Microsomal glycerolphosphate acyltransferase inactivation by fatty acids

1990 ◽  
Vol 68 (9) ◽  
pp. 1255-1260 ◽  
Author(s):  
V. Durocher ◽  
M. Miller ◽  
M. A. Rodriguez
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Serum Albumin ◽  
Membrane Lipids ◽  
Lipid Synthesis ◽  
Acyltransferase Activity ◽  
Molar Ratios ◽  
Rat Adipose Tissue

Glycerolphosphate acyltransferase activity in microsomes from rat adipose tissue is shown to decrease with time upon incubation with adipose tissue cytosolic fraction. The inactivation can be prevented with serum albumin and seems to be caused by an increase in endogenous free fatty acid as a consequence of the action of cytosolic lipase(s) on the membrane lipids. Similar inactivation can be observed after short incubation of microsomes with oleic acid at micromolar concentrations. Diacylglycerol acyltransferase is also inhibited by oleic acid, although to a lesser degree. In contrast, glucose-6-phosphatase and NADPH – cytochrome reductase activities are not changed. The oleic acid effect appears to occur upon binding to the microsomal membranes and can be prevented by bovine serum albumin at protein/fatty acid molar ratios above one. These results suggest that free fatty acids may be involved in the modulation of triacylglycerol synthetic enzymes.Key words: glycerolphosphate acyltransferase, fatty acids, microsomal enzymes, lipid synthesis.

Effect of increasing stearoyl coenzyme A desaturase mRNA concentrations using forage and concentrate diets on the fatty acid composition of ovine adipose tissue

2002 ◽  
Vol 2002 ◽  
pp. 206-206 ◽  
Author(s):  
Z.C.T.R. Daniel ◽  
R.J. Wynn ◽  
A.M. Salter ◽  
P.J. Buttery
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid Composition ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Stearic Acid ◽  
Acid Composition ◽  
Coenzyme A ◽  
Saturated Fatty Acids ◽  
Mrna Levels

Compared to meat from other animals lamb contains high levels of saturated fat, particularly stearic acid which comprises 18% of the total fatty acids (Enser et al, 1996). This stearic acid can be desaturated in the tissue by stearoyl coenzyme A desaturase (SCD) to produce oleic acid. In sheep SCD is produced from a single gene and the levels of SCD mRNA in the tissue correlate well with oleic acid (Ward et al, 1998, Barber et al, 2000) suggesting that an upregulation of SCD activity may increase the relative proportions of unsaturated and saturated fatty acids and so significantly improve the nutritional quality of sheep meat. Our recent studies have shown that insulin increases SCD mRNA levels and monounsaturated fatty acid synthesis in cultured ovine adipose tissue explants (Daniel et al, 2001). The present study was designed to investigate whether feeding a diet believed to manipulate SCD mRNA concentrations would significantly alter the fatty acid composition of lamb.

Effects of unsaturated fatty acid deprivation on neutral lipid synthesis in Saccharomyces cerevisiae

1982 ◽  
Vol 152 (2) ◽  
pp. 747-756
Author(s):  
T M Buttke ◽  
A L Pyle
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Lipid Metabolism ◽  
Cell Growth ◽  
Unsaturated Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
Lipid Synthesis ◽  
Yeast Cells

The effects of unsaturated fatty acid deprivation on lipid synthesis in Saccharomyces cerevisiae strain GL7 were determined by following the incorporation of [14C]acetate. Compared to yeast cells grown with oleic acid, unsaturated fatty acid-deprived cells contained 200 times as much 14C label in squalene, with correspondingly less label in 2,3-oxidosqualene and 2,3;22,23-dioxidosqualene. Cells deprived of either methionine or cholesterol did not accumulate squalene, demonstrating that the effect of unsaturated fatty acid starvation on squalene oxidation was not due to an inhibition of cell growth. Cells deprived of olefinic supplements displayed additional changes in lipid metabolism: (i) an increase in 14C-labeled diacylglycerides, (ii) a decrease in 14C-labeled triacylglycerides, and (iii) increased levels of 14C-labeled decanoic and dodecanoic fatty acids. The changes in squalene oxidation and acylglyceride metabolism in unsaturated fatty acid-deprived cells were readily reversed by adding oleic acid. Pulse-chase studies demonstrated that the [14C]squalene and 14C-labeled diacylglycerides which accumulated during starvation were further metabolized when cells were resupplemented with oleic acid. These results demonstrate that unsaturated fatty acids are essential for normal lipid metabolism in yeasts.

