THE EFFECT OF HOMOGENIZATION ON FREE AND ESTERIFIED FATTY ACID POOLS IN ADIPOSE TISSUE

1965 ◽  
Vol 43 (2) ◽  
pp. 271-280 ◽  
Author(s):  
David Rubinstein ◽  
Anna M. Daniel ◽  
Sylvester Chiu ◽  
John C. Beck
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Incubation Medium ◽  
Specific Activity ◽  
Tissue Cell ◽  
Intact Tissue ◽  
Adipose Tissue Cell ◽  
Specific Activities ◽  
Presence And Absence

The effect of homogenization of adipose tissue on fatty acid pools was studied with palmitate-1-C14 in the presence and absence of epinephrine. Addition of epinephrine to intact tissue in an incubation medium high in FFA increases the specific activity of the tissue FFA. When the tissue is incubated in a medium low in FFA, epinephrine induces an increase in the concentration and radioactivity of the tissue FFA. Epinephrine decreases the esterification of palmitate-1-C14 by intact tissue, regardless of the FFA concentration in the medium. This decrease is unrelated to the specific activities of either the medium or the tissue FFA. In homogenates, the decrease in incorporation of palmitate-1-C14 is proportional to the decrease in the specific activity of the FFA induced by epinephrine. Under the influence of epinephrine, FFA released from adipose tissue that was previously charged with palmitate-1-C14 have a specific activity about six times as great as the glyceride fatty acids. This difference is abolished by homogenization of the tissue. These results suggest that the newly synthesized triglycerides exist as a separate pool and are more readily hydrolyzed, thereby contributing FFA to an intracellular FFA pool. The existence of multiple pools of glycerides and FFA in the adipose tissue cell is dependent on the architecture of the cell.

THE EFFECT OF VARIOUS SACCHARIDES ON THE RELEASE OF NON ESTERIFIED FATTY ACIDS FROM ADIPOSE TISSUE IN VITRO

1962 ◽  
Vol 40 (4) ◽  
pp. 455-458 ◽  
Author(s):  
W. F. Perry ◽  
R. J. Tjaden
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Incubation Medium ◽  
Epididymal Adipose Tissue ◽  
Tissue Cell ◽  
Glycerol Phosphate ◽  
Esterified Fatty Acids ◽  
Adipose Tissue Cell ◽  
Other Substances

Rat epididymal adipose tissue was incubated in a phosphate–albumin medium to ascertain the effect of various saccharides and other substances on the release of non-esterified fatty acids (NEFA) into the medium. It was found that incubation with glucose, mannose, fructose, and 2-deoxy glucose resulted in less release of NEFA from the tissue into the incubation medium. Incubation with galactose, sucrose, lactose, D-ribose, D-xylose, L-xylose, D-arabinose, L-arabinose, D-lyxose, sodium pyruvate, glycerol, and glycerol phosphate showed no differences from the control in release of NEFA into the incubation medium. These results are consistent with the theory that the NEFA-lowering action of glucose is due to esterification of free fatty acid within the adipose tissue cell by glycerol phosphate.

THE EFFECT OF VARIOUS SACCHARIDES ON THE RELEASE OF NON ESTERIFIED FATTY ACIDS FROM ADIPOSE TISSUE IN VITRO

1962 ◽  
Vol 40 (1) ◽  
pp. 455-458
Author(s):  
W. F. Perry ◽  
R. J. Tjaden
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Incubation Medium ◽  
Epididymal Adipose Tissue ◽  
Tissue Cell ◽  
Glycerol Phosphate ◽  
Esterified Fatty Acids ◽  
Adipose Tissue Cell ◽  
Other Substances

Rat epididymal adipose tissue was incubated in a phosphate–albumin medium to ascertain the effect of various saccharides and other substances on the release of non-esterified fatty acids (NEFA) into the medium. It was found that incubation with glucose, mannose, fructose, and 2-deoxy glucose resulted in less release of NEFA from the tissue into the incubation medium. Incubation with galactose, sucrose, lactose, D-ribose, D-xylose, L-xylose, D-arabinose, L-arabinose, D-lyxose, sodium pyruvate, glycerol, and glycerol phosphate showed no differences from the control in release of NEFA into the incubation medium. These results are consistent with the theory that the NEFA-lowering action of glucose is due to esterification of free fatty acid within the adipose tissue cell by glycerol phosphate.

