Fatty acid synthesis in brown adipose tissue in relation to whole body synthesis in the cold-acclimated golden hamster (Mesocricetus auratus)

Author(s):  
Paul Trayhurn
Nutrition ◽  
2014 ◽  
Vol 30 (4) ◽  
pp. 473-480 ◽  
Author(s):  
Suélem Aparecida de França ◽  
Maísa Pavani dos Santos ◽  
Roger Vinícius Nunes Queiroz da Costa ◽  
Mendalli Froelich ◽  
Samyra Lopes Buzelle ◽  
...  

1987 ◽  
Vol 243 (2) ◽  
pp. 437-442 ◽  
Author(s):  
M G Buckley ◽  
E A Rath

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.


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 ◽  
...  

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.


1993 ◽  
Vol 295 (1) ◽  
pp. 171-176 ◽  
Author(s):  
M C Sugden ◽  
M J Holness

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.


1983 ◽  
Vol 3 (3) ◽  
pp. 217-224 ◽  
Author(s):  
Nancy J. Rothwell ◽  
Michael J. Stock ◽  
Paul Trayhurn

Fatty-acid synthesis has been measured in vivo with 3H2O in cafeteria-fed rats exhibiting diet-induced thermogenesis. Synthesis was decreased in brown adipose tissue, the liver, white adipose tissue, and the carcass of the cafeteria-fed animals compared to rats fed the normal stock diet. Whole-body synthesis was also decreased in the cafeteria-fed group. Diet-induced thermogenesis, in contrast to cold-induced non-shivering thermogenesis does not lead to increased fatty-acid synthesis and this is presumably due to the inhibitory effects on lipogenesis of the high dietary fat intake characteristic of cafeteria diets. The results also indicate that the energy cost of body fat deposition in cafeteria-fed rats is lower than in animals fed a low-fat/high-carbohydrate stock diet.


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