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.

Cold exposure potentiates the effect of insulin on in vivo glucose uptake

1987 ◽  
Vol 253 (2) ◽  
pp. E179-E186 ◽  
Author(s):  
A. L. Vallerand ◽  
F. Perusse ◽  
L. J. Bukowiecki
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Glucose Uptake ◽  
White Adipose Tissue ◽  
Cold Exposure ◽  
Skeletal Muscles ◽  
Insulin Injection ◽  
Peripheral Tissues ◽  
Brown Adipose ◽  
Insulin Responses

The effects of cold exposure (48 h at 4 degrees C) and insulin injection (0.5 U/kg iv) on the rates of net 2-[3H]deoxyglucose uptake (Ki) in peripheral tissues were investigated in warm-acclimated rats (25 degrees C). Cold exposure and insulin treatment independently increased Ki values in skeletal muscles (soleus, extensor digitorum longus, and vastus lateralis), heart, white adipose tissue (subcutaneous, gonadal, and retroperitoneal), and brown adipose tissue (P less than 0.01). The effects of cold exposure were particularly evident in brown adipose tissue where the Ki increased greater than 100 times. When the two treatments were combined (insulin injection in cold-exposed rats), it was found that cold exposure synergistically enhanced the maximal insulin responses for glucose uptake in brown adipose tissue, all white adipose tissue depots, and skeletal muscles investigated. The results indicate that cold exposure induces an "insulin-like" effect on Ki that does not appear to be specifically associated with shivering thermogenesis in skeletal muscles, because that effect was observed in all insulin-sensitive tissues. The data also demonstrate that cold exposure significantly potentiates the maximal insulin responses for glucose uptake in the same tissues. This potentialization may result from an enhanced responsiveness of peripheral tissues to insulin, possibly occurring at metabolic steps lying beyond the insulin receptor and an increased tissue blood flow augmenting glucose and insulin availability and thereby amplifying glucose uptake.

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.

Impairment of iodothyronine 5′-deiodinase activity in brown adipose tissue and its acute stimulation by cold in selenium deficiency

1991 ◽  
Vol 69 (6) ◽  
pp. 782-785 ◽  
Author(s):  
John R. Arthur ◽  
Fergus Nicol ◽  
Geoffrey J. Beckett ◽  
Paul Trayhurn
Keyword(s):  
Adipose Tissue ◽  
Glutathione Peroxidase ◽  
Brown Adipose Tissue ◽  
Cold Exposure ◽  
Selenium Deficiency ◽  
Type Ii ◽  
Deficient Diet ◽  
Deiodinase Activity ◽  
Brown Adipose ◽  
Thermogenic Response

The activity of the type II iodothyronine 5′-deiodinase enzyme in brown adipose tissue has been examined in rats fed a selenium-deficient diet. Iodothyronine 5′-deiodinase activity was threefold lower in brown adipose tissue of deficient rats than in control animals. The activity of glutathione peroxidase, a biochemical index of selenium deficiency, was also greatly decreased in deficient animals. Cytochrome oxidase activity in brown fat was, however, unaltered by selenium deficiency. Acute exposure to cold (4 °C for 18 h) resulted in a substantial increase in iodothyronine 5′-deiodinase activity in brown adipose tissue of control rats, but the stimulatory effect of cold was attenuated in selenium-deficient animals. These results support the concept that the iodothyronine 5′-deiodinases are selenium-dependent enzymes, and indicate that the thermogenic response to cold may be impaired in selenium deficiency.Key words: iodothyronine 5′-deiodinase, glutathione peroxidase, selenium deficiency, brown adipose tissue, cold exposure.

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

Chronic norepinephrine infusion stimulates glucose uptake in white and brown adipose tissues

1994 ◽  
Vol 266 (3) ◽  
pp. R914-R920 ◽  
Author(s):  
X. Liu ◽  
F. Perusse ◽  
L. J. Bukowiecki
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Glucose Uptake ◽  
White Adipose Tissue ◽  
Cold Exposure ◽  
Skeletal Muscles ◽  
Interscapular Brown Adipose Tissue ◽  
Peripheral Tissues ◽  
Glucose Levels ◽  
Brown Adipose

Cold exposure activates the sympathetic nervous system and markedly stimulates glucose uptake in rat peripheral tissues [A. L. Vallerand, F. Perusse, and L. J. Bukowiecki. Am. J. Physiol 259 (Regulatory Integrative Comp. Physiol. 28): R1043-R1049, 1990]. To test whether norepinephrine (NE) mimics the effects of cold exposure, we estimated the effects of chronic NE treatment on tissue glucose uptake by determining the glucose metabolic index using the 2-[1,2-3H(N)]deoxy-D-glucose method. NE was administered in conscious rats at various doses (ranging from 1.9 to 25.1 nmol.kg-1.min-1) during 4 days via minipumps implanted subcutaneously. At doses > 10 nmol.kg-1.min-1, NE maximally stimulated glucose uptake in interscapular brown adipose tissue (approximately 50 times above controls) and epididymal white adipose tissue (approximately 3 times above controls). NE infusion (18.8 nmol.kg-1.min-1) increased the circulating levels of NE from 1.1 +/- 0.1 to 19.2 +/- 0.4 nM (P < 0.001), which is in the range of concentrations for the stimulatory effects of NE on glucose uptake in isolated brown adipocytes. At all concentrations tested, NE infusion did not stimulate glucose uptake in the heart and skeletal muscles. NE treatment did not significantly alter plasma insulin or glucose levels but increased the concentration of circulating free fatty acids. The capacity of brown adipose tissue for NE stimulation of glucose uptake (expressed per g of tissue) was much higher than that of white adipose tissue (100 times), various types of white or red skeletal muscles (10-80 times), or the heart (3-4 times).(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals A randomized trial of cold-exposure on energy expenditure and supraclavicular brown adipose tissue volume in humans

Metabolism ◽  
2016 ◽  
Vol 65 (6) ◽  
pp. 926-934 ◽  
Author(s):  
Thobias Romu ◽  
Camilla Vavruch ◽  
Olof Dahlqvist-Leinhard ◽  
Joakim Tallberg ◽  
Nils Dahlström ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Energy Expenditure ◽  
Brown Adipose Tissue ◽  
Randomized Trial ◽  
Cold Exposure ◽  
Tissue Volume ◽  
Brown Adipose ◽  
Adipose Tissue Volume
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