scholarly journals Evidence that noradrenaline increases pyruvate dehydrogenase activity and decreases acetyl-CoA carboxylase activity in rat interscapular brown adipose tissue in vivo

1985 ◽  
Vol 228 (3) ◽  
pp. 751-755 ◽  
Author(s):  
J M Gibbins ◽  
R M Denton ◽  
J G McCormack
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Pyruvate Dehydrogenase ◽  
Acid Synthesis ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Carboxylase Activity ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose

The rate of fatty acid synthesis in interscapular brown adipose tissue of female cold-adapted rats, as measured by the incorporation of 3H from 3H2O into tissue lipid, was decreased by about 70% after injection of noradrenaline. There was a similar decrease in the activity of acetyl-CoA carboxylase. In contrast, the proportion of pyruvate dehydrogenase in its active non-phosphorylated form was greatly increased after injection of noradrenaline. This finding suggests that the oxidation of glucose may be important in noradrenaline-induced thermogenesis in rat brown adipose tissue.

scholarly journals Acute effects in vivo of anti-insulin serum on rates of fatty acid synthesis and activities of acetyl-coenzyme A carboxylase and pyruvate dehydrogenase in liver and epididymal adipose tissue of fed rats

1976 ◽  
Vol 160 (2) ◽  
pp. 413-416 ◽  
Author(s):  
D Stansbie ◽  
R W Brownsey ◽  
M Crettaz ◽  
R M Denton
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Pyruvate Dehydrogenase ◽  
Acid Synthesis ◽  
Epididymal Adipose Tissue ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Carboxylase Activity

Plasma insulin concentrations in fed rats were altered acutely by administration of glucose or anti-insulin serum. Rates of fatty acid synthesis in adipose tissue and liver were estimated from the incorporation of 3H from 3H2O. In the adipose tissue dehydrogenase and acetyl-CoA carboxylase were evident. In liver, although changes in rates of fatty acid synthesis were found, the initial activity of pyruvate dehydrogenase did not alter, but small parallel changes in acetyl-CoA carboxylase activity were observed.

scholarly journals Regulation of fatty acid synthesis and malonyl-CoA content in mouse brown adipose tissue in response to cold-exposure, starvation or re-feeding

1987 ◽  
Vol 243 (2) ◽  
pp. 437-442 ◽  
Author(s):  
M G Buckley ◽  
E A Rath
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Brown Adipose Tissue ◽  
Fatty Acid Synthesis ◽  
Cold Exposure ◽  
Acid Synthesis ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Malonyl Coa ◽  
Brown Adipose

1. The effect of nutritional status on fatty acid synthesis in brown adipose tissue was compared with the effect of cold-exposure. Fatty acid synthesis was measured in vivo by 3H2O incorporation into tissue lipids. The activities of acetyl-CoA carboxylase and fatty acid synthetase and the tissue concentrations of malonyl-CoA and citrate were assayed. 2. In brown adipose tissue of control mice, the tissue content of malonyl-CoA was 13 nmol/g wet wt., higher than values reported in other tissues. From the total tissue water content, the minimum possible concentration was estimated to be 30 microM 3. There were parallel changes in fatty acid synthesis, malonyl-CoA content and acetyl-CoA carboxylase activity in response to starvation and re-feeding. 4. There was no correlation between measured rates of fatty acid synthesis and malonyl-CoA content and acetyl-CoA carboxylase activity in acute cold-exposure. The results suggest there is simultaneous fatty acid synthesis and oxidation in brown adipose tissue of cold-exposed mice. This is probably effected not by decreases in the malonyl-CoA content, but by increases in the concentration of free long-chain fatty acyl-CoA or enhanced peroxisomal oxidation, allowing shorter-chain fatty acids to enter the mitochondria independent of carnitine acyltransferase (overt form) activity.

scholarly journals Evidence for a high fatty acid synthesis activity in interscapular brown adipose tissue of genetically obese Zucker rats

