of the same littermates fed with the same diet were used as control. After 32 wk of diet, obesity induced a large increase in plasma insulin and lipid levels. A significant decrease in the plasma vitamin E/triglycerides ratio (p<0.005) and an increase in plasma thiobarbituric reactive substances (TBARS) (p<0.005) were also observed. Plasma selenium and vitamin E increased in all supplemented rats. The plasma insulin level was decreased by selenion supplementation and the vitamin E/triglycerides ratio was completely corrected by double supplementation with Selenion + vitamin E. TBARS were also efficiently decreased in two obese groups receiving vitamin E. In plasma, adipose tissue and aorta, obesity induced an increase in palmitic acid (C16:0), a very large increase in monounsaturated fatty acids (palmitoleic acid C16:1, stearic acid C18:1) associated with a decrease in polyunsaturated n-6 fatty acids (linoleic acid C18:2 n-6, arachidonic C20:4 n-6). These alterations in fatty acid distribution were only partly modulated by Se and vitamin E supplements. However, in the aorta, antioxidant treatment in obese rats significantly reduced the increase in C16:0 and C16:1 (p<0.05 and p<0.01, respectively) and the decrease in arachidonic acid (p<0.05). These changes could be beneficial in the reduction of insulin resistance and help to protect the vascular endothelium.

Adipose Tissue↗