scholarly journals Modulation of lipid-synthesizing enzymes by insulin in differentiated ob17 adipose-like cells

1983 ◽  
Vol 214 (2) ◽  
pp. 443-449 ◽  
Author(s):  
P Grimaldi ◽  
C Forest ◽  
P Poli ◽  
R Negrel ◽  
G Ailhaud
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Specific Activity ◽  
Fatty Acid Synthetase ◽  
Lipid Synthesis ◽  
Acid Synthesis ◽  
Acetate Incorporation ◽  
Long Term Effects ◽  
Response Curves ◽  
Glycerol 3 Phosphate Dehydrogenase

ob17 cells convert into adipose-like cells when maintained in the presence of physiological concentrations of insulin and tri-iodothyronine. After this conversion, insulin removal from differentiated ob17 cells gives within 24-48 h a large decrease in fatty acid synthetase, glycerol 3-phosphate dehydrogenase and acid:CoA ligase activities, as well as in the rate of fatty acid synthesis determined by [14C]acetate incorporation into lipids. All parameters are restored by insulin addition to initial values within 24-48 h. Dose-response curves of insulin on the restoration of glycerol 3-phosphate dehydrogenase activity and of fatty acid synthesis give half-maximally effective concentrations close to 1 nM, in agreement with the affinity for insulin of the insulin receptors previously characterized in these cells. Immunotitration experiments indicate that the changes in the specific activity of fatty acid synthetase are due to parallel changes in the cellular enzyme content. Therefore the ob17 cell line should be a useful model to study the long-term effects of insulin on the modulation of lipid synthesis in adipose cells.

scholarly journals Lipogenic enzymes in rat maternal adipose tissue in the perinatal period

1980 ◽  
Vol 186 (3) ◽  
pp. 937-944 ◽  
Author(s):  
P A Sinnett-Smith ◽  
R G Vernon ◽  
R J Mayer
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Pyruvate Dehydrogenase ◽  
Fatty Acid Biosynthesis ◽  
Specific Activity ◽  
Fatty Acid Synthetase ◽  
Acid Synthesis ◽  
Acetyl Coa Carboxylase ◽  
Acid Biosynthesis

1. The specific activities of fatty acid synthetase, acetyl-CoA carboxylase and pyruvate dehydrogenase were measured in rat adipose-tissue extracts in pregnancy and lactation. Fatty acid synthetase specific activity correlates very closely with the rate of fatty acid synthesis, the enzyme specific activity decreasing after mid-pregnancy in a manner very similar to the rate of fatty acid synthesis. Acetyl-CoA carboxylase specific activity also decreases dramatically after mid-pregnancy. Initial pyruvate dehydrogenase specific activity shows a decrease between 2 days pre partum and 2 days post partum, but total enzyme activity shows no significant change in the same period. 2. Immunotitrations of fatty acid synthetase and pyruvate dehydrogenase activities were carried out; the titrations showed that the change in the fatty acid synthetase activity is due to a change in the enzyme amount; the amount of pyruvate dyhydrogenase does not change. Therefore the decrease in fatty acid biosynthesis in subcutaneous and parametrial adipose tissue in late pregnancy and early lactation is associated with a decrease in the amount of at least one of the enzymes involved in fatty acid biosynthesis. The correlation of these events with known hormonal changes is discussed.

In vivo and in vitro lipogenesis and aspects of metabolism in ovines: Effect of environmental temperature and dietary lipid supplementation

2000 ◽  
Vol 80 (1) ◽  
pp. 59-67 ◽  
Author(s):  
J. A. Moibi ◽  
R. J. Christopherson ◽  
E. K. Okine
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Cold Exposure ◽  
Average Daily Gain ◽  
Acid Synthesis ◽  
Dietary Lipid ◽  
Acetate Incorporation ◽  
Lipid Supplementation

Twenty-four wether lambs were randomly allocated to six treatments to investigate the effect of temperature and dietary lipid supplements on fatty acid synthesis and metabolic activity in sheep. The treatments consisted of four groups exposed to either cold (0 °C) or warm temperature (+23 °C) and given ad libitum access to either a control barley-based diet or with lipid supplementation. Two other groups were placed on the dietary regimen at 0 °C, but pair-fed to intake of animals in the +23 °C environment. At 5 wk, fatty acid synthesis was measured by [1-14C]acetate incorporation into tissue lipids. Cold exposure and dietary lipid supplementation had no effect (P > 0.05) on in vivo fatty acid synthesis rates in either longissimus dorsi or the liver. In both subcutaneous and mesenteric adipose tissue depots, the rate of acetate incorporation into tissue lipid was not significantly affected by cold exposure. In the perirenal fat depot, cold exposure increased (P < 0.05) the rate of fatty acid synthesis, while lipid supplementation decreased (P < 0.05) the rate in all tissue adipose depots. In vitro, mesenteric and perirenal adipose tissues from cold pair-fed animals had higher (P < 0.05) rates of fatty acid synthesis compared to tissues from animals in the warm environment. However, there was no effect of dietary lipid supplementation in these two fat depots. Metabolic heat production, and energy and nitrogen excretion by animals were increased (P < 0.05) by cold exposure while lipid supplementation had the opposite effect (P < 0.05). The relationship between average daily gain and feed intake was linear at both warm and cold environments, but with higher (P < 0.05) average daily gain at all levels of intake in the cold compared to the warm environment. Results indicate that both environment and diet regulate metabolic activity in sheep. However, there were differences in lipogenic response by tissues to the treatments. Key words: Environmental temperature, dietary lipid, fatty acid synthesis, metabolic rate, sheep