Removal and mobilization of individual free fatty acids in dogs

1962 ◽  
Vol 202 (2) ◽  
pp. 370-374 ◽  
Author(s):  
Harvey I. Miller ◽  
Martin Gold ◽  
John J. Spitzer
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Free Fatty Acid ◽  
Free Fatty Acids ◽  
Thoracic Duct Lymph ◽  
Similar Distribution ◽  
Arterial Blood ◽  
Oleic And Linoleic Acids

Plasma free fatty acids were determined chemically and by gas chromatography in different anatomical sites. The myocardium removed palmitic and oleic acids and lesser amounts of stearic and linoleic acids. Electrically stimulated skeletal muscle took up oleic acid in greatest quantities. Liver showed consistent removal of stearic, oleic, and linoleic acids and an occasional uptake of other acids. The splanchnic area did not remove or mobilize free fatty acids. The composition of free fatty acids in thoracic duct lymph was similar to that in arterial blood, with the exception of a higher percentage of linoleic and possibly oleic acid. The total and free fatty acid fractions of the inguinal subcutaneous adipose tissue showed a similar distribution of fatty acids. Both were relatively high in oleic and linoleic acids. Free fatty acid released by adipose tissue had a lower oleic and linoleic acid content than that present in the cell.

Non-Dependence of the Saturation of Depot Fat on Temperature and Photoperiod in a Hibernating Mosquito

1967 ◽  
Vol 46 (3) ◽  
pp. 487-490
Author(s):  
EMILE VAN HANDEL
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid Composition ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Culex Pipiens ◽  
Adult Stage ◽  
Unsaturated Fat ◽  
Winter Conditions ◽  
Fat Composition

1. The fatty acid composition of the triglycerides synthesized from sugar was determined in female Culex pipiens, a mosquito that overwinters in the adult stage. 2. The fat had approximately the same composition when synthesized at 5, 10, 20, or 30° C. 3. At each of these temperatures the fat composition was the same, whether a photo-period of 8 hr. or of 14 hr. was used. 4. The main fatty acids were palmitic (30%), palmitoleic (50%) and oleic acid (15%). 5. These results do not support a hypothesis that adipose tissue of poikilothermic animals synthesizes a more unsaturated fat under winter conditions.

scholarly journals The relative significance of acetate and glucose as precursors for lipid synthesis in liver and adipose tissue from ruminants

1967 ◽  
Vol 105 (2) ◽  
pp. 529-536 ◽  
Author(s):  
R. W. Hanson ◽  
F. J. Ballard
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Lipid Synthesis ◽  
Synthetase Activity ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Relative Significance ◽  
Liver Slices ◽  
Rat Adipose Tissue ◽  
Glucose 6 Phosphate Dehydrogenase

1. The incorporation of labelled glucose into lipid by liver slices from sheep and cows is considerably less than that by liver slices from the rat, although oxidation to carbon dioxide occurs to a similar extent. ATP citrate lyase and NADP malate dehydrogenase are inactive in both sheep and cow liver but active in rat liver. The absence of the citrate-cleavage pathway of lipogenesis in ruminant liver has been confirmed by the negligible amounts of C-3 of aspartate incorporated into fatty acids. 2. Considerable amounts of [14C]acetate are incorporated into fatty acids and non-saponifiable lipid in rat and ruminant liver. Acetyl-CoA synthetase, the initial enzyme in the metabolism of acetate, has a high activity in liver from rat and ruminants. 3. In adipose tissue from ruminants more acetate than glucose is converted into lipids, whereas the converse is true in rat adipose tissue. The greater incorporation of [14C]acetate into fatty acids in adipose tissue from the ruminant as compared with the non-ruminant may be caused, in part, by the higher activity of acetyl-CoA synthetase activity in the ruminant. 4. The results suggest that, in both liver and adipose tissue from ruminants, acetate is a more important source of lipid than glucose. 5. Two enzymes of the hexose monophosphate shunt, glucose 6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase, are active in both tissues and from the three species.

