Brown adipose tissue and thermogenesis in hypophysectomized rats in relation to temperature acclimation

1984 ◽  
Vol 400 (2) ◽  
pp. 171-177 ◽  
Author(s):  
Marie-Claude Laury ◽  
Fatima Azma ◽  
Louis Zizine ◽  
Rene Portet
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Temperature Acclimation ◽  
Brown Adipose ◽  
Hypophysectomized Rats

Growth of interscapular brown adipose tissue in cold-acclimated hypophysectomized rats maintained on thyroxine and corticosterone

1982 ◽  
Vol 60 (8) ◽  
pp. 838-842 ◽  
Author(s):  
Mathias Fellenz ◽  
Joan Triandafillou ◽  
Cynthia Gwilliam ◽  
Jean Himms-Hagen
Keyword(s):  
Molecular Weight ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Relative Proportion ◽  
Pituitary Hormones ◽  
Proton Conductance ◽  
Polypeptide Composition ◽  
Interscapular Brown Adipose Tissue ◽  
Brown Adipose ◽  
Hypophysectomized Rats

Brown adipose tissue (BAT) of rats is known to grow in response to acclimation to cold. The growth is accompanied by changes in mitochondrial polypeptide composition (an increase in the relative proportion of a polypeptide of molecular weight 32 000, known to be associated with the thermogenic proton conductance pathway). The mediator of the change in mitochondrial polypeptide composition is unknown. The objective of these experiments was to find out whether any of the pituitary hormones might be the mediator. Treatment of rats with growth hormone failed to alter BAT size or mitochondrial polypeptide composition. BAT grew and the change in BAT mitochondrial polypeptide composition occurred in cold-acclimated hypophysectomized rats, maintained on thyroxine and corticosterone to ensure their survival in the cold. It is concluded that none of the pituitary hormones is the mediator for the cold-induced change in BAT mitochondrial polypeptide composition or is required to exert a direct effect on BAT for cold-induced BAT growth to occur. It also seems unlikely that more than a maintenance amount of glucocorticoids is required for normal cold-induced growth of BAT; these hormones are thus also unlikely to mediate the change in BAT mitochondrial polypeptide composition. The requirement for no more than a maintenance amount of thyroxine for BAT growth and for the cold-induced change in BAT mitochondrial polypeptide composition confirms previous conclusions drawn from studies on cold-acclimated thyroidectomized rats.

Adrenergically stimulated blood flow in brown adipose tissue is not dependent on thermogenesis

2015 ◽  
Vol 308 (9) ◽  
pp. E822-E829 ◽  
Author(s):  
Gustavo Abreu-Vieira ◽  
Carolina E. Hagberg ◽  
Kirsty L. Spalding ◽  
Barbara Cannon ◽  
Jan Nedergaard
Keyword(s):  
Blood Flow ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Uncoupling Protein ◽  
Temperature Acclimation ◽  
The Body ◽  
Doppler Imaging ◽  
Dependent Manner ◽  
Brown Adipose

Brown adipose tissue (BAT) thermogenesis relies on blood flow to be supplied with nutrients and oxygen and for the distribution of the generated heat to the rest of the body. Therefore, it is fundamental to understand the mechanisms by which blood flow is regulated and its relation to thermogenesis. Here, we present high-resolution laser-Doppler imaging (HR-LDR) as a novel method for noninvasive in vivo measurement of BAT blood flow in mice. Using HR-LDR, we found that norepinephrine stimulation increases BAT blood flow in a dose-dependent manner and that this response is profoundly modulated by environmental temperature acclimation. Surprisingly, we found that mice lacking uncoupling protein 1 (UCP1) have fully preserved BAT blood flow response to norepinephrine despite failing to perform thermogenesis. BAT blood flow was not directly correlated to systemic glycemia, but glucose injections could transiently increase tissue perfusion. Inguinal white adipose tissue, also known as a brite/beige adipose tissue, was also sensitive to cold acclimation and similarly increased blood flow in response to norepinephrine. In conclusion, using a novel noninvasive method to detect BAT perfusion, we demonstrate that adrenergically stimulated BAT blood flow is qualitatively and quantitatively fully independent of thermogenesis, and therefore, it is not a reliable parameter for the estimation of BAT activation and heat generation.