LIPOGENESIS IN ADIPOSE TISSUE OF MEAL-FED RATS: A POSSIBLE REGULATORY ROLE OF α-GLYCEROPHOSPHATE FORMATION

1967 ◽  
Vol 45 (2) ◽  
pp. 201-214 ◽  
Author(s):  
Gilbert A. Leveille
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Incubation Medium ◽  
Control Mechanism ◽  
Acid Synthesis ◽  
Fatty Acyl ◽  
Epididymal Adipose Tissue ◽  
Malic Dehydrogenase

The incorporation of acetate-1-14C into fatty acids by isolated epididymal adipose tissue of fed and fasted rats adapted to a single daily 2-hour meal (meal eaters) or fed ad libitum (nibblers) was investigated. Fasting (22 hours) markedly depressed lipogenesis whereas fatty acid synthesis increased linearly with time of refeeding in meal-fed but not in nibbling rats. The activities of glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, and NADP-malic dehydrogenase in adipose tissue of meal-fed or nibbling rats were not altered as a consequence of a 22-hour fast or of subsequent feeding for 2 hours. The incorporation of acetate-1-l4C into fatty acids by adipose tissue of fasted meal-eating or nibbling animals was markedly enhanced by the addition of unlabeled pyruvate or oxaloacetate to the incubation medium. This stimulatory effect was not observed with adipose tissue front fed meal-eating rats. The addition of unlabeled glucose and insulin to the incubation medium markedly enhanced acetate-1-14C incorporation into fatty acids by isolated adipose tissue and completely overcame any effect of fasting. Adipose tissue converted pyruvate-1-14C, -2-14C, or -3-14C to fatty acids and glyceride-glycerol. The results obtained are consistent with the functioning of a pathway in adipose tissue involving mitochondrial carboxylation of pyruvate to oxaloacetate, and equilibration of the newly formed oxaloacetate with malate and fumarate, followed by cytoplasmic conversion of oxaloacetate to phosphoenol pyruvate. The data are interpreted to support a control mechanism in which fatty acid synthesis is inhibited by tissue fatty acids and fatty acyl-CoA derivatives. The inhibition could in turn be reduced by the availability of α-glycerophosphate, for the esterification of fatty acids. This control mechanism is proposed as the explanation for the refeeding response observed in adipose tissue of meal-fed rats.

scholarly journals FATTY ACID COMPOSITION AND DISTRIBUTION OF 14C-GLUCOSE ACTIVITY IN LIPID CLASSES OF PORCINE SUBCUTANEOUS FAT

1974 ◽  
Vol 54 (4) ◽  
pp. 645-650 ◽  
Author(s):  
A. W. MYRES ◽  
J. P. BOWLAND
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Unsaturated Fatty Acids ◽  
Specific Activity ◽  
Subcutaneous Fat ◽  
Free Form ◽  
Considerable Proportion

Subcutaneous backfat samples from pigs receiving diets with or without 250 ppm supplemental copper were separated into glycerides (GLY) and free fatty acids (FFA) and the fatty acid composition of each fraction was determined. In addition, the effect of dietary copper on the distribution of 14C- from U-14C-glucose between GLY and FFA in depot fat was examined. The basal diet consisted of 90.1% barley and 7.5% herring meal. Results from three experiments suggest that copper may act in adipose tissue of the pig by increasing the proportion of unsaturated fatty acids (UFA) in both the FFA and GLY fractions in animals of 60–70 kg liveweight. The distribution of 14C activity in the fatty acids of the GLY and FFA fractions indicated a higher specific activity of the FFA fraction compared with that of the GLY fatty acids. The GLY/FFA ratio was lower for copper-supplemented animals kept in a cold environment. The overall data suggest that a considerable proportion of newly synthesized acids exists in adipose tissue in the free form.

Incorporation of Na-1-14C-acetate into the fatty acids of two insect parasites (Hymenoptera) reared on different hosts

1971 ◽  
Vol 49 (10) ◽  
pp. 1297-1300 ◽  
Author(s):  
J. S. Barlow ◽  
G. K. Bracken
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Dietary Fat ◽  
Palmitoleic Acid ◽  
Galleria Mellonella ◽  
Specific Activity ◽  
Host Tissue ◽  
Metabolic Rates ◽  
Specific Activities ◽  
Insect Parasites

Sodium-1-14C-acetate was injected into larvae of the parasite, Exeristes comstockii, reared on Galleria mellonella or on Lucilia sericata. The concentration and specific activities of the fatty acids in the larvae were measured 24 h later. The concentration of palmitoleic acid was 10 times greater in C. comstockii when it grew on L. sericata but the specific activity of this fatty acid was the same on either host. It is concluded that the level of palmitoleic acid and probably other fatty acids in the parasite is controlled predominantly by changes in metabolic rates which are regulated by the concentration of the fatty acid in the parasite's diet, that is, host tissue. Direct deposition of dietary fat would not accomplish this result.Another parasite, Itoplectus conquisitor, reared on G. mellonella was also examined.

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.

