β-Adrenergic modulation of triglyceridemia under increased energy expenditure

1998 ◽  
Vol 274 (6) ◽  
pp. R1769-R1776 ◽  
Author(s):  
Line Mantha ◽  
Yves Deshaies
Keyword(s):  
Adipose Tissue ◽  
Energy Expenditure ◽  
Cold Exposure ◽  
Serum Insulin ◽  
Nonesterified Fatty Acid ◽  
Specific Response ◽  
Acute Administration ◽  
Brown Adipose ◽  
Adrenergic Antagonist ◽  
Acute Increase

This study aimed to identify the metabolic steps involved in the acute hypotriglyceridemia brought about by increased energy expenditure (cold exposure) and to assess the causative involvement of some determinants of triglyceride (TG) metabolism as well as that of the β-adrenergic pathway. Rats were kept at 24°C or exposed to 10°C for 3 h after acute administration of the β-adrenergic antagonist propranolol (Prop) or vehicle. Cold exposure increased the rate of TG secretion (Triton WR1339 method) into the circulation by 50% ( P < 0.0005), an effect that was blunted by Prop. The cold-induced increase in TG secretion was closely related to changes in circulating nonesterified fatty acid levels, but not with serum insulin concentrations. Despite an increase in TG secretion, serum TG levels after acute cold exposure fell to 50% ( P < 0.002) of those measured at 24°C, indicating that the lowering of serum TG was entirely due to an increase in their rate of intravascular hydrolysis. This was confirmed by observing a 70% increase ( P < 0.002) in the rate of clearance of an exogenous TG emulsion in cold-exposed rats compared with those kept in the warm. Prop treatment before cold exposure decreased (∼30%, P < 0.005) the cold-induced stimulation of TG hydrolysis. The increased TG clearance rate in cold-exposed animals occurred in the absence of any change in the intravascular availability of lipoprotein lipase (LPL). In contrast, the activity of LPL displayed a tissue-specific response to cold exposure, being reduced by one-half in white adipose tissue ( P < 0.0005) and increased in brown adipose tissue (130%, P < 0.0001) and the heart (50%, P < 0.001). These findings show that, in the postprandial state, an acute increase in energy expenditure induced by cold exposure results in a lowering of serum TG entirely due to an increase in their rate of intravascular hydrolysis and that serum TGs are lowered despite an increase in the rate of TG secretion into the circulation. More efficient TG hydrolysis occurs independently of the intravascular availability of LPL. The study further shows that the effects of cold exposure on serum TG concentration and their rates of secretion and clearance are in large part mediated by the β-adrenergic pathway.

Serotonin effect on deiodinating activity in the rat

2003 ◽  
Vol 81 (7) ◽  
pp. 747-751 ◽  
Author(s):  
Alessio Sullo ◽  
Guglielmo Brizzi ◽  
Nicola Maffulli
Keyword(s):  
Adipose Tissue ◽  
Energy Expenditure ◽  
Brown Adipose Tissue ◽  
Heat Production ◽  
Cold Exposure ◽  
Type Ii ◽  
Indirect Measure ◽  
Peripheral Tissues ◽  
Brown Adipose ◽  
The Brain

Serotonin (5-HT) and thyroid hormones are part of a complex system modulating eating behaviour and energy expenditure. 5'-Deiodinase (5'-D) converts the relatively inactive thyroxine (T4) to triiodothyronine (T3), and its activity is an indirect measure of T3 production in peripheral tissues, particularly in the brain, intrascapular brown adipose tissue (IBAT), heart, liver, and kidney. We evaluated the effect of 5-HT on 5'-D activity during basal conditions and after short (30 min) cold exposure (thyroid stimulating hormone stimulation test, TST). 5'-D activity was assessed in the liver, heart, brain, kidney, and IBAT. TST increases 5'-D activity in the brain, heart, and IBAT and decreases it in kidney, leaving it unchanged in the liver. 5-HT alone did not modify 5'-D activity in the organs under study but decreased it in the IBAT, heart, and brain when injected before the TST was administered. Our results confirm the important role of 5-HT in thermoregulation, given its peripheral site of action, in modulating heat production controlling intracellular T3 production. These effects are more evident when heat production is upregulated during cold exposure in organs containing type II 5'-D, such as the brain, heart, and IBAT, which are able to modify their function during conditions that alter energy balance. In conclusion, 5-HT may also act peripherally directly on the thyroid and organs containing type II 5'-D, thus controlling energy expenditure through heat production.Key words: serotonin, deiodinase activity, thyroid hormone, brown adipose tissue, thermogenesis, rat organs.