Lipolysis in brown adipose tissue of cold- and heat-acclimated hamsters

1977 ◽  
Vol 43 (6) ◽  
pp. 1007-1011 ◽  
Author(s):  
T. Rabi ◽  
Y. Cassuto ◽  
A. Gutman
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Incubation Medium ◽  
Temperature Acclimation ◽  
The Other ◽  
Glycerol Release ◽  
Tissue Slices ◽  
Brown Adipose ◽  
And Control

Rates of release of free fatty acids (FFA) and glycerol to the incubation medium by brown adipose tissue (BAT) slices isolated from heat-acclimated (H), cold-acclimated (C), and control (N) hamsters in the absence or presence of epinephrine (E) were studied. Rates of FFA and glycerol release by tissue slices isolated from H and N animals were similar. In tissue slices isolated from C animals rate of release of FFA and glycerol was three times as high. Addition of E to the incubation medium (200 microgram/ml) had no effect on the rate of FFA and glycerol release of slices from C animals, but tripled the rates of slices from N, resulting in similar values for the two groups. In slices from H animals the rate of release was lower than in the other two groups, increasing only 1.5-fold. Pretreatment of N animals with triiodothyronine (T3; 0.8 microgram/100 g daily for 7 days) doubled the rates of FFA and glycerol release. Addition of E to the medium affected both pretreated and nontreated slices similarly. Two possible mechanisms by which temperature acclimation controls the lipolytic rate of BAT are suggested by 1) the concentration of specific enzymes and 2) cellular metabolites and hormones which activate existing systems. It seems that both operate in temperature-acclimated hamsters.

The influence of growth hormone and thyroxine on iodothyronine deiodinase activity in the liver, kidney and brown adipose tissue in hypophysectomized rats

1991 ◽  
Vol 125 (2) ◽  
pp. 219-226 ◽  
Author(s):  
Liv S. Bjørn-Hansen Gøtzsche ◽  
Allan Flyvbjerg ◽  
Sally Marshall ◽  
Karin D. Jørgensen ◽  
Jørgen Weeke
Keyword(s):  
Enzyme Activity ◽  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Body Weight Gain ◽  
Iodothyronine Deiodinase ◽  
Deiodinase Activity ◽  
Brown Adipose ◽  
Significant Difference ◽  
Liver And Kidney ◽  
Hypophysectomized Rats

Abstract. The effects of GH and T4 substitution on peripheral iodothyronine deiodinase activity in the liver, kidney and brown adipose tissue of hypophysectomized rats were investigated. Animals were treated with GH (140 μg hGH/day), T4 (3 μg/day), GH plus T4 (same doses), or saline. Rats were killed 0, 4, 7 or 11 days after treatment was started. Non-hypophysectomized, age matched rats were killed after 0 and 11 days and served as controls. GH plus T4 restored body weight gain to normal, whereas GH alone and T4 alone did not. Tissue deiodinase activity and T3 concentrations were severely depressed in the hypophysectomized rats compared with non-hypophysectomized controls (to less than 10%). GH substitution in hypophysectomized rats led to a slight but significant elevation in tissue iodothyronine deiodinase activity in the liver and kidney, without concomitant increases in T3. Deiodinase activity in brown adipose tissue did not differ from that in saline-treated controls. T4 administration normalized deiodinase activity and tissue T3 content in all the evaluated tissues. GH plus T4 resulted in a lesser increase in deiodinase activity than T4 alone in the liver and kidney (p<0.01 at day 11), whereas no significant difference was observed in brown adipose tissue. In conclusion, GH stimulates iodothyronine deiodinase activity of the liver and kidney in hypophysectomized rats. Moreover, when GH is administered together with T4, the T4-stimulated enzyme activity in the liver and kidney is downregulated, suggesting that GH attenuates (or modulates) the T4 effect on this specific enzyme activity.

Functional characterization of human brown adipose tissue metabolism

2020 ◽  
Vol 477 (7) ◽  
pp. 1261-1286 ◽  
Author(s):  
Marie Anne Richard ◽  
Hannah Pallubinsky ◽  
Denis P. Blondin
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Functional Characterization ◽  
Human Infants ◽  
Positron Emission ◽  
Brown Adipose ◽  
Treatment Of Obesity ◽  
And Function

Brown adipose tissue (BAT) has long been described according to its histological features as a multilocular, lipid-containing tissue, light brown in color, that is also responsive to the cold and found especially in hibernating mammals and human infants. Its presence in both hibernators and human infants, combined with its function as a heat-generating organ, raised many questions about its role in humans. Early characterizations of the tissue in humans focused on its progressive atrophy with age and its apparent importance for cold-exposed workers. However, the use of positron emission tomography (PET) with the glucose tracer [18F]fluorodeoxyglucose ([18F]FDG) made it possible to begin characterizing the possible function of BAT in adult humans, and whether it could play a role in the prevention or treatment of obesity and type 2 diabetes (T2D). This review focuses on the in vivo functional characterization of human BAT, the methodological approaches applied to examine these features and addresses critical gaps that remain in moving the field forward. Specifically, we describe the anatomical and biomolecular features of human BAT, the modalities and applications of non-invasive tools such as PET and magnetic resonance imaging coupled with spectroscopy (MRI/MRS) to study BAT morphology and function in vivo, and finally describe the functional characteristics of human BAT that have only been possible through the development and application of such tools.

Sign in / Sign up

Export Citation Format

Share Document