Fatty acid esterifying enzymes in rat adipose tissue homogenates

1968 ◽  
Vol 46 (9) ◽  
pp. 1039-1045 ◽  
Author(s):  
Anna M. Daniel ◽  
David Rubinstein
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Acid Phosphatase ◽  
Chain Length ◽  
Significant Alteration ◽  
Ph Optimum ◽  
Tissue Homogenates ◽  
Rat Adipose Tissue

Some characteristics of enzymes in homogenates of rat adipose tissue concerned with esterification of fatty acids have been investigated. Acyl-CoA thiokinase is the most active of the enzymes studied, with optimal concentrations of palmitate and ATP being 2 mM and 25 mM respectively. The thiokinase has a pH optimum between 8 and 10 and reacts with fatty acids ranging in chain length from C4 to C22, with the greatest activity towards palmitate. About 50% of the activity is found in the 100 000 × g supernatant. Acyl-CoA : α-glycerolphosphate acyltransferase and acyl-CoA deacylase have pH optima between 7 and 8. Albumin at a concentration of 1% activates the former, while the latter is inhibited by concentrations of albumin greater than 0.5%. Deacylase activity is found almost entirely in the 100 000 × g supernatant. Both the acyl-CoA : α-glycerolphosphate acyltransferase and the acyl-CoA : diglyceride acyltransferase lose much of their activity upon fractionation. The pH optimum of the acyl-CoA : diglyceride acyltransferase ranges from pH 7 to 9, while that of the phosphatidc acid phosphatase is 6. The latter enzyme is distributed equally between particulate and soluble portions of the homogenate. When these enzymes are assayed in homogenates from fed and fasted animals, a significant alteration is found only in the level of acyl-CoA deacylase, which is decreased. The properties of these enzymes can be related to the extent and type of esterification in homogenates from fed and fasted animals.

scholarly journals Triacylglycerol biosynthesis in rat adipose-tissue homogenates

1976 ◽  
Vol 159 (3) ◽  
pp. 571-577 ◽  
Author(s):  
W W Christie ◽  
M L Hunter ◽  
R G Vernon
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Oleic Acid ◽  
Linoleic Acid ◽  
Stearic Acid ◽  
Palmitic Acid ◽  
Positional Distribution ◽  
Triacylglycerol Biosynthesis ◽  
Tissue Homogenates ◽  
Rat Adipose Tissue

The optimum cofactor requirements for triacylglycerol biosynthesis in rat adipose-tissue homogenates containing mitochondrial, microsomal and cytosolic fractions were investigated. In general the optimum concentrations of cofactors for triacylglycerol biosynthesis were found to differ from those for total fatty acid esterification. The results provided further evidence for the key role of phosphatidate phosphohydrolase in the regulation of triacylglycerol biosynthesis. Albumin was included in the incubation medium to permit the use of concentrations of added fatty acids that would swamp the effects of endogenous fatty acids. The addition of albumin had little effect on the incorporation of palmitic acid and stearic acid into lipids including triacylglycerols. By contrast, a critical concentration of albumin (about 60 μM) was required before incorporation of oleic acid or linoleic acid into triacylglycerols occurred. The system was used to study the incorporation of different 1-14C-labelled fatty acids from a mixture of unesterified fatty acids [palmitic acid 30%; stearic acid 10%; oleic acid 40%; linoleic acid 20% (molar percentages)] separately into the positions 1,2 and 3 of triacyl-sn-glycerols. In general the stereo-specific distribution of the labelled fatty acids incorporated into triacylglycerols paralleled the normal distribution of fatty acids within rat adipose-tissue triacylglycerols, suggesting that the specificities of the relevant acyltrasferases have the major role in determining the positional distribution of fatty acids within triacylglycerols.

