Brown adipose tissue—a factor in the survival of harp seal pups

The respiratory characteristics of mitochondria isolated from the subcutaneous brown adipose tissue of newborn harp seals indicate that the tissue is thermogenically active. Temperature recordings in vivo revealed, in fact, that the tissue was maintained at a temperature close to that of the body core during immersion of the pups in ice-water. Beta-adrenergic blockade markedly increased the cooling rates at both locations in ice-water, while curarization, accompanied by artificial respiration did not. We conclude that nonshivering thermogenesis through activated brown adipose tissue plays a decisive role in the defence against cold in the newborn harp seal.

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Activation of brown adipose tissue thermogenesis in recovery from anesthetic hypothermia in rats

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1991.261.2.r301 ◽

1991 ◽

Vol 261 (2) ◽

pp. R301-R304 ◽

Cited By ~ 6

Author(s):

Y. Shimizu ◽

M. Saito

Keyword(s):

Adipose Tissue ◽

Brown Adipose Tissue ◽

Rectal Temperature ◽

Recovery Phase ◽

Adrenergic Blockade ◽

Appreciable Change ◽

Brown Adipose ◽

Steady Level ◽

Brown Adipose Tissue Thermogenesis

Changes of brown adipose tissue (BAT) thermogenesis in the recovery from anesthetic hypothermia were studied by measuring the temperatures of the interscapular BAT and rectum or the tissue uptake of 2-deoxyglucose (2-DG) in rats. After intraperitoneal injection of pentobarbital sodium (50 mg/kg), rectal temperature decreased to reach a steady level of approximately 33 degrees C (steady phase) and then increased gradually (recovery phase). The temperature of the interscapular BAT was significantly higher than rectal temperature in the recovery phase. The uptake of 2-DG in vivo in BAT was low in the steady phase but increased greatly in the recovery phase. The increase in 2-DG uptake was suppressed after surgical sympathetic denervation or when rectal temperature was maintained at approximately 37.5 degrees C. In the heart, skeletal muscle, and white adipose tissue, there was no appreciable change in 2-DG uptake except a slight increase in the heart. beta-Adrenergic blockade attenuated the changes in BAT temperature and 2-DG uptake seen during the recovery phase. It was concluded that BAT significantly contributes to heat production in recovery from anesthetic hypothermia.

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

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.00494.2014 ◽

2015 ◽

Vol 308 (9) ◽

pp. E822-E829 ◽

Cited By ~ 19

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.

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Vitamin D Regulates Fatty Acid Composition in Subcutaneous Adipose Tissue Through Elovl3

Endocrinology ◽

10.1210/en.2015-1674 ◽

2016 ◽

Vol 157 (1) ◽

pp. 91-97 ◽

Cited By ~ 23

Author(s):

Lijuan Ji ◽

Mihir Gupta ◽

Brian J. Feldman

Keyword(s):

Vitamin D ◽

Adipose Tissue ◽

Brown Adipose Tissue ◽

Nuclear Hormone Receptor ◽

The Body ◽

Vdr Gene ◽

Fa Composition ◽

Brown Adipose ◽

The Impact

Abstract Fatty acids (FAs) are a major energy source in the body. White adipose tissue (WAT) is a primary site where FAs are stored as triacylglycerols. Brown adipose tissue also stores and recruits FAs as a carbon source for uncoupled β-oxidation during thermogenesis. The deletion of the vitamin D nuclear hormone receptor (VDR) gene in mice (VDRKO) results in a lean WAT phenotype with increased levels of expression of the brown adipose tissue marker Ucp1 in the WAT. However, the impact of vitamin D/VDR on FA composition in WAT has not been explored in detail. To address this question, we examined the FA composition of sc and visceral white adipose depots of VDRKO mice. We found that the levels of a subset of saturated and monounsaturated FAs of C18-C24 are specifically increased in the sc adipose depot in VDRKO mice. We revealed that a specific elongase enzyme (Elovl3), which has an important role in brown fat biology, is directly regulated by VDR and likely contributes to the altered FA composition in VDRKO mice. We also demonstrate that Elovl3 is regulated by vitamin D in vivo and tissue specifically in the sc WAT depot. We discovered that regulation of Elovl3 expression is mediated by ligand-dependent VDR occupancy of a negative-response element in the promoter proximal region of the Elovl3 gene. These data suggest that vitamin D/VDR tissue specifically modulates FA composition in sc WAT through direct regulation of Elovl3 expression.

