Impacts of a Balanced Omega 6:3 Diet on Fatty Acid Deposition in White and Brown Adipose Tissue and Circulating Plasma in the Hibernating Arctic Ground Squirrel

Chronic cold exposure of rats (9 days at 5°C) induces an alteration of the fatty acid composition of phospholipids in brown adipose tissue. The alteration is due to an increase of the unsaturation degree of these lipids. The phenomenon can be reproduced by 10−7 mole. h−1 administration of noradrenaline for 9 days in rats kept at 25°C. Thus, phospholipid alteration in brown fat of cold exposed rats is most probably a consequence of the increase of sympathetic tone which occurs in this tissue during exposure to cold.

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

Biochemical Journal ◽

10.1042/bj2430437 ◽

1987 ◽

Vol 243 (2) ◽

pp. 437-442 ◽

Cited By ~ 20

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.

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Muscle and brown adipose tissue fatty acid profiles in cold-exposed rats.

The Japanese Journal of Physiology ◽

10.2170/jjphysiol.37.783 ◽

1987 ◽

Vol 37 (5) ◽

pp. 783-796 ◽

Cited By ~ 8

Author(s):

Koji OGAWA ◽

Tomie OHNO ◽

Akihiro KUROSHIMA

Keyword(s):

Adipose Tissue ◽

Fatty Acid ◽

Brown Adipose Tissue ◽

Fatty Acid Profiles ◽

Adipose Tissue Fatty Acid ◽

Tissue Fatty Acid ◽

Brown Adipose

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Regulation of brown adipose tissue lipogenesis by thyroid hormone and the sympathetic nervous system

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1993.265.2.e252 ◽

1993 ◽

Vol 265 (2) ◽

pp. E252-E258 ◽

Cited By ~ 2

Author(s):

W. J. Yeh ◽

P. Leahy ◽

H. C. Freake

Keyword(s):

Nervous System ◽

Adipose Tissue ◽

Fatty Acid ◽

Thyroid Hormone ◽

Sympathetic Nervous System ◽

Brown Adipose Tissue ◽

Fatty Acid Synthase ◽

Northern Analysis ◽

Brown Adipose ◽

Sympathetic Nervous

Thyroid hormone regulates lipogenesis differently in rat liver and brown adipose tissue (BAT). In the hypothyroid state, lipogenesis is suppressed in liver but enhanced in BAT. Here we investigated the mechanisms underlying increased lipogenesis in hypothyroid BAT. Housing the animals at 28 degrees C decreased lipogenesis in hypothyroid BAT to euthyroid levels. Denervation resulted in a 90% reduction in lipogenesis in hypothyroid BAT such that levels were lower than in euthyroid tissue. Thyroid hormone treatment of hypothyroid rats stimulated fatty acid synthesis in denervated BAT, as in liver, but decreased it in intact BAT. Steady-state levels of mRNA encoding acetyl-CoA carboxylase, fatty-acid synthase, and spor 14 were measured in similar animals by Northern analysis. The expression of these mRNAs mirrored the lipogenic data, showing that both thyroid hormone and the sympathetic nervous system work at a pretranslational level in this tissue. These data suggest that the increased BAT lipogenesis found with hypothyroidism is mediated by the sympathetic nervous system to counter the reduction in metabolic rate in these animals.

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