1982 ◽  
Vol 204 (2) ◽  
pp. 503-507 ◽  
Author(s):  
M Lavau ◽  
R Bazin ◽  
Z Karaoghlanian ◽  
C Guichard
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Brown Adipose Tissue ◽  
Fatty Acid Synthetase ◽  
High Fatty Acid ◽  
Acid Synthesis ◽  
Zucker Rats ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose

Obese (fa/fa) rats (30 days old) exhibited a 50% increase in the weight of interscapular brown adipose tissue compared with their lean (Fa/fa) littermates. The tissue weight increase was accounted for by an increased fat content. Lipogenesis in vivo, as assessed by the incorporation of 3H from 3H2O into lipid, was increased 5-fold in brown adipose tissue of obese as compared with lean rats. Accordingly, acetyl-CoA carboxylase, fatty acid synthetase, citrate-cleavage enzyme and malic enzyme in this tissue were 4-8 times more active in obese than in lean rats.

scholarly journals Developmental changes in fatty acid synthesis in interscapular brown adipose tissue of lean and genetically obese (ob/ob) mice

1983 ◽  
Vol 212 (2) ◽  
pp. 393-398 ◽  
Author(s):  
S W Mercer ◽  
P Trayhurn
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Brown Adipose Tissue ◽  
Fatty Acid Synthesis ◽  
Acid Synthesis ◽  
Obese Mice ◽  
Carbohydrate Diet ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose

Fatty acid synthesis was measured in vivo with 3H2O in interscapular brown adipose tissue of lean and genetically obese (ob/ob) mice. At 26 days of age, before the development of hyperphagia, synthesis in brown adipose tissue was higher in the obese than in the lean mice; synthesis was also elevated in the liver, white adipose tissue and carcass of the obese mice. At 8 weeks of age, when hyperphagia was well established, synthesis remained elevated in all tissues of the obese mice, with the exception of brown adipose tissue. Elevated synthesis rates were not apparent in brown adipose tissue of the obese mice at 14 days of age, nor at 35 days of age. These results demonstrate that brown adipose tissue in ob/ob mice has a transitory hyperlipogenesis at, and just after, weaning on to a low-fat/high-carbohydrate diet. Once hyperphagia has developed, by week 5 of life, brown adipose tissue is the only major lipogenic tissue in the obese mice not to exhibit elevated rates of fatty acid synthesis; this suggests that insulin resistance develops much more rapidly in brown adipose tissue than in other lipogenic tissues of the ob/ob mouse.

Effect of exercise training on the rates of fatty acid synthesis in mice

1984 ◽  
Vol 62 (6) ◽  
pp. 695-699 ◽  
Author(s):  
Denis Richard ◽  
Paul Trayhurn
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Brown Adipose Tissue ◽  
Fatty Acid Synthesis ◽  
High Capacity ◽  
Acid Synthesis ◽  
Training Programme ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose

The present study has investigated the respective effects of training and exercise on the rates of fatty acid synthesis in mice. Male C57B1 10ScSn mice were trained by forced swimming in a tank at 36°C for 2 h each day for a 28-day period. Rates of fatty acid synthesis were determined in vivo by measuring the incorporation of tritium from 3H2O into tissue fatty acids. At the end of the training programme, both sedentary and trained mice were assigned to either exercising or resting groups. The results obtained show that both training and exercise affected the rates of fatty acid synthesis, regardless of whether the results are expressed per gram of tissue or per whole tissue. Training led to significant decreases in the rates of synthesis in the liver, interscapular brown adipose tissue, epididymal white adipose tissue, and the remaining carcass, particularly in resting mice. The rates of fatty acid synthesis in the major lipogenic tissues were also lower during exercise than under sedentary conditions. The reduction in synthesis in brown adipose tissue was noteworthy in view of the high capacity of this tissue for fatty acid synthesis. In conclusion, it is suggested that in exercise-trained mice carbohydrate is shunted away from the synthesis of lipid in favour of energy storage as glycogen.

scholarly journals Evidence that fatty acid synthesis in the interscapular brown adipose tissue of cold-adapted rats is increased in vivo by insulin by mechanisms involving parallel activation of pyruvate dehydrogenase and acetyl-coenzyme A carboxylase