scholarly journals Hepatic lipogenesis in young rats given proteins of different quality

1984 ◽  
Vol 52 (1) ◽  
pp. 131-137 ◽  
Author(s):  
G. R. Herzberg ◽  
Minda Rogerson
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Protein Quality ◽  
Fatty Acid Synthetase ◽  
Acid Synthesis ◽  
Hepatic Lipogenesis ◽  
Atp Citrate Lyase ◽  
Specific Activities ◽  
Glucose 6 Phosphate Dehydrogenase

1. The effect of feeding casein, lactalbumin, soya-bean protein, gluten or gelatin on hepatic lipogenesis and the levels of hepatic fatty acid synthetase (FAS), glucose-6-phosphate dehydrogenase (EC 1. 1. 1.49; G6PD), malic enzyme (EC 1. 1. 1.40; ME) ATP-citrate lyase (EC 4. 1. 3. 8; CL), acetyl CoA carboxylase (EC 6.4.1.2; ACCx) and glucokinase (EC 2. 7. 1. 2; GK) was examined in young growing rats.2. The total activities of ACCx, FAS, CL, GK, G6PD, GK, ME and fatty acid synthesis in vivo were positively correlated with protein quality.3. The specific activities of ACCx, FAS, CL, G6PD and fatty acid synthesis in vivo were positively correlated with protein quality.4. The specific activities of GK and ME were unrelated to protein quality.5. The results demonstrate a dissociation between ME and hepatic lipogenesis and suggest a role for the NADPH generated by ME which is not related to the needs of fatty acid synthesis.

scholarly journals The role of dietary protein in hepatic lipogenesis in the young rat

1981 ◽  
Vol 45 (3) ◽  
pp. 529-538 ◽  
Author(s):  
G. R. Herzberg ◽  
Minda Rogerson
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Dietary Protein ◽  
Fatty Acid Synthetase ◽  
Acid Synthesis ◽  
Hepatic Lipogenesis ◽  
Hepatic Fatty Acid ◽  
Cleavage Enzyme ◽  
Glucose 6 Phosphate Dehydrogenase

1. The effect of varying dietary levels of casein (40–140 g/kg) on hepatic lipogenesis and the levels of hepatic fatty acid synthetase (FAS), glucose-6-phosphate dehydrogenase (EC 1.1.1.49; G6PD), malic enzyme (EC 1.1.1.40; ME), citrate cleavage enzyme (EC 4.1.3.8;CCE), acetyl CoA carboxylase (EC 6.4.1.2; AcCx), glucokinase (EC 2.7.1.2; GK), and pyruvate dehydrogenase (PDH) was examined in young, growing rats.2. The activities of AcCx, FAS, G6PD and in vivo fatty acid synthesis were generally found to increase with increased dietary protein.3. The levels of GK and PDH were not related to dietary protein.4. ME decreased with increasing dietary protein.5. The results demonstrate a dissociation between hepatic fatty acid synthesis and ME and suggest that when rats consume low-protein diets the NADPH needed for fatty acid synthesis is generated primarily by ME but that as the level of dietary protein is increased the contribution of ME is reduced while that of the phosphogluconate pathway becomes more important.

scholarly journals Effect of Diet Supplementation on the Expression of Bovine Genes Associated with Fatty Acid Synthesis and Metabolism

2010 ◽  
Vol 4 ◽  
pp. BBI.S4168 ◽  
Author(s):  
Sandeep J. Joseph ◽  
Kelly R. Robbins ◽  
Enrique Pavan ◽  
Scott L. Pratt ◽  
Susan K. Duckett ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Corn Oil ◽  
Fatty Acid Content ◽  
Fatty Acid Synthetase ◽  
Health Benefit ◽  
Acid Synthesis ◽  
Animal Origin ◽  
Expression Of Genes ◽  
Diet Supplementation