Platelet Aggregation in Finnish Men and Its Relation to Fatty Acids in Platelets, Plasma and Adipose Tissue

1985 ◽  
Vol 54 (03) ◽  
pp. 563-569 ◽  
Author(s):  
M K Salo ◽  
E Vartiainen ◽  
P Puska ◽  
T Nikkari
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Platelet Aggregation ◽  
Acid Composition ◽  
Saturated Fatty Acids ◽  
Free Living ◽  
Ω3 Fatty Acids ◽  
Induced Aggregation

SummaryPlatelet aggregation and its relation to fatty acid composition of platelets, plasma and adipose tissue was determined in 196 randomly selected, free-living, 40-49-year-old men in two regions of Finland (east and southwest) with a nearly twofold difference in the IHD rate.There were no significant east-southwest differences in platelet aggregation induced with ADP, thrombin or epinephrine. ADP-induced platelet secondary aggregation showed significant negative associations with all C20-C22 ω3-fatty acids in platelets (r = -0.26 - -0.40) and with the platelet 20: 5ω3/20: 4ω 6 and ω3/ ω6 ratios, but significant positive correlations with the contents of 18:2 in adipose tissue (r = 0.20) and plasma triglycerides (TG) (r = 0.29). Epinephrine-induced aggregation correlated negatively with 20: 5ω 3 in plasma cholesteryl esters (CE) (r = -0.23) and TG (r = -0.29), and positively with the total percentage of saturated fatty acids in platelets (r = 0.33), but had no significant correlations with any of the ω6-fatty acids. Thrombin-induced aggregation correlated negatively with the ω3/6ω ratio in adipose tissue (r = -0.25) and the 20: 3ω6/20: 4ω 6 ratio in plasma CE (r = -0.27) and free fatty acids (FFA) (r = -0.23), and positively with adipose tissue 18:2 (r = 0.23) and 20:4ω6 (r = 0.22) in plasma phospholipids (PL).The percentages of prostanoid precursors in platelet lipids, i. e. 20: 3ω 6, 20: 4ω 6 and 20 :5ω 3, correlated best with the same fatty acids in plasma CE (r = 0.32 - 0.77) and PL (r = 0.28 - 0.74). Platelet 20: 5ω 3 had highly significant negative correlations with the percentage of 18:2 in adipose tissue and all plasma lipid fractions (r = -0.35 - -0.44).These results suggest that, among a free-living population, relatively small changes in the fatty acid composition of plasma and platelets may be reflected in significant differences in platelet aggregation, and that an increase in linoleate-rich vegetable fat in the diet may not affect platelet function favourably unless it is accompanied by an adequate supply of ω3 fatty acids.

scholarly journals Circulating fatty acid profiles are associated with protein energy wasting in maintenance hemodialysis patients: a cross-sectional study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ban-Hock Khor ◽  
◽  
Sharmela Sahathevan ◽  
Ayesha Sualeheen ◽  
Mohammad Syafiq Md Ali ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Nutritional Status ◽  
Serum Albumin ◽  
Saturated Fatty Acids ◽  
Maintenance Hemodialysis ◽  
Model Assessment ◽  
Cross Sectional ◽  
Markers Of Inflammation

AbstractThe metabolic impact of circulating fatty acids (FAs) in patients requiring hemodialysis (HD) is unknown. We investigated the associations between plasma triglyceride (TG) FAs and markers of inflammation, insulin resistance, nutritional status and body composition. Plasma TG-FAs were measured using gas chromatography in 341 patients on HD (age = 55.2 ± 14.0 years and 54.3% males). Cross-sectional associations of TG-FAs with 13 markers were examined using multivariate linear regression adjusted for potential confounders. Higher levels of TG saturated fatty acids were associated with greater body mass index (BMI, r = 0.230), waist circumference (r = 0.203), triceps skinfold (r = 0.197), fat tissue index (r = 0.150), serum insulin (r = 0.280), and homeostatic model assessment of insulin resistance (r = 0.276), but lower malnutrition inflammation score (MIS, r =  − 0.160). Greater TG monounsaturated fatty acid levels were associated with lower lean tissue index (r =  − 0.197) and serum albumin (r =  − 0.188), but higher MIS (r = 0.176). Higher levels of TG n-3 polyunsaturated fatty acids (PUFAs) were associated with lower MIS (r =  − 0.168) and interleukin-6 concentrations (r =  − 0.115). Higher levels of TG n-6 PUFAs were associated with lower BMI (r =  − 0.149) but greater serum albumin (r = 0.112). In conclusion, TG monounsaturated fatty acids were associated with poor nutritional status, while TG n-3 PUFAs were associated with good nutritional status. On the other hand, TG saturated fatty acids and TG n-6 PUFAs had both favorable and unfavorable associations with nutritional parameters.

Sign in / Sign up

Export Citation Format

Share Document