1977 ◽  
Vol 166 (3) ◽  
pp. 627-630 ◽  
Author(s):  
J G McCormack ◽  
R M Denton
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Brown Adipose Tissue ◽  
Fatty Acid Synthesis ◽  
Pyruvate Dehydrogenase ◽  
Plasma Insulin ◽  
Acid Synthesis ◽  
Interscapular Brown Adipose Tissue ◽  
Cold Adapted ◽  
Brown Adipose

Plasma insulin concentrations in cold-adapted rats were altered acutely by administration of glucose or anti-insulin serum. Rates of fatty acid synthesis in interscapular brown adipose tissue were determined from the incorporation of 3H from 3H2O into tissue lipid. Rates of synthesis were greatly elevated after glucose administration and markedly decreased after injection with anti-insulin serum. Parallel changes in the initial activities of both acetyl-CoA carboxylase and pyruvate dehydrogenase were observed under these conditions, but no changes in total activities were evident. The results suggest that this tissue is an important site of fatty acid synthesis in the cold-adapted rat and that this feature of the tissue is sensitive to changes in plasma insulin concentrations.

Fatty acid synthesis and generation of glycerol-3-phosphate in brown adipose tissue from rats fed a cafeteria diet

2008 ◽  
Vol 86 (7) ◽  
pp. 416-423 ◽  
Author(s):  
Valéria E. Chaves ◽  
Danúbia Frasson ◽  
Maria E.S. Martins-Santos ◽  
Luiz C.C. Navegantes ◽  
Victor D. Galban ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Brown Adipose Tissue ◽  
Glucose Uptake ◽  
Fatty Acid Synthesis ◽  
Fatty Acid Content ◽  
Acid Synthesis ◽  
Cafeteria Diet ◽  
Brown Adipose

In vivo fatty acid synthesis and the pathways of glycerol-3-phosphate (G3P) production were investigated in brown adipose tissue (BAT) from rats fed a cafeteria diet for 3 weeks. In spite of BAT activation, the diet promoted an increase in the carcass fatty acid content. Plasma insulin levels were markedly increased in cafeteria diet-fed rats. Two insulin-sensitive processes, in vivo fatty acid synthesis and in vivo glucose uptake (which was used to evaluate G3P generation via glycolysis) were increased in BAT from rats fed the cafeteria diet. Direct glycerol phosphorylation, evaluated by glycerokinase (GyK) activity and incorporation of [U-14C]glycerol into triacylglycerol (TAG)–glycerol, was also markedly increased in BAT from these rats. In contrast, the cafeteria diet induced a marked reduction of BAT glyceroneogenesis, evaluated by phosphoenolpyruvate carboxykinase-C activity and incorporation of [1-14C]pyruvate into TAG–glycerol. BAT denervation resulted in an approximately 50% reduction of GyK activity, but did not significantly affect BAT in vivo fatty acid synthesis, in vivo glucose uptake, or glyceroneogenesis. The data suggest that the supply of G3P for BAT TAG synthesis can be adjusted independently from the sympathetic nervous system and solely by reciprocal changes in the generation of G3P via glycolysis and via glyceroneogenesis, with no participation of direct phosphorylation of glycerol by GyK.

scholarly journals Physiological modulation of the uptake and fate of glucose in brown adipose tissue

1993 ◽  
Vol 295 (1) ◽  
pp. 171-176 ◽  
Author(s):  
M C Sugden ◽  
M J Holness
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Brown Adipose Tissue ◽  
Fatty Acid Synthesis ◽  
Diurnal Cycle ◽  
Acid Synthesis ◽  
Pregnant Rats ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose ◽  
Ad Libitum