Insulin and metabolic efficiency in rats. II. Effects of NE and cold exposure

1986 ◽  
Vol 251 (6) ◽  
pp. R1118-R1125
Author(s):  
T. J. Bartness ◽  
C. J. Billington ◽  
A. S. Levine ◽  
J. E. Morley ◽  
N. E. Rowland ◽  
...  
Keyword(s):  
Body Weight ◽  
Adipose Tissue ◽  
Food Intake ◽  
Energy Expenditure ◽  
Cold Exposure ◽  
Diabetic Rats ◽  
Metabolic Efficiency ◽  
Maximal Energy ◽  
Brown Adipose

The role of insulin in metabolic efficiency (ME, i.e., efficiency of body wt gain) was examined under conditions of maximal energy expenditure in control and diabetic rats. Long-lasting insulin was administered using a protocol that did not affect food intake and increased ME in both groups. Half the animals were injected chronically with norepinephrine (NE). NE alone in controls decreased body weight and ME and increased brown adipose tissue (BAT) growth, thermogenic potential [cytochrome c oxidase activity (COA)], and lipoprotein lipases (LPL) activity; however, in diabetics, body weight, ME, and food intake all decreased and only BAT LPL activity and DNA content increased. The combination of NE and insulin increased BAT protein and COA in diabetics; in controls, all BAT measures were further increased and ME was intermediate to that of either treatment alone. Cold exposure decreased body weight and ME, increased food intake and qualitatively produced similar increases in BAT growth, COA, and LPL activity in both controls and diabetics. In diabetics, combined cold exposure and insulin did not affect the increase in BAT growth or LPL activity resulting from either treatment alone, but in controls this combination decreased BAT growth and COA. It is concluded that, even under conditions of maximal energy expenditure, both extremes of basal insulin status result in decreased BAT growth and thermogenic potential, but have opposite effects on ME.

Gender Differences in the Response to Short-term Cold Exposure in Young Adults

2020 ◽  
Vol 105 (5) ◽  
pp. e1938-e1948
Author(s):  
Laura A Mengel ◽  
Hatti Seidl ◽  
Beate Brandl ◽  
Thomas Skurk ◽  
Christina Holzapfel ◽  
...  
Keyword(s):  
Energy Expenditure ◽  
Cold Exposure ◽  
Resting Energy Expenditure ◽  
Specific Response ◽  
Hormonal Changes ◽  
Short Term ◽  
Cross Sectional ◽  
Brown Adipose ◽  
The Impact ◽  
Gender Specific

Abstract Context Cold exposure (CE) has been shown to enhance energy expenditure by activating brown adipose tissue thermogenesis and metabolism in humans. However, it remains to be elucidated if there are gender-specific differences in cold-induced thermogenesis and metabolism. Objective To study the impact of mild CE on resting energy expenditure (REE) and metabolism in males compared with females. Setting A cross-sectional study. Participants 117 healthy young Caucasians participated in this study (58 males). Mean age was 25.1 ± 3.6 years and mean body mass index 22.3 ± 1.7 kg/m2. Intervention Participants underwent a short-term CE using water perfused mattresses to activate nonshivering thermogenesis. Main Outcome Measures REE was assessed before and 2 hours after CE followed by blood sampling. Selected metabolites and hormones were measured. Skin temperatures were monitored at various sites throughout the experiment. Results Participants showed a significant increase in REE after CE (6.5%, P &lt; .001). This increase did not differ between genders (P = .908). However, there were differences between males and females in changes of plasma glucose (–5.1% versus –7.4%, P = .024), leptin (–14.3% versus –30.1%, P &lt; .001) and adiponectin (5.4% versus 12.8%, P = .018) after CE. We observed a significant decrease of the supraclavicular skin temperature in men (–0.3%, P = .034), but not in women (0.3%, P = .326)(P = .019 between genders). Conclusions We did not observe a difference in the thermogenic response, measured as change of REE, to CE in women compared with men. However, we found that some metabolic and hormonal changes were more pronounced in women than in men suggesting a gender-specific response to cold.