Effects of cold acclimation on lipid metabolism in adipose tissue

1961 ◽  
Vol 200 (4) ◽  
pp. 847-850 ◽  
Author(s):  
Judith K. Patkin ◽  
E. J. Masoro
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Lipid Metabolism ◽  
Cold Acclimation ◽  
Long Chain Fatty Acids ◽  
Synthetic Capacity ◽  
And Control ◽  
Long Chain ◽  
Chain Fatty Acids

Cold acclimation is known to alter hepatic lipid metabolism. Liver slices from cold-acclimated rats have a greatly depressed capacity to synthesize long-chain fatty acids from acctate-1-C14. Since adipose tissue is the major site of lipogenic activity in the intact animal, its fatty acid synthetic capacity was studied. In contrast to the liver, it was found that adipose tissue from the cold-acclimated rat synthesized three to six times as much long-chain fatty acids per milligram of tissue protein as the adipose tissue from the control rat living at 25°C. Evidence is presented indicating that adipose tissue from cold-acclimated and control rats esterify long-chain fatty acids at the same rate. The ability of adipose tissue to oxidize palmitic acid to CO2 was found to be unaltered by cold acclimation. The fate of the large amount of fatty acid synthesized in the adipose tissue of cold-acclimated rats is discussed.

Role of the AMP-activated protein kinase in regulating fatty acid metabolism during exerciseThis paper is one of a selection of papers published in this Special Issue, entitled 14th International Biochemistry of Exercise Conference – Muscles as Molecular and Metabolic Machines, and has undergone the Journal’s usual peer review process.

2009 ◽  
Vol 34 (3) ◽  
pp. 315-322 ◽  
Author(s):  
Gregory R. Steinberg
Keyword(s):  
Skeletal Muscle ◽  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid ◽  
Protein Kinase ◽  
Fatty Acid Metabolism ◽  
Acid Metabolism ◽  
Moderate Intensity ◽  
Amp Activated Protein Kinase

During moderate-intensity exercise, fatty acids are the predominant substrate for working skeletal muscle. The release of fatty acids from adipose tissue stores, combined with the ability of skeletal muscle to actively fine tune the gradient between fatty acid and carbohydrate metabolism, depending on substrate availability and energetic demands, requires a coordinated system of metabolic control. Over the past decade, since the discovery that AMP-activated protein kinase (AMPK) was increased in accordance with exercise intensity, there has been significant interest in the proposed role of this ancient stress-sensing kinase as a critical integrative switch controlling metabolic responses during exercise. In this review, studies examining the role of AMPK as a regulator of fatty acid metabolism in both adipose tissue and skeletal muscle during exercise will be discussed. Exercise induces activation of AMPK in adipocytes and regulates triglyceride hydrolysis and esterfication through phosphorylation of hormone sensitive lipase (HSL) and glycerol-3-phosphate acyl-transferase, respectively. In skeletal muscle, exercise-induced activation of AMPK is associated with increases in fatty acid uptake, phosphorylation of HSL, and increased fatty acid oxidation, which is thought to occur via the acetyl-CoA carboxylase-malony-CoA-CPT-1 signalling axis. Despite the importance of AMPK in regulating fatty acid metabolism under resting conditions, recent evidence from transgenic models of AMPK deficiency suggest that alternative signalling pathways may also be important for the control of fatty acid metabolism during exercise.

scholarly journals Regulation of lipogenic capacity in lactating rats

1982 ◽  
Vol 208 (3) ◽  
pp. 611-618 ◽  
Author(s):  
M R Grigor ◽  
A Geursen ◽  
M J Sneyd ◽  
S M Warren
Keyword(s):  
Mammary Gland ◽  
Fatty Acid ◽  
Malic Enzyme ◽  
Fatty Acid Synthase ◽  
Specific Activity ◽  
Mammary Glands ◽  
Lipogenic Enzymes ◽  
Pregnancy And Lactation ◽  
Specific Activities

1. The rate of mammary-gland lipogenesis measured in vivo from 3H2O was suppressed after decreasing the milk demand by decreasing the number of pups from ten to two or three, as well as by giving diets containing lipid [Grigor & Warren (1980) Biochem. J. 188, 61-65]. 2. The specific activities of the lipogenic enzymes fatty acid synthase, glucose 6-phosphate dehydrogenase and ‘malic’ enzyme increased between 6- and 10-fold in the mammary gland and between 2- and 3-fold in the livers during the first 10 days of lactation. The increases in specific activity coupled with the doubling of liver mass which occurred during pregnancy and lactation resulted in considerable differences in total liver activities when compared with virgin animals. 3. Although consumption of a diet containing 20% peanut oil suppressed the activities of the three lipogenic enzymes in the livers, only the ‘malic’ enzyme was affected in the mammary glands. 4. In contrast, decreased milk demand did not affect the specific activities of any of the liver enzymes, whereas it resulted in suppression of all three lipogenic enzymes of the mammary glands. There was no effect on either the cytoplasmic malate dehydrogenase or the lactate dehydrogenase of the mammary gland. 5. In all the experiments performed, the activity of the fatty acid synthase correlated with the amount of material precipitated by the rabbit antibody raised against rat fatty acid synthase.

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