Glucose utilization indices (GUI values) and rates of fatty acid synthesis in interscapular brown adipose tissue (IBAT) varied during the diurnal cycle in virgin and late-pregnant rats permitted unrestricted access to food. In virgin rats, peak GUI values and lipogenic rates were observed at the end of the dark (feeding) phase, but were not sustained during the light phase. Whereas peak GUI values were comparable with those observed during re-feeding after 24 h starvation, maximum rates of IBAT fatty acid synthesis in virgin rats during the diurnal cycle were only approx. 25% of those measured during re-feeding after 24 h starvation. Despite hyperphagia, GUI values during the diurnal cycle in late-pregnant rats fed ad libitum were generally lower than those of age-matched virgin controls. The percentage of pyruvate dehydrogenase complex present in the active form (PDHa) was also significantly decreased. Suppression of GUI and PDHa was not parallelled by suppression of fatty acid synthesis. IBAT GUI values in late-pregnant rats during chow re-feeding ad libitum after 24 h starvation were only 25% of those of corresponding virgin controls, and stimulation of fatty acid synthesis was also dramatically attenuated. The suppression of IBAT GUI values after re-feeding in pregnancy was not due to depletion of GLUT 4 protein. The results are discussed in relation to the importance of glucose as a precursor for fatty acid synthesis in IBAT.

Brown adipose tissue after ventromedial hypothalamic lesions in rats

1985 ◽  
Vol 248 (1) ◽  
pp. E20-E25 ◽  
Author(s):  
M. Saito ◽  
Y. Minokoshi ◽  
T. Shimazu
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Lipid Droplets ◽  
Temperature Response ◽  
Sympathetic Nerves ◽  
Acid Synthesis ◽  
Ventromedial Hypothalamus ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose ◽  
Obese Rats

The interscapular brown adipose tissue (IBAT) from obese rats with lesions of the ventromedial hypothalamus (VMH) was approximately 5 times heavier than those from controls. This hypertrophy of IBAT was associated with a marked enlargement of constituent adipocytes and their apparent transformation from multiloculated structure of lipid droplets into the uniloculated structure. The rate of fatty acid synthesis in IBAT of the obese rats was less than one-tenth of that in control rats and approximated the value in white adipose tissue (WAT) when they were starved for 24 h. When rats were fed, the synthetic rate was increased, but the lipogenic response of IBAT in the obese rats was much greater than that in controls, the extent of the response being comparable to that of WAT. The IBAT temperature rose rapidly on electrical stimulation of the sympathetic nerves to the tissue in control rats, whereas the temperature response was reduced markedly in the obese rats. It was suggested that thermogenesis in BAT was impaired in obese rats with VMH lesions by decreasing triglyceride turnover in BAT, probably due to dysfunction of the sympathetic nervous system and a consequent transformation of BAT into WAT.

Transient upregulation of IGF-I gene expression in brown adipose tissue of cold-exposed rats

1997 ◽  
Vol 272 (3) ◽  
pp. E453-E460 ◽  
Author(s):  
C. Duchamp ◽  
K. A. Burton ◽  
A. Geloen ◽  
M. J. Dauncey
Keyword(s):  
Adipose Tissue ◽  
Food Intake ◽  
Brown Adipose Tissue ◽  
Unit Weight ◽  
Mrna Levels ◽  
Interscapular Brown Adipose Tissue ◽  
Total Rna ◽  
Brown Adipose ◽  
Igf I

The possible involvement of locally produced insulin-like growth factor I (IGF-I) in the cold-induced hyperplasia of interscapular brown adipose tissue (BAT) was investigated in 2-, 4-, and 7-day cold-exposed (CE, 4 degrees C) rats by measuring BAT IGF-I expression at a time when extensive BAT cell proliferation occurs. By comparison with thermoneutral (25 degrees C) controls, plasma IGF-I decreased in CE rats despite an increased food intake, whereas BAT IGF-I peptide increased markedly to peak after 4 days at 4 degrees C. The ratio of class 1 to class 2 IGF-I mRNA was much higher in BAT than in liver. BAT IGF-I mRNA levels per unit weight total RNA doubled after 2 days at 4 degrees C but decreased thereafter to the level in controls. Upregulation of BAT IGF-I mRNA also occurred in CE rats with a food intake restricted to the level of controls. The transient cold-induced upregulation of BAT IGF-I (per unit weight total RNA) suggests that IGF-I plays a role in the early cold-induced BAT hyperplasia that occurs in vivo.

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