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Functional characterization of human brown adipose tissue metabolism

Biochemical Journal ◽

10.1042/bcj20190464 ◽

2020 ◽

Vol 477 (7) ◽

pp. 1261-1286 ◽

Cited By ~ 3

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.

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Faculty Opinions recommendation of Cold but not sympathomimetics activates human brown adipose tissue in vivo.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.723897883.793548350 ◽

2018 ◽

Author(s):

Michael Symonds

Keyword(s):

Adipose Tissue ◽

Brown Adipose Tissue ◽

Brown Adipose

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TAF7L modulates brown adipose tissue formation

eLife ◽

10.7554/elife.02811 ◽

2014 ◽

Vol 3 ◽

Cited By ~ 12

Author(s):

Haiying Zhou ◽

Bo Wan ◽

Ivan Grubisic ◽

Tommy Kaplan ◽

Robert Tjian

Keyword(s):

Adipose Tissue ◽

Brown Adipose Tissue ◽

Core Promoter ◽

Uncoupling Protein ◽

Dna Looping ◽

Chromatin Interactions ◽

Brown Adipose ◽

Important Regulator

Brown adipose tissue (BAT) plays an essential role in metabolic homeostasis by dissipating energy via thermogenesis through uncoupling protein 1 (UCP1). Previously, we reported that the TATA-binding protein associated factor 7L (TAF7L) is an important regulator of white adipose tissue (WAT) differentiation. In this study, we show that TAF7L also serves as a molecular switch between brown fat and muscle lineages in vivo and in vitro. In adipose tissue, TAF7L-containing TFIID complexes associate with PPARγ to mediate DNA looping between distal enhancers and core promoter elements. Our findings suggest that the presence of the tissue-specific TAF7L subunit in TFIID functions to promote long-range chromatin interactions during BAT lineage specification.

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Noradrenaline-induced calorigenesis in warm- or cold-acclimated rats. In vivo estimation of adrenoceptor concentration of noradrenaline effecting half-maximal response

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y80-161 ◽

1980 ◽

Vol 58 (9) ◽

pp. 1072-1077 ◽

Cited By ~ 9

Author(s):

Florent Depocas ◽

Gloria Zaror-Behrens ◽

Suzanne Lacelle

Keyword(s):

Adipose Tissue ◽

Steady State ◽

Brown Adipose Tissue ◽

Maximal Response ◽

Brown Adipose ◽

Acclimation Group ◽

Arterial Plasma ◽

State Concentration ◽

Na Uptake

Desmethylimipramine (DMI, 1 mg DMI∙HCl kg−1) and normetanephrine (NMN, 1 μg min−1 g−0.74) were used to inhibit, respectively, neuronal and extraneuronal uptakes of noradrenaline (NA) during calorigenesis induced in barbital-sedated warm-acclimated (WA) or cold-acclimated (CA) rats by infusion of NA, a procedure which mimics the effects of NA released within calorigenic tissues in response to cold exposure. The doses of the inhibitors were selected for maximal effectiveness in potentiating calorigenic response and for minimal side effects. For rats of either acclimation group treated with DMI and NMN, with DMI only, or with neither inhibitor the doses of NA required to evoke approximately half-maximal calorigenic responses were, respectively, 0.5, 1.0, and 3.5 ng min−1 g−0.74. The corresponding steady-state concentrations of NA in arterial plasma averaged 14.3, 21.7, and 43.2 nM in the three groups of WA rats and 10.0, 14.8, and 31.9 nM in the three groups of CA rats. Reduction by NA uptake inhibitors of the circulating levels of NA necessary to stimulate calorigenesis, half-maximally, presumably in brown adipose tissue, indicates a reduction in the steepness of the NA concentration gradient between capillary plasma and synaptic clefts in that tissue. The steady-state concentration of NA in blood plasma of rats treated with DMI and NMN and infused with NA at a dose of 0.5 ng min−1 g−0.74 (~1 × 10−8 M) is a good estimate of the NA concentration required at calorigenic adrenoceptors to effect half-maximal activation. Presumably, this concentration is also an estimate of that resulting from NA released at nerve endings during cold-induced activation of nonshivering thermogenesis at half-maximal rates in brown adipose tissue.

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