The Presence of Active Brown Adipose Tissue Determines Cold-Induced Energy Expenditure and Oxylipin Profiles in Humans

2020 ◽  
Vol 105 (7) ◽  
pp. 2203-2216 ◽  
Author(s):  
Oana C Kulterer ◽  
Laura Niederstaetter ◽  
Carsten T Herz ◽  
Alexander R Haug ◽  
Andrea Bileck ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Energy Expenditure ◽  
Brown Adipose Tissue ◽  
Cold Exposure ◽  
Fdg Pet ◽  
Brown Adipose ◽  
Pet Ct ◽  
18F Fdg ◽  
Fdg Pet Ct

Abstract Background Accumulating evidence links brown adipose tissue (BAT) to increased cold-induced energy expenditure (CIEE) and regulation of lipid metabolism in humans. BAT has also been proposed as a novel source for biologically active lipid mediators including polyunsaturated fatty acids (PUFAs) and oxylipins. However, little is known about cold-mediated differences in energy expenditure and various lipid species between individuals with detectable BAT positive (BATpos) and those without BAT negative (BATneg). Methods Here we investigated a unique cohort of matched BATpos and BATneg individuals identified by 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography ([18F]-FDG PET/CT). BAT function, CIEE, and circulating oxylipins, were analyzed before and after short-term cold exposure using [18F]-FDG PET/CT, indirect calorimetry, and high-resolution mass spectrometry, respectively. Results We found that active BAT is the major determinant of CIEE since only BATpos individuals experienced significantly increased energy expenditure in response to cold. A single bout of moderate cold exposure resulted in the dissipation of an additional 20 kcal excess energy in BATpos but not in BATneg individuals. The presence of BAT was associated with a unique systemic PUFA and oxylipin profile characterized by increased levels of anti-inflammatory omega-3 fatty acids as well as cytochrome P450 products but decreased concentrations of some proinflammatory hydroxyeicosatetraenoic acids when compared with BATneg individuals. Notably, cold exposure raised circulating levels of various lipids, including the recently identified BAT-derived circulating factors (BATokines) DiHOME and 12-HEPE, only in BATpos individuals. Conclusions In summary, our data emphasize that BAT in humans is a major contributor toward cold-mediated energy dissipation and a critical organ in the regulation of the systemic lipid pool.

scholarly journals Cold and Exercise: Therapeutic Tools to Activate Brown Adipose Tissue and Combat Obesity

Biology ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 9 ◽  
Author(s):  
Carmem Peres Valgas da Silva ◽  
Diego Hernández-Saavedra ◽  
Joseph White ◽  
Kristin Stanford
Keyword(s):  
Type 2 Diabetes ◽  
Adipose Tissue ◽  
Energy Expenditure ◽  
Brown Adipose Tissue ◽  
Cold Exposure ◽  
Lipid Uptake ◽  
Mitochondrial Uncoupling ◽  
Bat Activity ◽  
Brown Adipose

The rise in obesity over the last several decades has reached pandemic proportions. Brown adipose tissue (BAT) is a thermogenic organ that is involved in energy expenditure and represents an attractive target to combat both obesity and type 2 diabetes. Cold exposure and exercise training are two stimuli that have been investigated with respect to BAT activation, metabolism, and the contribution of BAT to metabolic health. These two stimuli are of great interest because they have both disparate and converging effects on BAT activation and metabolism. Cold exposure is an effective mechanism to stimulate BAT activity and increase glucose and lipid uptake through mitochondrial uncoupling, resulting in metabolic benefits including elevated energy expenditure and increased insulin sensitivity. Exercise is a therapeutic tool that has marked benefits on systemic metabolism and affects several tissues, including BAT. Compared to cold exposure, studies focused on BAT metabolism and exercise display conflicting results; the majority of studies in rodents and humans demonstrate a reduction in BAT activity and reduced glucose and lipid uptake and storage. In addition to investigations of energy uptake and utilization, recent studies have focused on the effects of cold exposure and exercise on the structural lipids in BAT and secreted factors released from BAT, termed batokines. Cold exposure and exercise induce opposite responses in terms of structural lipids, but an important overlap exists between the effects of cold and exercise on batokines. In this review, we will discuss the similarities and differences of cold exposure and exercise in relation to their effects on BAT activity and metabolism and its relevance for the prevention of obesity and the development of type 2 diabetes.