Conjugated linoleic acids (CLA) are of important nutritional and health benefit to human. Food products of animal origin are their major dietary source and their concentration increases with high concentrate diets fed to animals. To examine the effects of diet supplementation on the expression of genes related to lipid metabolism, 28 Angus steers were fed either pasture only, pasture with soybean hulls and corn oil, pasture with corn grain, or high concentrate diet. At slaughter, samples of subcutaneous adipose tissue were collected, from which RNA was extracted. Relative abundance of gene expression was measured using Affymetrix GeneChip Bovine Genome array. An ANOVA model nested within gene was used to analyze the background adjusted, normalized average difference of probe-level intensities. To control experiment wise error, a false discovery rate of 0.01 was imposed on all contrasts. Expression of several genes involved in the synthesis of enzymes related to fatty acid metabolism and lipogenesis such as stearoyl-CoA desaturase (SCD), fatty acid synthetase (FASN), lipoprotein lipase (LPL), fatty-acyl elongase (LCE) along with several trancription factors and co-activators involved in lipogenesis were found to be differentially expressed. Confirmatory RT-qPCR was done to validate the microarray results, which showed satisfactory correspondence between the two platforms. Results show that changes in diet by increasing dietary energy intake by supplementing high concentrate diet have effects on the transcription of genes encoding enzymes involved in fat metabolism which in turn has effects on fatty acid content in the carcass tissue as well as carcass quality. Corn supplementation either as oil or grain appeared to significantly alter the expression of genes directly associated with fatty acid synthesis.

Reversal of EPTC Induced Fatty Acid Synthesis Inhibition

Weed Science ◽  
1975 ◽  
Vol 23 (2) ◽  
pp. 90-92 ◽  
Author(s):  
R. E. Wilkinson ◽  
A. E. Smith
Keyword(s):  
Fatty Acids ◽  
Zea Mays ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Spinacia Oleracea ◽  
Acid Synthesis ◽  
Acetate Incorporation ◽  
Naphthalic Anhydride ◽  
Synthesis Inhibition ◽  
Fatty Acid Synthesis Inhibition

EPTC (S-ethyl dipropylthiocarbamate), 1,8-naphthalic anhydride (NA),N,N-dialryl-2,2-dichloroacetamide (R-25788),CDAA(N,N-diallyl-2-chloroacetamide) and CDEC (2-chloroallyl diethyldithiocarbamate) at concentrations of 10-5M inhibited the incorporation of acetate-1-14C (Ac∗) into fatty acids of isolated spinach (Spinacia oleraceaL.) chloroplasts. Lower concentrations of these chemicals did not affect acetate incorporation into fatty acids. However, the inhibition by EPTC at 10-5M was counteracted by NA and R-25788 [agriculturally important antidotes for EPTC injury to corn (Zea maysL.)] at 10-7M.

scholarly journals Chronic ethanol administration depresses fatty acid synthesis in rat adipose tissue

1988 ◽  
Vol 251 (2) ◽  
pp. 547-551 ◽  
Author(s):  
J S Wilson ◽  
M A Korsten ◽  
L P Donnelly ◽  
P W Colley ◽  
J B Somer ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Fatty Acid Synthetase ◽  
Acid Synthesis ◽  
Chronic Ethanol ◽  
Ethanol Administration ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Chronic Ethanol Administration

Administration of ethanol as part of a nutritionally adequate liquid diet to female Wistar rats was found to depress markedly incorporation of labelled glucose into adipose-tissue acylglycerol fatty acids. Similar results with labelled pyruvate and acetate suggested inhibition of the fatty-acid-synthesis pathway at, or distal to, the acetyl-CoA carboxylase step. Activities of acetyl-CoA carboxylase and fatty acid synthetase were markedly lower in ethanol-fed animals. The activity of another lipogenic enzyme, phosphatidate phosphohydrolase, was not affected by chronic ethanol feeding. These findings suggest that chronic ethanol administration has marked effects on adipose-tissue lipogenesis.

Translational control by mTOR-independent routes: how eIF6 organizes metabolism

2016 ◽  
Vol 44 (6) ◽  
pp. 1667-1673 ◽  
Author(s):  
Annarita Miluzio ◽  
Sara Ricciardi ◽  
Nicola Manfrini ◽  
Roberta Alfieri ◽  
Stefania Oliveto ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Insulin Sensitivity ◽  
Fatty Acid Synthesis ◽  
Translational Control ◽  
Metabolic Diseases ◽  
Lipid Synthesis ◽  
Acid Synthesis ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Translational Machinery

Over the past few years, there has been a growing interest in the interconnection between translation and metabolism. Important oncogenic pathways, like those elicited by c-Myc transcription factor and mTOR kinase, couple the activation of the translational machinery with glycolysis and fatty acid synthesis. Eukaryotic initiation factor 6 (eIF6) is a factor necessary for 60S ribosome maturation. eIF6 acts also as a cytoplasmic translation initiation factor, downstream of growth factor stimulation. eIF6 is up-regulated in several tumor types. Data on mice models have demonstrated that eIF6 cytoplasmic activity is rate-limiting for Myc-induced lymphomagenesis. In spite of this, eIF6 is neither transcriptionally regulated by Myc, nor post-transcriptionally regulated by mTOR. eIF6 stimulates a glycolytic and fatty acid synthesis program necessary for tumor growth. eIF6 increases the translation of transcription factors necessary for lipogenesis, such as CEBP/β, ATF4 and CEBP/δ. Insulin stimulation leads to an increase in translation and fat synthesis blunted by eIF6 deficiency. Paradoxycally, long-term inhibition of eIF6 activity increases insulin sensitivity, suggesting that the translational activation observed upon insulin and growth factors stimulation acts as a feed-forward mechanism regulating lipid synthesis. The data on the role that eIF6 plays in cancer and in insulin sensitivity make it a tempting pharmacological target for cancers and metabolic diseases. We speculate that eIF6 inhibition will be particularly effective especially when mTOR sensitivity to rapamycin is abrogated by RAS mutations.

scholarly journals Regulation of hepatic lipogenesis by dietary maize oil or tripalmitin in the meal-fed mouse

1980 ◽  
Vol 43 (3) ◽  
pp. 571-579 ◽  
Author(s):  
G. R. Herzberg ◽  
N. Janmohamed
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Malic Enzyme ◽  
Fatty Acid Synthetase ◽  
Acid Synthesis ◽  
Hepatic Lipogenesis ◽  
Meal Feeding ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Maize Oil

The effect of varying dietary levels of maize oil and tripalmitin (0–250 g fat/kg) on hepatic lipogenesis and the levels of hepatic fatty acid synthetase (FAS), glucose-6-phosphate dehydrogenase (EC 1.1.1.49; G6PD), malic enzyme (EC 1.1.1.38, 1.1.1.39, 1.1.1.40; ME) and glucokinase (EC 2.7.1.2; GK) was examined in meal-fed mice.2. Meal-fed mice compared to mice fed ad lib. show enhanced hepatic lipogenesis as demonstrated by an increased rate of in vivo fatty acid synthesis and increased levels of FAS, ME and G6PD. The level of GK in meal-fed mice was unchanged by meal feeding.3. Maize oil more effectively reduced in vivo hepatic lipogenesis than tripalmitin in meal-fed mice.4. Maize oil more effectively reduced the hepatic levels of FAS, G6PD, ME and GK than tripalmitin in meal-fed mice.5. The increased inhibition by maize oil is observed at all levels of fat in the diet investigated and has been shown not to be due to decreased carbohydrate intake nor to differences between the absorption of maize oil and tripalmitin.

scholarly journals Localization of chloroplastic fatty acid synthesis de novo in the stroma

1985 ◽  
Vol 226 (2) ◽  
pp. 551-556 ◽  
Author(s):  
K A Walker ◽  
J L Harwood
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
High Speed ◽  
De Novo ◽  
Fatty Acid Synthetase ◽  
Acid Synthesis ◽  
Synthetic Activity ◽  
Bisphosphate Carboxylase ◽  
Osmotic Lysis ◽  
Almost All

The synthesis of fatty acids de novo from [2-14C]malonyl-CoA was studied in fractions from lettuce (Lactuca sativa) and pea (Pisum sativum) chloroplasts. When lettuce chloroplasts were subjected to osmotic lysis, disintegration through a Yeda press and high-speed centrifugation, essentially all of the fatty-acid-synthetic activity was found to be soluble. The distribution of the activity in various chloroplast fractions was similar to that of soluble marker enzymes such as ribulose-1,5-bisphosphate carboxylase and NADP+-linked glyceraldehyde-3-phosphate dehydrogenase. Marked differences were apparent in the quality of products from fatty acid synthesis de novo in the various fractions of chloroplasts. Thus soluble fractions produced predominantly stearate, whereas those containing membranes produced a greater proportion of palmitate. In pea chloroplasts, osmotic lysis released almost all of the fatty acid synthetase into the stromal fraction. In this instance, no major alterations in the products of fatty acid synthesis were observed. The fatty-acid-synthetic activity of the stromal fraction was still soluble after prolonged ultracentrifugation. The results show clearly the soluble nature of fatty acid synthesis de novo in lettuce and pea chloroplasts. Thus fatty acid synthesis measured in microsomal fractions from such plant tissues is not due to the presence of chloroplastic membranes.

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