scholarly journals Brown adipose tissue oxidative metabolism contributes to energy expenditure during acute cold exposure in humans

2012 ◽  
Vol 122 (2) ◽  
pp. 545-552 ◽  
Author(s):  
Véronique Ouellet ◽  
Sébastien M. Labbé ◽  
Denis P. Blondin ◽  
Serge Phoenix ◽  
Brigitte Guérin ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Energy Expenditure ◽  
Brown Adipose Tissue ◽  
Cold Exposure ◽  
Oxidative Metabolism ◽  
Acute Cold Exposure ◽  
Brown Adipose

scholarly journals Inhibition of a Novel CLK1-THRAP3-PPARγ Axis Improves Insulin Sensitivity

2021 ◽  
Vol 12 ◽  
Author(s):  
Zhenguo Wang ◽  
Xiaojing Gao ◽  
Qingrun Li ◽  
Hongwen Zhu ◽  
Xiangjie Zhao ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Insulin Sensitivity ◽  
Energy Expenditure ◽  
Cold Exposure ◽  
Thyroid Hormone Receptor ◽  
Critical Role ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Receptor Associated Protein ◽  
Brown Adipose

Increasing energy expenditure by promoting “browning” in adipose tissues is a promising strategy to prevent obesity and associated diabetes. To uncover potential targets of cold exposure, which induces energy expenditure, we performed phosphoproteomics profiling in brown adipose tissue of mice housed in mild cold environment at 16°C. We identified CDC2-like kinase 1 (CLK1) as one of the kinases that were significantly downregulated by mild cold exposure. In addition, genetic knockout of CLK1 or chemical inhibition in mice ameliorated diet-induced obesity and insulin resistance at 22°C. Through proteomics, we uncovered thyroid hormone receptor-associated protein 3 (THRAP3) as an interacting partner of CLK1, further confirmed by co-immunoprecipitation assays. We further demonstrated that CLK1 phosphorylates THRAP3 at Ser243, which is required for its regulatory interaction with phosphorylated peroxisome proliferator-activated receptor gamma (PPARγ), resulting in impaired adipose tissue browning and insulin sensitivity. These data suggest that CLK1 plays a critical role in controlling energy expenditure through the CLK1-THRAP3-PPARγ axis.

Adaptive Activation of Thyroid Hormone and Energy Expenditure

2005 ◽  
Vol 25 (3-4) ◽  
pp. 191-208 ◽  
Author(s):  
Antonio C. Bianco ◽  
Ana Luiza Maia ◽  
Wagner Seixas da Silva ◽  
Marcelo A. Christoffolete
Keyword(s):  
Skeletal Muscle ◽  
Adipose Tissue ◽  
Thyroid Hormone ◽  
Energy Expenditure ◽  
Cold Exposure ◽  
Biological Knowledge ◽  
Iodothyronine Deiodinase ◽  
Brown Adipose ◽  
Adult Humans

The mechanisms by which thyroid hormone accelerates energy expenditure are poorly understood. In the brown adipose tissue (BAT), activation of thyroid hormone by type 2 iodothyronine deiodinase (D2) has been known to play a role in adaptive energy expenditure during cold exposure in human newborns and other small mammals. Although BAT is not present in significant amounts in normal adult humans, recent studies have found substantial amounts of D2 in skeletal muscle, a metabolically relevant tissue in humans. This article reviews current biological knowledge about D2 and adaptive T3 production and their roles in energy expenditure.

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